syntax: functions require return type. remove ->

The purpose of this is:

 * Only one way to do things
 * Changing a function with void return type to return a possible
   error becomes a 1 character change, subtly encouraging
   people to use errors.

See #632

Here are some imperfect sed commands for performing this update:

remove arrow:

```
sed -i 's/\(\bfn\b.*\)-> /\1/g' $(find . -name "*.zig")
```

add void:

```
sed -i 's/\(\bfn\b.*\))\s*{/\1) void {/g' $(find ../ -name "*.zig")
```

Some cleanup may be necessary, but this should do the bulk of the work.

build.zig

@@ -10,7 +10,7 @@ const ArrayList = std.ArrayList;
 const Buffer = std.Buffer;
 const io = std.io;
 
-pub fn build(b: &Builder) -> %void {
+pub fn build(b: &Builder) %void {
     const mode = b.standardReleaseOptions();
 
     var docgen_exe = b.addExecutable("docgen", "doc/docgen.zig");
@@ -121,7 +121,7 @@ pub fn build(b: &Builder) -> %void {
     test_step.dependOn(tests.addGenHTests(b, test_filter));
 }
 
-fn dependOnLib(lib_exe_obj: &std.build.LibExeObjStep, dep: &const LibraryDep) {
+fn dependOnLib(lib_exe_obj: &std.build.LibExeObjStep, dep: &const LibraryDep) void {
     for (dep.libdirs.toSliceConst()) |lib_dir| {
         lib_exe_obj.addLibPath(lib_dir);
     }
@@ -136,7 +136,7 @@ fn dependOnLib(lib_exe_obj: &std.build.LibExeObjStep, dep: &const LibraryDep) {
     }
 }
 
-fn addCppLib(b: &Builder, lib_exe_obj: &std.build.LibExeObjStep, cmake_binary_dir: []const u8, lib_name: []const u8) {
+fn addCppLib(b: &Builder, lib_exe_obj: &std.build.LibExeObjStep, cmake_binary_dir: []const u8, lib_name: []const u8) void {
     const lib_prefix = if (lib_exe_obj.target.isWindows()) "" else "lib";
     lib_exe_obj.addObjectFile(os.path.join(b.allocator, cmake_binary_dir, "zig_cpp",
         b.fmt("{}{}{}", lib_prefix, lib_name, lib_exe_obj.target.libFileExt())) catch unreachable);
@@ -149,7 +149,7 @@ const LibraryDep = struct {
     includes: ArrayList([]const u8),
 };
 
-fn findLLVM(b: &Builder, llvm_config_exe: []const u8) -> %LibraryDep {
+fn findLLVM(b: &Builder, llvm_config_exe: []const u8) %LibraryDep {
     const libs_output = try b.exec([][]const u8{llvm_config_exe, "--libs", "--system-libs"});
     const includes_output = try b.exec([][]const u8{llvm_config_exe, "--includedir"});
     const libdir_output = try b.exec([][]const u8{llvm_config_exe, "--libdir"});
@@ -197,7 +197,7 @@ fn findLLVM(b: &Builder, llvm_config_exe: []const u8) -> %LibraryDep {
     return result;
 }
 
-pub fn installStdLib(b: &Builder, stdlib_files: []const u8) {
+pub fn installStdLib(b: &Builder, stdlib_files: []const u8) void {
     var it = mem.split(stdlib_files, ";");
     while (it.next()) |stdlib_file| {
         const src_path = os.path.join(b.allocator, "std", stdlib_file) catch unreachable;
@@ -206,7 +206,7 @@ pub fn installStdLib(b: &Builder, stdlib_files: []const u8) {
     }
 }
 
-pub fn installCHeaders(b: &Builder, c_header_files: []const u8) {
+pub fn installCHeaders(b: &Builder, c_header_files: []const u8) void {
     var it = mem.split(c_header_files, ";");
     while (it.next()) |c_header_file| {
         const src_path = os.path.join(b.allocator, "c_headers", c_header_file) catch unreachable;
@@ -215,7 +215,7 @@ pub fn installCHeaders(b: &Builder, c_header_files: []const u8) {
     }
 }
 
-fn nextValue(index: &usize, build_info: []const u8) -> []const u8 {
+fn nextValue(index: &usize, build_info: []const u8) []const u8 {
     const start = *index;
     while (true) : (*index += 1) {
         switch (build_info[*index]) {

doc/docgen.zig

@@ -12,7 +12,7 @@ const exe_ext = std.build.Target(std.build.Target.Native).exeFileExt();
 const obj_ext = std.build.Target(std.build.Target.Native).oFileExt();
 const tmp_dir_name = "docgen_tmp";
 
-pub fn main() -> %void {
+pub fn main() %void {
     // TODO use a more general purpose allocator here
     var inc_allocator = try std.heap.IncrementingAllocator.init(max_doc_file_size);
     defer inc_allocator.deinit();
@@ -91,7 +91,7 @@ const Tokenizer = struct {
         Eof,
     };
 
-    fn init(source_file_name: []const u8, buffer: []const u8) -> Tokenizer {
+    fn init(source_file_name: []const u8, buffer: []const u8) Tokenizer {
         return Tokenizer {
             .buffer = buffer,
             .index = 0,
@@ -101,7 +101,7 @@ const Tokenizer = struct {
         };
     }
 
-    fn next(self: &Tokenizer) -> Token {
+    fn next(self: &Tokenizer) Token {
         var result = Token {
             .id = Token.Id.Eof,
             .start = self.index,
@@ -193,7 +193,7 @@ const Tokenizer = struct {
         line_end: usize,
     };
 
-    fn getTokenLocation(self: &Tokenizer, token: &const Token) -> Location {
+    fn getTokenLocation(self: &Tokenizer, token: &const Token) Location {
         var loc = Location {
             .line = 0,
             .column = 0,
@@ -220,7 +220,7 @@ const Tokenizer = struct {
 
 error ParseError;
 
-fn parseError(tokenizer: &Tokenizer, token: &const Token, comptime fmt: []const u8, args: ...) -> error {
+fn parseError(tokenizer: &Tokenizer, token: &const Token, comptime fmt: []const u8, args: ...) error {
     const loc = tokenizer.getTokenLocation(token);
     warn("{}:{}:{}: error: " ++ fmt ++ "\n", tokenizer.source_file_name, loc.line + 1, loc.column + 1, args);
     if (loc.line_start <= loc.line_end) {
@@ -243,13 +243,13 @@ fn parseError(tokenizer: &Tokenizer, token: &const Token, comptime fmt: []const
     return error.ParseError;
 }
 
-fn assertToken(tokenizer: &Tokenizer, token: &const Token, id: Token.Id) -> %void {
+fn assertToken(tokenizer: &Tokenizer, token: &const Token, id: Token.Id) %void {
     if (token.id != id) {
         return parseError(tokenizer, token, "expected {}, found {}", @tagName(id), @tagName(token.id));
     }
 }
 
-fn eatToken(tokenizer: &Tokenizer, id: Token.Id) -> %Token {
+fn eatToken(tokenizer: &Tokenizer, id: Token.Id) %Token {
     const token = tokenizer.next();
     try assertToken(tokenizer, token, id);
     return token;
@@ -316,7 +316,7 @@ const Action = enum {
     Close,
 };
 
-fn genToc(allocator: &mem.Allocator, tokenizer: &Tokenizer) -> %Toc {
+fn genToc(allocator: &mem.Allocator, tokenizer: &Tokenizer) %Toc {
     var urls = std.HashMap([]const u8, Token, mem.hash_slice_u8, mem.eql_slice_u8).init(allocator);
     errdefer urls.deinit();
 
@@ -540,7 +540,7 @@ fn genToc(allocator: &mem.Allocator, tokenizer: &Tokenizer) -> %Toc {
     };
 }
 
-fn urlize(allocator: &mem.Allocator, input: []const u8) -> %[]u8 {
+fn urlize(allocator: &mem.Allocator, input: []const u8) %[]u8 {
     var buf = try std.Buffer.initSize(allocator, 0);
     defer buf.deinit();
 
@@ -560,7 +560,7 @@ fn urlize(allocator: &mem.Allocator, input: []const u8) -> %[]u8 {
     return buf.toOwnedSlice();
 }
 
-fn escapeHtml(allocator: &mem.Allocator, input: []const u8) -> %[]u8 {
+fn escapeHtml(allocator: &mem.Allocator, input: []const u8) %[]u8 {
     var buf = try std.Buffer.initSize(allocator, 0);
     defer buf.deinit();
 
@@ -604,7 +604,7 @@ test "term color" {
     assert(mem.eql(u8, result, "A<span class=\"t32\">green</span>B"));
 }
 
-fn termColor(allocator: &mem.Allocator, input: []const u8) -> %[]u8 {
+fn termColor(allocator: &mem.Allocator, input: []const u8) %[]u8 {
     var buf = try std.Buffer.initSize(allocator, 0);
     defer buf.deinit();
 
@@ -686,7 +686,7 @@ fn termColor(allocator: &mem.Allocator, input: []const u8) -> %[]u8 {
 
 error ExampleFailedToCompile;
 
-fn genHtml(allocator: &mem.Allocator, tokenizer: &Tokenizer, toc: &Toc, out: &io.OutStream, zig_exe: []const u8) -> %void {
+fn genHtml(allocator: &mem.Allocator, tokenizer: &Tokenizer, toc: &Toc, out: &io.OutStream, zig_exe: []const u8) %void {
     var code_progress_index: usize = 0;
     for (toc.nodes) |node| {
         switch (node) {
@@ -977,7 +977,7 @@ fn genHtml(allocator: &mem.Allocator, tokenizer: &Tokenizer, toc: &Toc, out: &io
 error ChildCrashed;
 error ChildExitError;
 
-fn exec(allocator: &mem.Allocator, args: []const []const u8) -> %os.ChildProcess.ExecResult {
+fn exec(allocator: &mem.Allocator, args: []const []const u8) %os.ChildProcess.ExecResult {
     const result = try os.ChildProcess.exec(allocator, args, null, null, max_doc_file_size);
     switch (result.term) {
         os.ChildProcess.Term.Exited => |exit_code| {

doc/langref.html.in

@@ -86,7 +86,7 @@
       {#code_begin|exe|hello#}
 const std = @import("std");
 
-pub fn main() -> %void {
+pub fn main() %void {
     // If this program is run without stdout attached, exit with an error.
     var stdout_file = try std.io.getStdOut();
     // If this program encounters pipe failure when printing to stdout, exit
@@ -102,7 +102,7 @@ pub fn main() -> %void {
       {#code_begin|exe|hello#}
 const warn = @import("std").debug.warn;
 
-pub fn main() -> void {
+pub fn main() void {
     warn("Hello, world!\n");
 }
       {#code_end#}
@@ -132,7 +132,7 @@ const assert = std.debug.assert;
 // error declaration, makes `error.ArgNotFound` available
 error ArgNotFound;
 
-pub fn main() -> %void {
+pub fn main() %void {
     // integers
     const one_plus_one: i32 = 1 + 1;
     warn("1 + 1 = {}\n", one_plus_one);
@@ -543,7 +543,7 @@ const c_string_literal =
       {#code_begin|test_err|cannot assign to constant#}
 const x = 1234;
 
-fn foo() {
+fn foo() void {
     // It works at global scope as well as inside functions.
     const y = 5678;
 
@@ -607,7 +607,7 @@ const binary_int = 0b11110000;
       known size, and is vulnerable to undefined behavior.
       </p>
       {#code_begin|syntax#}
-fn divide(a: i32, b: i32) -> i32 {
+fn divide(a: i32, b: i32) i32 {
     return a / b;
 }
       {#code_end#}
@@ -644,12 +644,12 @@ const yet_another_hex_float = 0x103.70P-5;
 const builtin = @import("builtin");
 const big = f64(1 << 40);
 
-export fn foo_strict(x: f64) -> f64 {
+export fn foo_strict(x: f64) f64 {
     @setFloatMode(this, builtin.FloatMode.Strict);
     return x + big - big;
 }
 
-export fn foo_optimized(x: f64) -> f64 {
+export fn foo_optimized(x: f64) f64 {
     return x + big - big;
 }
       {#code_end#}
@@ -660,10 +660,10 @@ export fn foo_optimized(x: f64) -> f64 {
       {#code_link_object|foo#}
 const warn = @import("std").debug.warn;
 
-extern fn foo_strict(x: f64) -> f64;
-extern fn foo_optimized(x: f64) -> f64;
+extern fn foo_strict(x: f64) f64;
+extern fn foo_optimized(x: f64) f64;
 
-pub fn main() -> %void {
+pub fn main() %void {
     const x = 0.001;
     warn("optimized = {}\n", foo_optimized(x));
     warn("strict = {}\n", foo_strict(x));
@@ -1358,7 +1358,7 @@ test "compile-time array initalization" {
 
 // call a function to initialize an array
 var more_points = []Point{makePoint(3)} ** 10;
-fn makePoint(x: i32) -> Point {
+fn makePoint(x: i32) Point {
     return Point {
         .x = x,
         .y = x * 2,
@@ -1552,14 +1552,14 @@ test "global variable alignment" {
     assert(@typeOf(slice) == []align(4) u8);
 }
 
-fn derp() align(@sizeOf(usize) * 2) -> i32 { return 1234; }
-fn noop1() align(1) {}
-fn noop4() align(4) {}
+fn derp() align(@sizeOf(usize) * 2) i32 { return 1234; }
+fn noop1() align(1) void {}
+fn noop4() align(4) void {}
 
 test "function alignment" {
     assert(derp() == 1234);
-    assert(@typeOf(noop1) == fn() align(1));
-    assert(@typeOf(noop4) == fn() align(4));
+    assert(@typeOf(noop1) == fn() align(1) void);
+    assert(@typeOf(noop4) == fn() align(4) void);
     noop1();
     noop4();
 }
@@ -1578,7 +1578,7 @@ test "pointer alignment safety" {
     const bytes = ([]u8)(array[0..]);
     assert(foo(bytes) == 0x11111111);
 }
-fn foo(bytes: []u8) -> u32 {
+fn foo(bytes: []u8) u32 {
     const slice4 = bytes[1..5];
     const int_slice = ([]u32)(@alignCast(4, slice4));
     return int_slice[0];
@@ -1710,7 +1710,7 @@ const Vec3 = struct {
     y: f32,
     z: f32,
 
-    pub fn init(x: f32, y: f32, z: f32) -> Vec3 {
+    pub fn init(x: f32, y: f32, z: f32) Vec3 {
         return Vec3 {
             .x = x,
             .y = y,
@@ -1718,7 +1718,7 @@ const Vec3 = struct {
         };
     }
 
-    pub fn dot(self: &const Vec3, other: &const Vec3) -> f32 {
+    pub fn dot(self: &const Vec3, other: &const Vec3) f32 {
         return self.x * other.x + self.y * other.y + self.z * other.z;
     }
 };
@@ -1750,7 +1750,7 @@ test "struct namespaced variable" {
 
 // struct field order is determined by the compiler for optimal performance.
 // however, you can still calculate a struct base pointer given a field pointer:
-fn setYBasedOnX(x: &f32, y: f32) {
+fn setYBasedOnX(x: &f32, y: f32) void {
     const point = @fieldParentPtr(Point, "x", x);
     point.y = y;
 }
@@ -1765,7 +1765,7 @@ test "field parent pointer" {
 
 // You can return a struct from a function. This is how we do generics
 // in Zig:
-fn LinkedList(comptime T: type) -> type {
+fn LinkedList(comptime T: type) type {
     return struct {
         pub const Node = struct {
             prev: ?&Node,
@@ -1862,7 +1862,7 @@ const Suit = enum {
     Diamonds,
     Hearts,
 
-    pub fn isClubs(self: Suit) -> bool {
+    pub fn isClubs(self: Suit) bool {
         return self == Suit.Clubs;
     }
 };
@@ -1919,14 +1919,14 @@ test "@tagName" {
       </p>
       {#code_begin|obj_err|parameter of type 'Foo' not allowed in function with calling convention 'ccc'#}
 const Foo = enum { A, B, C };
-export fn entry(foo: Foo) { }
+export fn entry(foo: Foo) void { }
       {#code_end#}
       <p>
       For a C-ABI-compatible enum, use <code class="zig">extern enum</code>:
       </p>
       {#code_begin|obj#}
 const Foo = extern enum { A, B, C };
-export fn entry(foo: Foo) { }
+export fn entry(foo: Foo) void { }
       {#code_end#}
       {#header_close#}
       <p>TODO packed enum</p>
@@ -2191,7 +2191,7 @@ test "while else" {
     assert(!rangeHasNumber(0, 10, 15));
 }
 
-fn rangeHasNumber(begin: usize, end: usize, number: usize) -> bool {
+fn rangeHasNumber(begin: usize, end: usize, number: usize) bool {
     var i = begin;
     // While loops are expressions. The result of the expression is the
     // result of the else clause of a while loop, which is executed when
@@ -2242,14 +2242,14 @@ test "while null capture" {
 }
 
 var numbers_left: u32 = undefined;
-fn eventuallyNullSequence() -> ?u32 {
+fn eventuallyNullSequence() ?u32 {
     return if (numbers_left == 0) null else blk: {
         numbers_left -= 1;
         break :blk numbers_left;
     };
 }
 error ReachedZero;
-fn eventuallyErrorSequence() -> %u32 {
+fn eventuallyErrorSequence() %u32 {
     return if (numbers_left == 0) error.ReachedZero else blk: {
         numbers_left -= 1;
         break :blk numbers_left;
@@ -2274,7 +2274,7 @@ test "inline while loop" {
     assert(sum == 9);
 }
 
-fn typeNameLength(comptime T: type) -> usize {
+fn typeNameLength(comptime T: type) usize {
     return @typeName(T).len;
 }
       {#code_end#}
@@ -2367,7 +2367,7 @@ test "inline for loop" {
     assert(sum == 9);
 }
 
-fn typeNameLength(comptime T: type) -> usize {
+fn typeNameLength(comptime T: type) usize {
     return @typeName(T).len;
 }
       {#code_end#}
@@ -2493,7 +2493,7 @@ const assert = std.debug.assert;
 const warn = std.debug.warn;
 
 // defer will execute an expression at the end of the current scope.
-fn deferExample() -> usize {
+fn deferExample() usize {
     var a: usize = 1;
 
     {
@@ -2512,7 +2512,7 @@ test "defer basics" {
 
 // If multiple defer statements are specified, they will be executed in
 // the reverse order they were run.
-fn deferUnwindExample() {
+fn deferUnwindExample() void {
     warn("\n");
 
     defer {
@@ -2539,7 +2539,7 @@ test "defer unwinding" {
 // This is especially useful in allowing a function to clean up properly
 // on error, and replaces goto error handling tactics as seen in c.
 error DeferError;
-fn deferErrorExample(is_error: bool) -> %void {
+fn deferErrorExample(is_error: bool) %void {
     warn("\nstart of function\n");
 
     // This will always be executed on exit
@@ -2587,7 +2587,7 @@ test "basic math" {
       {#code_end#}
       <p>In fact, this is how assert is implemented:</p>
       {#code_begin|test_err#}
-fn assert(ok: bool) {
+fn assert(ok: bool) void {
     if (!ok) unreachable; // assertion failure
 }
 
@@ -2630,7 +2630,7 @@ test "type of unreachable" {
       the <code>noreturn</code> type is compatible with every other type. Consider:
       </p>
       {#code_begin|test#}
-fn foo(condition: bool, b: u32) {
+fn foo(condition: bool, b: u32) void {
     const a = if (condition) b else return;
     @panic("do something with a");
 }
@@ -2641,14 +2641,14 @@ test "noreturn" {
       <p>Another use case for <code>noreturn</code> is the <code>exit</code> function:</p>
       {#code_begin|test#}
       {#target_windows#}
-pub extern "kernel32" stdcallcc fn ExitProcess(exit_code: c_uint) -> noreturn;
+pub extern "kernel32" stdcallcc fn ExitProcess(exit_code: c_uint) noreturn;
 
 test "foo" {
     const value = bar() catch ExitProcess(1);
     assert(value == 1234);
 }
 
-fn bar() -> %u32 {
+fn bar() %u32 {
     return 1234;
 }
 
@@ -2660,7 +2660,7 @@ const assert = @import("std").debug.assert;
 const assert = @import("std").debug.assert;
 
 // Functions are declared like this
-fn add(a: i8, b: i8) -> i8 {
+fn add(a: i8, b: i8) i8 {
     if (a == 0) {
         // You can still return manually if needed.
         return b;
@@ -2671,34 +2671,34 @@ fn add(a: i8, b: i8) -> i8 {
 
 // The export specifier makes a function externally visible in the generated
 // object file, and makes it use the C ABI.
-export fn sub(a: i8, b: i8) -> i8 { return a - b; }
+export fn sub(a: i8, b: i8) i8 { return a - b; }
 
 // The extern specifier is used to declare a function that will be resolved
 // at link time, when linking statically, or at runtime, when linking
 // dynamically.
 // The stdcallcc specifier changes the calling convention of the function.
-extern "kernel32" stdcallcc fn ExitProcess(exit_code: u32) -> noreturn;
-extern "c" fn atan2(a: f64, b: f64) -> f64;
+extern "kernel32" stdcallcc fn ExitProcess(exit_code: u32) noreturn;
+extern "c" fn atan2(a: f64, b: f64) f64;
 
 // The @setCold builtin tells the optimizer that a function is rarely called.
-fn abort() -> noreturn {
+fn abort() noreturn {
     @setCold(true);
     while (true) {}
 }
 
 // nakedcc makes a function not have any function prologue or epilogue.
 // This can be useful when integrating with assembly.
-nakedcc fn _start() -> noreturn {
+nakedcc fn _start() noreturn {
     abort();
 }
 
 // The pub specifier allows the function to be visible when importing.
 // Another file can use @import and call sub2
-pub fn sub2(a: i8, b: i8) -> i8 { return a - b; }
+pub fn sub2(a: i8, b: i8) i8 { return a - b; }
 
 // Functions can be used as values and are equivalent to pointers.
-const call2_op = fn (a: i8, b: i8) -> i8;
-fn do_op(fn_call: call2_op, op1: i8, op2: i8) -> i8 {
+const call2_op = fn (a: i8, b: i8) i8;
+fn do_op(fn_call: call2_op, op1: i8, op2: i8) i8 {
     return fn_call(op1, op2);
 }
 
@@ -2712,11 +2712,11 @@ test "function" {
 const assert = @import("std").debug.assert;
 
 comptime {
-    assert(@typeOf(foo) == fn());
-    assert(@sizeOf(fn()) == @sizeOf(?fn()));
+    assert(@typeOf(foo) == fn()void);
+    assert(@sizeOf(fn()void) == @sizeOf(?fn()void));
 }
 
-fn foo() { }
+fn foo() void { }
       {#code_end#}
       {#header_open|Pass-by-value Parameters#}
       <p>
@@ -2728,7 +2728,7 @@ const Foo = struct {
     x: i32,
 };
 
-fn bar(foo: Foo) {}
+fn bar(foo: Foo) void {}
 
 test "pass aggregate type by value to function" {
     bar(Foo {.x = 12,});
@@ -2743,7 +2743,7 @@ const Foo = struct {
     x: i32,
 };
 
-fn bar(foo: &const Foo) {}
+fn bar(foo: &const Foo) void {}
 
 test "implicitly cast to const pointer" {
     bar(Foo {.x = 12,});
@@ -2798,7 +2798,7 @@ error UnexpectedToken;
 error InvalidChar;
 error Overflow;
 
-pub fn parseU64(buf: []const u8, radix: u8) -> %u64 {
+pub fn parseU64(buf: []const u8, radix: u8) %u64 {
     var x: u64 = 0;
 
     for (buf) |c| {
@@ -2822,7 +2822,7 @@ pub fn parseU64(buf: []const u8, radix: u8) -> %u64 {
     return x;
 }
 
-fn charToDigit(c: u8) -> u8 {
+fn charToDigit(c: u8) u8 {
     return switch (c) {
         '0' ... '9' => c - '0',
         'A' ... 'Z' => c - 'A' + 10,
@@ -2857,7 +2857,7 @@ test "parse u64" {
       </ul>
       <p>If you want to provide a default value, you can use the <code>catch</code> binary operator:</p>
       {#code_begin|syntax#}
-fn doAThing(str: []u8) {
+fn doAThing(str: []u8) void {
     const number = parseU64(str, 10) catch 13;
     // ...
 }
@@ -2870,7 +2870,7 @@ fn doAThing(str: []u8) {
       <p>Let's say you wanted to return the error if you got one, otherwise continue with the
       function logic:</p>
       {#code_begin|syntax#}
-fn doAThing(str: []u8) -> %void {
+fn doAThing(str: []u8) %void {
     const number = parseU64(str, 10) catch |err| return err;
     // ...
 }
@@ -2879,7 +2879,7 @@ fn doAThing(str: []u8) -> %void {
         There is a shortcut for this. The <code>try</code> expression:
       </p>
       {#code_begin|syntax#}
-fn doAThing(str: []u8) -> %void {
+fn doAThing(str: []u8) %void {
     const number = try parseU64(str, 10);
     // ...
 }
@@ -2907,7 +2907,7 @@ fn doAThing(str: []u8) -> %void {
       the <code>if</code> and <code>switch</code> expression:
       </p>
       {#code_begin|syntax#}
-fn doAThing(str: []u8) {
+fn doAThing(str: []u8) void {
     if (parseU64(str, 10)) |number| {
         doSomethingWithNumber(number);
     } else |err| switch (err) {
@@ -2929,7 +2929,7 @@ fn doAThing(str: []u8) {
       Example:
       </p>
       {#code_begin|syntax#}
-fn createFoo(param: i32) -> %Foo {
+fn createFoo(param: i32) %Foo {
     const foo = try tryToAllocateFoo();
     // now we have allocated foo. we need to free it if the function fails.
     // but we want to return it if the function succeeds.
@@ -3018,9 +3018,9 @@ struct Foo *do_a_thing(void) {
       <p>Zig code</p>
       {#code_begin|syntax#}
 // malloc prototype included for reference
-extern fn malloc(size: size_t) -> ?&u8;
+extern fn malloc(size: size_t) ?&u8;
 
-fn doAThing() -> ?&Foo {
+fn doAThing() ?&Foo {
     const ptr = malloc(1234) ?? return null;
     // ...
 }
@@ -3047,7 +3047,7 @@ fn doAThing() -> ?&Foo {
         In Zig you can accomplish the same thing:
       </p>
       {#code_begin|syntax#}
-fn doAThing(nullable_foo: ?&Foo) {
+fn doAThing(nullable_foo: ?&Foo) void {
     // do some stuff
 
     if (nullable_foo) |foo| {
@@ -3104,13 +3104,13 @@ fn doAThing(nullable_foo: ?&Foo) {
       Compile-time parameters is how Zig implements generics. It is compile-time duck typing.
       </p>
       {#code_begin|syntax#}
-fn max(comptime T: type, a: T, b: T) -> T {
+fn max(comptime T: type, a: T, b: T) T {
     return if (a > b) a else b;
 }
-fn gimmeTheBiggerFloat(a: f32, b: f32) -> f32 {
+fn gimmeTheBiggerFloat(a: f32, b: f32) f32 {
     return max(f32, a, b);
 }
-fn gimmeTheBiggerInteger(a: u64, b: u64) -> u64 {
+fn gimmeTheBiggerInteger(a: u64, b: u64) u64 {
     return max(u64, a, b);
 }
       {#code_end#}
@@ -3132,13 +3132,13 @@ fn gimmeTheBiggerInteger(a: u64, b: u64) -> u64 {
       For example, if we were to introduce another function to the above snippet:
       </p>
       {#code_begin|test_err|unable to evaluate constant expression#}
-fn max(comptime T: type, a: T, b: T) -> T {
+fn max(comptime T: type, a: T, b: T) T {
     return if (a > b) a else b;
 }
 test "try to pass a runtime type" {
     foo(false);
 }
-fn foo(condition: bool) {
+fn foo(condition: bool) void {
     const result = max(
         if (condition) f32 else u64,
         1234,
@@ -3157,7 +3157,7 @@ fn foo(condition: bool) {
       For example:
       </p>
       {#code_begin|test_err|operator not allowed for type 'bool'#}
-fn max(comptime T: type, a: T, b: T) -> T {
+fn max(comptime T: type, a: T, b: T) T {
     return if (a > b) a else b;
 }
 test "try to compare bools" {
@@ -3170,7 +3170,7 @@ test "try to compare bools" {
       if we wanted to:
       </p>
       {#code_begin|test#}
-fn max(comptime T: type, a: T, b: T) -> T {
+fn max(comptime T: type, a: T, b: T) T {
     if (T == bool) {
         return a or b;
     } else if (a > b) {
@@ -3193,7 +3193,7 @@ test "try to compare bools" {
       this:
       </p>
       {#code_begin|syntax#}
-fn max(a: bool, b: bool) -> bool {
+fn max(a: bool, b: bool) bool {
     return a or b;
 }
       {#code_end#}
@@ -3224,7 +3224,7 @@ const assert = @import("std").debug.assert;
 
 const CmdFn = struct {
     name: []const u8,
-    func: fn(i32) -> i32,
+    func: fn(i32) i32,
 };
 
 const cmd_fns = []CmdFn{
@@ -3232,11 +3232,11 @@ const cmd_fns = []CmdFn{
     CmdFn {.name = "two", .func = two},
     CmdFn {.name = "three", .func = three},
 };
-fn one(value: i32) -> i32 { return value + 1; }
-fn two(value: i32) -> i32 { return value + 2; }
-fn three(value: i32) -> i32 { return value + 3; }
+fn one(value: i32) i32 { return value + 1; }
+fn two(value: i32) i32 { return value + 2; }
+fn three(value: i32) i32 { return value + 3; }
 
-fn performFn(comptime prefix_char: u8, start_value: i32) -> i32 {
+fn performFn(comptime prefix_char: u8, start_value: i32) i32 {
     var result: i32 = start_value;
     comptime var i = 0;
     inline while (i < cmd_fns.len) : (i += 1) {
@@ -3262,7 +3262,7 @@ test "perform fn" {
       {#code_begin|syntax#}
 // From the line:
 // assert(performFn('t', 1) == 6);
-fn performFn(start_value: i32) -> i32 {
+fn performFn(start_value: i32) i32 {
     var result: i32 = start_value;
     result = two(result);
     result = three(result);
@@ -3272,7 +3272,7 @@ fn performFn(start_value: i32) -> i32 {
       {#code_begin|syntax#}
 // From the line:
 // assert(performFn('o', 0) == 1);
-fn performFn(start_value: i32) -> i32 {
+fn performFn(start_value: i32) i32 {
     var result: i32 = start_value;
     result = one(result);
     return result;
@@ -3281,7 +3281,7 @@ fn performFn(start_value: i32) -> i32 {
       {#code_begin|syntax#}
 // From the line:
 // assert(performFn('w', 99) == 99);
-fn performFn(start_value: i32) -> i32 {
+fn performFn(start_value: i32) i32 {
     var result: i32 = start_value;
     return result;
 }
@@ -3302,7 +3302,7 @@ fn performFn(start_value: i32) -> i32 {
       If this cannot be accomplished, the compiler will emit an error. For example:
       </p>
       {#code_begin|test_err|unable to evaluate constant expression#}
-extern fn exit() -> noreturn;
+extern fn exit() noreturn;
 
 test "foo" {
     comptime {
@@ -3335,7 +3335,7 @@ test "foo" {
       {#code_begin|test#}
 const assert = @import("std").debug.assert;
 
-fn fibonacci(index: u32) -> u32 {
+fn fibonacci(index: u32) u32 {
     if (index < 2) return index;
     return fibonacci(index - 1) + fibonacci(index - 2);
 }
@@ -3356,7 +3356,7 @@ test "fibonacci" {
       {#code_begin|test_err|operation caused overflow#}
 const assert = @import("std").debug.assert;
 
-fn fibonacci(index: u32) -> u32 {
+fn fibonacci(index: u32) u32 {
     //if (index < 2) return index;
     return fibonacci(index - 1) + fibonacci(index - 2);
 }
@@ -3379,7 +3379,7 @@ test "fibonacci" {
       {#code_begin|test_err|evaluation exceeded 1000 backwards branches#}
 const assert = @import("std").debug.assert;
 
-fn fibonacci(index: i32) -> i32 {
+fn fibonacci(index: i32) i32 {
     //if (index < 2) return index;
     return fibonacci(index - 1) + fibonacci(index - 2);
 }
@@ -3402,7 +3402,7 @@ test "fibonacci" {
       {#code_begin|test_err|encountered @panic at compile-time#}
 const assert = @import("std").debug.assert;
 
-fn fibonacci(index: i32) -> i32 {
+fn fibonacci(index: i32) i32 {
     if (index < 2) return index;
     return fibonacci(index - 1) + fibonacci(index - 2);
 }
@@ -3430,7 +3430,7 @@ test "fibonacci" {
 const first_25_primes = firstNPrimes(25);
 const sum_of_first_25_primes = sum(first_25_primes);
 
-fn firstNPrimes(comptime n: usize) -> [n]i32 {
+fn firstNPrimes(comptime n: usize) [n]i32 {
     var prime_list: [n]i32 = undefined;
     var next_index: usize = 0;
     var test_number: i32 = 2;
@@ -3451,7 +3451,7 @@ fn firstNPrimes(comptime n: usize) -> [n]i32 {
     return prime_list;
 }
 
-fn sum(numbers: []const i32) -> i32 {
+fn sum(numbers: []const i32) i32 {
     var result: i32 = 0;
     for (numbers) |x| {
         result += x;
@@ -3487,7 +3487,7 @@ test "variable values" {
       the type <code>i32</code>. In Zig we refer to the type as <code>List(i32)</code>.
       </p>
       {#code_begin|syntax#}
-fn List(comptime T: type) -> type {
+fn List(comptime T: type) type {
     return struct {
         items: []T,
         len: usize,
@@ -3526,7 +3526,7 @@ const warn = @import("std").debug.warn;
 const a_number: i32 = 1234;
 const a_string = "foobar";
 
-pub fn main() {
+pub fn main() void {
     warn("here is a string: '{}' here is a number: {}\n", a_string, a_number);
 }
       {#code_end#}
@@ -3537,7 +3537,7 @@ pub fn main() {
 
       {#code_begin|syntax#}
 /// Calls print and then flushes the buffer.
-pub fn printf(self: &OutStream, comptime format: []const u8, args: ...) -> %void {
+pub fn printf(self: &OutStream, comptime format: []const u8, args: ...) %void {
     const State = enum {
         Start,
         OpenBrace,
@@ -3609,7 +3609,7 @@ pub fn printf(self: &OutStream, comptime format: []const u8, args: ...) -> %void
       and emits a function that actually looks like this:
       </p>
       {#code_begin|syntax#}
-pub fn printf(self: &OutStream, arg0: i32, arg1: []const u8) -> %void {
+pub fn printf(self: &OutStream, arg0: i32, arg1: []const u8) %void {
     try self.write("here is a string: '");
     try self.printValue(arg0);
     try self.write("' here is a number: ");
@@ -3623,7 +3623,7 @@ pub fn printf(self: &OutStream, arg0: i32, arg1: []const u8) -> %void {
       on the type:
       </p>
       {#code_begin|syntax#}
-pub fn printValue(self: &OutStream, value: var) -> %void {
+pub fn printValue(self: &OutStream, value: var) %void {
     const T = @typeOf(value);
     if (@isInteger(T)) {
         return self.printInt(T, value);
@@ -3665,7 +3665,7 @@ const a_number: i32 = 1234;
 const a_string = "foobar";
 const fmt = "here is a string: '{}' here is a number: {}\n";
 
-pub fn main() {
+pub fn main() void {
     warn(fmt, a_string, a_number);
 }
       {#code_end#}
@@ -4101,7 +4101,7 @@ test "inline function call" {
     assert(@inlineCall(add, 3, 9) == 12);
 }
 
-fn add(a: i32, b: i32) -> i32 { return a + b; }
+fn add(a: i32, b: i32) i32 { return a + b; }
       {#code_end#}
       <p>
       Unlike a normal function call, however, <code>@inlineCall</code> guarantees that the call
@@ -4246,8 +4246,8 @@ fn add(a: i32, b: i32) -&gt; i32 { a + b }</code></pre>
 const Derp = @OpaqueType();
 const Wat = @OpaqueType();
 
-extern fn bar(d: &Derp);
-export fn foo(w: &Wat) {
+extern fn bar(d: &Derp) void;
+export fn foo(w: &Wat) void {
     bar(w);
 }
 
@@ -4552,7 +4552,7 @@ pub const TypeId = enum {
       {#code_begin|syntax#}
 const Builder = @import("std").build.Builder;
 
-pub fn build(b: &Builder) -> %void {
+pub fn build(b: &Builder) %void {
     const exe = b.addExecutable("example", "example.zig");
     exe.setBuildMode(b.standardReleaseOptions());
     b.default_step.dependOn(&exe.step);
@@ -4612,7 +4612,7 @@ test "safety check" {
 comptime {
     assert(false);
 }
-fn assert(ok: bool) {
+fn assert(ok: bool) void {
     if (!ok) unreachable; // assertion failure
 }
       {#code_end#}
@@ -4694,7 +4694,7 @@ comptime {
       {#code_begin|exe_err#}
 const math = @import("std").math;
 const warn = @import("std").debug.warn;
-pub fn main() -> %void {
+pub fn main() %void {
     var byte: u8 = 255;
 
     byte = if (math.add(u8, byte, 1)) |result| result else |err| {
@@ -4722,7 +4722,7 @@ pub fn main() -> %void {
       </p>
       {#code_begin|exe#}
 const warn = @import("std").debug.warn;
-pub fn main() -> %void {
+pub fn main() %void {
     var byte: u8 = 255;
 
     var result: u8 = undefined;
@@ -4818,7 +4818,7 @@ comptime {
       the <code>if</code> expression:</p>
       {#code_begin|exe|test#}
 const warn = @import("std").debug.warn;
-pub fn main() {
+pub fn main() void {
     const nullable_number: ?i32 = null;
 
     if (nullable_number) |number| {
@@ -4838,7 +4838,7 @@ comptime {
 
 error UnableToReturnNumber;
 
-fn getNumberOrFail() -> %i32 {
+fn getNumberOrFail() %i32 {
     return error.UnableToReturnNumber;
 }
       {#code_end#}
@@ -4848,7 +4848,7 @@ fn getNumberOrFail() -> %i32 {
       {#code_begin|exe#}
 const warn = @import("std").debug.warn;
 
-pub fn main() {
+pub fn main() void {
     const result = getNumberOrFail();
 
     if (result) |number| {
@@ -4860,7 +4860,7 @@ pub fn main() {
 
 error UnableToReturnNumber;
 
-fn getNumberOrFail() -> %i32 {
+fn getNumberOrFail() %i32 {
     return error.UnableToReturnNumber;
 }
       {#code_end#}
@@ -5177,9 +5177,9 @@ pub const have_error_return_tracing = true;
       {#header_open|C String Literals#}
       {#code_begin|exe#}
       {#link_libc#}
-extern fn puts(&const u8);
+extern fn puts(&const u8) void;
 
-pub fn main() {
+pub fn main() void {
     puts(c"this has a null terminator");
     puts(
         c\\and so
@@ -5202,7 +5202,7 @@ const c = @cImport({
     @cDefine("_NO_CRT_STDIO_INLINE", "1");
     @cInclude("stdio.h");
 });
-pub fn main() {
+pub fn main() void {
     _ = c.printf(c"hello\n");
 }
       {#code_end#}
@@ -5237,7 +5237,7 @@ const c = @cImport({
 const base64 = @import("std").base64;
 
 export fn decode_base_64(dest_ptr: &u8, dest_len: usize,
-    source_ptr: &const u8, source_len: usize) -> usize
+    source_ptr: &const u8, source_len: usize) usize
 {
     const src = source_ptr[0..source_len];
     const dest = dest_ptr[0..dest_len];
@@ -5268,7 +5268,7 @@ int main(int argc, char **argv) {
       {#code_begin|syntax#}
 const Builder = @import("std").build.Builder;
 
-pub fn build(b: &Builder) -> %void {
+pub fn build(b: &Builder) %void {
     const obj = b.addObject("base64", "base64.zig");
 
     const exe = b.addCExecutable("test");
@@ -5498,7 +5498,7 @@ const string_alias = []u8;
 const StructName = struct {};
 const StructAlias = StructName;
 
-fn functionName(param_name: TypeName) {
+fn functionName(param_name: TypeName) void {
     var functionPointer = functionName;
     functionPointer();
     functionPointer = otherFunction;
@@ -5506,14 +5506,14 @@ fn functionName(param_name: TypeName) {
 }
 const functionAlias = functionName;
 
-fn ListTemplateFunction(comptime ChildType: type, comptime fixed_size: usize) -> type {
+fn ListTemplateFunction(comptime ChildType: type, comptime fixed_size: usize) type {
     return List(ChildType, fixed_size);
 }
 
-fn ShortList(comptime T: type, comptime n: usize) -> type {
+fn ShortList(comptime T: type, comptime n: usize) type {
     return struct {
         field_name: [n]T,
-        fn methodName() {}
+        fn methodName() void {}
     };
 }
 
@@ -5526,7 +5526,7 @@ const xml_document =
 const XmlParser = struct {};
 
 // The initials BE (Big Endian) are just another word in Zig identifier names.
-fn readU32Be() -> u32 {}
+fn readU32Be() u32 {}
       {#code_end#}
       <p>
       See the Zig Standard Library for more examples.
@@ -5558,7 +5558,7 @@ UseDecl = "use" Expression ";"
 
 ExternDecl = "extern" option(String) (FnProto | VariableDeclaration) ";"
 
-FnProto = option("nakedcc" | "stdcallcc" | "extern") "fn" option(Symbol) ParamDeclList option("align" "(" Expression ")") option("section" "(" Expression ")") option("-&gt;" TypeExpr)
+FnProto = option("nakedcc" | "stdcallcc" | "extern") "fn" option(Symbol) ParamDeclList option("align" "(" Expression ")") option("section" "(" Expression ")") TypeExpr
 
 FnDef = option("inline" | "export") FnProto Block
 

example/cat/main.zig

@@ -5,7 +5,7 @@ const os = std.os;
 const warn = std.debug.warn;
 const allocator = std.debug.global_allocator;
 
-pub fn main() -> %void {
+pub fn main() %void {
     var args_it = os.args();
     const exe = try unwrapArg(??args_it.next(allocator));
     var catted_anything = false;
@@ -36,12 +36,12 @@ pub fn main() -> %void {
     }
 }
 
-fn usage(exe: []const u8) -> %void {
+fn usage(exe: []const u8) %void {
     warn("Usage: {} [FILE]...\n", exe);
     return error.Invalid;
 }
 
-fn cat_file(stdout: &io.File, file: &io.File) -> %void {
+fn cat_file(stdout: &io.File, file: &io.File) %void {
     var buf: [1024 * 4]u8 = undefined;
 
     while (true) {
@@ -61,7 +61,7 @@ fn cat_file(stdout: &io.File, file: &io.File) -> %void {
     }
 }
 
-fn unwrapArg(arg: %[]u8) -> %[]u8 {
+fn unwrapArg(arg: %[]u8) %[]u8 {
     return arg catch |err| {
         warn("Unable to parse command line: {}\n", err);
         return err;

example/guess_number/main.zig

@@ -5,7 +5,7 @@ const fmt = std.fmt;
 const Rand = std.rand.Rand;
 const os = std.os;
 
-pub fn main() -> %void {
+pub fn main() %void {
     var stdout_file = try io.getStdOut();
     var stdout_file_stream = io.FileOutStream.init(&stdout_file);
     const stdout = &stdout_file_stream.stream;

example/hello_world/hello.zig

@@ -1,6 +1,6 @@
 const std = @import("std");
 
-pub fn main() -> %void {
+pub fn main() %void {
     // If this program is run without stdout attached, exit with an error.
     var stdout_file = try std.io.getStdOut();
     // If this program encounters pipe failure when printing to stdout, exit

example/hello_world/hello_libc.zig

@@ -7,7 +7,7 @@ const c = @cImport({
 
 const msg = c"Hello, world!\n";
 
-export fn main(argc: c_int, argv: &&u8) -> c_int {
+export fn main(argc: c_int, argv: &&u8) c_int {
     if (c.printf(msg) != c_int(c.strlen(msg)))
         return -1;
 

example/hello_world/hello_windows.zig

@@ -1,6 +1,6 @@
 use @import("std").os.windows;
 
-export fn WinMain(hInstance: HINSTANCE, hPrevInstance: HINSTANCE, lpCmdLine: PWSTR, nCmdShow: INT) -> INT {
+export fn WinMain(hInstance: HINSTANCE, hPrevInstance: HINSTANCE, lpCmdLine: PWSTR, nCmdShow: INT) INT {
     _ = MessageBoxA(null, c"hello", c"title", 0);
     return 0;
 }

example/mix_o_files/base64.zig

@@ -1,6 +1,6 @@
 const base64 = @import("std").base64;
 
-export fn decode_base_64(dest_ptr: &u8, dest_len: usize, source_ptr: &const u8, source_len: usize) -> usize {
+export fn decode_base_64(dest_ptr: &u8, dest_len: usize, source_ptr: &const u8, source_len: usize) usize {
     const src = source_ptr[0..source_len];
     const dest = dest_ptr[0..dest_len];
     const base64_decoder = base64.standard_decoder_unsafe;

example/mix_o_files/build.zig

@@ -1,6 +1,6 @@
 const Builder = @import("std").build.Builder;
 
-pub fn build(b: &Builder) -> %void {
+pub fn build(b: &Builder) %void {
     const obj = b.addObject("base64", "base64.zig");
 
     const exe = b.addCExecutable("test");

example/shared_library/build.zig

@@ -1,6 +1,6 @@
 const Builder = @import("std").build.Builder;
 
-pub fn build(b: &Builder) -> %void {
+pub fn build(b: &Builder) %void {
     const lib = b.addSharedLibrary("mathtest", "mathtest.zig", b.version(1, 0, 0));
 
     const exe = b.addCExecutable("test");

example/shared_library/mathtest.zig

@@ -1,3 +1,3 @@
-export fn add(a: i32, b: i32) -> i32 {
+export fn add(a: i32, b: i32) i32 {
     return a + b;
 }

src-self-hosted/ast.zig

@@ -20,7 +20,7 @@ pub const Node = struct {
         FloatLiteral,
     };
 
-    pub fn iterate(base: &Node, index: usize) -> ?&Node {
+    pub fn iterate(base: &Node, index: usize) ?&Node {
         return switch (base.id) {
             Id.Root => @fieldParentPtr(NodeRoot, "base", base).iterate(index),
             Id.VarDecl => @fieldParentPtr(NodeVarDecl, "base", base).iterate(index),
@@ -35,7 +35,7 @@ pub const Node = struct {
         };
     }
 
-    pub fn destroy(base: &Node, allocator: &mem.Allocator) {
+    pub fn destroy(base: &Node, allocator: &mem.Allocator) void {
         return switch (base.id) {
             Id.Root => allocator.destroy(@fieldParentPtr(NodeRoot, "base", base)),
             Id.VarDecl => allocator.destroy(@fieldParentPtr(NodeVarDecl, "base", base)),
@@ -55,7 +55,7 @@ pub const NodeRoot = struct {
     base: Node,
     decls: ArrayList(&Node),
 
-    pub fn iterate(self: &NodeRoot, index: usize) -> ?&Node {
+    pub fn iterate(self: &NodeRoot, index: usize) ?&Node {
         if (index < self.decls.len) {
             return self.decls.items[self.decls.len - index - 1];
         }
@@ -76,7 +76,7 @@ pub const NodeVarDecl = struct {
     align_node: ?&Node,
     init_node: ?&Node,
 
-    pub fn iterate(self: &NodeVarDecl, index: usize) -> ?&Node {
+    pub fn iterate(self: &NodeVarDecl, index: usize) ?&Node {
         var i = index;
 
         if (self.type_node) |type_node| {
@@ -102,7 +102,7 @@ pub const NodeIdentifier = struct {
     base: Node,
     name_token: Token,
 
-    pub fn iterate(self: &NodeIdentifier, index: usize) -> ?&Node {
+    pub fn iterate(self: &NodeIdentifier, index: usize) ?&Node {
         return null;
     }
 };
@@ -113,7 +113,7 @@ pub const NodeFnProto = struct {
     fn_token: Token,
     name_token: ?Token,
     params: ArrayList(&Node),
-    return_type: ?&Node,
+    return_type: &Node,
     var_args_token: ?Token,
     extern_token: ?Token,
     inline_token: ?Token,
@@ -122,7 +122,7 @@ pub const NodeFnProto = struct {
     lib_name: ?&Node, // populated if this is an extern declaration
     align_expr: ?&Node, // populated if align(A) is present
 
-    pub fn iterate(self: &NodeFnProto, index: usize) -> ?&Node {
+    pub fn iterate(self: &NodeFnProto, index: usize) ?&Node {
         var i = index;
 
         if (self.body_node) |body_node| {
@@ -130,10 +130,8 @@ pub const NodeFnProto = struct {
             i -= 1;
         }
 
-        if (self.return_type) |return_type| {
-            if (i < 1) return return_type;
-            i -= 1;
-        }
+        if (i < 1) return self.return_type;
+        i -= 1;
 
         if (self.align_expr) |align_expr| {
             if (i < 1) return align_expr;
@@ -160,7 +158,7 @@ pub const NodeParamDecl = struct {
     type_node: &Node,
     var_args_token: ?Token,
 
-    pub fn iterate(self: &NodeParamDecl, index: usize) -> ?&Node {
+    pub fn iterate(self: &NodeParamDecl, index: usize) ?&Node {
         var i = index;
 
         if (i < 1) return self.type_node;
@@ -176,7 +174,7 @@ pub const NodeBlock = struct {
     end_token: Token,
     statements: ArrayList(&Node),
 
-    pub fn iterate(self: &NodeBlock, index: usize) -> ?&Node {
+    pub fn iterate(self: &NodeBlock, index: usize) ?&Node {
         var i = index;
 
         if (i < self.statements.len) return self.statements.items[i];
@@ -198,7 +196,7 @@ pub const NodeInfixOp = struct {
         BangEqual,
     };
 
-    pub fn iterate(self: &NodeInfixOp, index: usize) -> ?&Node {
+    pub fn iterate(self: &NodeInfixOp, index: usize) ?&Node {
         var i = index;
 
         if (i < 1) return self.lhs;
@@ -234,7 +232,7 @@ pub const NodePrefixOp = struct {
         volatile_token: ?Token,
     };
 
-    pub fn iterate(self: &NodePrefixOp, index: usize) -> ?&Node {
+    pub fn iterate(self: &NodePrefixOp, index: usize) ?&Node {
         var i = index;
 
         switch (self.op) {
@@ -258,7 +256,7 @@ pub const NodeIntegerLiteral = struct {
     base: Node,
     token: Token,
 
-    pub fn iterate(self: &NodeIntegerLiteral, index: usize) -> ?&Node {
+    pub fn iterate(self: &NodeIntegerLiteral, index: usize) ?&Node {
         return null;
     }
 };
@@ -267,7 +265,7 @@ pub const NodeFloatLiteral = struct {
     base: Node,
     token: Token,
 
-    pub fn iterate(self: &NodeFloatLiteral, index: usize) -> ?&Node {
+    pub fn iterate(self: &NodeFloatLiteral, index: usize) ?&Node {
         return null;
     }
 };

src-self-hosted/llvm.zig

@@ -7,7 +7,7 @@ pub const ModuleRef = removeNullability(c.LLVMModuleRef);
 pub const ContextRef = removeNullability(c.LLVMContextRef);
 pub const BuilderRef = removeNullability(c.LLVMBuilderRef);
 
-fn removeNullability(comptime T: type) -> type {
+fn removeNullability(comptime T: type) type {
     comptime assert(@typeId(T) == builtin.TypeId.Nullable);
     return T.Child;
 }

src-self-hosted/main.zig

@@ -20,7 +20,7 @@ error ZigInstallationNotFound;
 
 const default_zig_cache_name = "zig-cache";
 
-pub fn main() -> %void {
+pub fn main() %void {
     main2() catch |err| {
         if (err != error.InvalidCommandLineArguments) {
             warn("{}\n", @errorName(err));
@@ -39,7 +39,7 @@ const Cmd = enum {
     Targets,
 };
 
-fn badArgs(comptime format: []const u8, args: ...) -> error {
+fn badArgs(comptime format: []const u8, args: ...) error {
     var stderr = try io.getStdErr();
     var stderr_stream_adapter = io.FileOutStream.init(&stderr);
     const stderr_stream = &stderr_stream_adapter.stream;
@@ -48,7 +48,7 @@ fn badArgs(comptime format: []const u8, args: ...) -> error {
     return error.InvalidCommandLineArguments;
 }
 
-pub fn main2() -> %void {
+pub fn main2() %void {
     const allocator = std.heap.c_allocator;
 
     const args = try os.argsAlloc(allocator);
@@ -472,7 +472,7 @@ pub fn main2() -> %void {
     }
 }
 
-fn printUsage(stream: &io.OutStream) -> %void {
+fn printUsage(stream: &io.OutStream) %void {
     try stream.write(
         \\Usage: zig [command] [options]
         \\
@@ -548,7 +548,7 @@ fn printUsage(stream: &io.OutStream) -> %void {
     );
 }
 
-fn printZen() -> %void {
+fn printZen() %void {
     var stdout_file = try io.getStdErr();
     try stdout_file.write(
         \\
@@ -569,7 +569,7 @@ fn printZen() -> %void {
 }
 
 /// Caller must free result
-fn resolveZigLibDir(allocator: &mem.Allocator, zig_install_prefix_arg: ?[]const u8) -> %[]u8 {
+fn resolveZigLibDir(allocator: &mem.Allocator, zig_install_prefix_arg: ?[]const u8) %[]u8 {
     if (zig_install_prefix_arg) |zig_install_prefix| {
         return testZigInstallPrefix(allocator, zig_install_prefix) catch |err| {
             warn("No Zig installation found at prefix {}: {}\n", zig_install_prefix_arg, @errorName(err));
@@ -585,7 +585,7 @@ fn resolveZigLibDir(allocator: &mem.Allocator, zig_install_prefix_arg: ?[]const
 }
 
 /// Caller must free result
-fn testZigInstallPrefix(allocator: &mem.Allocator, test_path: []const u8) -> %[]u8 {
+fn testZigInstallPrefix(allocator: &mem.Allocator, test_path: []const u8) %[]u8 {
     const test_zig_dir = try os.path.join(allocator, test_path, "lib", "zig");
     errdefer allocator.free(test_zig_dir);
 
@@ -599,7 +599,7 @@ fn testZigInstallPrefix(allocator: &mem.Allocator, test_path: []const u8) -> %[]
 }
 
 /// Caller must free result
-fn findZigLibDir(allocator: &mem.Allocator) -> %[]u8 {
+fn findZigLibDir(allocator: &mem.Allocator) %[]u8 {
     const self_exe_path = try os.selfExeDirPath(allocator);
     defer allocator.free(self_exe_path);
 

src-self-hosted/module.zig

@@ -110,7 +110,7 @@ pub const Module = struct {
     };
 
     pub fn create(allocator: &mem.Allocator, name: []const u8, root_src_path: ?[]const u8, target: &const Target,
-        kind: Kind, build_mode: builtin.Mode, zig_lib_dir: []const u8, cache_dir: []const u8) -> %&Module
+        kind: Kind, build_mode: builtin.Mode, zig_lib_dir: []const u8, cache_dir: []const u8) %&Module
     {
         var name_buffer = try Buffer.init(allocator, name);
         errdefer name_buffer.deinit();
@@ -185,11 +185,11 @@ pub const Module = struct {
         return module_ptr;
     }
 
-    fn dump(self: &Module) {
+    fn dump(self: &Module) void {
         c.LLVMDumpModule(self.module);
     }
 
-    pub fn destroy(self: &Module) {
+    pub fn destroy(self: &Module) void {
         c.LLVMDisposeBuilder(self.builder);
         c.LLVMDisposeModule(self.module);
         c.LLVMContextDispose(self.context);
@@ -198,7 +198,7 @@ pub const Module = struct {
         self.allocator.destroy(self);
     }
 
-    pub fn build(self: &Module) -> %void {
+    pub fn build(self: &Module) %void {
         if (self.llvm_argv.len != 0) {
             var c_compatible_args = try std.cstr.NullTerminated2DArray.fromSlices(self.allocator,
                 [][]const []const u8 { [][]const u8{"zig (LLVM option parsing)"}, self.llvm_argv, });
@@ -244,16 +244,16 @@ pub const Module = struct {
         var parser = Parser.init(&tokenizer, self.allocator, root_src_real_path);
         defer parser.deinit();
 
-        const root_node = try parser.parse();
-        defer parser.freeAst(root_node);
+        const tree = try parser.parse();
+        defer tree.deinit();
 
         var stderr_file = try std.io.getStdErr();
         var stderr_file_out_stream = std.io.FileOutStream.init(&stderr_file);
         const out_stream = &stderr_file_out_stream.stream;
-        try parser.renderAst(out_stream, root_node);
+        try parser.renderAst(out_stream, tree.root_node);
 
         warn("====fmt:====\n");
-        try parser.renderSource(out_stream, root_node);
+        try parser.renderSource(out_stream, tree.root_node);
 
         warn("====ir:====\n");
         warn("TODO\n\n");
@@ -263,11 +263,11 @@ pub const Module = struct {
         
     }
 
-    pub fn link(self: &Module, out_file: ?[]const u8) -> %void {
+    pub fn link(self: &Module, out_file: ?[]const u8) %void {
         warn("TODO link");
     }
 
-    pub fn addLinkLib(self: &Module, name: []const u8, provided_explicitly: bool) -> %&LinkLib {
+    pub fn addLinkLib(self: &Module, name: []const u8, provided_explicitly: bool) %&LinkLib {
         const is_libc = mem.eql(u8, name, "c");
 
         if (is_libc) {
@@ -297,7 +297,7 @@ pub const Module = struct {
     }
 };
 
-fn printError(comptime format: []const u8, args: ...) -> %void {
+fn printError(comptime format: []const u8, args: ...) %void {
     var stderr_file = try std.io.getStdErr();
     var stderr_file_out_stream = std.io.FileOutStream.init(&stderr_file);
     const out_stream = &stderr_file_out_stream.stream;

src-self-hosted/parser.zig

@@ -20,14 +20,25 @@ pub const Parser = struct {
     put_back_tokens: [2]Token,
     put_back_count: usize,
     source_file_name: []const u8,
-    cleanup_root_node: ?&ast.NodeRoot,
+
+    pub const Tree = struct {
+        root_node: &ast.NodeRoot,
+
+        pub fn deinit(self: &const Tree) void {
+            // TODO free the whole arena
+        }
+    };
 
     // This memory contents are used only during a function call. It's used to repurpose memory;
-    // specifically so that freeAst can be guaranteed to succeed.
+    // we reuse the same bytes for the stack data structure used by parsing, tree rendering, and
+    // source rendering.
     const utility_bytes_align = @alignOf( union { a: RenderAstFrame, b: State, c: RenderState } );
     utility_bytes: []align(utility_bytes_align) u8,
 
-    pub fn init(tokenizer: &Tokenizer, allocator: &mem.Allocator, source_file_name: []const u8) -> Parser {
+    /// `allocator` should be an arena allocator. Parser never calls free on anything. After you're
+    /// done with a Parser, free the arena. After the arena is freed, no member functions of Parser
+    /// may be called.
+    pub fn init(tokenizer: &Tokenizer, allocator: &mem.Allocator, source_file_name: []const u8) Parser {
         return Parser {
             .allocator = allocator,
             .tokenizer = tokenizer,
@@ -35,12 +46,10 @@ pub const Parser = struct {
             .put_back_count = 0,
             .source_file_name = source_file_name,
             .utility_bytes = []align(utility_bytes_align) u8{},
-            .cleanup_root_node = null,
         };
     }
 
-    pub fn deinit(self: &Parser) {
-        assert(self.cleanup_root_node == null);
+    pub fn deinit(self: &Parser) void {
         self.allocator.free(self.utility_bytes);
     }
 
@@ -54,7 +63,7 @@ pub const Parser = struct {
         NullableField: &?&ast.Node,
         List: &ArrayList(&ast.Node),
 
-        pub fn store(self: &const DestPtr, value: &ast.Node) -> %void {
+        pub fn store(self: &const DestPtr, value: &ast.Node) %void {
             switch (*self) {
                 DestPtr.Field => |ptr| *ptr = value,
                 DestPtr.NullableField => |ptr| *ptr = value,
@@ -88,52 +97,16 @@ pub const Parser = struct {
         Statement: &ast.NodeBlock,
     };
 
-    pub fn freeAst(self: &Parser, root_node: &ast.NodeRoot) {
-        // utility_bytes is big enough to do this iteration since we were able to do
-        // the parsing in the first place
-        comptime assert(@sizeOf(State) >= @sizeOf(&ast.Node));
-
-        var stack = self.initUtilityArrayList(&ast.Node);
-        defer self.deinitUtilityArrayList(stack);
-
-        stack.append(&root_node.base) catch unreachable;
-        while (stack.popOrNull()) |node| {
-            var i: usize = 0;
-            while (node.iterate(i)) |child| : (i += 1) {
-                if (child.iterate(0) != null) {
-                    stack.append(child) catch unreachable;
-                } else {
-                    child.destroy(self.allocator);
-                }
-            }
-            node.destroy(self.allocator);
-        }
-    }
-
-    pub fn parse(self: &Parser) -> %&ast.NodeRoot {
-        const result = self.parseInner() catch |err| x: {
-            if (self.cleanup_root_node) |root_node| {
-                self.freeAst(root_node);
-            }
-            break :x err;
-        };
-        self.cleanup_root_node = null;
-        return result;
-    }
-
-    pub fn parseInner(self: &Parser) -> %&ast.NodeRoot {
+    /// Returns an AST tree, allocated with the parser's allocator.
+    /// Result should be freed with `freeAst` when done.
+    pub fn parse(self: &Parser) %Tree {
         var stack = self.initUtilityArrayList(State);
         defer self.deinitUtilityArrayList(stack);
 
-        const root_node = x: {
-            const root_node = try self.createRoot();
-            errdefer self.allocator.destroy(root_node);
-            // This stack append has to succeed for freeAst to work
-            try stack.append(State.TopLevel);
-            break :x root_node;
-        };
-        assert(self.cleanup_root_node == null);
-        self.cleanup_root_node = root_node;
+        const root_node = try self.createRoot();
+        // TODO  errdefer arena free root node
+
+        try stack.append(State.TopLevel);
 
         while (true) {
             //{
@@ -159,7 +132,7 @@ pub const Parser = struct {
                             stack.append(State { .TopLevelExtern = token }) catch unreachable;
                             continue;
                         },
-                        Token.Id.Eof => return root_node,
+                        Token.Id.Eof => return Tree {.root_node = root_node},
                         else => {
                             self.putBackToken(token);
                             // TODO shouldn't need this cast
@@ -439,15 +412,11 @@ pub const Parser = struct {
                     if (token.id == Token.Id.Keyword_align) {
                         @panic("TODO fn proto align");
                     }
-                    if (token.id == Token.Id.Arrow) {
-                        stack.append(State {
-                            .TypeExpr = DestPtr {.NullableField = &fn_proto.return_type},
-                        }) catch unreachable;
-                        continue;
-                    } else {
-                        self.putBackToken(token);
-                        continue;
-                    }
+                    self.putBackToken(token);
+                    stack.append(State {
+                        .TypeExpr = DestPtr {.Field = &fn_proto.return_type},
+                    }) catch unreachable;
+                    continue;
                 },
 
                 State.ParamDecl => |fn_proto| {
@@ -575,9 +544,8 @@ pub const Parser = struct {
         }
     }
 
-    fn createRoot(self: &Parser) -> %&ast.NodeRoot {
+    fn createRoot(self: &Parser) %&ast.NodeRoot {
         const node = try self.allocator.create(ast.NodeRoot);
-        errdefer self.allocator.destroy(node);
 
         *node = ast.NodeRoot {
             .base = ast.Node {.id = ast.Node.Id.Root},
@@ -587,10 +555,9 @@ pub const Parser = struct {
     }
 
     fn createVarDecl(self: &Parser, visib_token: &const ?Token, mut_token: &const Token, comptime_token: &const ?Token,
-        extern_token: &const ?Token) -> %&ast.NodeVarDecl
+        extern_token: &const ?Token) %&ast.NodeVarDecl
     {
         const node = try self.allocator.create(ast.NodeVarDecl);
-        errdefer self.allocator.destroy(node);
 
         *node = ast.NodeVarDecl {
             .base = ast.Node {.id = ast.Node.Id.VarDecl},
@@ -610,10 +577,9 @@ pub const Parser = struct {
     }
 
     fn createFnProto(self: &Parser, fn_token: &const Token, extern_token: &const ?Token,
-        cc_token: &const ?Token, visib_token: &const ?Token, inline_token: &const ?Token) -> %&ast.NodeFnProto
+        cc_token: &const ?Token, visib_token: &const ?Token, inline_token: &const ?Token) %&ast.NodeFnProto
     {
         const node = try self.allocator.create(ast.NodeFnProto);
-        errdefer self.allocator.destroy(node);
 
         *node = ast.NodeFnProto {
             .base = ast.Node {.id = ast.Node.Id.FnProto},
@@ -621,7 +587,7 @@ pub const Parser = struct {
             .name_token = null,
             .fn_token = *fn_token,
             .params = ArrayList(&ast.Node).init(self.allocator),
-            .return_type = null,
+            .return_type = undefined,
             .var_args_token = null,
             .extern_token = *extern_token,
             .inline_token = *inline_token,
@@ -633,9 +599,8 @@ pub const Parser = struct {
         return node;
     }
 
-    fn createParamDecl(self: &Parser) -> %&ast.NodeParamDecl {
+    fn createParamDecl(self: &Parser) %&ast.NodeParamDecl {
         const node = try self.allocator.create(ast.NodeParamDecl);
-        errdefer self.allocator.destroy(node);
 
         *node = ast.NodeParamDecl {
             .base = ast.Node {.id = ast.Node.Id.ParamDecl},
@@ -648,9 +613,8 @@ pub const Parser = struct {
         return node;
     }
 
-    fn createBlock(self: &Parser, begin_token: &const Token) -> %&ast.NodeBlock {
+    fn createBlock(self: &Parser, begin_token: &const Token) %&ast.NodeBlock {
         const node = try self.allocator.create(ast.NodeBlock);
-        errdefer self.allocator.destroy(node);
 
         *node = ast.NodeBlock {
             .base = ast.Node {.id = ast.Node.Id.Block},
@@ -661,9 +625,8 @@ pub const Parser = struct {
         return node;
     }
 
-    fn createInfixOp(self: &Parser, op_token: &const Token, op: &const ast.NodeInfixOp.InfixOp) -> %&ast.NodeInfixOp {
+    fn createInfixOp(self: &Parser, op_token: &const Token, op: &const ast.NodeInfixOp.InfixOp) %&ast.NodeInfixOp {
         const node = try self.allocator.create(ast.NodeInfixOp);
-        errdefer self.allocator.destroy(node);
 
         *node = ast.NodeInfixOp {
             .base = ast.Node {.id = ast.Node.Id.InfixOp},
@@ -675,9 +638,8 @@ pub const Parser = struct {
         return node;
     }
 
-    fn createPrefixOp(self: &Parser, op_token: &const Token, op: &const ast.NodePrefixOp.PrefixOp) -> %&ast.NodePrefixOp {
+    fn createPrefixOp(self: &Parser, op_token: &const Token, op: &const ast.NodePrefixOp.PrefixOp) %&ast.NodePrefixOp {
         const node = try self.allocator.create(ast.NodePrefixOp);
-        errdefer self.allocator.destroy(node);
 
         *node = ast.NodePrefixOp {
             .base = ast.Node {.id = ast.Node.Id.PrefixOp},
@@ -688,9 +650,8 @@ pub const Parser = struct {
         return node;
     }
 
-    fn createIdentifier(self: &Parser, name_token: &const Token) -> %&ast.NodeIdentifier {
+    fn createIdentifier(self: &Parser, name_token: &const Token) %&ast.NodeIdentifier {
         const node = try self.allocator.create(ast.NodeIdentifier);
-        errdefer self.allocator.destroy(node);
 
         *node = ast.NodeIdentifier {
             .base = ast.Node {.id = ast.Node.Id.Identifier},
@@ -699,9 +660,8 @@ pub const Parser = struct {
         return node;
     }
 
-    fn createIntegerLiteral(self: &Parser, token: &const Token) -> %&ast.NodeIntegerLiteral {
+    fn createIntegerLiteral(self: &Parser, token: &const Token) %&ast.NodeIntegerLiteral {
         const node = try self.allocator.create(ast.NodeIntegerLiteral);
-        errdefer self.allocator.destroy(node);
 
         *node = ast.NodeIntegerLiteral {
             .base = ast.Node {.id = ast.Node.Id.IntegerLiteral},
@@ -710,9 +670,8 @@ pub const Parser = struct {
         return node;
     }
 
-    fn createFloatLiteral(self: &Parser, token: &const Token) -> %&ast.NodeFloatLiteral {
+    fn createFloatLiteral(self: &Parser, token: &const Token) %&ast.NodeFloatLiteral {
         const node = try self.allocator.create(ast.NodeFloatLiteral);
-        errdefer self.allocator.destroy(node);
 
         *node = ast.NodeFloatLiteral {
             .base = ast.Node {.id = ast.Node.Id.FloatLiteral},
@@ -721,40 +680,36 @@ pub const Parser = struct {
         return node;
     }
 
-    fn createAttachIdentifier(self: &Parser, dest_ptr: &const DestPtr, name_token: &const Token) -> %&ast.NodeIdentifier {
+    fn createAttachIdentifier(self: &Parser, dest_ptr: &const DestPtr, name_token: &const Token) %&ast.NodeIdentifier {
         const node = try self.createIdentifier(name_token);
-        errdefer self.allocator.destroy(node);
         try dest_ptr.store(&node.base);
         return node;
     }
 
-    fn createAttachParamDecl(self: &Parser, list: &ArrayList(&ast.Node)) -> %&ast.NodeParamDecl {
+    fn createAttachParamDecl(self: &Parser, list: &ArrayList(&ast.Node)) %&ast.NodeParamDecl {
         const node = try self.createParamDecl();
-        errdefer self.allocator.destroy(node);
         try list.append(&node.base);
         return node;
     }
 
     fn createAttachFnProto(self: &Parser, list: &ArrayList(&ast.Node), fn_token: &const Token,
         extern_token: &const ?Token, cc_token: &const ?Token, visib_token: &const ?Token,
-        inline_token: &const ?Token) -> %&ast.NodeFnProto
+        inline_token: &const ?Token) %&ast.NodeFnProto
     {
         const node = try self.createFnProto(fn_token, extern_token, cc_token, visib_token, inline_token);
-        errdefer self.allocator.destroy(node);
         try list.append(&node.base);
         return node;
     }
 
     fn createAttachVarDecl(self: &Parser, list: &ArrayList(&ast.Node), visib_token: &const ?Token,
-        mut_token: &const Token, comptime_token: &const ?Token, extern_token: &const ?Token) -> %&ast.NodeVarDecl
+        mut_token: &const Token, comptime_token: &const ?Token, extern_token: &const ?Token) %&ast.NodeVarDecl
     {
         const node = try self.createVarDecl(visib_token, mut_token, comptime_token, extern_token);
-        errdefer self.allocator.destroy(node);
         try list.append(&node.base);
         return node;
     }
 
-    fn parseError(self: &Parser, token: &const Token, comptime fmt: []const u8, args: ...) -> error {
+    fn parseError(self: &Parser, token: &const Token, comptime fmt: []const u8, args: ...) error {
         const loc = self.tokenizer.getTokenLocation(token);
         warn("{}:{}:{}: error: " ++ fmt ++ "\n", self.source_file_name, loc.line + 1, loc.column + 1, args);
         warn("{}\n", self.tokenizer.buffer[loc.line_start..loc.line_end]);
@@ -775,24 +730,24 @@ pub const Parser = struct {
         return error.ParseError;
     }
 
-    fn expectToken(self: &Parser, token: &const Token, id: @TagType(Token.Id)) -> %void {
+    fn expectToken(self: &Parser, token: &const Token, id: @TagType(Token.Id)) %void {
         if (token.id != id) {
             return self.parseError(token, "expected {}, found {}", @tagName(id), @tagName(token.id));
         }
     }
 
-    fn eatToken(self: &Parser, id: @TagType(Token.Id)) -> %Token {
+    fn eatToken(self: &Parser, id: @TagType(Token.Id)) %Token {
         const token = self.getNextToken();
         try self.expectToken(token, id);
         return token;
     }
 
-    fn putBackToken(self: &Parser, token: &const Token) {
+    fn putBackToken(self: &Parser, token: &const Token) void {
         self.put_back_tokens[self.put_back_count] = *token;
         self.put_back_count += 1;
     }
 
-    fn getNextToken(self: &Parser) -> Token {
+    fn getNextToken(self: &Parser) Token {
         if (self.put_back_count != 0) {
             const put_back_index = self.put_back_count - 1;
             const put_back_token = self.put_back_tokens[put_back_index];
@@ -808,7 +763,7 @@ pub const Parser = struct {
         indent: usize,
     };
 
-    pub fn renderAst(self: &Parser, stream: &std.io.OutStream, root_node: &ast.NodeRoot) -> %void {
+    pub fn renderAst(self: &Parser, stream: &std.io.OutStream, root_node: &ast.NodeRoot) %void {
         var stack = self.initUtilityArrayList(RenderAstFrame);
         defer self.deinitUtilityArrayList(stack);
 
@@ -847,7 +802,7 @@ pub const Parser = struct {
         Indent: usize,
     };
 
-    pub fn renderSource(self: &Parser, stream: &std.io.OutStream, root_node: &ast.NodeRoot) -> %void {
+    pub fn renderSource(self: &Parser, stream: &std.io.OutStream, root_node: &ast.NodeRoot) %void {
         var stack = self.initUtilityArrayList(RenderState);
         defer self.deinitUtilityArrayList(stack);
 
@@ -1039,14 +994,12 @@ pub const Parser = struct {
                     if (fn_proto.align_expr != null) {
                         @panic("TODO");
                     }
-                    if (fn_proto.return_type) |return_type| {
-                        try stream.print(" -> ");
-                        if (fn_proto.body_node) |body_node| {
-                            try stack.append(RenderState { .Expression = body_node});
-                            try stack.append(RenderState { .Text = " "});
-                        }
-                        try stack.append(RenderState { .Expression = return_type});
+                    try stream.print(" ");
+                    if (fn_proto.body_node) |body_node| {
+                        try stack.append(RenderState { .Expression = body_node});
+                        try stack.append(RenderState { .Text = " "});
                     }
+                    try stack.append(RenderState { .Expression = fn_proto.return_type});
                 },
                 RenderState.Statement => |base| {
                     switch (base.id) {
@@ -1066,7 +1019,7 @@ pub const Parser = struct {
         }
     }
 
-    fn initUtilityArrayList(self: &Parser, comptime T: type) -> ArrayList(T) {
+    fn initUtilityArrayList(self: &Parser, comptime T: type) ArrayList(T) {
         const new_byte_count = self.utility_bytes.len - self.utility_bytes.len % @sizeOf(T);
         self.utility_bytes = self.allocator.alignedShrink(u8, utility_bytes_align, self.utility_bytes, new_byte_count);
         const typed_slice = ([]T)(self.utility_bytes);
@@ -1077,7 +1030,7 @@ pub const Parser = struct {
         };
     }
 
-    fn deinitUtilityArrayList(self: &Parser, list: var) {
+    fn deinitUtilityArrayList(self: &Parser, list: var) void {
         self.utility_bytes = ([]align(utility_bytes_align) u8)(list.items);
     }
 
@@ -1085,7 +1038,7 @@ pub const Parser = struct {
 
 var fixed_buffer_mem: [100 * 1024]u8 = undefined;
 
-fn testParse(source: []const u8, allocator: &mem.Allocator) -> %[]u8 {
+fn testParse(source: []const u8, allocator: &mem.Allocator) %[]u8 {
     var padded_source: [0x100]u8 = undefined;
     std.mem.copy(u8, padded_source[0..source.len], source);
     padded_source[source.len + 0] = '\n';
@@ -1096,30 +1049,34 @@ fn testParse(source: []const u8, allocator: &mem.Allocator) -> %[]u8 {
     var parser = Parser.init(&tokenizer, allocator, "(memory buffer)");
     defer parser.deinit();
 
-    const root_node = try parser.parse();
-    defer parser.freeAst(root_node);
+    const tree = try parser.parse();
+    defer tree.deinit();
 
     var buffer = try std.Buffer.initSize(allocator, 0);
     var buffer_out_stream = io.BufferOutStream.init(&buffer);
-    try parser.renderSource(&buffer_out_stream.stream, root_node);
+    try parser.renderSource(&buffer_out_stream.stream, tree.root_node);
     return buffer.toOwnedSlice();
 }
 
+error TestFailed;
+error NondeterministicMemoryUsage;
+error MemoryLeakDetected;
+
 // TODO test for memory leaks
 // TODO test for valid frees
-fn testCanonical(source: []const u8) {
+fn testCanonical(source: []const u8) %void {
     const needed_alloc_count = x: {
         // Try it once with unlimited memory, make sure it works
         var fixed_allocator = mem.FixedBufferAllocator.init(fixed_buffer_mem[0..]);
         var failing_allocator = std.debug.FailingAllocator.init(&fixed_allocator.allocator, @maxValue(usize));
-        const result_source = testParse(source, &failing_allocator.allocator) catch @panic("test failed");
+        const result_source = try testParse(source, &failing_allocator.allocator);
         if (!mem.eql(u8, result_source, source)) {
             warn("\n====== expected this output: =========\n");
             warn("{}", source);
             warn("\n======== instead found this: =========\n");
             warn("{}", result_source);
             warn("\n======================================\n");
-            @panic("test failed");
+            return error.TestFailed;
         }
         failing_allocator.allocator.free(result_source);
         break :x failing_allocator.index;
@@ -1130,7 +1087,7 @@ fn testCanonical(source: []const u8) {
         var fixed_allocator = mem.FixedBufferAllocator.init(fixed_buffer_mem[0..]);
         var failing_allocator = std.debug.FailingAllocator.init(&fixed_allocator.allocator, fail_index);
         if (testParse(source, &failing_allocator.allocator)) |_| {
-            @panic("non-deterministic memory usage");
+            return error.NondeterministicMemoryUsage;
         } else |err| {
             assert(err == error.OutOfMemory);
             // TODO make this pass
@@ -1139,19 +1096,19 @@ fn testCanonical(source: []const u8) {
             //        fail_index, needed_alloc_count,
             //        failing_allocator.allocated_bytes, failing_allocator.freed_bytes,
             //        failing_allocator.index, failing_allocator.deallocations);
-            //    @panic("memory leak detected");
+            //    return error.MemoryLeakDetected;
             //}
         }
     }
 }
 
 test "zig fmt" {
-    testCanonical(
-        \\extern fn puts(s: &const u8) -> c_int;
+    try testCanonical(
+        \\extern fn puts(s: &const u8) c_int;
         \\
     );
 
-    testCanonical(
+    try testCanonical(
         \\const a = b;
         \\pub const a = b;
         \\var a = b;
@@ -1163,44 +1120,44 @@ test "zig fmt" {
         \\
     );
 
-    testCanonical(
+    try testCanonical(
         \\extern var foo: c_int;
         \\
     );
 
-    testCanonical(
+    try testCanonical(
         \\var foo: c_int align(1);
         \\
     );
 
-    testCanonical(
-        \\fn main(argc: c_int, argv: &&u8) -> c_int {
+    try testCanonical(
+        \\fn main(argc: c_int, argv: &&u8) c_int {
         \\    const a = b;
         \\}
         \\
     );
 
-    testCanonical(
-        \\fn foo(argc: c_int, argv: &&u8) -> c_int {
+    try testCanonical(
+        \\fn foo(argc: c_int, argv: &&u8) c_int {
         \\    return 0;
         \\}
         \\
     );
 
-    testCanonical(
-        \\extern fn f1(s: &align(&u8) u8) -> c_int;
+    try testCanonical(
+        \\extern fn f1(s: &align(&u8) u8) c_int;
         \\
     );
 
-    testCanonical(
-        \\extern fn f1(s: &&align(1) &const &volatile u8) -> c_int;
-        \\extern fn f2(s: &align(1) const &align(1) volatile &const volatile u8) -> c_int;
-        \\extern fn f3(s: &align(1) const volatile u8) -> c_int;
+    try testCanonical(
+        \\extern fn f1(s: &&align(1) &const &volatile u8) c_int;
+        \\extern fn f2(s: &align(1) const &align(1) volatile &const volatile u8) c_int;
+        \\extern fn f3(s: &align(1) const volatile u8) c_int;
         \\
     );
 
-    testCanonical(
-        \\fn f1(a: bool, b: bool) -> bool {
+    try testCanonical(
+        \\fn f1(a: bool, b: bool) bool {
         \\    a != b;
         \\    return a == b;
         \\}

src-self-hosted/target.zig

@@ -11,7 +11,7 @@ pub const Target = union(enum) {
     Native,
     Cross: CrossTarget,
 
-    pub fn oFileExt(self: &const Target) -> []const u8 {
+    pub fn oFileExt(self: &const Target) []const u8 {
         const environ = switch (*self) {
             Target.Native => builtin.environ,
             Target.Cross => |t| t.environ,
@@ -22,28 +22,28 @@ pub const Target = union(enum) {
         };
     }
 
-    pub fn exeFileExt(self: &const Target) -> []const u8 {
+    pub fn exeFileExt(self: &const Target) []const u8 {
         return switch (self.getOs()) {
             builtin.Os.windows => ".exe",
             else => "",
         };
     }
 
-    pub fn getOs(self: &const Target) -> builtin.Os {
+    pub fn getOs(self: &const Target) builtin.Os {
         return switch (*self) {
             Target.Native => builtin.os,
             Target.Cross => |t| t.os,
         };
     }
 
-    pub fn isDarwin(self: &const Target) -> bool {
+    pub fn isDarwin(self: &const Target) bool {
         return switch (self.getOs()) {
             builtin.Os.ios, builtin.Os.macosx => true,
             else => false,
         };
     }
 
-    pub fn isWindows(self: &const Target) -> bool {
+    pub fn isWindows(self: &const Target) bool {
         return switch (self.getOs()) {
             builtin.Os.windows => true,
             else => false,
@@ -51,7 +51,7 @@ pub const Target = union(enum) {
     }
 };
 
-pub fn initializeAll() {
+pub fn initializeAll() void {
     c.LLVMInitializeAllTargets();
     c.LLVMInitializeAllTargetInfos();
     c.LLVMInitializeAllTargetMCs();

src-self-hosted/tokenizer.zig

@@ -53,7 +53,7 @@ pub const Token = struct {
         KeywordId{.bytes="while", .id = Id.Keyword_while},
     };
 
-    fn getKeyword(bytes: []const u8) -> ?Id {
+    fn getKeyword(bytes: []const u8) ?Id {
         for (keywords) |kw| {
             if (mem.eql(u8, kw.bytes, bytes)) {
                 return kw.id;
@@ -146,7 +146,7 @@ pub const Tokenizer = struct {
         line_end: usize,
     };
 
-    pub fn getTokenLocation(self: &Tokenizer, token: &const Token) -> Location {
+    pub fn getTokenLocation(self: &Tokenizer, token: &const Token) Location {
         var loc = Location {
             .line = 0,
             .column = 0,
@@ -171,13 +171,13 @@ pub const Tokenizer = struct {
     }
 
     /// For debugging purposes
-    pub fn dump(self: &Tokenizer, token: &const Token) {
+    pub fn dump(self: &Tokenizer, token: &const Token) void {
         std.debug.warn("{} \"{}\"\n", @tagName(token.id), self.buffer[token.start..token.end]);
     }
 
     /// buffer must end with "\n\n\n". This is so that attempting to decode
     /// a the 3 trailing bytes of a 4-byte utf8 sequence is never a buffer overflow.
-    pub fn init(buffer: []const u8) -> Tokenizer {
+    pub fn init(buffer: []const u8) Tokenizer {
         std.debug.assert(buffer[buffer.len - 1] == '\n');
         std.debug.assert(buffer[buffer.len - 2] == '\n');
         std.debug.assert(buffer[buffer.len - 3] == '\n');
@@ -212,7 +212,7 @@ pub const Tokenizer = struct {
         Period2,
     };
 
-    pub fn next(self: &Tokenizer) -> Token {
+    pub fn next(self: &Tokenizer) Token {
         if (self.pending_invalid_token) |token| {
             self.pending_invalid_token = null;
             return token;
@@ -528,11 +528,11 @@ pub const Tokenizer = struct {
         return result;
     }
 
-    pub fn getTokenSlice(self: &const Tokenizer, token: &const Token) -> []const u8 {
+    pub fn getTokenSlice(self: &const Tokenizer, token: &const Token) []const u8 {
         return self.buffer[token.start..token.end];
     }
 
-    fn checkLiteralCharacter(self: &Tokenizer) {
+    fn checkLiteralCharacter(self: &Tokenizer) void {
         if (self.pending_invalid_token != null) return;
         const invalid_length = self.getInvalidCharacterLength();
         if (invalid_length == 0) return;
@@ -543,7 +543,7 @@ pub const Tokenizer = struct {
         };
     }
 
-    fn getInvalidCharacterLength(self: &Tokenizer) -> u3 {
+    fn getInvalidCharacterLength(self: &Tokenizer) u3 {
         const c0 = self.buffer[self.index];
         if (c0 < 0x80) {
             if (c0 < 0x20 or c0 == 0x7f) {
@@ -636,7 +636,7 @@ test "tokenizer - illegal unicode codepoints" {
     testTokenize("//\xe2\x80\xaa", []Token.Id{});
 }
 
-fn testTokenize(source: []const u8, expected_tokens: []const Token.Id) {
+fn testTokenize(source: []const u8, expected_tokens: []const Token.Id) void {
     // (test authors, just make this bigger if you need it)
     var padded_source: [0x100]u8 = undefined;
     std.mem.copy(u8, padded_source[0..source.len], source);

src/analyze.cpp

@@ -918,9 +918,7 @@ TypeTableEntry *get_fn_type(CodeGen *g, FnTypeId *fn_type_id) {
     if (fn_type_id->alignment != 0) {
         buf_appendf(&fn_type->name, " align(%" PRIu32 ")", fn_type_id->alignment);
     }
-    if (fn_type_id->return_type->id != TypeTableEntryIdVoid) {
-        buf_appendf(&fn_type->name, " -> %s", buf_ptr(&fn_type_id->return_type->name));
-    }
+    buf_appendf(&fn_type->name, " %s", buf_ptr(&fn_type_id->return_type->name));
     skip_debug_info = skip_debug_info || !fn_type_id->return_type->di_type;
 
     // next, loop over the parameters again and compute debug information
@@ -1082,7 +1080,7 @@ TypeTableEntry *get_generic_fn_type(CodeGen *g, FnTypeId *fn_type_id) {
         const char *comma_str = (i == 0) ? "" : ",";
         buf_appendf(&fn_type->name, "%svar", comma_str);
     }
-    buf_appendf(&fn_type->name, ")->var");
+    buf_appendf(&fn_type->name, ")var");
 
     fn_type->data.fn.fn_type_id = *fn_type_id;
     fn_type->data.fn.is_generic = true;
@@ -2665,7 +2663,7 @@ static bool scope_is_root_decls(Scope *scope) {
 
 static void wrong_panic_prototype(CodeGen *g, AstNode *proto_node, TypeTableEntry *fn_type) {
     add_node_error(g, proto_node,
-            buf_sprintf("expected 'fn([]const u8, ?&builtin.StackTrace) -> unreachable', found '%s'",
+            buf_sprintf("expected 'fn([]const u8, ?&builtin.StackTrace) unreachable', found '%s'",
                 buf_ptr(&fn_type->name)));
 }
 

src/ast_render.cpp

@@ -450,10 +450,9 @@ static void render_node_extra(AstRender *ar, AstNode *node, bool grouped) {
                 }
 
                 AstNode *return_type_node = node->data.fn_proto.return_type;
-                if (return_type_node != nullptr) {
-                    fprintf(ar->f, " -> ");
-                    render_node_grouped(ar, return_type_node);
-                }
+                assert(return_type_node != nullptr);
+                fprintf(ar->f, " ");
+                render_node_grouped(ar, return_type_node);
                 break;
             }
         case NodeTypeFnDef:

src/parser.cpp

@@ -84,11 +84,6 @@ static AstNode *ast_create_node(ParseContext *pc, NodeType type, Token *first_to
     return node;
 }
 
-static AstNode *ast_create_void_type_node(ParseContext *pc, Token *token) {
-    AstNode *node = ast_create_node(pc, NodeTypeSymbol, token);
-    node->data.symbol_expr.symbol = pc->void_buf;
-    return node;
-}
 
 static void parse_asm_template(ParseContext *pc, AstNode *node) {
     Buf *asm_template = node->data.asm_expr.asm_template;
@@ -2245,7 +2240,7 @@ static AstNode *ast_parse_block(ParseContext *pc, size_t *token_index, bool mand
 }
 
 /*
-FnProto = option("nakedcc" | "stdcallcc" | "extern") "fn" option(Symbol) ParamDeclList option("align" "(" Expression ")") option("section" "(" Expression ")") option("->" TypeExpr)
+FnProto = option("nakedcc" | "stdcallcc" | "extern") "fn" option(Symbol) ParamDeclList option("align" "(" Expression ")") option("section" "(" Expression ")") TypeExpr
 */
 static AstNode *ast_parse_fn_proto(ParseContext *pc, size_t *token_index, bool mandatory, VisibMod visib_mod) {
     Token *first_token = &pc->tokens->at(*token_index);
@@ -2320,12 +2315,7 @@ static AstNode *ast_parse_fn_proto(ParseContext *pc, size_t *token_index, bool m
         ast_eat_token(pc, token_index, TokenIdRParen);
         next_token = &pc->tokens->at(*token_index);
     }
-    if (next_token->id == TokenIdArrow) {
-        *token_index += 1;
-        node->data.fn_proto.return_type = ast_parse_type_expr(pc, token_index, false);
-    } else {
-        node->data.fn_proto.return_type = ast_create_void_type_node(pc, next_token);
-    }
+    node->data.fn_proto.return_type = ast_parse_type_expr(pc, token_index, true);
 
     return node;
 }

src/translate_c.cpp

@@ -920,7 +920,7 @@ static AstNode *trans_type(Context *c, const Type *ty, const SourceLocation &sou
                     //     void foo(void) -> Foo;
                     // we want to keep the return type AST node.
                     if (is_c_void_type(proto_node->data.fn_proto.return_type)) {
-                        proto_node->data.fn_proto.return_type = nullptr;
+                        proto_node->data.fn_proto.return_type = trans_create_node_symbol_str(c, "void");
                     }
                 }
 

std/array_list.zig

@@ -4,11 +4,11 @@ const assert = debug.assert;
 const mem = std.mem;
 const Allocator = mem.Allocator;
 
-pub fn ArrayList(comptime T: type) -> type {
+pub fn ArrayList(comptime T: type) type {
     return AlignedArrayList(T, @alignOf(T));
 }
 
-pub fn AlignedArrayList(comptime T: type, comptime A: u29) -> type{
+pub fn AlignedArrayList(comptime T: type, comptime A: u29) type{
     return struct {
         const Self = this;
 
@@ -20,7 +20,7 @@ pub fn AlignedArrayList(comptime T: type, comptime A: u29) -> type{
         allocator: &Allocator,
 
         /// Deinitialize with `deinit` or use `toOwnedSlice`.
-        pub fn init(allocator: &Allocator) -> Self {
+        pub fn init(allocator: &Allocator) Self {
             return Self {
                 .items = []align(A) T{},
                 .len = 0,
@@ -28,22 +28,22 @@ pub fn AlignedArrayList(comptime T: type, comptime A: u29) -> type{
             };
         }
 
-        pub fn deinit(l: &Self) {
+        pub fn deinit(l: &Self) void {
             l.allocator.free(l.items);
         }
 
-        pub fn toSlice(l: &Self) -> []align(A) T {
+        pub fn toSlice(l: &Self) []align(A) T {
             return l.items[0..l.len];
         }
 
-        pub fn toSliceConst(l: &const Self) -> []align(A) const T {
+        pub fn toSliceConst(l: &const Self) []align(A) const T {
             return l.items[0..l.len];
         }
 
         /// ArrayList takes ownership of the passed in slice. The slice must have been
         /// allocated with `allocator`.
         /// Deinitialize with `deinit` or use `toOwnedSlice`.
-        pub fn fromOwnedSlice(allocator: &Allocator, slice: []align(A) T) -> Self {
+        pub fn fromOwnedSlice(allocator: &Allocator, slice: []align(A) T) Self {
             return Self {
                 .items = slice,
                 .len = slice.len,
@@ -52,35 +52,35 @@ pub fn AlignedArrayList(comptime T: type, comptime A: u29) -> type{
         }
 
         /// The caller owns the returned memory. ArrayList becomes empty.
-        pub fn toOwnedSlice(self: &Self) -> []align(A) T {
+        pub fn toOwnedSlice(self: &Self) []align(A) T {
             const allocator = self.allocator;
             const result = allocator.alignedShrink(T, A, self.items, self.len);
             *self = init(allocator);
             return result;
         }
 
-        pub fn append(l: &Self, item: &const T) -> %void {
+        pub fn append(l: &Self, item: &const T) %void {
             const new_item_ptr = try l.addOne();
             *new_item_ptr = *item;
         }
 
-        pub fn appendSlice(l: &Self, items: []align(A) const T) -> %void {
+        pub fn appendSlice(l: &Self, items: []align(A) const T) %void {
             try l.ensureCapacity(l.len + items.len);
             mem.copy(T, l.items[l.len..], items);
             l.len += items.len;
         }
 
-        pub fn resize(l: &Self, new_len: usize) -> %void {
+        pub fn resize(l: &Self, new_len: usize) %void {
             try l.ensureCapacity(new_len);
             l.len = new_len;
         }
 
-        pub fn shrink(l: &Self, new_len: usize) {
+        pub fn shrink(l: &Self, new_len: usize) void {
             assert(new_len <= l.len);
             l.len = new_len;
         }
 
-        pub fn ensureCapacity(l: &Self, new_capacity: usize) -> %void {
+        pub fn ensureCapacity(l: &Self, new_capacity: usize) %void {
             var better_capacity = l.items.len;
             if (better_capacity >= new_capacity) return;
             while (true) {
@@ -90,7 +90,7 @@ pub fn AlignedArrayList(comptime T: type, comptime A: u29) -> type{
             l.items = try l.allocator.alignedRealloc(T, A, l.items, better_capacity);
         }
 
-        pub fn addOne(l: &Self) -> %&T {
+        pub fn addOne(l: &Self) %&T {
             const new_length = l.len + 1;
             try l.ensureCapacity(new_length);
             const result = &l.items[l.len];
@@ -98,12 +98,12 @@ pub fn AlignedArrayList(comptime T: type, comptime A: u29) -> type{
             return result;
         }
 
-        pub fn pop(self: &Self) -> T {
+        pub fn pop(self: &Self) T {
             self.len -= 1;
             return self.items[self.len];
         }
 
-        pub fn popOrNull(self: &Self) -> ?T {
+        pub fn popOrNull(self: &Self) ?T {
             if (self.len == 0)
                 return null;
             return self.pop();

std/base64.zig

@@ -11,7 +11,7 @@ pub const Base64Encoder = struct {
     pad_char: u8,
 
     /// a bunch of assertions, then simply pass the data right through.
-    pub fn init(alphabet_chars: []const u8, pad_char: u8) -> Base64Encoder {
+    pub fn init(alphabet_chars: []const u8, pad_char: u8) Base64Encoder {
         assert(alphabet_chars.len == 64);
         var char_in_alphabet = []bool{false} ** 256;
         for (alphabet_chars) |c| {
@@ -27,12 +27,12 @@ pub const Base64Encoder = struct {
     }
 
     /// ceil(source_len * 4/3)
-    pub fn calcSize(source_len: usize) -> usize {
+    pub fn calcSize(source_len: usize) usize {
         return @divTrunc(source_len + 2, 3) * 4;
     }
 
     /// dest.len must be what you get from ::calcSize.
-    pub fn encode(encoder: &const Base64Encoder, dest: []u8, source: []const u8) {
+    pub fn encode(encoder: &const Base64Encoder, dest: []u8, source: []const u8) void {
         assert(dest.len == Base64Encoder.calcSize(source.len));
 
         var i: usize = 0;
@@ -90,7 +90,7 @@ pub const Base64Decoder = struct {
     char_in_alphabet: [256]bool,
     pad_char: u8,
 
-    pub fn init(alphabet_chars: []const u8, pad_char: u8) -> Base64Decoder {
+    pub fn init(alphabet_chars: []const u8, pad_char: u8) Base64Decoder {
         assert(alphabet_chars.len == 64);
 
         var result = Base64Decoder{
@@ -111,7 +111,7 @@ pub const Base64Decoder = struct {
     }
 
     /// If the encoded buffer is detected to be invalid, returns error.InvalidPadding.
-    pub fn calcSize(decoder: &const Base64Decoder, source: []const u8) -> %usize {
+    pub fn calcSize(decoder: &const Base64Decoder, source: []const u8) %usize {
         if (source.len % 4 != 0) return error.InvalidPadding;
         return calcDecodedSizeExactUnsafe(source, decoder.pad_char);
     }
@@ -119,7 +119,7 @@ pub const Base64Decoder = struct {
     /// dest.len must be what you get from ::calcSize.
     /// invalid characters result in error.InvalidCharacter.
     /// invalid padding results in error.InvalidPadding.
-    pub fn decode(decoder: &const Base64Decoder, dest: []u8, source: []const u8) -> %void {
+    pub fn decode(decoder: &const Base64Decoder, dest: []u8, source: []const u8) %void {
         assert(dest.len == (decoder.calcSize(source) catch unreachable));
         assert(source.len % 4 == 0);
 
@@ -168,7 +168,7 @@ error OutputTooSmall;
 pub const Base64DecoderWithIgnore = struct {
     decoder: Base64Decoder,
     char_is_ignored: [256]bool,
-    pub fn init(alphabet_chars: []const u8, pad_char: u8, ignore_chars: []const u8) -> Base64DecoderWithIgnore {
+    pub fn init(alphabet_chars: []const u8, pad_char: u8, ignore_chars: []const u8) Base64DecoderWithIgnore {
         var result = Base64DecoderWithIgnore {
             .decoder = Base64Decoder.init(alphabet_chars, pad_char),
             .char_is_ignored = []bool{false} ** 256,
@@ -185,7 +185,7 @@ pub const Base64DecoderWithIgnore = struct {
     }
 
     /// If no characters end up being ignored or padding, this will be the exact decoded size.
-    pub fn calcSizeUpperBound(encoded_len: usize) -> %usize {
+    pub fn calcSizeUpperBound(encoded_len: usize) %usize {
         return @divTrunc(encoded_len, 4) * 3;
     }
 
@@ -193,7 +193,7 @@ pub const Base64DecoderWithIgnore = struct {
     /// Invalid padding results in error.InvalidPadding.
     /// Decoding more data than can fit in dest results in error.OutputTooSmall. See also ::calcSizeUpperBound.
     /// Returns the number of bytes writen to dest.
-    pub fn decode(decoder_with_ignore: &const Base64DecoderWithIgnore, dest: []u8, source: []const u8) -> %usize {
+    pub fn decode(decoder_with_ignore: &const Base64DecoderWithIgnore, dest: []u8, source: []const u8) %usize {
         const decoder = &decoder_with_ignore.decoder;
 
         var src_cursor: usize = 0;
@@ -293,7 +293,7 @@ pub const Base64DecoderUnsafe = struct {
     char_to_index: [256]u8,
     pad_char: u8,
 
-    pub fn init(alphabet_chars: []const u8, pad_char: u8) -> Base64DecoderUnsafe {
+    pub fn init(alphabet_chars: []const u8, pad_char: u8) Base64DecoderUnsafe {
         assert(alphabet_chars.len == 64);
         var result = Base64DecoderUnsafe {
             .char_to_index = undefined,
@@ -307,13 +307,13 @@ pub const Base64DecoderUnsafe = struct {
     }
 
     /// The source buffer must be valid.
-    pub fn calcSize(decoder: &const Base64DecoderUnsafe, source: []const u8) -> usize {
+    pub fn calcSize(decoder: &const Base64DecoderUnsafe, source: []const u8) usize {
         return calcDecodedSizeExactUnsafe(source, decoder.pad_char);
     }
 
     /// dest.len must be what you get from ::calcDecodedSizeExactUnsafe.
     /// invalid characters or padding will result in undefined values.
-    pub fn decode(decoder: &const Base64DecoderUnsafe, dest: []u8, source: []const u8) {
+    pub fn decode(decoder: &const Base64DecoderUnsafe, dest: []u8, source: []const u8) void {
         assert(dest.len == decoder.calcSize(source));
 
         var src_index: usize = 0;
@@ -359,7 +359,7 @@ pub const Base64DecoderUnsafe = struct {
     }
 };
 
-fn calcDecodedSizeExactUnsafe(source: []const u8, pad_char: u8) -> usize {
+fn calcDecodedSizeExactUnsafe(source: []const u8, pad_char: u8) usize {
     if (source.len == 0) return 0;
     var result = @divExact(source.len, 4) * 3;
     if (source[source.len - 1] == pad_char) {
@@ -378,7 +378,7 @@ test "base64" {
     comptime (testBase64() catch unreachable);
 }
 
-fn testBase64() -> %void {
+fn testBase64() %void {
     try testAllApis("",       "");
     try testAllApis("f",      "Zg==");
     try testAllApis("fo",     "Zm8=");
@@ -412,7 +412,7 @@ fn testBase64() -> %void {
     try testOutputTooSmallError("AAAAAA==");
 }
 
-fn testAllApis(expected_decoded: []const u8, expected_encoded: []const u8) -> %void {
+fn testAllApis(expected_decoded: []const u8, expected_encoded: []const u8) %void {
     // Base64Encoder
     {
         var buffer: [0x100]u8 = undefined;
@@ -449,7 +449,7 @@ fn testAllApis(expected_decoded: []const u8, expected_encoded: []const u8) -> %v
     }
 }
 
-fn testDecodeIgnoreSpace(expected_decoded: []const u8, encoded: []const u8) -> %void {
+fn testDecodeIgnoreSpace(expected_decoded: []const u8, encoded: []const u8) %void {
     const standard_decoder_ignore_space = Base64DecoderWithIgnore.init(
         standard_alphabet_chars, standard_pad_char, " ");
     var buffer: [0x100]u8 = undefined;
@@ -459,7 +459,7 @@ fn testDecodeIgnoreSpace(expected_decoded: []const u8, encoded: []const u8) -> %
 }
 
 error ExpectedError;
-fn testError(encoded: []const u8, expected_err: error) -> %void {
+fn testError(encoded: []const u8, expected_err: error) %void {
     const standard_decoder_ignore_space = Base64DecoderWithIgnore.init(
         standard_alphabet_chars, standard_pad_char, " ");
     var buffer: [0x100]u8 = undefined;
@@ -475,7 +475,7 @@ fn testError(encoded: []const u8, expected_err: error) -> %void {
     } else |err| if (err != expected_err) return err;
 }
 
-fn testOutputTooSmallError(encoded: []const u8) -> %void {
+fn testOutputTooSmallError(encoded: []const u8) %void {
     const standard_decoder_ignore_space = Base64DecoderWithIgnore.init(
         standard_alphabet_chars, standard_pad_char, " ");
     var buffer: [0x100]u8 = undefined;

std/buf_map.zig

@@ -9,14 +9,14 @@ pub const BufMap = struct {
 
     const BufMapHashMap = HashMap([]const u8, []const u8, mem.hash_slice_u8, mem.eql_slice_u8);
 
-    pub fn init(allocator: &Allocator) -> BufMap {
+    pub fn init(allocator: &Allocator) BufMap {
         var self = BufMap {
             .hash_map = BufMapHashMap.init(allocator),
         };
         return self;
     }
 
-    pub fn deinit(self: &BufMap) {
+    pub fn deinit(self: &BufMap) void {
         var it = self.hash_map.iterator();
         while (true) {
             const entry = it.next() ?? break; 
@@ -27,7 +27,7 @@ pub const BufMap = struct {
         self.hash_map.deinit();
     }
 
-    pub fn set(self: &BufMap, key: []const u8, value: []const u8) -> %void {
+    pub fn set(self: &BufMap, key: []const u8, value: []const u8) %void {
         if (self.hash_map.get(key)) |entry| {
             const value_copy = try self.copy(value);
             errdefer self.free(value_copy);
@@ -42,32 +42,32 @@ pub const BufMap = struct {
         }
     }
 
-    pub fn get(self: &BufMap, key: []const u8) -> ?[]const u8 {
+    pub fn get(self: &BufMap, key: []const u8) ?[]const u8 {
         const entry = self.hash_map.get(key) ?? return null;
         return entry.value;
     }
 
-    pub fn delete(self: &BufMap, key: []const u8) {
+    pub fn delete(self: &BufMap, key: []const u8) void {
         const entry = self.hash_map.remove(key) ?? return;
         self.free(entry.key);
         self.free(entry.value);
     }
 
-    pub fn count(self: &const BufMap) -> usize {
+    pub fn count(self: &const BufMap) usize {
         return self.hash_map.size;
     }
 
-    pub fn iterator(self: &const BufMap) -> BufMapHashMap.Iterator {
+    pub fn iterator(self: &const BufMap) BufMapHashMap.Iterator {
         return self.hash_map.iterator();
     }
 
-    fn free(self: &BufMap, value: []const u8) {
+    fn free(self: &BufMap, value: []const u8) void {
         // remove the const
         const mut_value = @ptrCast(&u8, value.ptr)[0..value.len];
         self.hash_map.allocator.free(mut_value);
     }
 
-    fn copy(self: &BufMap, value: []const u8) -> %[]const u8 {
+    fn copy(self: &BufMap, value: []const u8) %[]const u8 {
         const result = try self.hash_map.allocator.alloc(u8, value.len);
         mem.copy(u8, result, value);
         return result;

std/buf_set.zig

@@ -7,14 +7,14 @@ pub const BufSet = struct {
 
     const BufSetHashMap = HashMap([]const u8, void, mem.hash_slice_u8, mem.eql_slice_u8);
 
-    pub fn init(a: &Allocator) -> BufSet {
+    pub fn init(a: &Allocator) BufSet {
         var self = BufSet {
             .hash_map = BufSetHashMap.init(a),
         };
         return self;
     }
 
-    pub fn deinit(self: &BufSet) {
+    pub fn deinit(self: &BufSet) void {
         var it = self.hash_map.iterator();
         while (true) {
             const entry = it.next() ?? break; 
@@ -24,7 +24,7 @@ pub const BufSet = struct {
         self.hash_map.deinit();
     }
 
-    pub fn put(self: &BufSet, key: []const u8) -> %void {
+    pub fn put(self: &BufSet, key: []const u8) %void {
         if (self.hash_map.get(key) == null) {
             const key_copy = try self.copy(key);
             errdefer self.free(key_copy);
@@ -32,30 +32,30 @@ pub const BufSet = struct {
         }
     }
 
-    pub fn delete(self: &BufSet, key: []const u8) {
+    pub fn delete(self: &BufSet, key: []const u8) void {
         const entry = self.hash_map.remove(key) ?? return;
         self.free(entry.key);
     }
 
-    pub fn count(self: &const BufSet) -> usize {
+    pub fn count(self: &const BufSet) usize {
         return self.hash_map.size;
     }
 
-    pub fn iterator(self: &const BufSet) -> BufSetHashMap.Iterator {
+    pub fn iterator(self: &const BufSet) BufSetHashMap.Iterator {
         return self.hash_map.iterator();
     }
 
-    pub fn allocator(self: &const BufSet) -> &Allocator {
+    pub fn allocator(self: &const BufSet) &Allocator {
         return self.hash_map.allocator;
     }
 
-    fn free(self: &BufSet, value: []const u8) {
+    fn free(self: &BufSet, value: []const u8) void {
         // remove the const
         const mut_value = @ptrCast(&u8, value.ptr)[0..value.len];
         self.hash_map.allocator.free(mut_value);
     }
 
-    fn copy(self: &BufSet, value: []const u8) -> %[]const u8 {
+    fn copy(self: &BufSet, value: []const u8) %[]const u8 {
         const result = try self.hash_map.allocator.alloc(u8, value.len);
         mem.copy(u8, result, value);
         return result;

std/buffer.zig

@@ -12,14 +12,14 @@ pub const Buffer = struct {
     list: ArrayList(u8),
 
     /// Must deinitialize with deinit.
-    pub fn init(allocator: &Allocator, m: []const u8) -> %Buffer {
+    pub fn init(allocator: &Allocator, m: []const u8) %Buffer {
         var self = try initSize(allocator, m.len);
         mem.copy(u8, self.list.items, m);
         return self;
     }
 
     /// Must deinitialize with deinit.
-    pub fn initSize(allocator: &Allocator, size: usize) -> %Buffer {
+    pub fn initSize(allocator: &Allocator, size: usize) %Buffer {
         var self = initNull(allocator);
         try self.resize(size);
         return self;
@@ -30,21 +30,21 @@ pub const Buffer = struct {
     /// * ::replaceContents
     /// * ::replaceContentsBuffer
     /// * ::resize
-    pub fn initNull(allocator: &Allocator) -> Buffer {
+    pub fn initNull(allocator: &Allocator) Buffer {
         return Buffer {
             .list = ArrayList(u8).init(allocator),
         };
     }
 
     /// Must deinitialize with deinit.
-    pub fn initFromBuffer(buffer: &const Buffer) -> %Buffer {
+    pub fn initFromBuffer(buffer: &const Buffer) %Buffer {
         return Buffer.init(buffer.list.allocator, buffer.toSliceConst());
     }
 
     /// Buffer takes ownership of the passed in slice. The slice must have been
     /// allocated with `allocator`.
     /// Must deinitialize with deinit.
-    pub fn fromOwnedSlice(allocator: &Allocator, slice: []u8) -> Buffer {
+    pub fn fromOwnedSlice(allocator: &Allocator, slice: []u8) Buffer {
         var self = Buffer {
             .list = ArrayList(u8).fromOwnedSlice(allocator, slice),
         };
@@ -54,7 +54,7 @@ pub const Buffer = struct {
 
     /// The caller owns the returned memory. The Buffer becomes null and
     /// is safe to `deinit`.
-    pub fn toOwnedSlice(self: &Buffer) -> []u8 {
+    pub fn toOwnedSlice(self: &Buffer) []u8 {
         const allocator = self.list.allocator;
         const result = allocator.shrink(u8, self.list.items, self.len());
         *self = initNull(allocator);
@@ -62,55 +62,55 @@ pub const Buffer = struct {
     }
 
 
-    pub fn deinit(self: &Buffer) {
+    pub fn deinit(self: &Buffer) void {
         self.list.deinit();
     }
 
-    pub fn toSlice(self: &Buffer) -> []u8 {
+    pub fn toSlice(self: &Buffer) []u8 {
         return self.list.toSlice()[0..self.len()];
     }
 
-    pub fn toSliceConst(self: &const Buffer) -> []const u8 {
+    pub fn toSliceConst(self: &const Buffer) []const u8 {
         return self.list.toSliceConst()[0..self.len()];
     }
 
-    pub fn shrink(self: &Buffer, new_len: usize) {
+    pub fn shrink(self: &Buffer, new_len: usize) void {
         assert(new_len <= self.len());
         self.list.shrink(new_len + 1);
         self.list.items[self.len()] = 0;
     }
 
-    pub fn resize(self: &Buffer, new_len: usize) -> %void {
+    pub fn resize(self: &Buffer, new_len: usize) %void {
         try self.list.resize(new_len + 1);
         self.list.items[self.len()] = 0;
     }
 
-    pub fn isNull(self: &const Buffer) -> bool {
+    pub fn isNull(self: &const Buffer) bool {
         return self.list.len == 0;
     }
 
-    pub fn len(self: &const Buffer) -> usize {
+    pub fn len(self: &const Buffer) usize {
         return self.list.len - 1;
     }
 
-    pub fn append(self: &Buffer, m: []const u8) -> %void {
+    pub fn append(self: &Buffer, m: []const u8) %void {
         const old_len = self.len();
         try self.resize(old_len + m.len);
         mem.copy(u8, self.list.toSlice()[old_len..], m);
     }
 
     // TODO: remove, use OutStream for this
-    pub fn appendFormat(self: &Buffer, comptime format: []const u8, args: ...) -> %void {
+    pub fn appendFormat(self: &Buffer, comptime format: []const u8, args: ...) %void {
         return fmt.format(self, append, format, args);
     }
 
     // TODO: remove, use OutStream for this
-    pub fn appendByte(self: &Buffer, byte: u8) -> %void {
+    pub fn appendByte(self: &Buffer, byte: u8) %void {
         return self.appendByteNTimes(byte, 1);
     }
 
     // TODO: remove, use OutStream for this
-    pub fn appendByteNTimes(self: &Buffer, byte: u8, count: usize) -> %void {
+    pub fn appendByteNTimes(self: &Buffer, byte: u8, count: usize) %void {
         var prev_size: usize = self.len();
         const new_size = prev_size + count;
         try self.resize(new_size);
@@ -121,29 +121,29 @@ pub const Buffer = struct {
         }
     }
 
-    pub fn eql(self: &const Buffer, m: []const u8) -> bool {
+    pub fn eql(self: &const Buffer, m: []const u8) bool {
         return mem.eql(u8, self.toSliceConst(), m);
     }
 
-    pub fn startsWith(self: &const Buffer, m: []const u8) -> bool {
+    pub fn startsWith(self: &const Buffer, m: []const u8) bool {
         if (self.len() < m.len) return false;
         return mem.eql(u8, self.list.items[0..m.len], m);
     }
 
-    pub fn endsWith(self: &const Buffer, m: []const u8) -> bool {
+    pub fn endsWith(self: &const Buffer, m: []const u8) bool {
         const l = self.len();
         if (l < m.len) return false;
         const start = l - m.len;
         return mem.eql(u8, self.list.items[start..l], m);
     }
 
-    pub fn replaceContents(self: &const Buffer, m: []const u8) -> %void {
+    pub fn replaceContents(self: &const Buffer, m: []const u8) %void {
         try self.resize(m.len);
         mem.copy(u8, self.list.toSlice(), m);
     }
 
     /// For passing to C functions.
-    pub fn ptr(self: &const Buffer) -> &u8 {
+    pub fn ptr(self: &const Buffer) &u8 {
         return self.list.items.ptr;
     }
 };

std/build.zig

@@ -90,7 +90,7 @@ pub const Builder = struct {
     };
 
     pub fn init(allocator: &Allocator, zig_exe: []const u8, build_root: []const u8,
-        cache_root: []const u8) -> Builder
+        cache_root: []const u8) Builder
     {
         var self = Builder {
             .zig_exe = zig_exe,
@@ -136,7 +136,7 @@ pub const Builder = struct {
         return self;
     }
 
-    pub fn deinit(self: &Builder) {
+    pub fn deinit(self: &Builder) void {
         self.lib_paths.deinit();
         self.include_paths.deinit();
         self.rpaths.deinit();
@@ -144,85 +144,85 @@ pub const Builder = struct {
         self.top_level_steps.deinit();
     }
 
-    pub fn setInstallPrefix(self: &Builder, maybe_prefix: ?[]const u8) {
+    pub fn setInstallPrefix(self: &Builder, maybe_prefix: ?[]const u8) void {
         self.prefix = maybe_prefix ?? "/usr/local"; // TODO better default
         self.lib_dir = os.path.join(self.allocator, self.prefix, "lib") catch unreachable;
         self.exe_dir = os.path.join(self.allocator, self.prefix, "bin") catch unreachable;
     }
 
-    pub fn addExecutable(self: &Builder, name: []const u8, root_src: ?[]const u8) -> &LibExeObjStep {
+    pub fn addExecutable(self: &Builder, name: []const u8, root_src: ?[]const u8) &LibExeObjStep {
         return LibExeObjStep.createExecutable(self, name, root_src);
     }
 
-    pub fn addObject(self: &Builder, name: []const u8, root_src: []const u8) -> &LibExeObjStep {
+    pub fn addObject(self: &Builder, name: []const u8, root_src: []const u8) &LibExeObjStep {
         return LibExeObjStep.createObject(self, name, root_src);
     }
 
     pub fn addSharedLibrary(self: &Builder, name: []const u8, root_src: ?[]const u8,
-        ver: &const Version) -> &LibExeObjStep
+        ver: &const Version) &LibExeObjStep
     {
         return LibExeObjStep.createSharedLibrary(self, name, root_src, ver);
     }
 
-    pub fn addStaticLibrary(self: &Builder, name: []const u8, root_src: ?[]const u8) -> &LibExeObjStep {
+    pub fn addStaticLibrary(self: &Builder, name: []const u8, root_src: ?[]const u8) &LibExeObjStep {
         return LibExeObjStep.createStaticLibrary(self, name, root_src);
     }
 
-    pub fn addTest(self: &Builder, root_src: []const u8) -> &TestStep {
+    pub fn addTest(self: &Builder, root_src: []const u8) &TestStep {
         const test_step = self.allocator.create(TestStep) catch unreachable;
         *test_step = TestStep.init(self, root_src);
         return test_step;
     }
 
-    pub fn addAssemble(self: &Builder, name: []const u8, src: []const u8) -> &LibExeObjStep {
+    pub fn addAssemble(self: &Builder, name: []const u8, src: []const u8) &LibExeObjStep {
         const obj_step = LibExeObjStep.createObject(self, name, null);
         obj_step.addAssemblyFile(src);
         return obj_step;
     }
 
-    pub fn addCStaticLibrary(self: &Builder, name: []const u8) -> &LibExeObjStep {
+    pub fn addCStaticLibrary(self: &Builder, name: []const u8) &LibExeObjStep {
         return LibExeObjStep.createCStaticLibrary(self, name);
     }
 
-    pub fn addCSharedLibrary(self: &Builder, name: []const u8, ver: &const Version) -> &LibExeObjStep {
+    pub fn addCSharedLibrary(self: &Builder, name: []const u8, ver: &const Version) &LibExeObjStep {
         return LibExeObjStep.createCSharedLibrary(self, name, ver);
     }
 
-    pub fn addCExecutable(self: &Builder, name: []const u8) -> &LibExeObjStep {
+    pub fn addCExecutable(self: &Builder, name: []const u8) &LibExeObjStep {
         return LibExeObjStep.createCExecutable(self, name);
     }
 
-    pub fn addCObject(self: &Builder, name: []const u8, src: []const u8) -> &LibExeObjStep {
+    pub fn addCObject(self: &Builder, name: []const u8, src: []const u8) &LibExeObjStep {
         return LibExeObjStep.createCObject(self, name, src);
     }
 
     /// ::argv is copied.
     pub fn addCommand(self: &Builder, cwd: ?[]const u8, env_map: &const BufMap,
-        argv: []const []const u8) -> &CommandStep
+        argv: []const []const u8) &CommandStep
     {
         return CommandStep.create(self, cwd, env_map, argv);
     }
 
-    pub fn addWriteFile(self: &Builder, file_path: []const u8, data: []const u8) -> &WriteFileStep {
+    pub fn addWriteFile(self: &Builder, file_path: []const u8, data: []const u8) &WriteFileStep {
         const write_file_step = self.allocator.create(WriteFileStep) catch unreachable;
         *write_file_step = WriteFileStep.init(self, file_path, data);
         return write_file_step;
     }
 
-    pub fn addLog(self: &Builder, comptime format: []const u8, args: ...) -> &LogStep {
+    pub fn addLog(self: &Builder, comptime format: []const u8, args: ...) &LogStep {
         const data = self.fmt(format, args);
         const log_step = self.allocator.create(LogStep) catch unreachable;
         *log_step = LogStep.init(self, data);
         return log_step;
     }
 
-    pub fn addRemoveDirTree(self: &Builder, dir_path: []const u8) -> &RemoveDirStep {
+    pub fn addRemoveDirTree(self: &Builder, dir_path: []const u8) &RemoveDirStep {
         const remove_dir_step = self.allocator.create(RemoveDirStep) catch unreachable;
         *remove_dir_step = RemoveDirStep.init(self, dir_path);
         return remove_dir_step;
     }
 
-    pub fn version(self: &const Builder, major: u32, minor: u32, patch: u32) -> Version {
+    pub fn version(self: &const Builder, major: u32, minor: u32, patch: u32) Version {
         return Version {
             .major = major,
             .minor = minor,
@@ -230,19 +230,19 @@ pub const Builder = struct {
         };
     }
 
-    pub fn addCIncludePath(self: &Builder, path: []const u8) {
+    pub fn addCIncludePath(self: &Builder, path: []const u8) void {
         self.include_paths.append(path) catch unreachable;
     }
 
-    pub fn addRPath(self: &Builder, path: []const u8) {
+    pub fn addRPath(self: &Builder, path: []const u8) void {
         self.rpaths.append(path) catch unreachable;
     }
 
-    pub fn addLibPath(self: &Builder, path: []const u8) {
+    pub fn addLibPath(self: &Builder, path: []const u8) void {
         self.lib_paths.append(path) catch unreachable;
     }
 
-    pub fn make(self: &Builder, step_names: []const []const u8) -> %void {
+    pub fn make(self: &Builder, step_names: []const []const u8) %void {
         var wanted_steps = ArrayList(&Step).init(self.allocator);
         defer wanted_steps.deinit();
 
@@ -260,7 +260,7 @@ pub const Builder = struct {
         }
     }
 
-    pub fn getInstallStep(self: &Builder) -> &Step {
+    pub fn getInstallStep(self: &Builder) &Step {
         if (self.have_install_step)
             return &self.install_tls.step;
 
@@ -269,7 +269,7 @@ pub const Builder = struct {
         return &self.install_tls.step;
     }
 
-    pub fn getUninstallStep(self: &Builder) -> &Step {
+    pub fn getUninstallStep(self: &Builder) &Step {
         if (self.have_uninstall_step)
             return &self.uninstall_tls.step;
 
@@ -278,7 +278,7 @@ pub const Builder = struct {
         return &self.uninstall_tls.step;
     }
 
-    fn makeUninstall(uninstall_step: &Step) -> %void {
+    fn makeUninstall(uninstall_step: &Step) %void {
         const uninstall_tls = @fieldParentPtr(TopLevelStep, "step", uninstall_step);
         const self = @fieldParentPtr(Builder, "uninstall_tls", uninstall_tls);
 
@@ -292,7 +292,7 @@ pub const Builder = struct {
         // TODO remove empty directories
     }
 
-    fn makeOneStep(self: &Builder, s: &Step) -> %void {
+    fn makeOneStep(self: &Builder, s: &Step) %void {
         if (s.loop_flag) {
             warn("Dependency loop detected:\n  {}\n", s.name);
             return error.DependencyLoopDetected;
@@ -313,7 +313,7 @@ pub const Builder = struct {
         try s.make();
     }
 
-    fn getTopLevelStepByName(self: &Builder, name: []const u8) -> %&Step {
+    fn getTopLevelStepByName(self: &Builder, name: []const u8) %&Step {
         for (self.top_level_steps.toSliceConst()) |top_level_step| {
             if (mem.eql(u8, top_level_step.step.name, name)) {
                 return &top_level_step.step;
@@ -323,7 +323,7 @@ pub const Builder = struct {
         return error.InvalidStepName;
     }
 
-    fn processNixOSEnvVars(self: &Builder) {
+    fn processNixOSEnvVars(self: &Builder) void {
         if (os.getEnvVarOwned(self.allocator, "NIX_CFLAGS_COMPILE")) |nix_cflags_compile| {
             var it = mem.split(nix_cflags_compile, " ");
             while (true) {
@@ -365,7 +365,7 @@ pub const Builder = struct {
         }
     }
 
-    pub fn option(self: &Builder, comptime T: type, name: []const u8, description: []const u8) -> ?T {
+    pub fn option(self: &Builder, comptime T: type, name: []const u8, description: []const u8) ?T {
         const type_id = comptime typeToEnum(T);
         const available_option = AvailableOption {
             .name = name,
@@ -418,7 +418,7 @@ pub const Builder = struct {
         }
     }
 
-    pub fn step(self: &Builder, name: []const u8, description: []const u8) -> &Step {
+    pub fn step(self: &Builder, name: []const u8, description: []const u8) &Step {
         const step_info = self.allocator.create(TopLevelStep) catch unreachable;
         *step_info = TopLevelStep {
             .step = Step.initNoOp(name, self.allocator),
@@ -428,7 +428,7 @@ pub const Builder = struct {
         return &step_info.step;
     }
 
-    pub fn standardReleaseOptions(self: &Builder) -> builtin.Mode {
+    pub fn standardReleaseOptions(self: &Builder) builtin.Mode {
         if (self.release_mode) |mode| return mode;
 
         const release_safe = self.option(bool, "release-safe", "optimizations on and safety on") ?? false;
@@ -449,7 +449,7 @@ pub const Builder = struct {
         return mode;
     }
 
-    pub fn addUserInputOption(self: &Builder, name: []const u8, value: []const u8) -> bool {
+    pub fn addUserInputOption(self: &Builder, name: []const u8, value: []const u8) bool {
         if (self.user_input_options.put(name, UserInputOption {
             .name = name,
             .value = UserValue { .Scalar = value },
@@ -486,7 +486,7 @@ pub const Builder = struct {
         return false;
     }
 
-    pub fn addUserInputFlag(self: &Builder, name: []const u8) -> bool {
+    pub fn addUserInputFlag(self: &Builder, name: []const u8) bool {
         if (self.user_input_options.put(name, UserInputOption {
             .name = name,
             .value = UserValue {.Flag = {} },
@@ -507,7 +507,7 @@ pub const Builder = struct {
         return false;
     }
 
-    fn typeToEnum(comptime T: type) -> TypeId {
+    fn typeToEnum(comptime T: type) TypeId {
         return switch (@typeId(T)) {
             builtin.TypeId.Int => TypeId.Int,
             builtin.TypeId.Float => TypeId.Float,
@@ -520,11 +520,11 @@ pub const Builder = struct {
         };
     }
 
-    fn markInvalidUserInput(self: &Builder) {
+    fn markInvalidUserInput(self: &Builder) void {
         self.invalid_user_input = true;
     }
 
-    pub fn typeIdName(id: TypeId) -> []const u8 {
+    pub fn typeIdName(id: TypeId) []const u8 {
         return switch (id) {
             TypeId.Bool => "bool",
             TypeId.Int => "int",
@@ -534,7 +534,7 @@ pub const Builder = struct {
         };
     }
 
-    pub fn validateUserInputDidItFail(self: &Builder) -> bool {
+    pub fn validateUserInputDidItFail(self: &Builder) bool {
         // make sure all args are used
         var it = self.user_input_options.iterator();
         while (true) {
@@ -548,11 +548,11 @@ pub const Builder = struct {
         return self.invalid_user_input;
     }
 
-    fn spawnChild(self: &Builder, argv: []const []const u8) -> %void {
+    fn spawnChild(self: &Builder, argv: []const []const u8) %void {
         return self.spawnChildEnvMap(null, &self.env_map, argv);
     }
 
-    fn printCmd(cwd: ?[]const u8, argv: []const []const u8) {
+    fn printCmd(cwd: ?[]const u8, argv: []const []const u8) void {
         if (cwd) |yes_cwd| warn("cd {} && ", yes_cwd);
         for (argv) |arg| {
             warn("{} ", arg);
@@ -561,7 +561,7 @@ pub const Builder = struct {
     }
 
     fn spawnChildEnvMap(self: &Builder, cwd: ?[]const u8, env_map: &const BufMap,
-        argv: []const []const u8) -> %void
+        argv: []const []const u8) %void
     {
         if (self.verbose) {
             printCmd(cwd, argv);
@@ -595,28 +595,28 @@ pub const Builder = struct {
         }
     }
 
-    pub fn makePath(self: &Builder, path: []const u8) -> %void {
+    pub fn makePath(self: &Builder, path: []const u8) %void {
         os.makePath(self.allocator, self.pathFromRoot(path)) catch |err| {
             warn("Unable to create path {}: {}\n", path, @errorName(err));
             return err;
         };
     }
 
-    pub fn installArtifact(self: &Builder, artifact: &LibExeObjStep) {
+    pub fn installArtifact(self: &Builder, artifact: &LibExeObjStep) void {
         self.getInstallStep().dependOn(&self.addInstallArtifact(artifact).step);
     }
 
-    pub fn addInstallArtifact(self: &Builder, artifact: &LibExeObjStep) -> &InstallArtifactStep {
+    pub fn addInstallArtifact(self: &Builder, artifact: &LibExeObjStep) &InstallArtifactStep {
         return InstallArtifactStep.create(self, artifact);
     }
 
     ///::dest_rel_path is relative to prefix path or it can be an absolute path
-    pub fn installFile(self: &Builder, src_path: []const u8, dest_rel_path: []const u8) {
+    pub fn installFile(self: &Builder, src_path: []const u8, dest_rel_path: []const u8) void {
         self.getInstallStep().dependOn(&self.addInstallFile(src_path, dest_rel_path).step);
     }
 
     ///::dest_rel_path is relative to prefix path or it can be an absolute path
-    pub fn addInstallFile(self: &Builder, src_path: []const u8, dest_rel_path: []const u8) -> &InstallFileStep {
+    pub fn addInstallFile(self: &Builder, src_path: []const u8, dest_rel_path: []const u8) &InstallFileStep {
         const full_dest_path = os.path.resolve(self.allocator, self.prefix, dest_rel_path) catch unreachable;
         self.pushInstalledFile(full_dest_path);
 
@@ -625,16 +625,16 @@ pub const Builder = struct {
         return install_step;
     }
 
-    pub fn pushInstalledFile(self: &Builder, full_path: []const u8) {
+    pub fn pushInstalledFile(self: &Builder, full_path: []const u8) void {
         _ = self.getUninstallStep();
         self.installed_files.append(full_path) catch unreachable;
     }
 
-    fn copyFile(self: &Builder, source_path: []const u8, dest_path: []const u8) -> %void {
+    fn copyFile(self: &Builder, source_path: []const u8, dest_path: []const u8) %void {
         return self.copyFileMode(source_path, dest_path, 0o666);
     }
 
-    fn copyFileMode(self: &Builder, source_path: []const u8, dest_path: []const u8, mode: usize) -> %void {
+    fn copyFileMode(self: &Builder, source_path: []const u8, dest_path: []const u8, mode: usize) %void {
         if (self.verbose) {
             warn("cp {} {}\n", source_path, dest_path);
         }
@@ -651,15 +651,15 @@ pub const Builder = struct {
         };
     }
 
-    fn pathFromRoot(self: &Builder, rel_path: []const u8) -> []u8 {
+    fn pathFromRoot(self: &Builder, rel_path: []const u8) []u8 {
         return os.path.resolve(self.allocator, self.build_root, rel_path) catch unreachable;
     }
 
-    pub fn fmt(self: &Builder, comptime format: []const u8, args: ...) -> []u8 {
+    pub fn fmt(self: &Builder, comptime format: []const u8, args: ...) []u8 {
         return fmt_lib.allocPrint(self.allocator, format, args) catch unreachable;
     }
 
-    fn getCCExe(self: &Builder) -> []const u8 {
+    fn getCCExe(self: &Builder) []const u8 {
         if (builtin.environ == builtin.Environ.msvc) {
             return "cl.exe";
         } else {
@@ -672,7 +672,7 @@ pub const Builder = struct {
         }
     }
 
-    pub fn findProgram(self: &Builder, names: []const []const u8, paths: []const []const u8) -> %[]const u8 {
+    pub fn findProgram(self: &Builder, names: []const []const u8, paths: []const []const u8) %[]const u8 {
         // TODO report error for ambiguous situations
         const exe_extension = (Target { .Native = {}}).exeFileExt();
         for (self.search_prefixes.toSliceConst()) |search_prefix| {
@@ -721,7 +721,7 @@ pub const Builder = struct {
         return error.FileNotFound;
     }
 
-    pub fn exec(self: &Builder, argv: []const []const u8) -> %[]u8 {
+    pub fn exec(self: &Builder, argv: []const []const u8) %[]u8 {
         const max_output_size = 100 * 1024;
         const result = try os.ChildProcess.exec(self.allocator, argv, null, null, max_output_size);
         switch (result.term) {
@@ -743,7 +743,7 @@ pub const Builder = struct {
         }
     }
 
-    pub fn addSearchPrefix(self: &Builder, search_prefix: []const u8) {
+    pub fn addSearchPrefix(self: &Builder, search_prefix: []const u8) void {
         self.search_prefixes.append(search_prefix) catch unreachable;
     }
 };
@@ -764,7 +764,7 @@ pub const Target = union(enum) {
     Native: void,
     Cross: CrossTarget,
 
-    pub fn oFileExt(self: &const Target) -> []const u8 {
+    pub fn oFileExt(self: &const Target) []const u8 {
         const environ = switch (*self) {
             Target.Native => builtin.environ,
             Target.Cross => |t| t.environ,
@@ -775,42 +775,42 @@ pub const Target = union(enum) {
         };
     }
 
-    pub fn exeFileExt(self: &const Target) -> []const u8 {
+    pub fn exeFileExt(self: &const Target) []const u8 {
         return switch (self.getOs()) {
             builtin.Os.windows => ".exe",
             else => "",
         };
     }
 
-    pub fn libFileExt(self: &const Target) -> []const u8 {
+    pub fn libFileExt(self: &const Target) []const u8 {
         return switch (self.getOs()) {
             builtin.Os.windows => ".lib",
             else => ".a",
         };
     }
 
-    pub fn getOs(self: &const Target) -> builtin.Os {
+    pub fn getOs(self: &const Target) builtin.Os {
         return switch (*self) {
             Target.Native => builtin.os,
             Target.Cross => |t| t.os,
         };
     }
 
-    pub fn isDarwin(self: &const Target) -> bool {
+    pub fn isDarwin(self: &const Target) bool {
         return switch (self.getOs()) {
             builtin.Os.ios, builtin.Os.macosx => true,
             else => false,
         };
     }
 
-    pub fn isWindows(self: &const Target) -> bool {
+    pub fn isWindows(self: &const Target) bool {
         return switch (self.getOs()) {
             builtin.Os.windows => true,
             else => false,
         };
     }
 
-    pub fn wantSharedLibSymLinks(self: &const Target) -> bool {
+    pub fn wantSharedLibSymLinks(self: &const Target) bool {
         return !self.isWindows();
     }
 };
@@ -865,58 +865,58 @@ pub const LibExeObjStep = struct {
     };
 
     pub fn createSharedLibrary(builder: &Builder, name: []const u8, root_src: ?[]const u8,
-        ver: &const Version) -> &LibExeObjStep
+        ver: &const Version) &LibExeObjStep
     {
         const self = builder.allocator.create(LibExeObjStep) catch unreachable;
         *self = initExtraArgs(builder, name, root_src, Kind.Lib, false, ver);
         return self;
     }
 
-    pub fn createCSharedLibrary(builder: &Builder, name: []const u8, version: &const Version) -> &LibExeObjStep {
+    pub fn createCSharedLibrary(builder: &Builder, name: []const u8, version: &const Version) &LibExeObjStep {
         const self = builder.allocator.create(LibExeObjStep) catch unreachable;
         *self = initC(builder, name, Kind.Lib, version, false);
         return self;
     }
 
-    pub fn createStaticLibrary(builder: &Builder, name: []const u8, root_src: ?[]const u8) -> &LibExeObjStep {
+    pub fn createStaticLibrary(builder: &Builder, name: []const u8, root_src: ?[]const u8) &LibExeObjStep {
         const self = builder.allocator.create(LibExeObjStep) catch unreachable;
         *self = initExtraArgs(builder, name, root_src, Kind.Lib, true, builder.version(0, 0, 0));
         return self;
     }
 
-    pub fn createCStaticLibrary(builder: &Builder, name: []const u8) -> &LibExeObjStep {
+    pub fn createCStaticLibrary(builder: &Builder, name: []const u8) &LibExeObjStep {
         const self = builder.allocator.create(LibExeObjStep) catch unreachable;
         *self = initC(builder, name, Kind.Lib, builder.version(0, 0, 0), true);
         return self;
     }
 
-    pub fn createObject(builder: &Builder, name: []const u8, root_src: []const u8) -> &LibExeObjStep {
+    pub fn createObject(builder: &Builder, name: []const u8, root_src: []const u8) &LibExeObjStep {
         const self = builder.allocator.create(LibExeObjStep) catch unreachable;
         *self = initExtraArgs(builder, name, root_src, Kind.Obj, false, builder.version(0, 0, 0));
         return self;
     }
 
-    pub fn createCObject(builder: &Builder, name: []const u8, src: []const u8) -> &LibExeObjStep {
+    pub fn createCObject(builder: &Builder, name: []const u8, src: []const u8) &LibExeObjStep {
         const self = builder.allocator.create(LibExeObjStep) catch unreachable;
         *self = initC(builder, name, Kind.Obj, builder.version(0, 0, 0), false);
         self.object_src = src;
         return self;
     }
 
-    pub fn createExecutable(builder: &Builder, name: []const u8, root_src: ?[]const u8) -> &LibExeObjStep {
+    pub fn createExecutable(builder: &Builder, name: []const u8, root_src: ?[]const u8) &LibExeObjStep {
         const self = builder.allocator.create(LibExeObjStep) catch unreachable;
         *self = initExtraArgs(builder, name, root_src, Kind.Exe, false, builder.version(0, 0, 0));
         return self;
     }
 
-    pub fn createCExecutable(builder: &Builder, name: []const u8) -> &LibExeObjStep {
+    pub fn createCExecutable(builder: &Builder, name: []const u8) &LibExeObjStep {
         const self = builder.allocator.create(LibExeObjStep) catch unreachable;
         *self = initC(builder, name, Kind.Exe, builder.version(0, 0, 0), false);
         return self;
     }
 
     fn initExtraArgs(builder: &Builder, name: []const u8, root_src: ?[]const u8, kind: Kind,
-        static: bool, ver: &const Version) -> LibExeObjStep
+        static: bool, ver: &const Version) LibExeObjStep
     {
         var self = LibExeObjStep {
             .strip = false,
@@ -956,7 +956,7 @@ pub const LibExeObjStep = struct {
         return self;
     }
 
-    fn initC(builder: &Builder, name: []const u8, kind: Kind, version: &const Version, static: bool) -> LibExeObjStep {
+    fn initC(builder: &Builder, name: []const u8, kind: Kind, version: &const Version, static: bool) LibExeObjStep {
         var self = LibExeObjStep {
             .builder = builder,
             .name = name,
@@ -996,7 +996,7 @@ pub const LibExeObjStep = struct {
         return self;
     }
 
-    fn computeOutFileNames(self: &LibExeObjStep) {
+    fn computeOutFileNames(self: &LibExeObjStep) void {
         switch (self.kind) {
             Kind.Obj => {
                 self.out_filename = self.builder.fmt("{}{}", self.name, self.target.oFileExt());
@@ -1031,7 +1031,7 @@ pub const LibExeObjStep = struct {
     }
 
     pub fn setTarget(self: &LibExeObjStep, target_arch: builtin.Arch, target_os: builtin.Os,
-        target_environ: builtin.Environ)
+        target_environ: builtin.Environ) void
     {
         self.target = Target {
             .Cross = CrossTarget {
@@ -1044,16 +1044,16 @@ pub const LibExeObjStep = struct {
     }
 
     // TODO respect this in the C args
-    pub fn setLinkerScriptPath(self: &LibExeObjStep, path: []const u8) {
+    pub fn setLinkerScriptPath(self: &LibExeObjStep, path: []const u8) void {
         self.linker_script = path;
     }
 
-    pub fn linkFramework(self: &LibExeObjStep, framework_name: []const u8) {
+    pub fn linkFramework(self: &LibExeObjStep, framework_name: []const u8) void {
         assert(self.target.isDarwin());
         self.frameworks.put(framework_name) catch unreachable;
     }
 
-    pub fn linkLibrary(self: &LibExeObjStep, lib: &LibExeObjStep) {
+    pub fn linkLibrary(self: &LibExeObjStep, lib: &LibExeObjStep) void {
         assert(self.kind != Kind.Obj);
         assert(lib.kind == Kind.Lib);
 
@@ -1074,26 +1074,26 @@ pub const LibExeObjStep = struct {
         }
     }
 
-    pub fn linkSystemLibrary(self: &LibExeObjStep, name: []const u8) {
+    pub fn linkSystemLibrary(self: &LibExeObjStep, name: []const u8) void {
         assert(self.kind != Kind.Obj);
         self.link_libs.put(name) catch unreachable;
     }
 
-    pub fn addSourceFile(self: &LibExeObjStep, file: []const u8) {
+    pub fn addSourceFile(self: &LibExeObjStep, file: []const u8) void {
         assert(self.kind != Kind.Obj);
         assert(!self.is_zig);
         self.source_files.append(file) catch unreachable;
     }
 
-    pub fn setVerboseLink(self: &LibExeObjStep, value: bool) {
+    pub fn setVerboseLink(self: &LibExeObjStep, value: bool) void {
         self.verbose_link = value;
     }
 
-    pub fn setBuildMode(self: &LibExeObjStep, mode: builtin.Mode) {
+    pub fn setBuildMode(self: &LibExeObjStep, mode: builtin.Mode) void {
         self.build_mode = mode;
     }
 
-    pub fn setOutputPath(self: &LibExeObjStep, file_path: []const u8) {
+    pub fn setOutputPath(self: &LibExeObjStep, file_path: []const u8) void {
         self.output_path = file_path;
 
         // catch a common mistake
@@ -1102,14 +1102,14 @@ pub const LibExeObjStep = struct {
         }
     }
 
-    pub fn getOutputPath(self: &LibExeObjStep) -> []const u8 {
+    pub fn getOutputPath(self: &LibExeObjStep) []const u8 {
         return if (self.output_path) |output_path|
             output_path
         else
             os.path.join(self.builder.allocator, self.builder.cache_root, self.out_filename) catch unreachable;
     }
 
-    pub fn setOutputHPath(self: &LibExeObjStep, file_path: []const u8) {
+    pub fn setOutputHPath(self: &LibExeObjStep, file_path: []const u8) void {
         self.output_h_path = file_path;
 
         // catch a common mistake
@@ -1118,24 +1118,24 @@ pub const LibExeObjStep = struct {
         }
     }
 
-    pub fn getOutputHPath(self: &LibExeObjStep) -> []const u8 {
+    pub fn getOutputHPath(self: &LibExeObjStep) []const u8 {
         return if (self.output_h_path) |output_h_path|
             output_h_path
         else
             os.path.join(self.builder.allocator, self.builder.cache_root, self.out_h_filename) catch unreachable;
     }
 
-    pub fn addAssemblyFile(self: &LibExeObjStep, path: []const u8) {
+    pub fn addAssemblyFile(self: &LibExeObjStep, path: []const u8) void {
         self.assembly_files.append(path) catch unreachable;
     }
 
-    pub fn addObjectFile(self: &LibExeObjStep, path: []const u8) {
+    pub fn addObjectFile(self: &LibExeObjStep, path: []const u8) void {
         assert(self.kind != Kind.Obj);
 
         self.object_files.append(path) catch unreachable;
     }
 
-    pub fn addObject(self: &LibExeObjStep, obj: &LibExeObjStep) {
+    pub fn addObject(self: &LibExeObjStep, obj: &LibExeObjStep) void {
         assert(obj.kind == Kind.Obj);
         assert(self.kind != Kind.Obj);
 
@@ -1152,15 +1152,15 @@ pub const LibExeObjStep = struct {
         self.include_dirs.append(self.builder.cache_root) catch unreachable;
     }
 
-    pub fn addIncludeDir(self: &LibExeObjStep, path: []const u8) {
+    pub fn addIncludeDir(self: &LibExeObjStep, path: []const u8) void {
         self.include_dirs.append(path) catch unreachable;
     }
 
-    pub fn addLibPath(self: &LibExeObjStep, path: []const u8) {
+    pub fn addLibPath(self: &LibExeObjStep, path: []const u8) void {
         self.lib_paths.append(path) catch unreachable;
     }
 
-    pub fn addPackagePath(self: &LibExeObjStep, name: []const u8, pkg_index_path: []const u8) {
+    pub fn addPackagePath(self: &LibExeObjStep, name: []const u8, pkg_index_path: []const u8) void {
         assert(self.is_zig);
 
         self.packages.append(Pkg {
@@ -1169,23 +1169,23 @@ pub const LibExeObjStep = struct {
         }) catch unreachable;
     }
 
-    pub fn addCompileFlags(self: &LibExeObjStep, flags: []const []const u8) {
+    pub fn addCompileFlags(self: &LibExeObjStep, flags: []const []const u8) void {
         for (flags) |flag| {
             self.cflags.append(flag) catch unreachable;
         }
     }
 
-    pub fn setNoStdLib(self: &LibExeObjStep, disable: bool) {
+    pub fn setNoStdLib(self: &LibExeObjStep, disable: bool) void {
         assert(!self.is_zig);
         self.disable_libc = disable;
     }
 
-    fn make(step: &Step) -> %void {
+    fn make(step: &Step) %void {
         const self = @fieldParentPtr(LibExeObjStep, "step", step);
         return if (self.is_zig) self.makeZig() else self.makeC();
     }
 
-    fn makeZig(self: &LibExeObjStep) -> %void {
+    fn makeZig(self: &LibExeObjStep) %void {
         const builder = self.builder;
 
         assert(self.is_zig);
@@ -1351,7 +1351,7 @@ pub const LibExeObjStep = struct {
         }
     }
 
-    fn appendCompileFlags(self: &LibExeObjStep, args: &ArrayList([]const u8)) {
+    fn appendCompileFlags(self: &LibExeObjStep, args: &ArrayList([]const u8)) void {
         if (!self.strip) {
             args.append("-g") catch unreachable;
         }
@@ -1396,7 +1396,7 @@ pub const LibExeObjStep = struct {
         }
     }
 
-    fn makeC(self: &LibExeObjStep) -> %void {
+    fn makeC(self: &LibExeObjStep) %void {
         const builder = self.builder;
 
         const cc = builder.getCCExe();
@@ -1635,7 +1635,7 @@ pub const TestStep = struct {
     target: Target,
     exec_cmd_args: ?[]const ?[]const u8,
 
-    pub fn init(builder: &Builder, root_src: []const u8) -> TestStep {
+    pub fn init(builder: &Builder, root_src: []const u8) TestStep {
         const step_name = builder.fmt("test {}", root_src);
         return TestStep {
             .step = Step.init(step_name, builder.allocator, make),
@@ -1651,28 +1651,28 @@ pub const TestStep = struct {
         };
     }
 
-    pub fn setVerbose(self: &TestStep, value: bool) {
+    pub fn setVerbose(self: &TestStep, value: bool) void {
         self.verbose = value;
     }
 
-    pub fn setBuildMode(self: &TestStep, mode: builtin.Mode) {
+    pub fn setBuildMode(self: &TestStep, mode: builtin.Mode) void {
         self.build_mode = mode;
     }
 
-    pub fn linkSystemLibrary(self: &TestStep, name: []const u8) {
+    pub fn linkSystemLibrary(self: &TestStep, name: []const u8) void {
         self.link_libs.put(name) catch unreachable;
     }
 
-    pub fn setNamePrefix(self: &TestStep, text: []const u8) {
+    pub fn setNamePrefix(self: &TestStep, text: []const u8) void {
         self.name_prefix = text;
     }
 
-    pub fn setFilter(self: &TestStep, text: ?[]const u8) {
+    pub fn setFilter(self: &TestStep, text: ?[]const u8) void {
         self.filter = text;
     }
 
     pub fn setTarget(self: &TestStep, target_arch: builtin.Arch, target_os: builtin.Os,
-        target_environ: builtin.Environ)
+        target_environ: builtin.Environ) void
     {
         self.target = Target {
             .Cross = CrossTarget {
@@ -1683,11 +1683,11 @@ pub const TestStep = struct {
         };
     }
 
-    pub fn setExecCmd(self: &TestStep, args: []const ?[]const u8) {
+    pub fn setExecCmd(self: &TestStep, args: []const ?[]const u8) void {
         self.exec_cmd_args = args;
     }
 
-    fn make(step: &Step) -> %void {
+    fn make(step: &Step) %void {
         const self = @fieldParentPtr(TestStep, "step", step);
         const builder = self.builder;
 
@@ -1781,7 +1781,7 @@ pub const CommandStep = struct {
 
     /// ::argv is copied.
     pub fn create(builder: &Builder, cwd: ?[]const u8, env_map: &const BufMap,
-        argv: []const []const u8) -> &CommandStep
+        argv: []const []const u8) &CommandStep
     {
         const self = builder.allocator.create(CommandStep) catch unreachable;
         *self = CommandStep {
@@ -1796,7 +1796,7 @@ pub const CommandStep = struct {
         return self;
     }
 
-    fn make(step: &Step) -> %void {
+    fn make(step: &Step) %void {
         const self = @fieldParentPtr(CommandStep, "step", step);
 
         const cwd = if (self.cwd) |cwd| self.builder.pathFromRoot(cwd) else self.builder.build_root;
@@ -1812,7 +1812,7 @@ const InstallArtifactStep = struct {
 
     const Self = this;
 
-    pub fn create(builder: &Builder, artifact: &LibExeObjStep) -> &Self {
+    pub fn create(builder: &Builder, artifact: &LibExeObjStep) &Self {
         const self = builder.allocator.create(Self) catch unreachable;
         const dest_dir = switch (artifact.kind) {
             LibExeObjStep.Kind.Obj => unreachable,
@@ -1836,7 +1836,7 @@ const InstallArtifactStep = struct {
         return self;
     }
 
-    fn make(step: &Step) -> %void {
+    fn make(step: &Step) %void {
         const self = @fieldParentPtr(Self, "step", step);
         const builder = self.builder;
 
@@ -1859,7 +1859,7 @@ pub const InstallFileStep = struct {
     src_path: []const u8,
     dest_path: []const u8,
 
-    pub fn init(builder: &Builder, src_path: []const u8, dest_path: []const u8) -> InstallFileStep {
+    pub fn init(builder: &Builder, src_path: []const u8, dest_path: []const u8) InstallFileStep {
         return InstallFileStep {
             .builder = builder,
             .step = Step.init(builder.fmt("install {}", src_path), builder.allocator, make),
@@ -1868,7 +1868,7 @@ pub const InstallFileStep = struct {
         };
     }
 
-    fn make(step: &Step) -> %void {
+    fn make(step: &Step) %void {
         const self = @fieldParentPtr(InstallFileStep, "step", step);
         try self.builder.copyFile(self.src_path, self.dest_path);
     }
@@ -1880,7 +1880,7 @@ pub const WriteFileStep = struct {
     file_path: []const u8,
     data: []const u8,
 
-    pub fn init(builder: &Builder, file_path: []const u8, data: []const u8) -> WriteFileStep {
+    pub fn init(builder: &Builder, file_path: []const u8, data: []const u8) WriteFileStep {
         return WriteFileStep {
             .builder = builder,
             .step = Step.init(builder.fmt("writefile {}", file_path), builder.allocator, make),
@@ -1889,7 +1889,7 @@ pub const WriteFileStep = struct {
         };
     }
 
-    fn make(step: &Step) -> %void {
+    fn make(step: &Step) %void {
         const self = @fieldParentPtr(WriteFileStep, "step", step);
         const full_path = self.builder.pathFromRoot(self.file_path);
         const full_path_dir = os.path.dirname(full_path);
@@ -1909,7 +1909,7 @@ pub const LogStep = struct {
     builder: &Builder,
     data: []const u8,
 
-    pub fn init(builder: &Builder, data: []const u8) -> LogStep {
+    pub fn init(builder: &Builder, data: []const u8) LogStep {
         return LogStep {
             .builder = builder,
             .step = Step.init(builder.fmt("log {}", data), builder.allocator, make),
@@ -1917,7 +1917,7 @@ pub const LogStep = struct {
         };
     }
 
-    fn make(step: &Step) -> %void {
+    fn make(step: &Step) %void {
         const self = @fieldParentPtr(LogStep, "step", step);
         warn("{}", self.data);
     }
@@ -1928,7 +1928,7 @@ pub const RemoveDirStep = struct {
     builder: &Builder,
     dir_path: []const u8,
 
-    pub fn init(builder: &Builder, dir_path: []const u8) -> RemoveDirStep {
+    pub fn init(builder: &Builder, dir_path: []const u8) RemoveDirStep {
         return RemoveDirStep {
             .builder = builder,
             .step = Step.init(builder.fmt("RemoveDir {}", dir_path), builder.allocator, make),
@@ -1936,7 +1936,7 @@ pub const RemoveDirStep = struct {
         };
     }
 
-    fn make(step: &Step) -> %void {
+    fn make(step: &Step) %void {
         const self = @fieldParentPtr(RemoveDirStep, "step", step);
 
         const full_path = self.builder.pathFromRoot(self.dir_path);
@@ -1949,12 +1949,12 @@ pub const RemoveDirStep = struct {
 
 pub const Step = struct {
     name: []const u8,
-    makeFn: fn(self: &Step) -> %void,
+    makeFn: fn(self: &Step) %void,
     dependencies: ArrayList(&Step),
     loop_flag: bool,
     done_flag: bool,
 
-    pub fn init(name: []const u8, allocator: &Allocator, makeFn: fn (&Step)->%void) -> Step {
+    pub fn init(name: []const u8, allocator: &Allocator, makeFn: fn (&Step)%void) Step {
         return Step {
             .name = name,
             .makeFn = makeFn,
@@ -1963,11 +1963,11 @@ pub const Step = struct {
             .done_flag = false,
         };
     }
-    pub fn initNoOp(name: []const u8, allocator: &Allocator) -> Step {
+    pub fn initNoOp(name: []const u8, allocator: &Allocator) Step {
         return init(name, allocator, makeNoOp);
     }
 
-    pub fn make(self: &Step) -> %void {
+    pub fn make(self: &Step) %void {
         if (self.done_flag)
             return;
 
@@ -1975,15 +1975,15 @@ pub const Step = struct {
         self.done_flag = true;
     }
 
-    pub fn dependOn(self: &Step, other: &Step) {
+    pub fn dependOn(self: &Step, other: &Step) void {
         self.dependencies.append(other) catch unreachable;
     }
 
-    fn makeNoOp(self: &Step) -> %void {}
+    fn makeNoOp(self: &Step) %void {}
 };
 
 fn doAtomicSymLinks(allocator: &Allocator, output_path: []const u8, filename_major_only: []const u8,
-    filename_name_only: []const u8) -> %void
+    filename_name_only: []const u8) %void
 {
     const out_dir = os.path.dirname(output_path);
     const out_basename = os.path.basename(output_path);

std/c/darwin.zig

@@ -1,5 +1,5 @@
-extern "c" fn __error() -> &c_int;
-pub extern "c" fn _NSGetExecutablePath(buf: &u8, bufsize: &u32) -> c_int;
+extern "c" fn __error() &c_int;
+pub extern "c" fn _NSGetExecutablePath(buf: &u8, bufsize: &u32) c_int;
 
 
 pub use @import("../os/darwin_errno.zig");
@@ -41,7 +41,7 @@ pub const sigset_t = u32;
 
 /// Renamed from `sigaction` to `Sigaction` to avoid conflict with function name.
 pub const Sigaction = extern struct {
-    handler: extern fn(c_int),
+    handler: extern fn(c_int)void,
     sa_mask: sigset_t,
     sa_flags: c_int,
 };

std/c/index.zig

@@ -9,43 +9,43 @@ pub use switch(builtin.os) {
 };
 const empty_import = @import("../empty.zig");
 
-pub extern "c" fn abort() -> noreturn;
-pub extern "c" fn exit(code: c_int) -> noreturn;
-pub extern "c" fn isatty(fd: c_int) -> c_int;
-pub extern "c" fn close(fd: c_int) -> c_int;
-pub extern "c" fn fstat(fd: c_int, buf: &Stat) -> c_int;
-pub extern "c" fn @"fstat$INODE64"(fd: c_int, buf: &Stat) -> c_int;
-pub extern "c" fn lseek(fd: c_int, offset: isize, whence: c_int) -> isize;
-pub extern "c" fn open(path: &const u8, oflag: c_int, ...) -> c_int;
-pub extern "c" fn raise(sig: c_int) -> c_int;
-pub extern "c" fn read(fd: c_int, buf: &c_void, nbyte: usize) -> isize;
-pub extern "c" fn stat(noalias path: &const u8, noalias buf: &Stat) -> c_int;
-pub extern "c" fn write(fd: c_int, buf: &const c_void, nbyte: usize) -> c_int;
+pub extern "c" fn abort() noreturn;
+pub extern "c" fn exit(code: c_int) noreturn;
+pub extern "c" fn isatty(fd: c_int) c_int;
+pub extern "c" fn close(fd: c_int) c_int;
+pub extern "c" fn fstat(fd: c_int, buf: &Stat) c_int;
+pub extern "c" fn @"fstat$INODE64"(fd: c_int, buf: &Stat) c_int;
+pub extern "c" fn lseek(fd: c_int, offset: isize, whence: c_int) isize;
+pub extern "c" fn open(path: &const u8, oflag: c_int, ...) c_int;
+pub extern "c" fn raise(sig: c_int) c_int;
+pub extern "c" fn read(fd: c_int, buf: &c_void, nbyte: usize) isize;
+pub extern "c" fn stat(noalias path: &const u8, noalias buf: &Stat) c_int;
+pub extern "c" fn write(fd: c_int, buf: &const c_void, nbyte: usize) c_int;
 pub extern "c" fn mmap(addr: ?&c_void, len: usize, prot: c_int, flags: c_int,
-    fd: c_int, offset: isize) -> ?&c_void;
-pub extern "c" fn munmap(addr: &c_void, len: usize) -> c_int;
-pub extern "c" fn unlink(path: &const u8) -> c_int;
-pub extern "c" fn getcwd(buf: &u8, size: usize) -> ?&u8;
-pub extern "c" fn waitpid(pid: c_int, stat_loc: &c_int, options: c_int) -> c_int;
-pub extern "c" fn fork() -> c_int;
-pub extern "c" fn pipe(fds: &c_int) -> c_int;
-pub extern "c" fn mkdir(path: &const u8, mode: c_uint) -> c_int;
-pub extern "c" fn symlink(existing: &const u8, new: &const u8) -> c_int;
-pub extern "c" fn rename(old: &const u8, new: &const u8) -> c_int;
-pub extern "c" fn chdir(path: &const u8) -> c_int;
+    fd: c_int, offset: isize) ?&c_void;
+pub extern "c" fn munmap(addr: &c_void, len: usize) c_int;
+pub extern "c" fn unlink(path: &const u8) c_int;
+pub extern "c" fn getcwd(buf: &u8, size: usize) ?&u8;
+pub extern "c" fn waitpid(pid: c_int, stat_loc: &c_int, options: c_int) c_int;
+pub extern "c" fn fork() c_int;
+pub extern "c" fn pipe(fds: &c_int) c_int;
+pub extern "c" fn mkdir(path: &const u8, mode: c_uint) c_int;
+pub extern "c" fn symlink(existing: &const u8, new: &const u8) c_int;
+pub extern "c" fn rename(old: &const u8, new: &const u8) c_int;
+pub extern "c" fn chdir(path: &const u8) c_int;
 pub extern "c" fn execve(path: &const u8, argv: &const ?&const u8,
-    envp: &const ?&const u8) -> c_int;
-pub extern "c" fn dup(fd: c_int) -> c_int;
-pub extern "c" fn dup2(old_fd: c_int, new_fd: c_int) -> c_int;
-pub extern "c" fn readlink(noalias path: &const u8, noalias buf: &u8, bufsize: usize) -> isize;
-pub extern "c" fn realpath(noalias file_name: &const u8, noalias resolved_name: &u8) -> ?&u8;
-pub extern "c" fn sigprocmask(how: c_int, noalias set: &const sigset_t, noalias oset: ?&sigset_t) -> c_int;
-pub extern "c" fn sigaction(sig: c_int, noalias act: &const Sigaction, noalias oact: ?&Sigaction) -> c_int;
-pub extern "c" fn nanosleep(rqtp: &const timespec, rmtp: ?&timespec) -> c_int;
-pub extern "c" fn setreuid(ruid: c_uint, euid: c_uint) -> c_int;
-pub extern "c" fn setregid(rgid: c_uint, egid: c_uint) -> c_int;
+    envp: &const ?&const u8) c_int;
+pub extern "c" fn dup(fd: c_int) c_int;
+pub extern "c" fn dup2(old_fd: c_int, new_fd: c_int) c_int;
+pub extern "c" fn readlink(noalias path: &const u8, noalias buf: &u8, bufsize: usize) isize;
+pub extern "c" fn realpath(noalias file_name: &const u8, noalias resolved_name: &u8) ?&u8;
+pub extern "c" fn sigprocmask(how: c_int, noalias set: &const sigset_t, noalias oset: ?&sigset_t) c_int;
+pub extern "c" fn sigaction(sig: c_int, noalias act: &const Sigaction, noalias oact: ?&Sigaction) c_int;
+pub extern "c" fn nanosleep(rqtp: &const timespec, rmtp: ?&timespec) c_int;
+pub extern "c" fn setreuid(ruid: c_uint, euid: c_uint) c_int;
+pub extern "c" fn setregid(rgid: c_uint, egid: c_uint) c_int;
 
-pub extern "c" fn malloc(usize) -> ?&c_void;
-pub extern "c" fn realloc(&c_void, usize) -> ?&c_void;
-pub extern "c" fn free(&c_void);
-pub extern "c" fn posix_memalign(memptr: &&c_void, alignment: usize, size: usize) -> c_int;
+pub extern "c" fn malloc(usize) ?&c_void;
+pub extern "c" fn realloc(&c_void, usize) ?&c_void;
+pub extern "c" fn free(&c_void) void;
+pub extern "c" fn posix_memalign(memptr: &&c_void, alignment: usize, size: usize) c_int;

std/c/linux.zig

@@ -1,5 +1,5 @@
 pub use @import("../os/linux_errno.zig");
 
-pub extern "c" fn getrandom(buf_ptr: &u8, buf_len: usize, flags: c_uint) -> c_int;
-extern "c" fn __errno_location() -> &c_int;
+pub extern "c" fn getrandom(buf_ptr: &u8, buf_len: usize, flags: c_uint) c_int;
+extern "c" fn __errno_location() &c_int;
 pub const _errno = __errno_location;

std/c/windows.zig

@@ -1 +1 @@
-pub extern "c" fn _errno() -> &c_int;
+pub extern "c" fn _errno() &c_int;

std/crypto/blake2.zig

@@ -9,7 +9,7 @@ const RoundParam = struct {
     a: usize, b: usize, c: usize, d: usize, x: usize, y: usize,
 };
 
-fn Rp(a: usize, b: usize, c: usize, d: usize, x: usize, y: usize) -> RoundParam {
+fn Rp(a: usize, b: usize, c: usize, d: usize, x: usize, y: usize) RoundParam {
     return RoundParam { .a = a, .b = b, .c = c, .d = d, .x = x, .y = y, };
 }
 
@@ -19,7 +19,7 @@ fn Rp(a: usize, b: usize, c: usize, d: usize, x: usize, y: usize) -> RoundParam
 pub const Blake2s224 = Blake2s(224);
 pub const Blake2s256 = Blake2s(256);
 
-fn Blake2s(comptime out_len: usize) -> type { return struct {
+fn Blake2s(comptime out_len: usize) type { return struct {
     const Self = this;
     const block_size = 64;
     const digest_size = out_len / 8;
@@ -48,7 +48,7 @@ fn Blake2s(comptime out_len: usize) -> type { return struct {
     buf:       [64]u8,
     buf_len:   u8,
 
-    pub fn init() -> Self {
+    pub fn init() Self {
         debug.assert(8 <= out_len and out_len <= 512);
 
         var s: Self = undefined;
@@ -56,7 +56,7 @@ fn Blake2s(comptime out_len: usize) -> type { return struct {
         return s;
     }
 
-    pub fn reset(d: &Self) {
+    pub fn reset(d: &Self) void {
         mem.copy(u32, d.h[0..], iv[0..]);
 
         // No key plus default parameters
@@ -65,13 +65,13 @@ fn Blake2s(comptime out_len: usize) -> type { return struct {
         d.buf_len = 0;
     }
 
-    pub fn hash(b: []const u8, out: []u8) {
+    pub fn hash(b: []const u8, out: []u8) void {
         var d = Self.init();
         d.update(b);
         d.final(out);
     }
 
-    pub fn update(d: &Self, b: []const u8) {
+    pub fn update(d: &Self, b: []const u8) void {
         var off: usize = 0;
 
         // Partial buffer exists from previous update. Copy into buffer then hash.
@@ -94,7 +94,7 @@ fn Blake2s(comptime out_len: usize) -> type { return struct {
         d.buf_len += u8(b[off..].len);
     }
 
-    pub fn final(d: &Self, out: []u8) {
+    pub fn final(d: &Self, out: []u8) void {
         debug.assert(out.len >= out_len / 8);
 
         mem.set(u8, d.buf[d.buf_len..], 0);
@@ -108,7 +108,7 @@ fn Blake2s(comptime out_len: usize) -> type { return struct {
         }
     }
 
-    fn round(d: &Self, b: []const u8, last: bool) {
+    fn round(d: &Self, b: []const u8, last: bool) void {
         debug.assert(b.len == 64);
 
         var m: [16]u32 = undefined;
@@ -236,7 +236,7 @@ test "blake2s256 streaming" {
 pub const Blake2b384 = Blake2b(384);
 pub const Blake2b512 = Blake2b(512);
 
-fn Blake2b(comptime out_len: usize) -> type { return struct {
+fn Blake2b(comptime out_len: usize) type { return struct {
     const Self = this;
     const block_size = 128;
     const digest_size = out_len / 8;
@@ -269,7 +269,7 @@ fn Blake2b(comptime out_len: usize) -> type { return struct {
     buf:       [128]u8,
     buf_len:   u8,
 
-    pub fn init() -> Self {
+    pub fn init() Self {
         debug.assert(8 <= out_len and out_len <= 512);
 
         var s: Self = undefined;
@@ -277,7 +277,7 @@ fn Blake2b(comptime out_len: usize) -> type { return struct {
         return s;
     }
 
-    pub fn reset(d: &Self) {
+    pub fn reset(d: &Self) void {
         mem.copy(u64, d.h[0..], iv[0..]);
 
         // No key plus default parameters
@@ -286,13 +286,13 @@ fn Blake2b(comptime out_len: usize) -> type { return struct {
         d.buf_len = 0;
     }
 
-    pub fn hash(b: []const u8, out: []u8) {
+    pub fn hash(b: []const u8, out: []u8) void {
         var d = Self.init();
         d.update(b);
         d.final(out);
     }
 
-    pub fn update(d: &Self, b: []const u8) {
+    pub fn update(d: &Self, b: []const u8) void {
         var off: usize = 0;
 
         // Partial buffer exists from previous update. Copy into buffer then hash.
@@ -315,7 +315,7 @@ fn Blake2b(comptime out_len: usize) -> type { return struct {
         d.buf_len += u8(b[off..].len);
     }
 
-    pub fn final(d: &Self, out: []u8) {
+    pub fn final(d: &Self, out: []u8) void {
         mem.set(u8, d.buf[d.buf_len..], 0);
         d.t += d.buf_len;
         d.round(d.buf[0..], true);
@@ -327,7 +327,7 @@ fn Blake2b(comptime out_len: usize) -> type { return struct {
         }
     }
 
-    fn round(d: &Self, b: []const u8, last: bool) {
+    fn round(d: &Self, b: []const u8, last: bool) void {
         debug.assert(b.len == 128);
 
         var m: [16]u64 = undefined;

std/crypto/md5.zig

@@ -10,7 +10,7 @@ const RoundParam = struct {
     k: usize, s: u32, t: u32
 };
 
-fn Rp(a: usize, b: usize, c: usize, d: usize, k: usize, s: u32, t: u32) -> RoundParam {
+fn Rp(a: usize, b: usize, c: usize, d: usize, k: usize, s: u32, t: u32) RoundParam {
     return RoundParam { .a = a, .b = b, .c = c, .d = d, .k = k, .s = s, .t = t };
 }
 
@@ -25,13 +25,13 @@ pub const Md5 = struct {
     buf_len: u8,
     total_len: u64,
 
-    pub fn init() -> Self {
+    pub fn init() Self {
         var d: Self = undefined;
         d.reset();
         return d;
     }
 
-    pub fn reset(d: &Self) {
+    pub fn reset(d: &Self) void {
         d.s[0] = 0x67452301;
         d.s[1] = 0xEFCDAB89;
         d.s[2] = 0x98BADCFE;
@@ -40,13 +40,13 @@ pub const Md5 = struct {
         d.total_len = 0;
     }
 
-    pub fn hash(b: []const u8, out: []u8) {
+    pub fn hash(b: []const u8, out: []u8) void {
         var d = Md5.init();
         d.update(b);
         d.final(out);
     }
 
-    pub fn update(d: &Self, b: []const u8) {
+    pub fn update(d: &Self, b: []const u8) void {
         var off: usize = 0;
 
         // Partial buffer exists from previous update. Copy into buffer then hash.
@@ -71,7 +71,7 @@ pub const Md5 = struct {
         d.total_len +%= b.len;
     }
 
-    pub fn final(d: &Self, out: []u8) {
+    pub fn final(d: &Self, out: []u8) void {
         debug.assert(out.len >= 16);
 
         // The buffer here will never be completely full.
@@ -103,7 +103,7 @@ pub const Md5 = struct {
         }
     }
 
-    fn round(d: &Self, b: []const u8) {
+    fn round(d: &Self, b: []const u8) void {
         debug.assert(b.len == 64);
 
         var s: [16]u32 = undefined;

std/crypto/sha1.zig

@@ -10,7 +10,7 @@ const RoundParam = struct {
     a: usize, b: usize, c: usize, d: usize, e: usize, i: u32,
 };
 
-fn Rp(a: usize, b: usize, c: usize, d: usize, e: usize, i: u32) -> RoundParam {
+fn Rp(a: usize, b: usize, c: usize, d: usize, e: usize, i: u32) RoundParam {
     return RoundParam { .a = a, .b = b, .c = c, .d = d, .e = e, .i = i };
 }
 
@@ -25,13 +25,13 @@ pub const Sha1 = struct {
     buf_len: u8,
     total_len: u64,
 
-    pub fn init() -> Self {
+    pub fn init() Self {
         var d: Self = undefined;
         d.reset();
         return d;
     }
 
-    pub fn reset(d: &Self) {
+    pub fn reset(d: &Self) void {
         d.s[0] = 0x67452301;
         d.s[1] = 0xEFCDAB89;
         d.s[2] = 0x98BADCFE;
@@ -41,13 +41,13 @@ pub const Sha1 = struct {
         d.total_len = 0;
     }
 
-    pub fn hash(b: []const u8, out: []u8) {
+    pub fn hash(b: []const u8, out: []u8) void {
         var d = Sha1.init();
         d.update(b);
         d.final(out);
     }
 
-    pub fn update(d: &Self, b: []const u8) {
+    pub fn update(d: &Self, b: []const u8) void {
         var off: usize = 0;
 
         // Partial buffer exists from previous update. Copy into buffer then hash.
@@ -71,7 +71,7 @@ pub const Sha1 = struct {
         d.total_len += b.len;
     }
 
-    pub fn final(d: &Self, out: []u8) {
+    pub fn final(d: &Self, out: []u8) void {
         debug.assert(out.len >= 20);
 
         // The buffer here will never be completely full.
@@ -103,7 +103,7 @@ pub const Sha1 = struct {
         }
     }
 
-    fn round(d: &Self, b: []const u8) {
+    fn round(d: &Self, b: []const u8) void {
         debug.assert(b.len == 64);
 
         var s: [16]u32 = undefined;

std/crypto/sha2.zig

@@ -13,7 +13,7 @@ const RoundParam256 = struct {
     i: usize, k: u32,
 };
 
-fn Rp256(a: usize, b: usize, c: usize, d: usize, e: usize, f: usize, g: usize, h: usize, i: usize, k: u32) -> RoundParam256 {
+fn Rp256(a: usize, b: usize, c: usize, d: usize, e: usize, f: usize, g: usize, h: usize, i: usize, k: u32) RoundParam256 {
     return RoundParam256 { .a = a, .b = b, .c = c, .d = d, .e = e, .f = f, .g = g, .h = h, .i = i, .k = k };
 }
 
@@ -56,7 +56,7 @@ const Sha256Params = Sha2Params32 {
 pub const Sha224 = Sha2_32(Sha224Params);
 pub const Sha256 = Sha2_32(Sha256Params);
 
-fn Sha2_32(comptime params: Sha2Params32) -> type { return struct {
+fn Sha2_32(comptime params: Sha2Params32) type { return struct {
     const Self = this;
     const block_size = 64;
     const digest_size = params.out_len / 8;
@@ -67,13 +67,13 @@ fn Sha2_32(comptime params: Sha2Params32) -> type { return struct {
     buf_len: u8,
     total_len: u64,
 
-    pub fn init() -> Self {
+    pub fn init() Self {
         var d: Self = undefined;
         d.reset();
         return d;
     }
 
-    pub fn reset(d: &Self) {
+    pub fn reset(d: &Self) void {
         d.s[0] = params.iv0;
         d.s[1] = params.iv1;
         d.s[2] = params.iv2;
@@ -86,13 +86,13 @@ fn Sha2_32(comptime params: Sha2Params32) -> type { return struct {
         d.total_len = 0;
     }
 
-    pub fn hash(b: []const u8, out: []u8) {
+    pub fn hash(b: []const u8, out: []u8) void {
         var d = Self.init();
         d.update(b);
         d.final(out);
     }
 
-    pub fn update(d: &Self, b: []const u8) {
+    pub fn update(d: &Self, b: []const u8) void {
         var off: usize = 0;
 
         // Partial buffer exists from previous update. Copy into buffer then hash.
@@ -116,7 +116,7 @@ fn Sha2_32(comptime params: Sha2Params32) -> type { return struct {
         d.total_len += b.len;
     }
 
-    pub fn final(d: &Self, out: []u8) {
+    pub fn final(d: &Self, out: []u8) void {
         debug.assert(out.len >= params.out_len / 8);
 
         // The buffer here will never be completely full.
@@ -151,7 +151,7 @@ fn Sha2_32(comptime params: Sha2Params32) -> type { return struct {
         }
     }
 
-    fn round(d: &Self, b: []const u8) {
+    fn round(d: &Self, b: []const u8) void {
         debug.assert(b.len == 64);
 
         var s: [64]u32 = undefined;
@@ -329,7 +329,7 @@ const RoundParam512 = struct {
     i: usize, k: u64,
 };
 
-fn Rp512(a: usize, b: usize, c: usize, d: usize, e: usize, f: usize, g: usize, h: usize, i: usize, k: u64) -> RoundParam512 {
+fn Rp512(a: usize, b: usize, c: usize, d: usize, e: usize, f: usize, g: usize, h: usize, i: usize, k: u64) RoundParam512 {
     return RoundParam512 { .a = a, .b = b, .c = c, .d = d, .e = e, .f = f, .g = g, .h = h, .i = i, .k = k };
 }
 
@@ -372,7 +372,7 @@ const Sha512Params = Sha2Params64 {
 pub const Sha384 = Sha2_64(Sha384Params);
 pub const Sha512 = Sha2_64(Sha512Params);
 
-fn Sha2_64(comptime params: Sha2Params64) -> type { return struct {
+fn Sha2_64(comptime params: Sha2Params64) type { return struct {
     const Self = this;
     const block_size = 128;
     const digest_size = params.out_len / 8;
@@ -383,13 +383,13 @@ fn Sha2_64(comptime params: Sha2Params64) -> type { return struct {
     buf_len: u8,
     total_len: u128,
 
-    pub fn init() -> Self {
+    pub fn init() Self {
         var d: Self = undefined;
         d.reset();
         return d;
     }
 
-    pub fn reset(d: &Self) {
+    pub fn reset(d: &Self) void {
         d.s[0] = params.iv0;
         d.s[1] = params.iv1;
         d.s[2] = params.iv2;
@@ -402,13 +402,13 @@ fn Sha2_64(comptime params: Sha2Params64) -> type { return struct {
         d.total_len = 0;
     }
 
-    pub fn hash(b: []const u8, out: []u8) {
+    pub fn hash(b: []const u8, out: []u8) void {
         var d = Self.init();
         d.update(b);
         d.final(out);
     }
 
-    pub fn update(d: &Self, b: []const u8) {
+    pub fn update(d: &Self, b: []const u8) void {
         var off: usize = 0;
 
         // Partial buffer exists from previous update. Copy into buffer then hash.
@@ -432,7 +432,7 @@ fn Sha2_64(comptime params: Sha2Params64) -> type { return struct {
         d.total_len += b.len;
     }
 
-    pub fn final(d: &Self, out: []u8) {
+    pub fn final(d: &Self, out: []u8) void {
         debug.assert(out.len >= params.out_len / 8);
 
         // The buffer here will never be completely full.
@@ -467,7 +467,7 @@ fn Sha2_64(comptime params: Sha2Params64) -> type { return struct {
         }
     }
 
-    fn round(d: &Self, b: []const u8) {
+    fn round(d: &Self, b: []const u8) void {
         debug.assert(b.len == 128);
 
         var s: [80]u64 = undefined;

std/crypto/sha3.zig

@@ -10,7 +10,7 @@ pub const Sha3_256 = Keccak(256, 0x06);
 pub const Sha3_384 = Keccak(384, 0x06);
 pub const Sha3_512 = Keccak(512, 0x06);
 
-fn Keccak(comptime bits: usize, comptime delim: u8) -> type { return struct {
+fn Keccak(comptime bits: usize, comptime delim: u8) type { return struct {
     const Self = this;
     const block_size = 200;
     const digest_size = bits / 8;
@@ -19,25 +19,25 @@ fn Keccak(comptime bits: usize, comptime delim: u8) -> type { return struct {
     offset: usize,
     rate: usize,
 
-    pub fn init() -> Self {
+    pub fn init() Self {
         var d: Self = undefined;
         d.reset();
         return d;
     }
 
-    pub fn reset(d: &Self) {
+    pub fn reset(d: &Self) void {
         mem.set(u8, d.s[0..], 0);
         d.offset = 0;
         d.rate = 200 - (bits / 4);
     }
 
-    pub fn hash(b: []const u8, out: []u8) {
+    pub fn hash(b: []const u8, out: []u8) void {
         var d = Self.init();
         d.update(b);
         d.final(out);
     }
 
-    pub fn update(d: &Self, b: []const u8) {
+    pub fn update(d: &Self, b: []const u8) void {
         var ip: usize = 0;
         var len = b.len;
         var rate = d.rate - d.offset;
@@ -62,7 +62,7 @@ fn Keccak(comptime bits: usize, comptime delim: u8) -> type { return struct {
         d.offset = offset + len;
     }
 
-    pub fn final(d: &Self, out: []u8) {
+    pub fn final(d: &Self, out: []u8) void {
         // padding
         d.s[d.offset] ^= delim;
         d.s[d.rate - 1] ^= 0x80;
@@ -109,7 +109,7 @@ const M5 = []const usize {
     0, 1, 2, 3, 4, 0, 1, 2, 3, 4
 };
 
-fn keccak_f(comptime F: usize, d: []u8) {
+fn keccak_f(comptime F: usize, d: []u8) void {
     debug.assert(d.len == F / 8);
 
     const B = F / 25;

std/crypto/test.zig

@@ -3,7 +3,7 @@ const mem = @import("../mem.zig");
 const fmt = @import("../fmt/index.zig");
 
 // Hash using the specified hasher `H` asserting `expected == H(input)`.
-pub fn assertEqualHash(comptime Hasher: var, comptime expected: []const u8, input: []const u8) {
+pub fn assertEqualHash(comptime Hasher: var, comptime expected: []const u8, input: []const u8) void {
     var h: [expected.len / 2]u8 = undefined;
     Hasher.hash(input, h[0..]);
 
@@ -11,7 +11,7 @@ pub fn assertEqualHash(comptime Hasher: var, comptime expected: []const u8, inpu
 }
 
 // Assert `expected` == `input` where `input` is a bytestring.
-pub fn assertEqual(comptime expected: []const u8, input: []const u8) {
+pub fn assertEqual(comptime expected: []const u8, input: []const u8) void {
     var expected_bytes: [expected.len / 2]u8 = undefined;
     for (expected_bytes) |*r, i| {
         *r = fmt.parseInt(u8, expected[2*i .. 2*i+2], 16) catch unreachable;

std/crypto/throughput_test.zig

@@ -18,7 +18,7 @@ const c = @cImport({
 
 const Mb = 1024 * 1024;
 
-pub fn main() -> %void {
+pub fn main() %void {
     var stdout_file = try std.io.getStdOut();
     var stdout_out_stream = std.io.FileOutStream.init(&stdout_file);
     const stdout = &stdout_out_stream.stream;

std/cstr.zig

@@ -3,13 +3,13 @@ const debug = std.debug;
 const mem = std.mem;
 const assert = debug.assert;
 
-pub fn len(ptr: &const u8) -> usize {
+pub fn len(ptr: &const u8) usize {
     var count: usize = 0;
     while (ptr[count] != 0) : (count += 1) {}
     return count;
 }
 
-pub fn cmp(a: &const u8, b: &const u8) -> i8 {
+pub fn cmp(a: &const u8, b: &const u8) i8 {
     var index: usize = 0;
     while (a[index] == b[index] and a[index] != 0) : (index += 1) {}
     if (a[index] > b[index]) {
@@ -21,11 +21,11 @@ pub fn cmp(a: &const u8, b: &const u8) -> i8 {
     }
 }
 
-pub fn toSliceConst(str: &const u8) -> []const u8 {
+pub fn toSliceConst(str: &const u8) []const u8 {
     return str[0..len(str)];
 }
 
-pub fn toSlice(str: &u8) -> []u8 {
+pub fn toSlice(str: &u8) []u8 {
     return str[0..len(str)];
 }
 
@@ -34,7 +34,7 @@ test "cstr fns" {
     testCStrFnsImpl();
 }
 
-fn testCStrFnsImpl() {
+fn testCStrFnsImpl() void {
     assert(cmp(c"aoeu", c"aoez") == -1);
     assert(len(c"123456789") == 9);
 }
@@ -42,7 +42,7 @@ fn testCStrFnsImpl() {
 /// Returns a mutable slice with exactly the same size which is guaranteed to
 /// have a null byte after it.
 /// Caller owns the returned memory.
-pub fn addNullByte(allocator: &mem.Allocator, slice: []const u8) -> %[]u8 {
+pub fn addNullByte(allocator: &mem.Allocator, slice: []const u8) %[]u8 {
     const result = try allocator.alloc(u8, slice.len + 1);
     mem.copy(u8, result, slice);
     result[slice.len] = 0;
@@ -56,7 +56,7 @@ pub const NullTerminated2DArray = struct {
 
     /// Takes N lists of strings, concatenates the lists together, and adds a null terminator
     /// Caller must deinit result
-    pub fn fromSlices(allocator: &mem.Allocator, slices: []const []const []const u8) -> %NullTerminated2DArray {
+    pub fn fromSlices(allocator: &mem.Allocator, slices: []const []const []const u8) %NullTerminated2DArray {
         var new_len: usize = 1; // 1 for the list null
         var byte_count: usize = 0;
         for (slices) |slice| {
@@ -96,7 +96,7 @@ pub const NullTerminated2DArray = struct {
         };
     }
 
-    pub fn deinit(self: &NullTerminated2DArray) {
+    pub fn deinit(self: &NullTerminated2DArray) void {
         const buf = @ptrCast(&u8, self.ptr);
         self.allocator.free(buf[0..self.byte_count]);
     }

std/debug/failing_allocator.zig

@@ -12,7 +12,7 @@ pub const FailingAllocator = struct {
     freed_bytes: usize,
     deallocations: usize,
 
-    pub fn init(allocator: &mem.Allocator, fail_index: usize) -> FailingAllocator {
+    pub fn init(allocator: &mem.Allocator, fail_index: usize) FailingAllocator {
         return FailingAllocator {
             .internal_allocator = allocator,
             .fail_index = fail_index,
@@ -28,7 +28,7 @@ pub const FailingAllocator = struct {
         };
     }
 
-    fn alloc(allocator: &mem.Allocator, n: usize, alignment: u29) -> %[]u8 {
+    fn alloc(allocator: &mem.Allocator, n: usize, alignment: u29) %[]u8 {
         const self = @fieldParentPtr(FailingAllocator, "allocator", allocator);
         if (self.index == self.fail_index) {
             return error.OutOfMemory;
@@ -39,7 +39,7 @@ pub const FailingAllocator = struct {
         return result;
     }
 
-    fn realloc(allocator: &mem.Allocator, old_mem: []u8, new_size: usize, alignment: u29) -> %[]u8 {
+    fn realloc(allocator: &mem.Allocator, old_mem: []u8, new_size: usize, alignment: u29) %[]u8 {
         const self = @fieldParentPtr(FailingAllocator, "allocator", allocator);
         if (new_size <= old_mem.len) {
             self.freed_bytes += old_mem.len - new_size;
@@ -55,7 +55,7 @@ pub const FailingAllocator = struct {
         return result;
     }
 
-    fn free(allocator: &mem.Allocator, bytes: []u8) {
+    fn free(allocator: &mem.Allocator, bytes: []u8) void {
         const self = @fieldParentPtr(FailingAllocator, "allocator", allocator);
         self.freed_bytes += bytes.len;
         self.deallocations += 1;

std/debug/index.zig

@@ -25,11 +25,11 @@ error TodoSupportCOFFDebugInfo;
 var stderr_file: io.File = undefined;
 var stderr_file_out_stream: io.FileOutStream = undefined;
 var stderr_stream: ?&io.OutStream = null;
-pub fn warn(comptime fmt: []const u8, args: ...) {
+pub fn warn(comptime fmt: []const u8, args: ...) void {
     const stderr = getStderrStream() catch return;
     stderr.print(fmt, args) catch return;
 }
-fn getStderrStream() -> %&io.OutStream {
+fn getStderrStream() %&io.OutStream {
     if (stderr_stream) |st| {
         return st;
     } else {
@@ -42,7 +42,7 @@ fn getStderrStream() -> %&io.OutStream {
 }
 
 var self_debug_info: ?&ElfStackTrace = null;
-pub fn getSelfDebugInfo() -> %&ElfStackTrace {
+pub fn getSelfDebugInfo() %&ElfStackTrace {
     if (self_debug_info) |info| {
         return info;
     } else {
@@ -53,7 +53,7 @@ pub fn getSelfDebugInfo() -> %&ElfStackTrace {
 }
 
 /// Tries to print the current stack trace to stderr, unbuffered, and ignores any error returned.
-pub fn dumpCurrentStackTrace() {
+pub fn dumpCurrentStackTrace() void {
     const stderr = getStderrStream() catch return;
     const debug_info = getSelfDebugInfo() catch |err| {
         stderr.print("Unable to open debug info: {}\n", @errorName(err)) catch return;
@@ -67,7 +67,7 @@ pub fn dumpCurrentStackTrace() {
 }
 
 /// Tries to print a stack trace to stderr, unbuffered, and ignores any error returned.
-pub fn dumpStackTrace(stack_trace: &const builtin.StackTrace) {
+pub fn dumpStackTrace(stack_trace: &const builtin.StackTrace) void {
     const stderr = getStderrStream() catch return;
     const debug_info = getSelfDebugInfo() catch |err| {
         stderr.print("Unable to open debug info: {}\n", @errorName(err)) catch return;
@@ -85,7 +85,7 @@ pub fn dumpStackTrace(stack_trace: &const builtin.StackTrace) {
 /// generated, and the `unreachable` statement triggers a panic.
 /// In ReleaseFast and ReleaseSmall modes, calls to this function can be
 /// optimized away.
-pub fn assert(ok: bool) {
+pub fn assert(ok: bool) void {
     if (!ok) {
         // In ReleaseFast test mode, we still want assert(false) to crash, so
         // we insert an explicit call to @panic instead of unreachable.
@@ -100,7 +100,7 @@ pub fn assert(ok: bool) {
 
 /// Call this function when you want to panic if the condition is not true.
 /// If `ok` is `false`, this function will panic in every release mode.
-pub fn assertOrPanic(ok: bool) {
+pub fn assertOrPanic(ok: bool) void {
     if (!ok) {
         @panic("assertion failure");
     }
@@ -108,7 +108,7 @@ pub fn assertOrPanic(ok: bool) {
 
 var panicking = false;
 /// This is the default panic implementation.
-pub fn panic(comptime format: []const u8, args: ...) -> noreturn {
+pub fn panic(comptime format: []const u8, args: ...) noreturn {
     // TODO an intrinsic that labels this as unlikely to be reached
 
     // TODO
@@ -130,7 +130,7 @@ pub fn panic(comptime format: []const u8, args: ...) -> noreturn {
     os.abort();
 }
 
-pub fn panicWithTrace(trace: &const builtin.StackTrace, comptime format: []const u8, args: ...) -> noreturn {
+pub fn panicWithTrace(trace: &const builtin.StackTrace, comptime format: []const u8, args: ...) noreturn {
     if (panicking) {
         os.abort();
     } else {
@@ -153,7 +153,7 @@ error PathNotFound;
 error InvalidDebugInfo;
 
 pub fn writeStackTrace(stack_trace: &const builtin.StackTrace, out_stream: &io.OutStream, allocator: &mem.Allocator,
-    debug_info: &ElfStackTrace, tty_color: bool) -> %void
+    debug_info: &ElfStackTrace, tty_color: bool) %void
 {
     var frame_index: usize = undefined;
     var frames_left: usize = undefined;
@@ -175,7 +175,7 @@ pub fn writeStackTrace(stack_trace: &const builtin.StackTrace, out_stream: &io.O
 }
 
 pub fn writeCurrentStackTrace(out_stream: &io.OutStream, allocator: &mem.Allocator,
-    debug_info: &ElfStackTrace, tty_color: bool, ignore_frame_count: usize) -> %void
+    debug_info: &ElfStackTrace, tty_color: bool, ignore_frame_count: usize) %void
 {
     var ignored_count: usize = 0;
 
@@ -191,7 +191,7 @@ pub fn writeCurrentStackTrace(out_stream: &io.OutStream, allocator: &mem.Allocat
     }
 }
 
-fn printSourceAtAddress(debug_info: &ElfStackTrace, out_stream: &io.OutStream, address: usize) -> %void {
+fn printSourceAtAddress(debug_info: &ElfStackTrace, out_stream: &io.OutStream, address: usize) %void {
     if (builtin.os == builtin.Os.windows) {
         return error.UnsupportedDebugInfo;
     }
@@ -232,7 +232,7 @@ fn printSourceAtAddress(debug_info: &ElfStackTrace, out_stream: &io.OutStream, a
     }
 }
 
-pub fn openSelfDebugInfo(allocator: &mem.Allocator) -> %&ElfStackTrace {
+pub fn openSelfDebugInfo(allocator: &mem.Allocator) %&ElfStackTrace {
     switch (builtin.object_format) {
         builtin.ObjectFormat.elf => {
             const st = try allocator.create(ElfStackTrace);
@@ -276,7 +276,7 @@ pub fn openSelfDebugInfo(allocator: &mem.Allocator) -> %&ElfStackTrace {
     }
 }
 
-fn printLineFromFile(allocator: &mem.Allocator, out_stream: &io.OutStream, line_info: &const LineInfo) -> %void {
+fn printLineFromFile(allocator: &mem.Allocator, out_stream: &io.OutStream, line_info: &const LineInfo) %void {
     var f = try io.File.openRead(line_info.file_name, allocator);
     defer f.close();
     // TODO fstat and make sure that the file has the correct size
@@ -320,17 +320,17 @@ pub const ElfStackTrace = struct {
     abbrev_table_list: ArrayList(AbbrevTableHeader),
     compile_unit_list: ArrayList(CompileUnit),
 
-    pub fn allocator(self: &const ElfStackTrace) -> &mem.Allocator {
+    pub fn allocator(self: &const ElfStackTrace) &mem.Allocator {
         return self.abbrev_table_list.allocator;
     }
 
-    pub fn readString(self: &ElfStackTrace) -> %[]u8 {
+    pub fn readString(self: &ElfStackTrace) %[]u8 {
         var in_file_stream = io.FileInStream.init(&self.self_exe_file);
         const in_stream = &in_file_stream.stream;
         return readStringRaw(self.allocator(), in_stream);
     }
 
-    pub fn close(self: &ElfStackTrace) {
+    pub fn close(self: &ElfStackTrace) void {
         self.self_exe_file.close();
         self.elf.close();
     }
@@ -387,7 +387,7 @@ const Constant = struct {
     payload: []u8,
     signed: bool,
 
-    fn asUnsignedLe(self: &const Constant) -> %u64 {
+    fn asUnsignedLe(self: &const Constant) %u64 {
         if (self.payload.len > @sizeOf(u64))
             return error.InvalidDebugInfo;
         if (self.signed)
@@ -406,7 +406,7 @@ const Die = struct {
         value: FormValue,
     };
 
-    fn getAttr(self: &const Die, id: u64) -> ?&const FormValue {
+    fn getAttr(self: &const Die, id: u64) ?&const FormValue {
         for (self.attrs.toSliceConst()) |*attr| {
             if (attr.id == id)
                 return &attr.value;
@@ -414,7 +414,7 @@ const Die = struct {
         return null;
     }
 
-    fn getAttrAddr(self: &const Die, id: u64) -> %u64 {
+    fn getAttrAddr(self: &const Die, id: u64) %u64 {
         const form_value = self.getAttr(id) ?? return error.MissingDebugInfo;
         return switch (*form_value) {
             FormValue.Address => |value| value,
@@ -422,7 +422,7 @@ const Die = struct {
         };
     }
 
-    fn getAttrSecOffset(self: &const Die, id: u64) -> %u64 {
+    fn getAttrSecOffset(self: &const Die, id: u64) %u64 {
         const form_value = self.getAttr(id) ?? return error.MissingDebugInfo;
         return switch (*form_value) {
             FormValue.Const => |value| value.asUnsignedLe(),
@@ -431,7 +431,7 @@ const Die = struct {
         };
     }
 
-    fn getAttrUnsignedLe(self: &const Die, id: u64) -> %u64 {
+    fn getAttrUnsignedLe(self: &const Die, id: u64) %u64 {
         const form_value = self.getAttr(id) ?? return error.MissingDebugInfo;
         return switch (*form_value) {
             FormValue.Const => |value| value.asUnsignedLe(),
@@ -439,7 +439,7 @@ const Die = struct {
         };
     }
 
-    fn getAttrString(self: &const Die, st: &ElfStackTrace, id: u64) -> %[]u8 {
+    fn getAttrString(self: &const Die, st: &ElfStackTrace, id: u64) %[]u8 {
         const form_value = self.getAttr(id) ?? return error.MissingDebugInfo;
         return switch (*form_value) {
             FormValue.String => |value| value,
@@ -462,7 +462,7 @@ const LineInfo = struct {
     file_name: []u8,
     allocator: &mem.Allocator,
 
-    fn deinit(self: &const LineInfo) {
+    fn deinit(self: &const LineInfo) void {
         self.allocator.free(self.file_name);
     }
 };
@@ -489,7 +489,7 @@ const LineNumberProgram = struct {
     prev_end_sequence: bool,
 
     pub fn init(is_stmt: bool, include_dirs: []const []const u8,
-        file_entries: &ArrayList(FileEntry), target_address: usize) -> LineNumberProgram
+        file_entries: &ArrayList(FileEntry), target_address: usize) LineNumberProgram
     {
         return LineNumberProgram {
             .address = 0,
@@ -512,7 +512,7 @@ const LineNumberProgram = struct {
         };
     }
 
-    pub fn checkLineMatch(self: &LineNumberProgram) -> %?LineInfo {
+    pub fn checkLineMatch(self: &LineNumberProgram) %?LineInfo {
         if (self.target_address >= self.prev_address and self.target_address < self.address) {
             const file_entry = if (self.prev_file == 0) {
                 return error.MissingDebugInfo;
@@ -544,7 +544,7 @@ const LineNumberProgram = struct {
     }
 };
 
-fn readStringRaw(allocator: &mem.Allocator, in_stream: &io.InStream) -> %[]u8 {
+fn readStringRaw(allocator: &mem.Allocator, in_stream: &io.InStream) %[]u8 {
     var buf = ArrayList(u8).init(allocator);
     while (true) {
         const byte = try in_stream.readByte();
@@ -555,58 +555,58 @@ fn readStringRaw(allocator: &mem.Allocator, in_stream: &io.InStream) -> %[]u8 {
     return buf.toSlice();
 }
 
-fn getString(st: &ElfStackTrace, offset: u64) -> %[]u8 {
+fn getString(st: &ElfStackTrace, offset: u64) %[]u8 {
     const pos = st.debug_str.offset + offset;
     try st.self_exe_file.seekTo(pos);
     return st.readString();
 }
 
-fn readAllocBytes(allocator: &mem.Allocator, in_stream: &io.InStream, size: usize) -> %[]u8 {
+fn readAllocBytes(allocator: &mem.Allocator, in_stream: &io.InStream, size: usize) %[]u8 {
     const buf = try global_allocator.alloc(u8, size);
     errdefer global_allocator.free(buf);
     if ((try in_stream.read(buf)) < size) return error.EndOfFile;
     return buf;
 }
 
-fn parseFormValueBlockLen(allocator: &mem.Allocator, in_stream: &io.InStream, size: usize) -> %FormValue {
+fn parseFormValueBlockLen(allocator: &mem.Allocator, in_stream: &io.InStream, size: usize) %FormValue {
     const buf = try readAllocBytes(allocator, in_stream, size);
     return FormValue { .Block = buf };
 }
 
-fn parseFormValueBlock(allocator: &mem.Allocator, in_stream: &io.InStream, size: usize) -> %FormValue {
+fn parseFormValueBlock(allocator: &mem.Allocator, in_stream: &io.InStream, size: usize) %FormValue {
     const block_len = try in_stream.readVarInt(builtin.Endian.Little, usize, size);
     return parseFormValueBlockLen(allocator, in_stream, block_len);
 }
 
-fn parseFormValueConstant(allocator: &mem.Allocator, in_stream: &io.InStream, signed: bool, size: usize) -> %FormValue {
+fn parseFormValueConstant(allocator: &mem.Allocator, in_stream: &io.InStream, signed: bool, size: usize) %FormValue {
     return FormValue { .Const = Constant {
         .signed = signed,
         .payload = try readAllocBytes(allocator, in_stream, size),
     }};
 }
 
-fn parseFormValueDwarfOffsetSize(in_stream: &io.InStream, is_64: bool) -> %u64 {
+fn parseFormValueDwarfOffsetSize(in_stream: &io.InStream, is_64: bool) %u64 {
     return if (is_64) try in_stream.readIntLe(u64)
     else u64(try in_stream.readIntLe(u32)) ;
 }
 
-fn parseFormValueTargetAddrSize(in_stream: &io.InStream) -> %u64 {
+fn parseFormValueTargetAddrSize(in_stream: &io.InStream) %u64 {
     return if (@sizeOf(usize) == 4) u64(try in_stream.readIntLe(u32))
     else if (@sizeOf(usize) == 8) try in_stream.readIntLe(u64)
     else unreachable;
 }
 
-fn parseFormValueRefLen(allocator: &mem.Allocator, in_stream: &io.InStream, size: usize) -> %FormValue {
+fn parseFormValueRefLen(allocator: &mem.Allocator, in_stream: &io.InStream, size: usize) %FormValue {
     const buf = try readAllocBytes(allocator, in_stream, size);
     return FormValue { .Ref = buf };
 }
 
-fn parseFormValueRef(allocator: &mem.Allocator, in_stream: &io.InStream, comptime T: type) -> %FormValue {
+fn parseFormValueRef(allocator: &mem.Allocator, in_stream: &io.InStream, comptime T: type) %FormValue {
     const block_len = try in_stream.readIntLe(T);
     return parseFormValueRefLen(allocator, in_stream, block_len);
 }
 
-fn parseFormValue(allocator: &mem.Allocator, in_stream: &io.InStream, form_id: u64, is_64: bool) -> %FormValue {
+fn parseFormValue(allocator: &mem.Allocator, in_stream: &io.InStream, form_id: u64, is_64: bool) %FormValue {
     return switch (form_id) {
         DW.FORM_addr => FormValue { .Address = try parseFormValueTargetAddrSize(in_stream) },
         DW.FORM_block1 => parseFormValueBlock(allocator, in_stream, 1),
@@ -656,7 +656,7 @@ fn parseFormValue(allocator: &mem.Allocator, in_stream: &io.InStream, form_id: u
     };
 }
 
-fn parseAbbrevTable(st: &ElfStackTrace) -> %AbbrevTable {
+fn parseAbbrevTable(st: &ElfStackTrace) %AbbrevTable {
     const in_file = &st.self_exe_file;
     var in_file_stream = io.FileInStream.init(in_file);
     const in_stream = &in_file_stream.stream;
@@ -688,7 +688,7 @@ fn parseAbbrevTable(st: &ElfStackTrace) -> %AbbrevTable {
 
 /// Gets an already existing AbbrevTable given the abbrev_offset, or if not found,
 /// seeks in the stream and parses it.
-fn getAbbrevTable(st: &ElfStackTrace, abbrev_offset: u64) -> %&const AbbrevTable {
+fn getAbbrevTable(st: &ElfStackTrace, abbrev_offset: u64) %&const AbbrevTable {
     for (st.abbrev_table_list.toSlice()) |*header| {
         if (header.offset == abbrev_offset) {
             return &header.table;
@@ -702,7 +702,7 @@ fn getAbbrevTable(st: &ElfStackTrace, abbrev_offset: u64) -> %&const AbbrevTable
     return &st.abbrev_table_list.items[st.abbrev_table_list.len - 1].table;
 }
 
-fn getAbbrevTableEntry(abbrev_table: &const AbbrevTable, abbrev_code: u64) -> ?&const AbbrevTableEntry {
+fn getAbbrevTableEntry(abbrev_table: &const AbbrevTable, abbrev_code: u64) ?&const AbbrevTableEntry {
     for (abbrev_table.toSliceConst()) |*table_entry| {
         if (table_entry.abbrev_code == abbrev_code)
             return table_entry;
@@ -710,7 +710,7 @@ fn getAbbrevTableEntry(abbrev_table: &const AbbrevTable, abbrev_code: u64) -> ?&
     return null;
 }
 
-fn parseDie(st: &ElfStackTrace, abbrev_table: &const AbbrevTable, is_64: bool) -> %Die {
+fn parseDie(st: &ElfStackTrace, abbrev_table: &const AbbrevTable, is_64: bool) %Die {
     const in_file = &st.self_exe_file;
     var in_file_stream = io.FileInStream.init(in_file);
     const in_stream = &in_file_stream.stream;
@@ -732,7 +732,7 @@ fn parseDie(st: &ElfStackTrace, abbrev_table: &const AbbrevTable, is_64: bool) -
     return result;
 }
 
-fn getLineNumberInfo(st: &ElfStackTrace, compile_unit: &const CompileUnit, target_address: usize) -> %LineInfo {
+fn getLineNumberInfo(st: &ElfStackTrace, compile_unit: &const CompileUnit, target_address: usize) %LineInfo {
     const compile_unit_cwd = try compile_unit.die.getAttrString(st, DW.AT_comp_dir);
 
     const in_file = &st.self_exe_file;
@@ -910,7 +910,7 @@ fn getLineNumberInfo(st: &ElfStackTrace, compile_unit: &const CompileUnit, targe
     return error.MissingDebugInfo;
 }
 
-fn scanAllCompileUnits(st: &ElfStackTrace) -> %void {
+fn scanAllCompileUnits(st: &ElfStackTrace) %void {
     const debug_info_end = st.debug_info.offset + st.debug_info.size;
     var this_unit_offset = st.debug_info.offset;
     var cu_index: usize = 0;
@@ -986,7 +986,7 @@ fn scanAllCompileUnits(st: &ElfStackTrace) -> %void {
     }
 }
 
-fn findCompileUnit(st: &ElfStackTrace, target_address: u64) -> %&const CompileUnit {
+fn findCompileUnit(st: &ElfStackTrace, target_address: u64) %&const CompileUnit {
     var in_file_stream = io.FileInStream.init(&st.self_exe_file);
     const in_stream = &in_file_stream.stream;
     for (st.compile_unit_list.toSlice()) |*compile_unit| {
@@ -1022,7 +1022,7 @@ fn findCompileUnit(st: &ElfStackTrace, target_address: u64) -> %&const CompileUn
     return error.MissingDebugInfo;
 }
 
-fn readInitialLength(in_stream: &io.InStream, is_64: &bool) -> %u64 {
+fn readInitialLength(in_stream: &io.InStream, is_64: &bool) %u64 {
     const first_32_bits = try in_stream.readIntLe(u32);
     *is_64 = (first_32_bits == 0xffffffff);
     if (*is_64) {
@@ -1033,7 +1033,7 @@ fn readInitialLength(in_stream: &io.InStream, is_64: &bool) -> %u64 {
     }
 }
 
-fn readULeb128(in_stream: &io.InStream) -> %u64 {
+fn readULeb128(in_stream: &io.InStream) %u64 {
     var result: u64 = 0;
     var shift: usize = 0;
 
@@ -1054,7 +1054,7 @@ fn readULeb128(in_stream: &io.InStream) -> %u64 {
     }
 }
 
-fn readILeb128(in_stream: &io.InStream) -> %i64 {
+fn readILeb128(in_stream: &io.InStream) %i64 {
     var result: i64 = 0;
     var shift: usize = 0;
 

std/elf.zig

@@ -81,14 +81,14 @@ pub const Elf = struct {
     prealloc_file: io.File,
 
     /// Call close when done.
-    pub fn openPath(elf: &Elf, allocator: &mem.Allocator, path: []const u8) -> %void {
+    pub fn openPath(elf: &Elf, allocator: &mem.Allocator, path: []const u8) %void {
         try elf.prealloc_file.open(path);
         try elf.openFile(allocator, &elf.prealloc_file);
         elf.auto_close_stream = true;
     }
 
     /// Call close when done.
-    pub fn openFile(elf: &Elf, allocator: &mem.Allocator, file: &io.File) -> %void {
+    pub fn openFile(elf: &Elf, allocator: &mem.Allocator, file: &io.File) %void {
         elf.allocator = allocator;
         elf.in_file = file;
         elf.auto_close_stream = false;
@@ -232,14 +232,14 @@ pub const Elf = struct {
         }
     }
 
-    pub fn close(elf: &Elf) {
+    pub fn close(elf: &Elf) void {
         elf.allocator.free(elf.section_headers);
 
         if (elf.auto_close_stream)
             elf.in_file.close();
     }
 
-    pub fn findSection(elf: &Elf, name: []const u8) -> %?&SectionHeader {
+    pub fn findSection(elf: &Elf, name: []const u8) %?&SectionHeader {
         var file_stream = io.FileInStream.init(elf.in_file);
         const in = &file_stream.stream;
 
@@ -263,7 +263,7 @@ pub const Elf = struct {
         return null;
     }
 
-    pub fn seekToSection(elf: &Elf, elf_section: &SectionHeader) -> %void {
+    pub fn seekToSection(elf: &Elf, elf_section: &SectionHeader) %void {
         try elf.in_file.seekTo(elf_section.offset);
     }
 };

std/endian.zig

@@ -1,19 +1,19 @@
 const mem = @import("mem.zig");
 const builtin = @import("builtin");
 
-pub fn swapIfLe(comptime T: type, x: T) -> T {
+pub fn swapIfLe(comptime T: type, x: T) T {
     return swapIf(builtin.Endian.Little, T, x);
 }
 
-pub fn swapIfBe(comptime T: type, x: T) -> T {
+pub fn swapIfBe(comptime T: type, x: T) T {
     return swapIf(builtin.Endian.Big, T, x);
 }
 
-pub fn swapIf(endian: builtin.Endian, comptime T: type, x: T) -> T {
+pub fn swapIf(endian: builtin.Endian, comptime T: type, x: T) T {
     return if (builtin.endian == endian) swap(T, x) else x;
 }
 
-pub fn swap(comptime T: type, x: T) -> T {
+pub fn swap(comptime T: type, x: T) T {
     var buf: [@sizeOf(T)]u8 = undefined;
     mem.writeInt(buf[0..], x, builtin.Endian.Little);
     return mem.readInt(buf, T, builtin.Endian.Big);

std/fmt/errol/enum3.zig

@@ -438,7 +438,7 @@ const Slab = struct {
     exp: i32,
 };
 
-fn slab(str: []const u8, exp: i32) -> Slab {
+fn slab(str: []const u8, exp: i32) Slab {
     return Slab {
         .str = str,
         .exp = exp,

std/fmt/errol/index.zig

@@ -13,7 +13,7 @@ pub const FloatDecimal = struct {
 };
 
 /// Corrected Errol3 double to ASCII conversion.
-pub fn errol3(value: f64, buffer: []u8) -> FloatDecimal {
+pub fn errol3(value: f64, buffer: []u8) FloatDecimal {
     const bits = @bitCast(u64, value);
     const i = tableLowerBound(bits);
     if (i < enum3.len and enum3[i] == bits) {
@@ -30,7 +30,7 @@ pub fn errol3(value: f64, buffer: []u8) -> FloatDecimal {
 }
 
 /// Uncorrected Errol3 double to ASCII conversion.
-fn errol3u(val: f64, buffer: []u8) -> FloatDecimal {
+fn errol3u(val: f64, buffer: []u8) FloatDecimal {
     // check if in integer or fixed range
 
     if (val > 9.007199254740992e15 and val < 3.40282366920938e+38) {
@@ -133,7 +133,7 @@ fn errol3u(val: f64, buffer: []u8) -> FloatDecimal {
     };
 }
 
-fn tableLowerBound(k: u64) -> usize {
+fn tableLowerBound(k: u64) usize {
     var i = enum3.len;
     var j: usize = 0;
 
@@ -153,7 +153,7 @@ fn tableLowerBound(k: u64) -> usize {
 ///   @in: The HP number.
 ///   @val: The double.
 ///   &returns: The HP number.
-fn hpProd(in: &const HP, val: f64) -> HP {
+fn hpProd(in: &const HP, val: f64) HP {
     var hi: f64 = undefined;
     var lo: f64 = undefined;
     split(in.val, &hi, &lo);
@@ -175,12 +175,12 @@ fn hpProd(in: &const HP, val: f64) -> HP {
 ///   @val: The double.
 ///   @hi: The high bits.
 ///   @lo: The low bits.
-fn split(val: f64, hi: &f64, lo: &f64) {
+fn split(val: f64, hi: &f64, lo: &f64) void {
     *hi = gethi(val);
     *lo = val - *hi;
 }
 
-fn gethi(in: f64) -> f64 {
+fn gethi(in: f64) f64 {
     const bits = @bitCast(u64, in);
     const new_bits = bits & 0xFFFFFFFFF8000000;
     return @bitCast(f64, new_bits);
@@ -188,7 +188,7 @@ fn gethi(in: f64) -> f64 {
 
 /// Normalize the number by factoring in the error.
 ///   @hp: The float pair.
-fn hpNormalize(hp: &HP) {
+fn hpNormalize(hp: &HP) void {
     const val = hp.val;
 
     hp.val += hp.off;
@@ -197,7 +197,7 @@ fn hpNormalize(hp: &HP) {
 
 /// Divide the high-precision number by ten.
 ///   @hp: The high-precision number
-fn hpDiv10(hp: &HP) {
+fn hpDiv10(hp: &HP) void {
     var val = hp.val;
 
     hp.val /= 10.0;
@@ -213,7 +213,7 @@ fn hpDiv10(hp: &HP) {
 
 /// Multiply the high-precision number by ten.
 ///   @hp: The high-precision number
-fn hpMul10(hp: &HP) {
+fn hpMul10(hp: &HP) void {
     const val = hp.val;
 
     hp.val *= 10.0;
@@ -233,7 +233,7 @@ fn hpMul10(hp: &HP) {
 ///  @val: The val.
 ///  @buf: The output buffer.
 ///  &return: The exponent.
-fn errolInt(val: f64, buffer: []u8) -> FloatDecimal {
+fn errolInt(val: f64, buffer: []u8) FloatDecimal {
     const pow19 = u128(1e19);
 
     assert((val > 9.007199254740992e15) and val < (3.40282366920938e38));
@@ -291,7 +291,7 @@ fn errolInt(val: f64, buffer: []u8) -> FloatDecimal {
 ///  @val: The val.
 ///  @buf: The output buffer.
 ///  &return: The exponent.
-fn errolFixed(val: f64, buffer: []u8) -> FloatDecimal {
+fn errolFixed(val: f64, buffer: []u8) FloatDecimal {
     assert((val >= 16.0) and (val < 9.007199254740992e15));
 
     const u = u64(val);
@@ -347,11 +347,11 @@ fn errolFixed(val: f64, buffer: []u8) -> FloatDecimal {
     };
 }
 
-fn fpnext(val: f64) -> f64 {
+fn fpnext(val: f64) f64 {
     return @bitCast(f64, @bitCast(u64, val) +% 1);
 }
 
-fn fpprev(val: f64) -> f64 {
+fn fpprev(val: f64) f64 {
     return @bitCast(f64, @bitCast(u64, val) -% 1);
 }
 
@@ -373,7 +373,7 @@ pub const c_digits_lut = []u8 {
     '9', '8', '9', '9',
 };
 
-fn u64toa(value_param: u64, buffer: []u8) -> usize {
+fn u64toa(value_param: u64, buffer: []u8) usize {
     var value = value_param;
     const kTen8: u64 = 100000000;
     const kTen9: u64 = kTen8 * 10;
@@ -606,7 +606,7 @@ fn u64toa(value_param: u64, buffer: []u8) -> usize {
     return buf_index;
 }
 
-fn fpeint(from: f64) -> u128 {
+fn fpeint(from: f64) u128 {
     const bits = @bitCast(u64, from);
     assert((bits & ((1 << 52) - 1)) == 0);
 
@@ -621,7 +621,7 @@ fn fpeint(from: f64) -> u128 {
 ///   @a: Integer a.
 ///   @b: Integer b.
 ///   &returns: An index within [0, 19).
-fn mismatch10(a: u64, b: u64) -> i32 {
+fn mismatch10(a: u64, b: u64) i32 {
     const pow10 = 10000000000;
     const af = a / pow10;
     const bf = b / pow10;

std/fmt/index.zig

@@ -24,8 +24,8 @@ const State = enum { // TODO put inside format function and make sure the name a
 /// Renders fmt string with args, calling output with slices of bytes.
 /// If `output` returns an error, the error is returned from `format` and
 /// `output` is not called again.
-pub fn format(context: var, output: fn(@typeOf(context), []const u8)->%void,
-    comptime fmt: []const u8, args: ...) -> %void
+pub fn format(context: var, output: fn(@typeOf(context), []const u8)%void,
+    comptime fmt: []const u8, args: ...) %void
 {
     comptime var start_index = 0;
     comptime var state = State.Start;
@@ -191,7 +191,7 @@ pub fn format(context: var, output: fn(@typeOf(context), []const u8)->%void,
     }
 }
 
-pub fn formatValue(value: var, context: var, output: fn(@typeOf(context), []const u8)->%void) -> %void {
+pub fn formatValue(value: var, context: var, output: fn(@typeOf(context), []const u8)%void) %void {
     const T = @typeOf(value);
     switch (@typeId(T)) {
         builtin.TypeId.Int => {
@@ -240,12 +240,12 @@ pub fn formatValue(value: var, context: var, output: fn(@typeOf(context), []cons
     }
 }
 
-pub fn formatAsciiChar(c: u8, context: var, output: fn(@typeOf(context), []const u8)->%void) -> %void {
+pub fn formatAsciiChar(c: u8, context: var, output: fn(@typeOf(context), []const u8)%void) %void {
     return output(context, (&c)[0..1]);
 }
 
 pub fn formatBuf(buf: []const u8, width: usize,
-    context: var, output: fn(@typeOf(context), []const u8)->%void) -> %void
+    context: var, output: fn(@typeOf(context), []const u8)%void) %void
 {
     try output(context, buf);
 
@@ -256,7 +256,7 @@ pub fn formatBuf(buf: []const u8, width: usize,
     }
 }
 
-pub fn formatFloat(value: var, context: var, output: fn(@typeOf(context), []const u8)->%void) -> %void {
+pub fn formatFloat(value: var, context: var, output: fn(@typeOf(context), []const u8)%void) %void {
     var x = f64(value);
 
     // Errol doesn't handle these special cases.
@@ -294,7 +294,7 @@ pub fn formatFloat(value: var, context: var, output: fn(@typeOf(context), []cons
     }
 }
 
-pub fn formatFloatDecimal(value: var, precision: usize, context: var, output: fn(@typeOf(context), []const u8)->%void) -> %void {
+pub fn formatFloatDecimal(value: var, precision: usize, context: var, output: fn(@typeOf(context), []const u8)%void) %void {
     var x = f64(value);
 
     // Errol doesn't handle these special cases.
@@ -336,7 +336,7 @@ pub fn formatFloatDecimal(value: var, precision: usize, context: var, output: fn
 
 
 pub fn formatInt(value: var, base: u8, uppercase: bool, width: usize,
-    context: var, output: fn(@typeOf(context), []const u8)->%void) -> %void
+    context: var, output: fn(@typeOf(context), []const u8)%void) %void
 {
     if (@typeOf(value).is_signed) {
         return formatIntSigned(value, base, uppercase, width, context, output);
@@ -346,7 +346,7 @@ pub fn formatInt(value: var, base: u8, uppercase: bool, width: usize,
 }
 
 fn formatIntSigned(value: var, base: u8, uppercase: bool, width: usize,
-    context: var, output: fn(@typeOf(context), []const u8)->%void) -> %void
+    context: var, output: fn(@typeOf(context), []const u8)%void) %void
 {
     const uint = @IntType(false, @typeOf(value).bit_count);
     if (value < 0) {
@@ -367,7 +367,7 @@ fn formatIntSigned(value: var, base: u8, uppercase: bool, width: usize,
 }
 
 fn formatIntUnsigned(value: var, base: u8, uppercase: bool, width: usize,
-    context: var, output: fn(@typeOf(context), []const u8)->%void) -> %void
+    context: var, output: fn(@typeOf(context), []const u8)%void) %void
 {
     // max_int_digits accounts for the minus sign. when printing an unsigned
     // number we don't need to do that.
@@ -405,7 +405,7 @@ fn formatIntUnsigned(value: var, base: u8, uppercase: bool, width: usize,
     }
 }
 
-pub fn formatIntBuf(out_buf: []u8, value: var, base: u8, uppercase: bool, width: usize) -> usize {
+pub fn formatIntBuf(out_buf: []u8, value: var, base: u8, uppercase: bool, width: usize) usize {
     var context = FormatIntBuf {
         .out_buf = out_buf,
         .index = 0,
@@ -417,12 +417,12 @@ const FormatIntBuf = struct {
     out_buf: []u8,
     index: usize,
 };
-fn formatIntCallback(context: &FormatIntBuf, bytes: []const u8) -> %void {
+fn formatIntCallback(context: &FormatIntBuf, bytes: []const u8) %void {
     mem.copy(u8, context.out_buf[context.index..], bytes);
     context.index += bytes.len;
 }
 
-pub fn parseInt(comptime T: type, buf: []const u8, radix: u8) -> %T {
+pub fn parseInt(comptime T: type, buf: []const u8, radix: u8) %T {
     if (!T.is_signed)
         return parseUnsigned(T, buf, radix);
     if (buf.len == 0)
@@ -446,7 +446,7 @@ test "fmt.parseInt" {
     assert(if (parseInt(u8, "256", 10)) |_| false else |err| err == error.Overflow);
 }
 
-pub fn parseUnsigned(comptime T: type, buf: []const u8, radix: u8) -> %T {
+pub fn parseUnsigned(comptime T: type, buf: []const u8, radix: u8) %T {
     var x: T = 0;
 
     for (buf) |c| {
@@ -459,7 +459,7 @@ pub fn parseUnsigned(comptime T: type, buf: []const u8, radix: u8) -> %T {
 }
 
 error InvalidChar;
-fn charToDigit(c: u8, radix: u8) -> %u8 {
+fn charToDigit(c: u8, radix: u8) %u8 {
     const value = switch (c) {
         '0' ... '9' => c - '0',
         'A' ... 'Z' => c - 'A' + 10,
@@ -473,7 +473,7 @@ fn charToDigit(c: u8, radix: u8) -> %u8 {
     return value;
 }
 
-fn digitToChar(digit: u8, uppercase: bool) -> u8 {
+fn digitToChar(digit: u8, uppercase: bool) u8 {
     return switch (digit) {
         0 ... 9 => digit + '0',
         10 ... 35 => digit + ((if (uppercase) u8('A') else u8('a')) - 10),
@@ -486,19 +486,19 @@ const BufPrintContext = struct {
 };
 
 error BufferTooSmall;
-fn bufPrintWrite(context: &BufPrintContext, bytes: []const u8) -> %void {
+fn bufPrintWrite(context: &BufPrintContext, bytes: []const u8) %void {
     if (context.remaining.len < bytes.len) return error.BufferTooSmall;
     mem.copy(u8, context.remaining, bytes);
     context.remaining = context.remaining[bytes.len..];
 }
 
-pub fn bufPrint(buf: []u8, comptime fmt: []const u8, args: ...) -> %[]u8 {
+pub fn bufPrint(buf: []u8, comptime fmt: []const u8, args: ...) %[]u8 {
     var context = BufPrintContext { .remaining = buf, };
     try format(&context, bufPrintWrite, fmt, args);
     return buf[0..buf.len - context.remaining.len];
 }
 
-pub fn allocPrint(allocator: &mem.Allocator, comptime fmt: []const u8, args: ...) -> %[]u8 {
+pub fn allocPrint(allocator: &mem.Allocator, comptime fmt: []const u8, args: ...) %[]u8 {
     var size: usize = 0;
     // Cannot fail because `countSize` cannot fail.
     format(&size, countSize, fmt, args) catch unreachable;
@@ -506,7 +506,7 @@ pub fn allocPrint(allocator: &mem.Allocator, comptime fmt: []const u8, args: ...
     return bufPrint(buf, fmt, args);
 }
 
-fn countSize(size: &usize, bytes: []const u8) -> %void {
+fn countSize(size: &usize, bytes: []const u8) %void {
     *size += bytes.len;
 }
 
@@ -528,7 +528,7 @@ test "buf print int" {
     assert(mem.eql(u8, bufPrintIntToSlice(buf, i32(-42), 10, false, 3), "-42"));
 }
 
-fn bufPrintIntToSlice(buf: []u8, value: var, base: u8, uppercase: bool, width: usize) -> []u8 {
+fn bufPrintIntToSlice(buf: []u8, value: var, base: u8, uppercase: bool, width: usize) []u8 {
     return buf[0..formatIntBuf(buf, value, base, uppercase, width)];
 }
 
@@ -644,7 +644,7 @@ test "fmt.format" {
     }
 }
 
-pub fn trim(buf: []const u8) -> []const u8 {
+pub fn trim(buf: []const u8) []const u8 {
     var start: usize = 0;
     while (start < buf.len and isWhiteSpace(buf[start])) : (start += 1) { }
 
@@ -671,7 +671,7 @@ test "fmt.trim" {
     assert(mem.eql(u8, "abc", trim("abc ")));
 }
 
-pub fn isWhiteSpace(byte: u8) -> bool {
+pub fn isWhiteSpace(byte: u8) bool {
     return switch (byte) {
         ' ', '\t', '\n', '\r' => true,
         else => false,

std/hash_map.zig

@@ -10,8 +10,8 @@ const want_modification_safety = builtin.mode != builtin.Mode.ReleaseFast;
 const debug_u32 = if (want_modification_safety) u32 else void;
 
 pub fn HashMap(comptime K: type, comptime V: type,
-    comptime hash: fn(key: K)->u32,
-    comptime eql: fn(a: K, b: K)->bool) -> type
+    comptime hash: fn(key: K)u32,
+    comptime eql: fn(a: K, b: K)bool) type
 {
     return struct {
         entries: []Entry,
@@ -39,7 +39,7 @@ pub fn HashMap(comptime K: type, comptime V: type,
             // used to detect concurrent modification
             initial_modification_count: debug_u32,
 
-            pub fn next(it: &Iterator) -> ?&Entry {
+            pub fn next(it: &Iterator) ?&Entry {
                 if (want_modification_safety) {
                     assert(it.initial_modification_count == it.hm.modification_count); // concurrent modification
                 }
@@ -56,7 +56,7 @@ pub fn HashMap(comptime K: type, comptime V: type,
             }
         };
 
-        pub fn init(allocator: &Allocator) -> Self {
+        pub fn init(allocator: &Allocator) Self {
             return Self {
                 .entries = []Entry{},
                 .allocator = allocator,
@@ -66,11 +66,11 @@ pub fn HashMap(comptime K: type, comptime V: type,
             };
         }
 
-        pub fn deinit(hm: &Self) {
+        pub fn deinit(hm: &Self) void {
             hm.allocator.free(hm.entries);
         }
 
-        pub fn clear(hm: &Self) {
+        pub fn clear(hm: &Self) void {
             for (hm.entries) |*entry| {
                 entry.used = false;
             }
@@ -80,7 +80,7 @@ pub fn HashMap(comptime K: type, comptime V: type,
         }
 
         /// Returns the value that was already there.
-        pub fn put(hm: &Self, key: K, value: &const V) -> %?V {
+        pub fn put(hm: &Self, key: K, value: &const V) %?V {
             if (hm.entries.len == 0) {
                 try hm.initCapacity(16);
             }
@@ -102,18 +102,18 @@ pub fn HashMap(comptime K: type, comptime V: type,
             return hm.internalPut(key, value);
         }
 
-        pub fn get(hm: &Self, key: K) -> ?&Entry {
+        pub fn get(hm: &Self, key: K) ?&Entry {
             if (hm.entries.len == 0) {
                 return null;
             }
             return hm.internalGet(key);
         }
 
-        pub fn contains(hm: &Self, key: K) -> bool {
+        pub fn contains(hm: &Self, key: K) bool {
             return hm.get(key) != null;
         }
 
-        pub fn remove(hm: &Self, key: K) -> ?&Entry {
+        pub fn remove(hm: &Self, key: K) ?&Entry {
             hm.incrementModificationCount();
             const start_index = hm.keyToIndex(key);
             {var roll_over: usize = 0; while (roll_over <= hm.max_distance_from_start_index) : (roll_over += 1) {
@@ -142,7 +142,7 @@ pub fn HashMap(comptime K: type, comptime V: type,
             return null;
         }
 
-        pub fn iterator(hm: &const Self) -> Iterator {
+        pub fn iterator(hm: &const Self) Iterator {
             return Iterator {
                 .hm = hm,
                 .count = 0,
@@ -151,7 +151,7 @@ pub fn HashMap(comptime K: type, comptime V: type,
             };
         }
 
-        fn initCapacity(hm: &Self, capacity: usize) -> %void {
+        fn initCapacity(hm: &Self, capacity: usize) %void {
             hm.entries = try hm.allocator.alloc(Entry, capacity);
             hm.size = 0;
             hm.max_distance_from_start_index = 0;
@@ -160,14 +160,14 @@ pub fn HashMap(comptime K: type, comptime V: type,
             }
         }
 
-        fn incrementModificationCount(hm: &Self) {
+        fn incrementModificationCount(hm: &Self) void {
             if (want_modification_safety) {
                 hm.modification_count +%= 1;
             }
         }
 
         /// Returns the value that was already there.
-        fn internalPut(hm: &Self, orig_key: K, orig_value: &const V) -> ?V {
+        fn internalPut(hm: &Self, orig_key: K, orig_value: &const V) ?V {
             var key = orig_key;
             var value = *orig_value;
             const start_index = hm.keyToIndex(key);
@@ -217,7 +217,7 @@ pub fn HashMap(comptime K: type, comptime V: type,
             unreachable; // put into a full map
         }
 
-        fn internalGet(hm: &Self, key: K) -> ?&Entry {
+        fn internalGet(hm: &Self, key: K) ?&Entry {
             const start_index = hm.keyToIndex(key);
             {var roll_over: usize = 0; while (roll_over <= hm.max_distance_from_start_index) : (roll_over += 1) {
                 const index = (start_index + roll_over) % hm.entries.len;
@@ -229,7 +229,7 @@ pub fn HashMap(comptime K: type, comptime V: type,
             return null;
         }
 
-        fn keyToIndex(hm: &Self, key: K) -> usize {
+        fn keyToIndex(hm: &Self, key: K) usize {
             return usize(hash(key)) % hm.entries.len;
         }
     };
@@ -254,10 +254,10 @@ test "basicHashMapTest" {
     assert(map.get(2) == null);
 }
 
-fn hash_i32(x: i32) -> u32 {
+fn hash_i32(x: i32) u32 {
     return @bitCast(u32, x);
 }
 
-fn eql_i32(a: i32, b: i32) -> bool {
+fn eql_i32(a: i32, b: i32) bool {
     return a == b;
 }

std/heap.zig

@@ -18,14 +18,14 @@ var c_allocator_state = Allocator {
     .freeFn = cFree,
 };
 
-fn cAlloc(self: &Allocator, n: usize, alignment: u29) -> %[]u8 {
+fn cAlloc(self: &Allocator, n: usize, alignment: u29) %[]u8 {
     return if (c.malloc(usize(n))) |buf|
         @ptrCast(&u8, buf)[0..n]
     else
         error.OutOfMemory;
 }
 
-fn cRealloc(self: &Allocator, old_mem: []u8, new_size: usize, alignment: u29) -> %[]u8 {
+fn cRealloc(self: &Allocator, old_mem: []u8, new_size: usize, alignment: u29) %[]u8 {
     const old_ptr = @ptrCast(&c_void, old_mem.ptr);
     if (c.realloc(old_ptr, new_size)) |buf| {
         return @ptrCast(&u8, buf)[0..new_size];
@@ -36,7 +36,7 @@ fn cRealloc(self: &Allocator, old_mem: []u8, new_size: usize, alignment: u29) ->
     }
 }
 
-fn cFree(self: &Allocator, old_mem: []u8) {
+fn cFree(self: &Allocator, old_mem: []u8) void {
     const old_ptr = @ptrCast(&c_void, old_mem.ptr);
     c.free(old_ptr);
 }
@@ -47,7 +47,7 @@ pub const IncrementingAllocator = struct {
     end_index: usize,
     heap_handle: if (builtin.os == Os.windows) os.windows.HANDLE else void,
 
-    fn init(capacity: usize) -> %IncrementingAllocator {
+    fn init(capacity: usize) %IncrementingAllocator {
         switch (builtin.os) {
             Os.linux, Os.macosx, Os.ios => {
                 const p = os.posix;
@@ -85,7 +85,7 @@ pub const IncrementingAllocator = struct {
         }
     }
 
-    fn deinit(self: &IncrementingAllocator) {
+    fn deinit(self: &IncrementingAllocator) void {
         switch (builtin.os) {
             Os.linux, Os.macosx, Os.ios => {
                 _ = os.posix.munmap(self.bytes.ptr, self.bytes.len);
@@ -97,15 +97,15 @@ pub const IncrementingAllocator = struct {
         }
     }
 
-    fn reset(self: &IncrementingAllocator) {
+    fn reset(self: &IncrementingAllocator) void {
         self.end_index = 0;
     }
 
-    fn bytesLeft(self: &const IncrementingAllocator) -> usize {
+    fn bytesLeft(self: &const IncrementingAllocator) usize {
         return self.bytes.len - self.end_index;
     }
 
-    fn alloc(allocator: &Allocator, n: usize, alignment: u29) -> %[]u8 {
+    fn alloc(allocator: &Allocator, n: usize, alignment: u29) %[]u8 {
         const self = @fieldParentPtr(IncrementingAllocator, "allocator", allocator);
         const addr = @ptrToInt(&self.bytes[self.end_index]);
         const rem = @rem(addr, alignment);
@@ -120,7 +120,7 @@ pub const IncrementingAllocator = struct {
         return result;
     }
 
-    fn realloc(allocator: &Allocator, old_mem: []u8, new_size: usize, alignment: u29) -> %[]u8 {
+    fn realloc(allocator: &Allocator, old_mem: []u8, new_size: usize, alignment: u29) %[]u8 {
         if (new_size <= old_mem.len) {
             return old_mem[0..new_size];
         } else {
@@ -130,7 +130,7 @@ pub const IncrementingAllocator = struct {
         }
     }
 
-    fn free(allocator: &Allocator, bytes: []u8) {
+    fn free(allocator: &Allocator, bytes: []u8) void {
         // Do nothing. That's the point of an incrementing allocator.
     }
 };

std/io.zig

@@ -50,7 +50,7 @@ error Unseekable;
 error EndOfFile;
 error FilePosLargerThanPointerRange;
 
-pub fn getStdErr() -> %File {
+pub fn getStdErr() %File {
     const handle = if (is_windows)
         try os.windowsGetStdHandle(system.STD_ERROR_HANDLE)
     else if (is_posix)
@@ -60,7 +60,7 @@ pub fn getStdErr() -> %File {
     return File.openHandle(handle);
 }
 
-pub fn getStdOut() -> %File {
+pub fn getStdOut() %File {
     const handle = if (is_windows)
         try os.windowsGetStdHandle(system.STD_OUTPUT_HANDLE)
     else if (is_posix)
@@ -70,7 +70,7 @@ pub fn getStdOut() -> %File {
     return File.openHandle(handle);
 }
 
-pub fn getStdIn() -> %File {
+pub fn getStdIn() %File {
     const handle = if (is_windows)
         try os.windowsGetStdHandle(system.STD_INPUT_HANDLE)
     else if (is_posix)
@@ -85,7 +85,7 @@ pub const FileInStream = struct {
     file: &File,
     stream: InStream,
 
-    pub fn init(file: &File) -> FileInStream {
+    pub fn init(file: &File) FileInStream {
         return FileInStream {
             .file = file,
             .stream = InStream {
@@ -94,7 +94,7 @@ pub const FileInStream = struct {
         };
     }
 
-    fn readFn(in_stream: &InStream, buffer: []u8) -> %usize {
+    fn readFn(in_stream: &InStream, buffer: []u8) %usize {
         const self = @fieldParentPtr(FileInStream, "stream", in_stream);
         return self.file.read(buffer);
     }
@@ -105,7 +105,7 @@ pub const FileOutStream = struct {
     file: &File,
     stream: OutStream,
 
-    pub fn init(file: &File) -> FileOutStream {
+    pub fn init(file: &File) FileOutStream {
         return FileOutStream {
             .file = file,
             .stream = OutStream {
@@ -114,7 +114,7 @@ pub const FileOutStream = struct {
         };
     }
 
-    fn writeFn(out_stream: &OutStream, bytes: []const u8) -> %void {
+    fn writeFn(out_stream: &OutStream, bytes: []const u8) %void {
         const self = @fieldParentPtr(FileOutStream, "stream", out_stream);
         return self.file.write(bytes);
     }
@@ -129,7 +129,7 @@ pub const File = struct {
     /// size buffer is too small, and the provided allocator is null, error.NameTooLong is returned.
     /// otherwise if the fixed size buffer is too small, allocator is used to obtain the needed memory.
     /// Call close to clean up.
-    pub fn openRead(path: []const u8, allocator: ?&mem.Allocator) -> %File {
+    pub fn openRead(path: []const u8, allocator: ?&mem.Allocator) %File {
         if (is_posix) {
             const flags = system.O_LARGEFILE|system.O_RDONLY;
             const fd = try os.posixOpen(path, flags, 0, allocator);
@@ -144,7 +144,7 @@ pub const File = struct {
     }
 
     /// Calls `openWriteMode` with 0o666 for the mode.
-    pub fn openWrite(path: []const u8, allocator: ?&mem.Allocator) -> %File {
+    pub fn openWrite(path: []const u8, allocator: ?&mem.Allocator) %File {
         return openWriteMode(path, 0o666, allocator);
 
     }
@@ -154,7 +154,7 @@ pub const File = struct {
     /// size buffer is too small, and the provided allocator is null, error.NameTooLong is returned.
     /// otherwise if the fixed size buffer is too small, allocator is used to obtain the needed memory.
     /// Call close to clean up.
-    pub fn openWriteMode(path: []const u8, mode: usize, allocator: ?&mem.Allocator) -> %File {
+    pub fn openWriteMode(path: []const u8, mode: usize, allocator: ?&mem.Allocator) %File {
         if (is_posix) {
             const flags = system.O_LARGEFILE|system.O_WRONLY|system.O_CREAT|system.O_CLOEXEC|system.O_TRUNC;
             const fd = try os.posixOpen(path, flags, mode, allocator);
@@ -170,7 +170,7 @@ pub const File = struct {
 
     }
 
-    pub fn openHandle(handle: os.FileHandle) -> File {
+    pub fn openHandle(handle: os.FileHandle) File {
         return File {
             .handle = handle,
         };
@@ -179,17 +179,17 @@ pub const File = struct {
 
     /// Upon success, the stream is in an uninitialized state. To continue using it,
     /// you must use the open() function.
-    pub fn close(self: &File) {
+    pub fn close(self: &File) void {
         os.close(self.handle);
         self.handle = undefined;
     }
 
     /// Calls `os.isTty` on `self.handle`.
-    pub fn isTty(self: &File) -> bool {
+    pub fn isTty(self: &File) bool {
         return os.isTty(self.handle);
     }
 
-    pub fn seekForward(self: &File, amount: isize) -> %void {
+    pub fn seekForward(self: &File, amount: isize) %void {
         switch (builtin.os) {
             Os.linux, Os.macosx, Os.ios => {
                 const result = system.lseek(self.handle, amount, system.SEEK_CUR);
@@ -218,7 +218,7 @@ pub const File = struct {
         }
     }
 
-    pub fn seekTo(self: &File, pos: usize) -> %void {
+    pub fn seekTo(self: &File, pos: usize) %void {
         switch (builtin.os) {
             Os.linux, Os.macosx, Os.ios => {
                 const ipos = try math.cast(isize, pos);
@@ -249,7 +249,7 @@ pub const File = struct {
         }
     }
 
-    pub fn getPos(self: &File) -> %usize {
+    pub fn getPos(self: &File) %usize {
         switch (builtin.os) {
             Os.linux, Os.macosx, Os.ios => {
                 const result = system.lseek(self.handle, 0, system.SEEK_CUR);
@@ -289,7 +289,7 @@ pub const File = struct {
         }
     }
 
-    pub fn getEndPos(self: &File) -> %usize {
+    pub fn getEndPos(self: &File) %usize {
         if (is_posix) {
             var stat: system.Stat = undefined;
             const err = system.getErrno(system.fstat(self.handle, &stat));
@@ -318,7 +318,7 @@ pub const File = struct {
         }
     }
 
-    pub fn read(self: &File, buffer: []u8) -> %usize {
+    pub fn read(self: &File, buffer: []u8) %usize {
         if (is_posix) {
             var index: usize = 0;
             while (index < buffer.len) {
@@ -360,7 +360,7 @@ pub const File = struct {
         }
     }
 
-    fn write(self: &File, bytes: []const u8) -> %void {
+    fn write(self: &File, bytes: []const u8) %void {
         if (is_posix) {
             try os.posixWrite(self.handle, bytes);
         } else if (is_windows) {
@@ -378,12 +378,12 @@ pub const InStream = struct {
     /// Return the number of bytes read. If the number read is smaller than buf.len, it
     /// means the stream reached the end. Reaching the end of a stream is not an error
     /// condition.
-    readFn: fn(self: &InStream, buffer: []u8) -> %usize,
+    readFn: fn(self: &InStream, buffer: []u8) %usize,
 
     /// Replaces `buffer` contents by reading from the stream until it is finished.
     /// If `buffer.len()` would exceed `max_size`, `error.StreamTooLong` is returned and
     /// the contents read from the stream are lost.
-    pub fn readAllBuffer(self: &InStream, buffer: &Buffer, max_size: usize) -> %void {
+    pub fn readAllBuffer(self: &InStream, buffer: &Buffer, max_size: usize) %void {
         try buffer.resize(0);
 
         var actual_buf_len: usize = 0;
@@ -408,7 +408,7 @@ pub const InStream = struct {
     /// memory would be greater than `max_size`, returns `error.StreamTooLong`.
     /// Caller owns returned memory.
     /// If this function returns an error, the contents from the stream read so far are lost.
-    pub fn readAllAlloc(self: &InStream, allocator: &mem.Allocator, max_size: usize) -> %[]u8 {
+    pub fn readAllAlloc(self: &InStream, allocator: &mem.Allocator, max_size: usize) %[]u8 {
         var buf = Buffer.initNull(allocator);
         defer buf.deinit();
 
@@ -420,7 +420,7 @@ pub const InStream = struct {
     /// Does not include the delimiter in the result.
     /// If `buffer.len()` would exceed `max_size`, `error.StreamTooLong` is returned and the contents
     /// read from the stream so far are lost.
-    pub fn readUntilDelimiterBuffer(self: &InStream, buffer: &Buffer, delimiter: u8, max_size: usize) -> %void {
+    pub fn readUntilDelimiterBuffer(self: &InStream, buffer: &Buffer, delimiter: u8, max_size: usize) %void {
         try buf.resize(0);
 
         while (true) {
@@ -443,7 +443,7 @@ pub const InStream = struct {
     /// Caller owns returned memory.
     /// If this function returns an error, the contents from the stream read so far are lost.
     pub fn readUntilDelimiterAlloc(self: &InStream, allocator: &mem.Allocator,
-        delimiter: u8, max_size: usize) -> %[]u8
+        delimiter: u8, max_size: usize) %[]u8
     {
         var buf = Buffer.initNull(allocator);
         defer buf.deinit();
@@ -455,43 +455,43 @@ pub const InStream = struct {
     /// Returns the number of bytes read. If the number read is smaller than buf.len, it
     /// means the stream reached the end. Reaching the end of a stream is not an error
     /// condition.
-    pub fn read(self: &InStream, buffer: []u8) -> %usize {
+    pub fn read(self: &InStream, buffer: []u8) %usize {
         return self.readFn(self, buffer);
     }
 
     /// Same as `read` but end of stream returns `error.EndOfStream`.
-    pub fn readNoEof(self: &InStream, buf: []u8) -> %void {
+    pub fn readNoEof(self: &InStream, buf: []u8) %void {
         const amt_read = try self.read(buf);
         if (amt_read < buf.len) return error.EndOfStream;
     }
 
     /// Reads 1 byte from the stream or returns `error.EndOfStream`.
-    pub fn readByte(self: &InStream) -> %u8 {
+    pub fn readByte(self: &InStream) %u8 {
         var result: [1]u8 = undefined;
         try self.readNoEof(result[0..]);
         return result[0];
     }
 
     /// Same as `readByte` except the returned byte is signed.
-    pub fn readByteSigned(self: &InStream) -> %i8 {
+    pub fn readByteSigned(self: &InStream) %i8 {
         return @bitCast(i8, try self.readByte());
     }
 
-    pub fn readIntLe(self: &InStream, comptime T: type) -> %T {
+    pub fn readIntLe(self: &InStream, comptime T: type) %T {
         return self.readInt(builtin.Endian.Little, T);
     }
 
-    pub fn readIntBe(self: &InStream, comptime T: type) -> %T {
+    pub fn readIntBe(self: &InStream, comptime T: type) %T {
         return self.readInt(builtin.Endian.Big, T);
     }
 
-    pub fn readInt(self: &InStream, endian: builtin.Endian, comptime T: type) -> %T {
+    pub fn readInt(self: &InStream, endian: builtin.Endian, comptime T: type) %T {
         var bytes: [@sizeOf(T)]u8 = undefined;
         try self.readNoEof(bytes[0..]);
         return mem.readInt(bytes, T, endian);
     }
 
-    pub fn readVarInt(self: &InStream, endian: builtin.Endian, comptime T: type, size: usize) -> %T {
+    pub fn readVarInt(self: &InStream, endian: builtin.Endian, comptime T: type, size: usize) %T {
         assert(size <= @sizeOf(T));
         assert(size <= 8);
         var input_buf: [8]u8 = undefined;
@@ -504,22 +504,22 @@ pub const InStream = struct {
 };
 
 pub const OutStream = struct {
-    writeFn: fn(self: &OutStream, bytes: []const u8) -> %void,
+    writeFn: fn(self: &OutStream, bytes: []const u8) %void,
 
-    pub fn print(self: &OutStream, comptime format: []const u8, args: ...) -> %void {
+    pub fn print(self: &OutStream, comptime format: []const u8, args: ...) %void {
         return std.fmt.format(self, self.writeFn, format, args);
     }
 
-    pub fn write(self: &OutStream, bytes: []const u8) -> %void {
+    pub fn write(self: &OutStream, bytes: []const u8) %void {
         return self.writeFn(self, bytes);
     }
 
-    pub fn writeByte(self: &OutStream, byte: u8) -> %void {
+    pub fn writeByte(self: &OutStream, byte: u8) %void {
         const slice = (&byte)[0..1];
         return self.writeFn(self, slice);
     }
 
-    pub fn writeByteNTimes(self: &OutStream, byte: u8, n: usize) -> %void {
+    pub fn writeByteNTimes(self: &OutStream, byte: u8, n: usize) %void {
         const slice = (&byte)[0..1];
         var i: usize = 0;
         while (i < n) : (i += 1) {
@@ -532,19 +532,19 @@ pub const OutStream = struct {
 /// a fixed size buffer of size `std.os.max_noalloc_path_len` is an attempted solution. If the fixed
 /// size buffer is too small, and the provided allocator is null, `error.NameTooLong` is returned.
 /// otherwise if the fixed size buffer is too small, allocator is used to obtain the needed memory.
-pub fn writeFile(path: []const u8, data: []const u8, allocator: ?&mem.Allocator) -> %void {
+pub fn writeFile(path: []const u8, data: []const u8, allocator: ?&mem.Allocator) %void {
     var file = try File.openWrite(path, allocator);
     defer file.close();
     try file.write(data);
 }
 
 /// On success, caller owns returned buffer.
-pub fn readFileAlloc(path: []const u8, allocator: &mem.Allocator) -> %[]u8 {
+pub fn readFileAlloc(path: []const u8, allocator: &mem.Allocator) %[]u8 {
     return readFileAllocExtra(path, allocator, 0);
 }
 /// On success, caller owns returned buffer.
 /// Allocates extra_len extra bytes at the end of the file buffer, which are uninitialized.
-pub fn readFileAllocExtra(path: []const u8, allocator: &mem.Allocator, extra_len: usize) -> %[]u8 {
+pub fn readFileAllocExtra(path: []const u8, allocator: &mem.Allocator, extra_len: usize) %[]u8 {
     var file = try File.openRead(path, allocator);
     defer file.close();
 
@@ -559,7 +559,7 @@ pub fn readFileAllocExtra(path: []const u8, allocator: &mem.Allocator, extra_len
 
 pub const BufferedInStream = BufferedInStreamCustom(os.page_size);
 
-pub fn BufferedInStreamCustom(comptime buffer_size: usize) -> type {
+pub fn BufferedInStreamCustom(comptime buffer_size: usize) type {
     return struct {
         const Self = this;
 
@@ -571,7 +571,7 @@ pub fn BufferedInStreamCustom(comptime buffer_size: usize) -> type {
         start_index: usize,
         end_index: usize,
 
-        pub fn init(unbuffered_in_stream: &InStream) -> Self {
+        pub fn init(unbuffered_in_stream: &InStream) Self {
             return Self {
                 .unbuffered_in_stream = unbuffered_in_stream,
                 .buffer = undefined,
@@ -589,7 +589,7 @@ pub fn BufferedInStreamCustom(comptime buffer_size: usize) -> type {
             };
         }
 
-        fn readFn(in_stream: &InStream, dest: []u8) -> %usize {
+        fn readFn(in_stream: &InStream, dest: []u8) %usize {
             const self = @fieldParentPtr(Self, "stream", in_stream);
 
             var dest_index: usize = 0;
@@ -630,7 +630,7 @@ pub fn BufferedInStreamCustom(comptime buffer_size: usize) -> type {
 
 pub const BufferedOutStream = BufferedOutStreamCustom(os.page_size);
 
-pub fn BufferedOutStreamCustom(comptime buffer_size: usize) -> type {
+pub fn BufferedOutStreamCustom(comptime buffer_size: usize) type {
     return struct {
         const Self = this;
 
@@ -641,7 +641,7 @@ pub fn BufferedOutStreamCustom(comptime buffer_size: usize) -> type {
         buffer: [buffer_size]u8,
         index: usize,
 
-        pub fn init(unbuffered_out_stream: &OutStream) -> Self {
+        pub fn init(unbuffered_out_stream: &OutStream) Self {
             return Self {
                 .unbuffered_out_stream = unbuffered_out_stream,
                 .buffer = undefined,
@@ -652,7 +652,7 @@ pub fn BufferedOutStreamCustom(comptime buffer_size: usize) -> type {
             };
         }
 
-        pub fn flush(self: &Self) -> %void {
+        pub fn flush(self: &Self) %void {
             if (self.index == 0)
                 return;
 
@@ -660,7 +660,7 @@ pub fn BufferedOutStreamCustom(comptime buffer_size: usize) -> type {
             self.index = 0;
         }
 
-        fn writeFn(out_stream: &OutStream, bytes: []const u8) -> %void {
+        fn writeFn(out_stream: &OutStream, bytes: []const u8) %void {
             const self = @fieldParentPtr(Self, "stream", out_stream);
 
             if (bytes.len >= self.buffer.len) {
@@ -689,7 +689,7 @@ pub const BufferOutStream = struct {
     buffer: &Buffer,
     stream: OutStream,
 
-    pub fn init(buffer: &Buffer) -> BufferOutStream {
+    pub fn init(buffer: &Buffer) BufferOutStream {
         return BufferOutStream {
             .buffer = buffer,
             .stream = OutStream {
@@ -698,7 +698,7 @@ pub const BufferOutStream = struct {
         };
     }
 
-    fn writeFn(out_stream: &OutStream, bytes: []const u8) -> %void {
+    fn writeFn(out_stream: &OutStream, bytes: []const u8) %void {
         const self = @fieldParentPtr(BufferOutStream, "stream", out_stream);
         return self.buffer.append(bytes);
     }

std/linked_list.zig

@@ -5,17 +5,17 @@ const mem = std.mem;
 const Allocator = mem.Allocator;
 
 /// Generic non-intrusive doubly linked list.
-pub fn LinkedList(comptime T: type) -> type {
+pub fn LinkedList(comptime T: type) type {
     return BaseLinkedList(T, void, "");
 }
 
 /// Generic intrusive doubly linked list.
-pub fn IntrusiveLinkedList(comptime ParentType: type, comptime field_name: []const u8) -> type {
+pub fn IntrusiveLinkedList(comptime ParentType: type, comptime field_name: []const u8) type {
     return BaseLinkedList(void, ParentType, field_name);
 }
 
 /// Generic doubly linked list.
-fn BaseLinkedList(comptime T: type, comptime ParentType: type, comptime field_name: []const u8) -> type {
+fn BaseLinkedList(comptime T: type, comptime ParentType: type, comptime field_name: []const u8) type {
     return struct {
         const Self = this;
 
@@ -25,7 +25,7 @@ fn BaseLinkedList(comptime T: type, comptime ParentType: type, comptime field_na
             next: ?&Node,
             data: T,
 
-            pub fn init(value: &const T) -> Node {
+            pub fn init(value: &const T) Node {
                 return Node {
                     .prev = null,
                     .next = null,
@@ -33,12 +33,12 @@ fn BaseLinkedList(comptime T: type, comptime ParentType: type, comptime field_na
                 };
             }
 
-            pub fn initIntrusive() -> Node {
+            pub fn initIntrusive() Node {
                 // TODO: when #678 is solved this can become `init`.
                 return Node.init({});
             }
 
-            pub fn toData(node: &Node) -> &ParentType {
+            pub fn toData(node: &Node) &ParentType {
                 comptime assert(isIntrusive());
                 return @fieldParentPtr(ParentType, field_name, node);
             }
@@ -52,7 +52,7 @@ fn BaseLinkedList(comptime T: type, comptime ParentType: type, comptime field_na
         ///
         /// Returns:
         ///     An empty linked list.
-        pub fn init() -> Self {
+        pub fn init() Self {
             return Self {
                 .first = null,
                 .last  = null,
@@ -60,7 +60,7 @@ fn BaseLinkedList(comptime T: type, comptime ParentType: type, comptime field_na
             };
         }
 
-        fn isIntrusive() -> bool {
+        fn isIntrusive() bool {
             return ParentType != void or field_name.len != 0;
         }
 
@@ -69,7 +69,7 @@ fn BaseLinkedList(comptime T: type, comptime ParentType: type, comptime field_na
         /// Arguments:
         ///     node: Pointer to a node in the list.
         ///     new_node: Pointer to the new node to insert.
-        pub fn insertAfter(list: &Self, node: &Node, new_node: &Node) {
+        pub fn insertAfter(list: &Self, node: &Node, new_node: &Node) void {
             new_node.prev = node;
             if (node.next) |next_node| {
                 // Intermediate node.
@@ -90,7 +90,7 @@ fn BaseLinkedList(comptime T: type, comptime ParentType: type, comptime field_na
         /// Arguments:
         ///     node: Pointer to a node in the list.
         ///     new_node: Pointer to the new node to insert.
-        pub fn insertBefore(list: &Self, node: &Node, new_node: &Node) {
+        pub fn insertBefore(list: &Self, node: &Node, new_node: &Node) void {
             new_node.next = node;
             if (node.prev) |prev_node| {
                 // Intermediate node.
@@ -110,7 +110,7 @@ fn BaseLinkedList(comptime T: type, comptime ParentType: type, comptime field_na
         ///
         /// Arguments:
         ///     new_node: Pointer to the new node to insert.
-        pub fn append(list: &Self, new_node: &Node) {
+        pub fn append(list: &Self, new_node: &Node) void {
             if (list.last) |last| {
                 // Insert after last.
                 list.insertAfter(last, new_node);
@@ -124,7 +124,7 @@ fn BaseLinkedList(comptime T: type, comptime ParentType: type, comptime field_na
         ///
         /// Arguments:
         ///     new_node: Pointer to the new node to insert.
-        pub fn prepend(list: &Self, new_node: &Node) {
+        pub fn prepend(list: &Self, new_node: &Node) void {
             if (list.first) |first| {
                 // Insert before first.
                 list.insertBefore(first, new_node);
@@ -143,7 +143,7 @@ fn BaseLinkedList(comptime T: type, comptime ParentType: type, comptime field_na
         ///
         /// Arguments:
         ///     node: Pointer to the node to be removed.
-        pub fn remove(list: &Self, node: &Node) {
+        pub fn remove(list: &Self, node: &Node) void {
             if (node.prev) |prev_node| {
                 // Intermediate node.
                 prev_node.next = node.next;
@@ -167,7 +167,7 @@ fn BaseLinkedList(comptime T: type, comptime ParentType: type, comptime field_na
         ///
         /// Returns:
         ///     A pointer to the last node in the list.
-        pub fn pop(list: &Self) -> ?&Node {
+        pub fn pop(list: &Self) ?&Node {
             const last = list.last ?? return null;
             list.remove(last);
             return last;
@@ -177,7 +177,7 @@ fn BaseLinkedList(comptime T: type, comptime ParentType: type, comptime field_na
         ///
         /// Returns:
         ///     A pointer to the first node in the list.
-        pub fn popFirst(list: &Self) -> ?&Node {
+        pub fn popFirst(list: &Self) ?&Node {
             const first = list.first ?? return null;
             list.remove(first);
             return first;
@@ -190,7 +190,7 @@ fn BaseLinkedList(comptime T: type, comptime ParentType: type, comptime field_na
         ///
         /// Returns:
         ///     A pointer to the new node.
-        pub fn allocateNode(list: &Self, allocator: &Allocator) -> %&Node {
+        pub fn allocateNode(list: &Self, allocator: &Allocator) %&Node {
             comptime assert(!isIntrusive());
             return allocator.create(Node);
         }
@@ -200,7 +200,7 @@ fn BaseLinkedList(comptime T: type, comptime ParentType: type, comptime field_na
         /// Arguments:
         ///     node: Pointer to the node to deallocate.
         ///     allocator: Dynamic memory allocator.
-        pub fn destroyNode(list: &Self, node: &Node, allocator: &Allocator) {
+        pub fn destroyNode(list: &Self, node: &Node, allocator: &Allocator) void {
             comptime assert(!isIntrusive());
             allocator.destroy(node);
         }
@@ -213,7 +213,7 @@ fn BaseLinkedList(comptime T: type, comptime ParentType: type, comptime field_na
         ///
         /// Returns:
         ///     A pointer to the new node.
-        pub fn createNode(list: &Self, data: &const T, allocator: &Allocator) -> %&Node {
+        pub fn createNode(list: &Self, data: &const T, allocator: &Allocator) %&Node {
             comptime assert(!isIntrusive());
             var node = try list.allocateNode(allocator);
             *node = Node.init(data);

std/math/acos.zig

@@ -6,7 +6,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn acos(x: var) -> @typeOf(x) {
+pub fn acos(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => acos32(x),
@@ -15,7 +15,7 @@ pub fn acos(x: var) -> @typeOf(x) {
     };
 }
 
-fn r32(z: f32) -> f32 {
+fn r32(z: f32) f32 {
     const pS0 =  1.6666586697e-01;
     const pS1 = -4.2743422091e-02;
     const pS2 = -8.6563630030e-03;
@@ -26,7 +26,7 @@ fn r32(z: f32) -> f32 {
     return p / q;
 }
 
-fn acos32(x: f32) -> f32 {
+fn acos32(x: f32) f32 {
     const pio2_hi = 1.5707962513e+00;
     const pio2_lo = 7.5497894159e-08;
 
@@ -73,7 +73,7 @@ fn acos32(x: f32) -> f32 {
     return 2 * (df + w);
 }
 
-fn r64(z: f64) -> f64 {
+fn r64(z: f64) f64 {
     const pS0: f64 =  1.66666666666666657415e-01;
     const pS1: f64 = -3.25565818622400915405e-01;
     const pS2: f64 =  2.01212532134862925881e-01;
@@ -90,7 +90,7 @@ fn r64(z: f64) -> f64 {
     return p / q;
 }
 
-fn acos64(x: f64) -> f64 {
+fn acos64(x: f64) f64 {
     const pio2_hi: f64 = 1.57079632679489655800e+00;
     const pio2_lo: f64 = 6.12323399573676603587e-17;
 

std/math/acosh.zig

@@ -8,7 +8,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn acosh(x: var) -> @typeOf(x) {
+pub fn acosh(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => acosh32(x),
@@ -18,7 +18,7 @@ pub fn acosh(x: var) -> @typeOf(x) {
 }
 
 // acosh(x) = log(x + sqrt(x * x - 1))
-fn acosh32(x: f32) -> f32 {
+fn acosh32(x: f32) f32 {
     const u = @bitCast(u32, x);
     const i = u & 0x7FFFFFFF;
 
@@ -36,7 +36,7 @@ fn acosh32(x: f32) -> f32 {
     }
 }
 
-fn acosh64(x: f64) -> f64 {
+fn acosh64(x: f64) f64 {
     const u = @bitCast(u64, x);
     const e = (u >> 52) & 0x7FF;
 

std/math/asin.zig

@@ -7,7 +7,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn asin(x: var) -> @typeOf(x) {
+pub fn asin(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => asin32(x),
@@ -16,7 +16,7 @@ pub fn asin(x: var) -> @typeOf(x) {
     };
 }
 
-fn r32(z: f32) -> f32 {
+fn r32(z: f32) f32 {
     const pS0 =  1.6666586697e-01;
     const pS1 = -4.2743422091e-02;
     const pS2 = -8.6563630030e-03;
@@ -27,7 +27,7 @@ fn r32(z: f32) -> f32 {
     return p / q;
 }
 
-fn asin32(x: f32) -> f32 {
+fn asin32(x: f32) f32 {
     const pio2 = 1.570796326794896558e+00;
 
     const hx: u32 = @bitCast(u32, x);
@@ -65,7 +65,7 @@ fn asin32(x: f32) -> f32 {
     }
 }
 
-fn r64(z: f64) -> f64 {
+fn r64(z: f64) f64 {
     const pS0: f64 =  1.66666666666666657415e-01;
     const pS1: f64 = -3.25565818622400915405e-01;
     const pS2: f64 =  2.01212532134862925881e-01;
@@ -82,7 +82,7 @@ fn r64(z: f64) -> f64 {
     return p / q;
 }
 
-fn asin64(x: f64) -> f64 {
+fn asin64(x: f64) f64 {
     const pio2_hi: f64 = 1.57079632679489655800e+00;
     const pio2_lo: f64 = 6.12323399573676603587e-17;
 

std/math/asinh.zig

@@ -8,7 +8,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn asinh(x: var) -> @typeOf(x) {
+pub fn asinh(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => asinh32(x),
@@ -18,7 +18,7 @@ pub fn asinh(x: var) -> @typeOf(x) {
 }
 
 // asinh(x) = sign(x) * log(|x| + sqrt(x * x + 1)) ~= x - x^3/6 + o(x^5)
-fn asinh32(x: f32) -> f32 {
+fn asinh32(x: f32) f32 {
     const u = @bitCast(u32, x);
     const i = u & 0x7FFFFFFF;
     const s = i >> 31;
@@ -50,7 +50,7 @@ fn asinh32(x: f32) -> f32 {
     return if (s != 0) -rx else rx;
 }
 
-fn asinh64(x: f64) -> f64 {
+fn asinh64(x: f64) f64 {
     const u = @bitCast(u64, x);
     const e = (u >> 52) & 0x7FF;
     const s = u >> 63;

std/math/atan.zig

@@ -7,7 +7,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn atan(x: var) -> @typeOf(x) {
+pub fn atan(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => atan32(x),
@@ -16,7 +16,7 @@ pub fn atan(x: var) -> @typeOf(x) {
     };
 }
 
-fn atan32(x_: f32) -> f32 {
+fn atan32(x_: f32) f32 {
     const atanhi = []const f32 {
         4.6364760399e-01, // atan(0.5)hi
         7.8539812565e-01, // atan(1.0)hi
@@ -108,7 +108,7 @@ fn atan32(x_: f32) -> f32 {
     }
 }
 
-fn atan64(x_: f64) -> f64 {
+fn atan64(x_: f64) f64 {
     const atanhi = []const f64 {
         4.63647609000806093515e-01, // atan(0.5)hi
         7.85398163397448278999e-01, // atan(1.0)hi

std/math/atan2.zig

@@ -22,7 +22,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-fn atan2(comptime T: type, x: T, y: T) -> T {
+fn atan2(comptime T: type, x: T, y: T) T {
     return switch (T) {
         f32 => atan2_32(x, y),
         f64 => atan2_64(x, y),
@@ -30,7 +30,7 @@ fn atan2(comptime T: type, x: T, y: T) -> T {
     };
 }
 
-fn atan2_32(y: f32, x: f32) -> f32 {
+fn atan2_32(y: f32, x: f32) f32 {
     const pi: f32    =  3.1415927410e+00;
     const pi_lo: f32 = -8.7422776573e-08;
 
@@ -115,7 +115,7 @@ fn atan2_32(y: f32, x: f32) -> f32 {
     }
 }
 
-fn atan2_64(y: f64, x: f64) -> f64 {
+fn atan2_64(y: f64, x: f64) f64 {
     const pi: f64    = 3.1415926535897931160E+00;
     const pi_lo: f64 = 1.2246467991473531772E-16;
 

std/math/atanh.zig

@@ -8,7 +8,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn atanh(x: var) -> @typeOf(x) {
+pub fn atanh(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => atanh_32(x),
@@ -18,7 +18,7 @@ pub fn atanh(x: var) -> @typeOf(x) {
 }
 
 // atanh(x) = log((1 + x) / (1 - x)) / 2 = log1p(2x / (1 - x)) / 2 ~= x + x^3 / 3 + o(x^5)
-fn atanh_32(x: f32) -> f32 {
+fn atanh_32(x: f32) f32 {
     const u = @bitCast(u32, x);
     const i = u & 0x7FFFFFFF;
     const s = u >> 31;
@@ -47,7 +47,7 @@ fn atanh_32(x: f32) -> f32 {
     return if (s != 0) -y else y;
 }
 
-fn atanh_64(x: f64) -> f64 {
+fn atanh_64(x: f64) f64 {
     const u = @bitCast(u64, x);
     const e = (u >> 52) & 0x7FF;
     const s = u >> 63;

std/math/cbrt.zig

@@ -8,7 +8,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn cbrt(x: var) -> @typeOf(x) {
+pub fn cbrt(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => cbrt32(x),
@@ -17,7 +17,7 @@ pub fn cbrt(x: var) -> @typeOf(x) {
     };
 }
 
-fn cbrt32(x: f32) -> f32 {
+fn cbrt32(x: f32) f32 {
     const B1: u32 = 709958130; // (127 - 127.0 / 3 - 0.03306235651) * 2^23
     const B2: u32 = 642849266; // (127 - 127.0 / 3 - 24 / 3 - 0.03306235651) * 2^23
 
@@ -57,7 +57,7 @@ fn cbrt32(x: f32) -> f32 {
     return f32(t);
 }
 
-fn cbrt64(x: f64) -> f64 {
+fn cbrt64(x: f64) f64 {
     const B1: u32 = 715094163;  // (1023 - 1023 / 3 - 0.03306235651 * 2^20
     const B2: u32 = 696219795;  // (1023 - 1023 / 3 - 54 / 3 - 0.03306235651 * 2^20
 

std/math/ceil.zig

@@ -9,7 +9,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn ceil(x: var) -> @typeOf(x) {
+pub fn ceil(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => ceil32(x),
@@ -18,7 +18,7 @@ pub fn ceil(x: var) -> @typeOf(x) {
     };
 }
 
-fn ceil32(x: f32) -> f32 {
+fn ceil32(x: f32) f32 {
     var u = @bitCast(u32, x);
     var e = i32((u >> 23) & 0xFF) - 0x7F;
     var m: u32 = undefined;
@@ -51,7 +51,7 @@ fn ceil32(x: f32) -> f32 {
     }
 }
 
-fn ceil64(x: f64) -> f64 {
+fn ceil64(x: f64) f64 {
     const u = @bitCast(u64, x);
     const e = (u >> 52) & 0x7FF;
     var y: f64 = undefined;

std/math/copysign.zig

@@ -2,7 +2,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn copysign(comptime T: type, x: T, y: T) -> T {
+pub fn copysign(comptime T: type, x: T, y: T) T {
     return switch (T) {
         f32 => copysign32(x, y),
         f64 => copysign64(x, y),
@@ -10,7 +10,7 @@ pub fn copysign(comptime T: type, x: T, y: T) -> T {
     };
 }
 
-fn copysign32(x: f32, y: f32) -> f32 {
+fn copysign32(x: f32, y: f32) f32 {
     const ux = @bitCast(u32, x);
     const uy = @bitCast(u32, y);
 
@@ -19,7 +19,7 @@ fn copysign32(x: f32, y: f32) -> f32 {
     return @bitCast(f32, h1 | h2);
 }
 
-fn copysign64(x: f64, y: f64) -> f64 {
+fn copysign64(x: f64, y: f64) f64 {
     const ux = @bitCast(u64, x);
     const uy = @bitCast(u64, y);
 

std/math/cos.zig

@@ -8,7 +8,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn cos(x: var) -> @typeOf(x) {
+pub fn cos(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => cos32(x),
@@ -36,7 +36,7 @@ const C5 =  4.16666666666665929218E-2;
 // NOTE: This is taken from the go stdlib. The musl implementation is much more complex.
 //
 // This may have slight differences on some edge cases and may need to replaced if so.
-fn cos32(x_: f32) -> f32 {
+fn cos32(x_: f32) f32 {
     @setFloatMode(this, @import("builtin").FloatMode.Strict);
 
     const pi4a = 7.85398125648498535156e-1;
@@ -89,7 +89,7 @@ fn cos32(x_: f32) -> f32 {
     }
 }
 
-fn cos64(x_: f64) -> f64 {
+fn cos64(x_: f64) f64 {
     const pi4a = 7.85398125648498535156e-1;
     const pi4b = 3.77489470793079817668E-8;
     const pi4c = 2.69515142907905952645E-15;

std/math/cosh.zig

@@ -10,7 +10,7 @@ const math = std.math;
 const expo2 = @import("expo2.zig").expo2;
 const assert = std.debug.assert;
 
-pub fn cosh(x: var) -> @typeOf(x) {
+pub fn cosh(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => cosh32(x),
@@ -22,7 +22,7 @@ pub fn cosh(x: var) -> @typeOf(x) {
 // cosh(x) = (exp(x) + 1 / exp(x)) / 2
 //         = 1 + 0.5 * (exp(x) - 1) * (exp(x) - 1) / exp(x)
 //         = 1 + (x * x) / 2 + o(x^4)
-fn cosh32(x: f32) -> f32 {
+fn cosh32(x: f32) f32 {
     const u = @bitCast(u32, x);
     const ux = u & 0x7FFFFFFF;
     const ax = @bitCast(f32, ux);
@@ -47,7 +47,7 @@ fn cosh32(x: f32) -> f32 {
     return expo2(ax);
 }
 
-fn cosh64(x: f64) -> f64 {
+fn cosh64(x: f64) f64 {
     const u = @bitCast(u64, x);
     const w = u32(u >> 32);
     const ax = @bitCast(f64, u & (@maxValue(u64) >> 1));

std/math/exp.zig

@@ -7,7 +7,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn exp(x: var) -> @typeOf(x) {
+pub fn exp(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => exp32(x),
@@ -16,7 +16,7 @@ pub fn exp(x: var) -> @typeOf(x) {
     };
 }
 
-fn exp32(x_: f32) -> f32 {
+fn exp32(x_: f32) f32 {
     const half = []f32 { 0.5, -0.5 };
     const ln2hi = 6.9314575195e-1;
     const ln2lo = 1.4286067653e-6;
@@ -93,7 +93,7 @@ fn exp32(x_: f32) -> f32 {
     }
 }
 
-fn exp64(x_: f64) -> f64 {
+fn exp64(x_: f64) f64 {
     const half = []const f64 { 0.5, -0.5 };
     const ln2hi: f64 = 6.93147180369123816490e-01;
     const ln2lo: f64 = 1.90821492927058770002e-10;

std/math/exp2.zig

@@ -7,7 +7,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn exp2(x: var) -> @typeOf(x) {
+pub fn exp2(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => exp2_32(x),
@@ -35,7 +35,7 @@ const exp2ft = []const f64 {
     0x1.5ab07dd485429p+0,
 };
 
-fn exp2_32(x: f32) -> f32 {
+fn exp2_32(x: f32) f32 {
     @setFloatMode(this, @import("builtin").FloatMode.Strict);
 
     const tblsiz = u32(exp2ft.len);
@@ -352,7 +352,7 @@ const exp2dt = []f64 {
     0x1.690f4b19e9471p+0, -0x1.9780p-45,
 };
 
-fn exp2_64(x: f64) -> f64 {
+fn exp2_64(x: f64) f64 {
     @setFloatMode(this, @import("builtin").FloatMode.Strict);
 
     const tblsiz     = u32(exp2dt.len / 2);

std/math/expm1.zig

@@ -9,7 +9,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn expm1(x: var) -> @typeOf(x) {
+pub fn expm1(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => expm1_32(x),
@@ -18,7 +18,7 @@ pub fn expm1(x: var) -> @typeOf(x) {
     };
 }
 
-fn expm1_32(x_: f32) -> f32 {
+fn expm1_32(x_: f32) f32 {
     @setFloatMode(this, builtin.FloatMode.Strict);
     const o_threshold: f32 = 8.8721679688e+01;
     const ln2_hi: f32      = 6.9313812256e-01;
@@ -145,7 +145,7 @@ fn expm1_32(x_: f32) -> f32 {
     }
 }
 
-fn expm1_64(x_: f64) -> f64 {
+fn expm1_64(x_: f64) f64 {
     @setFloatMode(this, builtin.FloatMode.Strict);
     const o_threshold: f64 = 7.09782712893383973096e+02;
     const ln2_hi: f64      = 6.93147180369123816490e-01;

std/math/expo2.zig

@@ -1,6 +1,6 @@
 const math = @import("index.zig");
 
-pub fn expo2(x: var) -> @typeOf(x) {
+pub fn expo2(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => expo2f(x),
@@ -9,7 +9,7 @@ pub fn expo2(x: var) -> @typeOf(x) {
     };
 }
 
-fn expo2f(x: f32) -> f32 {
+fn expo2f(x: f32) f32 {
     const k: u32 = 235;
     const kln2 = 0x1.45C778p+7;
 
@@ -18,7 +18,7 @@ fn expo2f(x: f32) -> f32 {
     return math.exp(x - kln2) * scale * scale;
 }
 
-fn expo2d(x: f64) -> f64 {
+fn expo2d(x: f64) f64 {
     const k: u32 = 2043;
     const kln2 = 0x1.62066151ADD8BP+10;
 

std/math/fabs.zig

@@ -7,7 +7,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn fabs(x: var) -> @typeOf(x) {
+pub fn fabs(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => fabs32(x),
@@ -16,13 +16,13 @@ pub fn fabs(x: var) -> @typeOf(x) {
     };
 }
 
-fn fabs32(x: f32) -> f32 {
+fn fabs32(x: f32) f32 {
     var u = @bitCast(u32, x);
     u &= 0x7FFFFFFF;
     return @bitCast(f32, u);
 }
 
-fn fabs64(x: f64) -> f64 {
+fn fabs64(x: f64) f64 {
     var u = @bitCast(u64, x);
     u &= @maxValue(u64) >> 1;
     return @bitCast(f64, u);

std/math/floor.zig

@@ -9,7 +9,7 @@ const assert = std.debug.assert;
 const std = @import("../index.zig");
 const math = std.math;
 
-pub fn floor(x: var) -> @typeOf(x) {
+pub fn floor(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => floor32(x),
@@ -18,7 +18,7 @@ pub fn floor(x: var) -> @typeOf(x) {
     };
 }
 
-fn floor32(x: f32) -> f32 {
+fn floor32(x: f32) f32 {
     var u = @bitCast(u32, x);
     const e = i32((u >> 23) & 0xFF) - 0x7F;
     var m: u32 = undefined;
@@ -52,7 +52,7 @@ fn floor32(x: f32) -> f32 {
     }
 }
 
-fn floor64(x: f64) -> f64 {
+fn floor64(x: f64) f64 {
     const u = @bitCast(u64, x);
     const e = (u >> 52) & 0x7FF;
     var y: f64 = undefined;

std/math/fma.zig

@@ -2,7 +2,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn fma(comptime T: type, x: T, y: T, z: T) -> T {
+pub fn fma(comptime T: type, x: T, y: T, z: T) T {
     return switch (T) {
         f32 => fma32(x, y, z),
         f64 => fma64(x, y ,z),
@@ -10,7 +10,7 @@ pub fn fma(comptime T: type, x: T, y: T, z: T) -> T {
     };
 }
 
-fn fma32(x: f32, y: f32, z: f32) -> f32 {
+fn fma32(x: f32, y: f32, z: f32) f32 {
     const xy = f64(x) * y;
     const xy_z = xy + z;
     const u = @bitCast(u64, xy_z);
@@ -24,7 +24,7 @@ fn fma32(x: f32, y: f32, z: f32) -> f32 {
     }
 }
 
-fn fma64(x: f64, y: f64, z: f64) -> f64 {
+fn fma64(x: f64, y: f64, z: f64) f64 {
     if (!math.isFinite(x) or !math.isFinite(y)) {
         return x * y + z;
     }
@@ -73,7 +73,7 @@ fn fma64(x: f64, y: f64, z: f64) -> f64 {
 
 const dd = struct { hi: f64, lo: f64, };
 
-fn dd_add(a: f64, b: f64) -> dd {
+fn dd_add(a: f64, b: f64) dd {
     var ret: dd = undefined;
     ret.hi = a + b;
     const s = ret.hi - a;
@@ -81,7 +81,7 @@ fn dd_add(a: f64, b: f64) -> dd {
     return ret;
 }
 
-fn dd_mul(a: f64, b: f64) -> dd {
+fn dd_mul(a: f64, b: f64) dd {
     var ret: dd = undefined;
     const split: f64 = 0x1.0p27 + 1.0;
 
@@ -103,7 +103,7 @@ fn dd_mul(a: f64, b: f64) -> dd {
     return ret;
 }
 
-fn add_adjusted(a: f64, b: f64) -> f64 {
+fn add_adjusted(a: f64, b: f64) f64 {
     var sum = dd_add(a, b);
     if (sum.lo != 0) {
         var uhii = @bitCast(u64, sum.hi);
@@ -117,7 +117,7 @@ fn add_adjusted(a: f64, b: f64) -> f64 {
     return sum.hi;
 }
 
-fn add_and_denorm(a: f64, b: f64, scale: i32) -> f64 {
+fn add_and_denorm(a: f64, b: f64, scale: i32) f64 {
     var sum = dd_add(a, b);
     if (sum.lo != 0) {
         var uhii = @bitCast(u64, sum.hi);

std/math/frexp.zig

@@ -8,7 +8,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-fn frexp_result(comptime T: type) -> type {
+fn frexp_result(comptime T: type) type {
     return struct {
         significand: T,
         exponent: i32,
@@ -17,7 +17,7 @@ fn frexp_result(comptime T: type) -> type {
 pub const frexp32_result = frexp_result(f32);
 pub const frexp64_result = frexp_result(f64);
 
-pub fn frexp(x: var) -> frexp_result(@typeOf(x)) {
+pub fn frexp(x: var) frexp_result(@typeOf(x)) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => frexp32(x),
@@ -26,7 +26,7 @@ pub fn frexp(x: var) -> frexp_result(@typeOf(x)) {
     };
 }
 
-fn frexp32(x: f32) -> frexp32_result {
+fn frexp32(x: f32) frexp32_result {
     var result: frexp32_result = undefined;
 
     var y = @bitCast(u32, x);
@@ -63,7 +63,7 @@ fn frexp32(x: f32) -> frexp32_result {
     return result;
 }
 
-fn frexp64(x: f64) -> frexp64_result {
+fn frexp64(x: f64) frexp64_result {
     var result: frexp64_result = undefined;
 
     var y = @bitCast(u64, x);

std/math/hypot.zig

@@ -9,7 +9,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn hypot(comptime T: type, x: T, y: T) -> T {
+pub fn hypot(comptime T: type, x: T, y: T) T {
     return switch (T) {
         f32 => hypot32(x, y),
         f64 => hypot64(x, y),
@@ -17,7 +17,7 @@ pub fn hypot(comptime T: type, x: T, y: T) -> T {
     };
 }
 
-fn hypot32(x: f32, y: f32) -> f32 {
+fn hypot32(x: f32, y: f32) f32 {
     var ux = @bitCast(u32, x);
     var uy = @bitCast(u32, y);
 
@@ -52,7 +52,7 @@ fn hypot32(x: f32, y: f32) -> f32 {
     return z * math.sqrt(f32(f64(x) * x + f64(y) * y));
 }
 
-fn sq(hi: &f64, lo: &f64, x: f64) {
+fn sq(hi: &f64, lo: &f64, x: f64) void {
     const split: f64 = 0x1.0p27 + 1.0;
     const xc = x * split;
     const xh = x - xc + xc;
@@ -61,7 +61,7 @@ fn sq(hi: &f64, lo: &f64, x: f64) {
     *lo = xh * xh - *hi + 2 * xh * xl + xl * xl;
 }
 
-fn hypot64(x: f64, y: f64) -> f64 {
+fn hypot64(x: f64, y: f64) f64 {
     var ux = @bitCast(u64, x);
     var uy = @bitCast(u64, y);
 

std/math/ilogb.zig

@@ -8,7 +8,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn ilogb(x: var) -> i32 {
+pub fn ilogb(x: var) i32 {
     const T = @typeOf(x);
     return switch (T) {
         f32 => ilogb32(x),
@@ -21,7 +21,7 @@ pub fn ilogb(x: var) -> i32 {
 const fp_ilogbnan = -1 - i32(@maxValue(u32) >> 1);
 const fp_ilogb0 = fp_ilogbnan;
 
-fn ilogb32(x: f32) -> i32 {
+fn ilogb32(x: f32) i32 {
     var u = @bitCast(u32, x);
     var e = i32((u >> 23) & 0xFF);
 
@@ -57,7 +57,7 @@ fn ilogb32(x: f32) -> i32 {
     return e - 0x7F;
 }
 
-fn ilogb64(x: f64) -> i32 {
+fn ilogb64(x: f64) i32 {
     var u = @bitCast(u64, x);
     var e = i32((u >> 52) & 0x7FF);
 

std/math/index.zig

@@ -35,13 +35,13 @@ pub const nan = @import("nan.zig").nan;
 pub const snan = @import("nan.zig").snan;
 pub const inf = @import("inf.zig").inf;
 
-pub fn approxEq(comptime T: type, x: T, y: T, epsilon: T) -> bool {
+pub fn approxEq(comptime T: type, x: T, y: T, epsilon: T) bool {
     assert(@typeId(T) == TypeId.Float);
     return fabs(x - y) < epsilon;
 }
 
 // TODO: Hide the following in an internal module.
-pub fn forceEval(value: var) {
+pub fn forceEval(value: var) void {
     const T = @typeOf(value);
     switch (T) {
         f32 => {
@@ -60,23 +60,23 @@ pub fn forceEval(value: var) {
     }
 }
 
-pub fn raiseInvalid() {
+pub fn raiseInvalid() void {
     // Raise INVALID fpu exception
 }
 
-pub fn raiseUnderflow() {
+pub fn raiseUnderflow() void {
     // Raise UNDERFLOW fpu exception
 }
 
-pub fn raiseOverflow() {
+pub fn raiseOverflow() void {
     // Raise OVERFLOW fpu exception
 }
 
-pub fn raiseInexact() {
+pub fn raiseInexact() void {
     // Raise INEXACT fpu exception
 }
 
-pub fn raiseDivByZero() {
+pub fn raiseDivByZero() void {
     // Raise INEXACT fpu exception
 }
 
@@ -175,7 +175,7 @@ test "math" {
 }
 
 
-pub fn min(x: var, y: var) -> @typeOf(x + y) {
+pub fn min(x: var, y: var) @typeOf(x + y) {
     return if (x < y) x else y;
 }
 
@@ -183,7 +183,7 @@ test "math.min" {
     assert(min(i32(-1), i32(2)) == -1);
 }
 
-pub fn max(x: var, y: var) -> @typeOf(x + y) {
+pub fn max(x: var, y: var) @typeOf(x + y) {
     return if (x > y) x else y;
 }
 
@@ -192,36 +192,36 @@ test "math.max" {
 }
 
 error Overflow;
-pub fn mul(comptime T: type, a: T, b: T) -> %T {
+pub fn mul(comptime T: type, a: T, b: T) %T {
     var answer: T = undefined;
     return if (@mulWithOverflow(T, a, b, &answer)) error.Overflow else answer;
 }
 
 error Overflow;
-pub fn add(comptime T: type, a: T, b: T) -> %T {
+pub fn add(comptime T: type, a: T, b: T) %T {
     var answer: T = undefined;
     return if (@addWithOverflow(T, a, b, &answer)) error.Overflow else answer;
 }
 
 error Overflow;
-pub fn sub(comptime T: type, a: T, b: T) -> %T {
+pub fn sub(comptime T: type, a: T, b: T) %T {
     var answer: T = undefined;
     return if (@subWithOverflow(T, a, b, &answer)) error.Overflow else answer;
 }
 
-pub fn negate(x: var) -> %@typeOf(x) {
+pub fn negate(x: var) %@typeOf(x) {
     return sub(@typeOf(x), 0, x);
 }
 
 error Overflow;
-pub fn shlExact(comptime T: type, a: T, shift_amt: Log2Int(T)) -> %T {
+pub fn shlExact(comptime T: type, a: T, shift_amt: Log2Int(T)) %T {
     var answer: T = undefined;
     return if (@shlWithOverflow(T, a, shift_amt, &answer)) error.Overflow else answer;
 }
 
 /// Shifts left. Overflowed bits are truncated.
 /// A negative shift amount results in a right shift.
-pub fn shl(comptime T: type, a: T, shift_amt: var) -> T {
+pub fn shl(comptime T: type, a: T, shift_amt: var) T {
     const abs_shift_amt = absCast(shift_amt);
     const casted_shift_amt = if (abs_shift_amt >= T.bit_count) return 0 else Log2Int(T)(abs_shift_amt);
 
@@ -245,7 +245,7 @@ test "math.shl" {
 
 /// Shifts right. Overflowed bits are truncated.
 /// A negative shift amount results in a lefft shift.
-pub fn shr(comptime T: type, a: T, shift_amt: var) -> T {
+pub fn shr(comptime T: type, a: T, shift_amt: var) T {
     const abs_shift_amt = absCast(shift_amt);
     const casted_shift_amt = if (abs_shift_amt >= T.bit_count) return 0 else Log2Int(T)(abs_shift_amt);
 
@@ -269,7 +269,7 @@ test "math.shr" {
 
 /// Rotates right. Only unsigned values can be rotated.
 /// Negative shift values results in shift modulo the bit count.
-pub fn rotr(comptime T: type, x: T, r: var) -> T {
+pub fn rotr(comptime T: type, x: T, r: var) T {
     if (T.is_signed) {
         @compileError("cannot rotate signed integer");
     } else {
@@ -288,7 +288,7 @@ test "math.rotr" {
 
 /// Rotates left. Only unsigned values can be rotated.
 /// Negative shift values results in shift modulo the bit count.
-pub fn rotl(comptime T: type, x: T, r: var) -> T {
+pub fn rotl(comptime T: type, x: T, r: var) T {
     if (T.is_signed) {
         @compileError("cannot rotate signed integer");
     } else {
@@ -306,7 +306,7 @@ test "math.rotl" {
 }
 
 
-pub fn Log2Int(comptime T: type) -> type {
+pub fn Log2Int(comptime T: type) type {
     return @IntType(false, log2(T.bit_count));
 }
 
@@ -315,7 +315,7 @@ test "math overflow functions" {
     comptime testOverflow();
 }
 
-fn testOverflow() {
+fn testOverflow() void {
     assert((mul(i32, 3, 4) catch unreachable) == 12);
     assert((add(i32, 3, 4) catch unreachable) == 7);
     assert((sub(i32, 3, 4) catch unreachable) == -1);
@@ -324,7 +324,7 @@ fn testOverflow() {
 
 
 error Overflow;
-pub fn absInt(x: var) -> %@typeOf(x) {
+pub fn absInt(x: var) %@typeOf(x) {
     const T = @typeOf(x);
     comptime assert(@typeId(T) == builtin.TypeId.Int); // must pass an integer to absInt
     comptime assert(T.is_signed); // must pass a signed integer to absInt
@@ -340,7 +340,7 @@ test "math.absInt" {
     testAbsInt();
     comptime testAbsInt();
 }
-fn testAbsInt() {
+fn testAbsInt() void {
     assert((absInt(i32(-10)) catch unreachable) == 10);
     assert((absInt(i32(10)) catch unreachable) == 10);
 }
@@ -349,7 +349,7 @@ pub const absFloat = @import("fabs.zig").fabs;
 
 error DivisionByZero;
 error Overflow;
-pub fn divTrunc(comptime T: type, numerator: T, denominator: T) -> %T {
+pub fn divTrunc(comptime T: type, numerator: T, denominator: T) %T {
     @setRuntimeSafety(false);
     if (denominator == 0)
         return error.DivisionByZero;
@@ -362,7 +362,7 @@ test "math.divTrunc" {
     testDivTrunc();
     comptime testDivTrunc();
 }
-fn testDivTrunc() {
+fn testDivTrunc() void {
     assert((divTrunc(i32, 5, 3) catch unreachable) == 1);
     assert((divTrunc(i32, -5, 3) catch unreachable) == -1);
     if (divTrunc(i8, -5, 0)) |_| unreachable else |err| assert(err == error.DivisionByZero);
@@ -374,7 +374,7 @@ fn testDivTrunc() {
 
 error DivisionByZero;
 error Overflow;
-pub fn divFloor(comptime T: type, numerator: T, denominator: T) -> %T {
+pub fn divFloor(comptime T: type, numerator: T, denominator: T) %T {
     @setRuntimeSafety(false);
     if (denominator == 0)
         return error.DivisionByZero;
@@ -387,7 +387,7 @@ test "math.divFloor" {
     testDivFloor();
     comptime testDivFloor();
 }
-fn testDivFloor() {
+fn testDivFloor() void {
     assert((divFloor(i32, 5, 3) catch unreachable) == 1);
     assert((divFloor(i32, -5, 3) catch unreachable) == -2);
     if (divFloor(i8, -5, 0)) |_| unreachable else |err| assert(err == error.DivisionByZero);
@@ -400,7 +400,7 @@ fn testDivFloor() {
 error DivisionByZero;
 error Overflow;
 error UnexpectedRemainder;
-pub fn divExact(comptime T: type, numerator: T, denominator: T) -> %T {
+pub fn divExact(comptime T: type, numerator: T, denominator: T) %T {
     @setRuntimeSafety(false);
     if (denominator == 0)
         return error.DivisionByZero;
@@ -416,7 +416,7 @@ test "math.divExact" {
     testDivExact();
     comptime testDivExact();
 }
-fn testDivExact() {
+fn testDivExact() void {
     assert((divExact(i32, 10, 5) catch unreachable) == 2);
     assert((divExact(i32, -10, 5) catch unreachable) == -2);
     if (divExact(i8, -5, 0)) |_| unreachable else |err| assert(err == error.DivisionByZero);
@@ -430,7 +430,7 @@ fn testDivExact() {
 
 error DivisionByZero;
 error NegativeDenominator;
-pub fn mod(comptime T: type, numerator: T, denominator: T) -> %T {
+pub fn mod(comptime T: type, numerator: T, denominator: T) %T {
     @setRuntimeSafety(false);
     if (denominator == 0)
         return error.DivisionByZero;
@@ -443,7 +443,7 @@ test "math.mod" {
     testMod();
     comptime testMod();
 }
-fn testMod() {
+fn testMod() void {
     assert((mod(i32, -5, 3) catch unreachable) == 1);
     assert((mod(i32, 5, 3) catch unreachable) == 2);
     if (mod(i32, 10, -1)) |_| unreachable else |err| assert(err == error.NegativeDenominator);
@@ -457,7 +457,7 @@ fn testMod() {
 
 error DivisionByZero;
 error NegativeDenominator;
-pub fn rem(comptime T: type, numerator: T, denominator: T) -> %T {
+pub fn rem(comptime T: type, numerator: T, denominator: T) %T {
     @setRuntimeSafety(false);
     if (denominator == 0)
         return error.DivisionByZero;
@@ -470,7 +470,7 @@ test "math.rem" {
     testRem();
     comptime testRem();
 }
-fn testRem() {
+fn testRem() void {
     assert((rem(i32, -5, 3) catch unreachable) == -2);
     assert((rem(i32, 5, 3) catch unreachable) == 2);
     if (rem(i32, 10, -1)) |_| unreachable else |err| assert(err == error.NegativeDenominator);
@@ -484,7 +484,7 @@ fn testRem() {
 
 /// Returns the absolute value of the integer parameter.
 /// Result is an unsigned integer.
-pub fn absCast(x: var) -> @IntType(false, @typeOf(x).bit_count) {
+pub fn absCast(x: var) @IntType(false, @typeOf(x).bit_count) {
     const uint = @IntType(false, @typeOf(x).bit_count);
     if (x >= 0)
         return uint(x);
@@ -506,7 +506,7 @@ test "math.absCast" {
 /// Returns the negation of the integer parameter.
 /// Result is a signed integer.
 error Overflow;
-pub fn negateCast(x: var) -> %@IntType(true, @typeOf(x).bit_count) {
+pub fn negateCast(x: var) %@IntType(true, @typeOf(x).bit_count) {
     if (@typeOf(x).is_signed)
         return negate(x);
 
@@ -533,7 +533,7 @@ test "math.negateCast" {
 /// Cast an integer to a different integer type. If the value doesn't fit, 
 /// return an error.
 error Overflow;
-pub fn cast(comptime T: type, x: var) -> %T {
+pub fn cast(comptime T: type, x: var) %T {
     comptime assert(@typeId(T) == builtin.TypeId.Int); // must pass an integer
     if (x > @maxValue(T)) {
         return error.Overflow;
@@ -542,7 +542,7 @@ pub fn cast(comptime T: type, x: var) -> %T {
     }
 }
 
-pub fn floorPowerOfTwo(comptime T: type, value: T) -> T {
+pub fn floorPowerOfTwo(comptime T: type, value: T) T {
     var x = value;
 
     comptime var i = 1;
@@ -558,7 +558,7 @@ test "math.floorPowerOfTwo" {
     comptime testFloorPowerOfTwo();
 }
 
-fn testFloorPowerOfTwo() {
+fn testFloorPowerOfTwo() void {
     assert(floorPowerOfTwo(u32, 63) == 32);
     assert(floorPowerOfTwo(u32, 64) == 64);
     assert(floorPowerOfTwo(u32, 65) == 64);

std/math/inf.zig

@@ -2,7 +2,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn inf(comptime T: type) -> T {
+pub fn inf(comptime T: type) T {
     return switch (T) {
         f32 => @bitCast(f32, math.inf_u32),
         f64 => @bitCast(f64, math.inf_u64),

std/math/isfinite.zig

@@ -2,7 +2,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn isFinite(x: var) -> bool {
+pub fn isFinite(x: var) bool {
     const T = @typeOf(x);
     switch (T) {
         f32 => {

std/math/isinf.zig

@@ -2,7 +2,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn isInf(x: var) -> bool {
+pub fn isInf(x: var) bool {
     const T = @typeOf(x);
     switch (T) {
         f32 => {
@@ -19,7 +19,7 @@ pub fn isInf(x: var) -> bool {
     }
 }
 
-pub fn isPositiveInf(x: var) -> bool {
+pub fn isPositiveInf(x: var) bool {
     const T = @typeOf(x);
     switch (T) {
         f32 => {
@@ -34,7 +34,7 @@ pub fn isPositiveInf(x: var) -> bool {
     }
 }
 
-pub fn isNegativeInf(x: var) -> bool {
+pub fn isNegativeInf(x: var) bool {
     const T = @typeOf(x);
     switch (T) {
         f32 => {

std/math/isnan.zig

@@ -2,7 +2,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn isNan(x: var) -> bool {
+pub fn isNan(x: var) bool {
     const T = @typeOf(x);
     switch (T) {
         f32 => {
@@ -21,7 +21,7 @@ pub fn isNan(x: var) -> bool {
 
 // Note: A signalling nan is identical to a standard right now by may have a different bit
 // representation in the future when required.
-pub fn isSignalNan(x: var) -> bool {
+pub fn isSignalNan(x: var) bool {
     return isNan(x);
 }
 

std/math/isnormal.zig

@@ -2,7 +2,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn isNormal(x: var) -> bool {
+pub fn isNormal(x: var) bool {
     const T = @typeOf(x);
     switch (T) {
         f32 => {

std/math/ln.zig

@@ -11,7 +11,7 @@ const assert = std.debug.assert;
 const builtin = @import("builtin");
 const TypeId = builtin.TypeId;
 
-pub fn ln(x: var) -> @typeOf(x) {
+pub fn ln(x: var) @typeOf(x) {
     const T = @typeOf(x);
     switch (@typeId(T)) {
         TypeId.FloatLiteral => {
@@ -34,7 +34,7 @@ pub fn ln(x: var) -> @typeOf(x) {
     }
 }
 
-pub fn ln_32(x_: f32) -> f32 {
+pub fn ln_32(x_: f32) f32 {
     @setFloatMode(this, @import("builtin").FloatMode.Strict);
 
     const ln2_hi: f32 = 6.9313812256e-01;
@@ -88,7 +88,7 @@ pub fn ln_32(x_: f32) -> f32 {
     return s * (hfsq + R) + dk * ln2_lo - hfsq + f + dk * ln2_hi;
 }
 
-pub fn ln_64(x_: f64) -> f64 {
+pub fn ln_64(x_: f64) f64 {
     const ln2_hi: f64 = 6.93147180369123816490e-01;
     const ln2_lo: f64 = 1.90821492927058770002e-10;
     const Lg1: f64 = 6.666666666666735130e-01;

std/math/log.zig

@@ -4,7 +4,7 @@ const builtin = @import("builtin");
 const TypeId = builtin.TypeId;
 const assert = std.debug.assert;
 
-pub fn log(comptime T: type, base: T, x: T) -> T {
+pub fn log(comptime T: type, base: T, x: T) T {
     if (base == 2) {
         return math.log2(x);
     } else if (base == 10) {

std/math/log10.zig

@@ -11,7 +11,7 @@ const assert = std.debug.assert;
 const builtin = @import("builtin");
 const TypeId = builtin.TypeId;
 
-pub fn log10(x: var) -> @typeOf(x) {
+pub fn log10(x: var) @typeOf(x) {
     const T = @typeOf(x);
     switch (@typeId(T)) {
         TypeId.FloatLiteral => {
@@ -34,7 +34,7 @@ pub fn log10(x: var) -> @typeOf(x) {
     }
 }
 
-pub fn log10_32(x_: f32) -> f32 {
+pub fn log10_32(x_: f32) f32 {
     const ivln10hi: f32  =  4.3432617188e-01;
     const ivln10lo: f32  = -3.1689971365e-05;
     const log10_2hi: f32 =  3.0102920532e-01;
@@ -94,7 +94,7 @@ pub fn log10_32(x_: f32) -> f32 {
     return dk * log10_2lo + (lo + hi) * ivln10lo + lo * ivln10hi + hi * ivln10hi + dk * log10_2hi;
 }
 
-pub fn log10_64(x_: f64) -> f64 {
+pub fn log10_64(x_: f64) f64 {
     const ivln10hi: f64  = 4.34294481878168880939e-01;
     const ivln10lo: f64  = 2.50829467116452752298e-11;
     const log10_2hi: f64 = 3.01029995663611771306e-01;

std/math/log1p.zig

@@ -10,7 +10,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn log1p(x: var) -> @typeOf(x) {
+pub fn log1p(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => log1p_32(x),
@@ -19,7 +19,7 @@ pub fn log1p(x: var) -> @typeOf(x) {
     };
 }
 
-fn log1p_32(x: f32) -> f32 {
+fn log1p_32(x: f32) f32 {
     const ln2_hi = 6.9313812256e-01;
     const ln2_lo = 9.0580006145e-06;
     const Lg1: f32 = 0xaaaaaa.0p-24;
@@ -95,7 +95,7 @@ fn log1p_32(x: f32) -> f32 {
     return s * (hfsq + R) + (dk * ln2_lo + c) - hfsq + f + dk * ln2_hi;
 }
 
-fn log1p_64(x: f64) -> f64 {
+fn log1p_64(x: f64) f64 {
     const ln2_hi: f64 = 6.93147180369123816490e-01;
     const ln2_lo: f64 = 1.90821492927058770002e-10;
     const Lg1: f64 = 6.666666666666735130e-01;

std/math/log2.zig

@@ -11,7 +11,7 @@ const assert = std.debug.assert;
 const builtin = @import("builtin");
 const TypeId = builtin.TypeId;
 
-pub fn log2(x: var) -> @typeOf(x) {
+pub fn log2(x: var) @typeOf(x) {
     const T = @typeOf(x);
     switch (@typeId(T)) {
         TypeId.FloatLiteral => {
@@ -37,12 +37,12 @@ pub fn log2(x: var) -> @typeOf(x) {
     }
 }
 
-pub fn log2_int(comptime T: type, x: T) -> T {
+pub fn log2_int(comptime T: type, x: T) T {
     assert(x != 0);
     return T.bit_count - 1 - T(@clz(x));
 }
 
-pub fn log2_32(x_: f32) -> f32 {
+pub fn log2_32(x_: f32) f32 {
     const ivln2hi: f32 =  1.4428710938e+00;
     const ivln2lo: f32 = -1.7605285393e-04;
     const Lg1: f32 = 0xaaaaaa.0p-24;
@@ -98,7 +98,7 @@ pub fn log2_32(x_: f32) -> f32 {
     return (lo + hi) * ivln2lo + lo * ivln2hi + hi * ivln2hi + f32(k);
 }
 
-pub fn log2_64(x_: f64) -> f64 {
+pub fn log2_64(x_: f64) f64 {
     const ivln2hi: f64 = 1.44269504072144627571e+00;
     const ivln2lo: f64 = 1.67517131648865118353e-10;
     const Lg1: f64 = 6.666666666666735130e-01;

std/math/modf.zig

@@ -7,7 +7,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-fn modf_result(comptime T: type) -> type {
+fn modf_result(comptime T: type) type {
     return struct {
         fpart: T,
         ipart: T,
@@ -16,7 +16,7 @@ fn modf_result(comptime T: type) -> type {
 pub const modf32_result = modf_result(f32);
 pub const modf64_result = modf_result(f64);
 
-pub fn modf(x: var) -> modf_result(@typeOf(x)) {
+pub fn modf(x: var) modf_result(@typeOf(x)) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => modf32(x),
@@ -25,7 +25,7 @@ pub fn modf(x: var) -> modf_result(@typeOf(x)) {
     };
 }
 
-fn modf32(x: f32) -> modf32_result {
+fn modf32(x: f32) modf32_result {
     var result: modf32_result = undefined;
 
     const u = @bitCast(u32, x);
@@ -70,7 +70,7 @@ fn modf32(x: f32) -> modf32_result {
     return result;
 }
 
-fn modf64(x: f64) -> modf64_result {
+fn modf64(x: f64) modf64_result {
     var result: modf64_result = undefined;
 
     const u = @bitCast(u64, x);

std/math/nan.zig

@@ -1,6 +1,6 @@
 const math = @import("index.zig");
 
-pub fn nan(comptime T: type) -> T {
+pub fn nan(comptime T: type) T {
     return switch (T) {
         f32 => @bitCast(f32, math.nan_u32),
         f64 => @bitCast(f64, math.nan_u64),
@@ -10,7 +10,7 @@ pub fn nan(comptime T: type) -> T {
 
 // Note: A signalling nan is identical to a standard right now by may have a different bit
 // representation in the future when required.
-pub fn snan(comptime T: type) -> T {
+pub fn snan(comptime T: type) T {
     return switch (T) {
         f32 => @bitCast(f32, math.nan_u32),
         f64 => @bitCast(f64, math.nan_u64),

std/math/pow.zig

@@ -27,7 +27,7 @@ const math = std.math;
 const assert = std.debug.assert;
 
 // This implementation is taken from the go stlib, musl is a bit more complex.
-pub fn pow(comptime T: type, x: T, y: T) -> T {
+pub fn pow(comptime T: type, x: T, y: T) T {
 
     @setFloatMode(this, @import("builtin").FloatMode.Strict);
 
@@ -170,7 +170,7 @@ pub fn pow(comptime T: type, x: T, y: T) -> T {
     return math.scalbn(a1, ae);
 }
 
-fn isOddInteger(x: f64) -> bool {
+fn isOddInteger(x: f64) bool {
     const r = math.modf(x);
     return r.fpart == 0.0 and i64(r.ipart) & 1 == 1;
 }

std/math/round.zig

@@ -9,7 +9,7 @@ const assert = std.debug.assert;
 const std = @import("../index.zig");
 const math = std.math;
 
-pub fn round(x: var) -> @typeOf(x) {
+pub fn round(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => round32(x),
@@ -18,7 +18,7 @@ pub fn round(x: var) -> @typeOf(x) {
     };
 }
 
-fn round32(x_: f32) -> f32 {
+fn round32(x_: f32) f32 {
     var x = x_;
     const u = @bitCast(u32, x);
     const e = (u >> 23) & 0xFF;
@@ -55,7 +55,7 @@ fn round32(x_: f32) -> f32 {
     }
 }
 
-fn round64(x_: f64) -> f64 {
+fn round64(x_: f64) f64 {
     var x = x_;
     const u = @bitCast(u64, x);
     const e = (u >> 52) & 0x7FF;

std/math/scalbn.zig

@@ -2,7 +2,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn scalbn(x: var, n: i32) -> @typeOf(x) {
+pub fn scalbn(x: var, n: i32) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => scalbn32(x, n),
@@ -11,7 +11,7 @@ pub fn scalbn(x: var, n: i32) -> @typeOf(x) {
     };
 }
 
-fn scalbn32(x: f32, n_: i32) -> f32 {
+fn scalbn32(x: f32, n_: i32) f32 {
     var y = x;
     var n = n_;
 
@@ -41,7 +41,7 @@ fn scalbn32(x: f32, n_: i32) -> f32 {
     return y * @bitCast(f32, u);
 }
 
-fn scalbn64(x: f64, n_: i32) -> f64 {
+fn scalbn64(x: f64, n_: i32) f64 {
     var y = x;
     var n = n_;
 

std/math/signbit.zig

@@ -2,7 +2,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn signbit(x: var) -> bool {
+pub fn signbit(x: var) bool {
     const T = @typeOf(x);
     return switch (T) {
         f32 => signbit32(x),
@@ -11,12 +11,12 @@ pub fn signbit(x: var) -> bool {
     };
 }
 
-fn signbit32(x: f32) -> bool {
+fn signbit32(x: f32) bool {
     const bits = @bitCast(u32, x);
     return bits >> 31 != 0;
 }
 
-fn signbit64(x: f64) -> bool {
+fn signbit64(x: f64) bool {
     const bits = @bitCast(u64, x);
     return bits >> 63 != 0;
 }

std/math/sin.zig

@@ -9,7 +9,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn sin(x: var) -> @typeOf(x) {
+pub fn sin(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => sin32(x),
@@ -37,7 +37,7 @@ const C5 =  4.16666666666665929218E-2;
 // NOTE: This is taken from the go stdlib. The musl implementation is much more complex.
 //
 // This may have slight differences on some edge cases and may need to replaced if so.
-fn sin32(x_: f32) -> f32 {
+fn sin32(x_: f32) f32 {
     @setFloatMode(this, @import("builtin").FloatMode.Strict);
 
     const pi4a = 7.85398125648498535156e-1;
@@ -91,7 +91,7 @@ fn sin32(x_: f32) -> f32 {
     }
 }
 
-fn sin64(x_: f64) -> f64 {
+fn sin64(x_: f64) f64 {
     const pi4a = 7.85398125648498535156e-1;
     const pi4b = 3.77489470793079817668E-8;
     const pi4c = 2.69515142907905952645E-15;

std/math/sinh.zig

@@ -10,7 +10,7 @@ const math = std.math;
 const assert = std.debug.assert;
 const expo2 = @import("expo2.zig").expo2;
 
-pub fn sinh(x: var) -> @typeOf(x) {
+pub fn sinh(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => sinh32(x),
@@ -22,7 +22,7 @@ pub fn sinh(x: var) -> @typeOf(x) {
 // sinh(x) = (exp(x) - 1 / exp(x)) / 2
 //         = (exp(x) - 1 + (exp(x) - 1) / exp(x)) / 2
 //         = x + x^3 / 6 + o(x^5)
-fn sinh32(x: f32) -> f32 {
+fn sinh32(x: f32) f32 {
     const u = @bitCast(u32, x);
     const ux = u & 0x7FFFFFFF;
     const ax = @bitCast(f32, ux);
@@ -53,7 +53,7 @@ fn sinh32(x: f32) -> f32 {
     return 2 * h * expo2(ax);
 }
 
-fn sinh64(x: f64) -> f64 {
+fn sinh64(x: f64) f64 {
     @setFloatMode(this, @import("builtin").FloatMode.Strict);
 
     const u = @bitCast(u64, x);

std/math/sqrt.zig

@@ -11,7 +11,7 @@ const assert = std.debug.assert;
 const builtin = @import("builtin");
 const TypeId = builtin.TypeId;
 
-pub fn sqrt(x: var) -> (if (@typeId(@typeOf(x)) == TypeId.Int) @IntType(false, @typeOf(x).bit_count / 2) else @typeOf(x)) {
+pub fn sqrt(x: var) (if (@typeId(@typeOf(x)) == TypeId.Int) @IntType(false, @typeOf(x).bit_count / 2) else @typeOf(x)) {
     const T = @typeOf(x);
     switch (@typeId(T)) {
         TypeId.FloatLiteral => {
@@ -50,7 +50,7 @@ pub fn sqrt(x: var) -> (if (@typeId(@typeOf(x)) == TypeId.Int) @IntType(false, @
     }
 }
 
-fn sqrt32(x: f32) -> f32 {
+fn sqrt32(x: f32) f32 {
     const tiny: f32 = 1.0e-30;
     const sign: i32 = @bitCast(i32, u32(0x80000000));
     var ix: i32 = @bitCast(i32, x);
@@ -129,7 +129,7 @@ fn sqrt32(x: f32) -> f32 {
 // NOTE: The original code is full of implicit signed -> unsigned assumptions and u32 wraparound
 // behaviour. Most intermediate i32 values are changed to u32 where appropriate but there are
 // potentially some edge cases remaining that are not handled in the same way.
-fn sqrt64(x: f64) -> f64 {
+fn sqrt64(x: f64) f64 {
     const tiny: f64 = 1.0e-300;
     const sign: u32 = 0x80000000;
     const u = @bitCast(u64, x);
@@ -308,7 +308,7 @@ test "math.sqrt64.special" {
     assert(math.isNan(sqrt64(math.nan(f64))));
 }
 
-fn sqrt_int(comptime T: type, value: T) -> @IntType(false, T.bit_count / 2) {
+fn sqrt_int(comptime T: type, value: T) @IntType(false, T.bit_count / 2) {
     var op = value;
     var res: T = 0;
     var one: T = 1 << (T.bit_count - 2);

std/math/tan.zig

@@ -9,7 +9,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn tan(x: var) -> @typeOf(x) {
+pub fn tan(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => tan32(x),
@@ -30,7 +30,7 @@ const Tq4 = -5.38695755929454629881E7;
 // NOTE: This is taken from the go stdlib. The musl implementation is much more complex.
 //
 // This may have slight differences on some edge cases and may need to replaced if so.
-fn tan32(x_: f32) -> f32 {
+fn tan32(x_: f32) f32 {
     @setFloatMode(this, @import("builtin").FloatMode.Strict);
 
     const pi4a = 7.85398125648498535156e-1;
@@ -81,7 +81,7 @@ fn tan32(x_: f32) -> f32 {
     return r;
 }
 
-fn tan64(x_: f64) -> f64 {
+fn tan64(x_: f64) f64 {
     const pi4a = 7.85398125648498535156e-1;
     const pi4b = 3.77489470793079817668E-8;
     const pi4c = 2.69515142907905952645E-15;

std/math/tanh.zig

@@ -10,7 +10,7 @@ const math = std.math;
 const assert = std.debug.assert;
 const expo2 = @import("expo2.zig").expo2;
 
-pub fn tanh(x: var) -> @typeOf(x) {
+pub fn tanh(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => tanh32(x),
@@ -22,7 +22,7 @@ pub fn tanh(x: var) -> @typeOf(x) {
 // tanh(x) = (exp(x) - exp(-x)) / (exp(x) + exp(-x))
 //         = (exp(2x) - 1) / (exp(2x) - 1 + 2)
 //         = (1 - exp(-2x)) / (exp(-2x) - 1 + 2)
-fn tanh32(x: f32) -> f32 {
+fn tanh32(x: f32) f32 {
     const u = @bitCast(u32, x);
     const ux = u & 0x7FFFFFFF;
     const ax = @bitCast(f32, ux);
@@ -66,7 +66,7 @@ fn tanh32(x: f32) -> f32 {
     }
 }
 
-fn tanh64(x: f64) -> f64 {
+fn tanh64(x: f64) f64 {
     const u = @bitCast(u64, x);
     const w = u32(u >> 32);
     const ax = @bitCast(f64, u & (@maxValue(u64) >> 1));

std/math/trunc.zig

@@ -8,7 +8,7 @@ const std = @import("../index.zig");
 const math = std.math;
 const assert = std.debug.assert;
 
-pub fn trunc(x: var) -> @typeOf(x) {
+pub fn trunc(x: var) @typeOf(x) {
     const T = @typeOf(x);
     return switch (T) {
         f32 => trunc32(x),
@@ -17,7 +17,7 @@ pub fn trunc(x: var) -> @typeOf(x) {
     };
 }
 
-fn trunc32(x: f32) -> f32 {
+fn trunc32(x: f32) f32 {
     const u = @bitCast(u32, x);
     var e = i32(((u >> 23) & 0xFF)) - 0x7F + 9;
     var m: u32 = undefined;
@@ -38,7 +38,7 @@ fn trunc32(x: f32) -> f32 {
     }
 }
 
-fn trunc64(x: f64) -> f64 {
+fn trunc64(x: f64) f64 {
     const u = @bitCast(u64, x);
     var e = i32(((u >> 52) & 0x7FF)) - 0x3FF + 12;
     var m: u64 = undefined;

std/math/x86_64/sqrt.zig

@@ -1,4 +1,4 @@
-pub fn sqrt32(x: f32) -> f32 {
+pub fn sqrt32(x: f32) f32 {
     return asm (
         \\sqrtss %%xmm0, %%xmm0
         : [ret] "={xmm0}" (-> f32)
@@ -6,7 +6,7 @@ pub fn sqrt32(x: f32) -> f32 {
     );
 }
 
-pub fn sqrt64(x: f64) -> f64 {
+pub fn sqrt64(x: f64) f64 {
     return asm (
         \\sqrtsd %%xmm0, %%xmm0
         : [ret] "={xmm0}" (-> f64)

std/mem.zig

@@ -10,7 +10,7 @@ pub const Allocator = struct {
     /// Allocate byte_count bytes and return them in a slice, with the
     /// slice's pointer aligned at least to alignment bytes.
     /// The returned newly allocated memory is undefined.
-    allocFn: fn (self: &Allocator, byte_count: usize, alignment: u29) -> %[]u8,
+    allocFn: fn (self: &Allocator, byte_count: usize, alignment: u29) %[]u8,
 
     /// If `new_byte_count > old_mem.len`:
     /// * `old_mem.len` is the same as what was returned from allocFn or reallocFn.
@@ -21,26 +21,26 @@ pub const Allocator = struct {
     /// * alignment <= alignment of old_mem.ptr
     ///
     /// The returned newly allocated memory is undefined.
-    reallocFn: fn (self: &Allocator, old_mem: []u8, new_byte_count: usize, alignment: u29) -> %[]u8,
+    reallocFn: fn (self: &Allocator, old_mem: []u8, new_byte_count: usize, alignment: u29) %[]u8,
 
     /// Guaranteed: `old_mem.len` is the same as what was returned from `allocFn` or `reallocFn`
-    freeFn: fn (self: &Allocator, old_mem: []u8),
+    freeFn: fn (self: &Allocator, old_mem: []u8) void,
 
-    fn create(self: &Allocator, comptime T: type) -> %&T {
+    fn create(self: &Allocator, comptime T: type) %&T {
         const slice = try self.alloc(T, 1);
         return &slice[0];
     }
 
-    fn destroy(self: &Allocator, ptr: var) {
+    fn destroy(self: &Allocator, ptr: var) void {
         self.free(ptr[0..1]);
     }
 
-    fn alloc(self: &Allocator, comptime T: type, n: usize) -> %[]T {
+    fn alloc(self: &Allocator, comptime T: type, n: usize) %[]T {
         return self.alignedAlloc(T, @alignOf(T), n);
     }
 
     fn alignedAlloc(self: &Allocator, comptime T: type, comptime alignment: u29,
-        n: usize) -> %[]align(alignment) T
+        n: usize) %[]align(alignment) T
     {
         const byte_count = try math.mul(usize, @sizeOf(T), n);
         const byte_slice = try self.allocFn(self, byte_count, alignment);
@@ -51,12 +51,12 @@ pub const Allocator = struct {
         return ([]align(alignment) T)(@alignCast(alignment, byte_slice));
     }
 
-    fn realloc(self: &Allocator, comptime T: type, old_mem: []T, n: usize) -> %[]T {
+    fn realloc(self: &Allocator, comptime T: type, old_mem: []T, n: usize) %[]T {
         return self.alignedRealloc(T, @alignOf(T), @alignCast(@alignOf(T), old_mem), n);
     }
 
     fn alignedRealloc(self: &Allocator, comptime T: type, comptime alignment: u29,
-        old_mem: []align(alignment) T, n: usize) -> %[]align(alignment) T
+        old_mem: []align(alignment) T, n: usize) %[]align(alignment) T
     {
         if (old_mem.len == 0) {
             return self.alloc(T, n);
@@ -75,12 +75,12 @@ pub const Allocator = struct {
     /// Reallocate, but `n` must be less than or equal to `old_mem.len`.
     /// Unlike `realloc`, this function cannot fail.
     /// Shrinking to 0 is the same as calling `free`.
-    fn shrink(self: &Allocator, comptime T: type, old_mem: []T, n: usize) -> []T {
+    fn shrink(self: &Allocator, comptime T: type, old_mem: []T, n: usize) []T {
         return self.alignedShrink(T, @alignOf(T), @alignCast(@alignOf(T), old_mem), n);
     }
 
     fn alignedShrink(self: &Allocator, comptime T: type, comptime alignment: u29,
-        old_mem: []align(alignment) T, n: usize) -> []align(alignment) T
+        old_mem: []align(alignment) T, n: usize) []align(alignment) T
     {
         if (n == 0) {
             self.free(old_mem);
@@ -97,7 +97,7 @@ pub const Allocator = struct {
         return ([]align(alignment) T)(@alignCast(alignment, byte_slice));
     }
 
-    fn free(self: &Allocator, memory: var) {
+    fn free(self: &Allocator, memory: var) void {
         const bytes = ([]const u8)(memory);
         if (bytes.len == 0)
             return;
@@ -111,7 +111,7 @@ pub const FixedBufferAllocator = struct {
     end_index: usize,
     buffer: []u8,
 
-    pub fn init(buffer: []u8) -> FixedBufferAllocator {
+    pub fn init(buffer: []u8) FixedBufferAllocator {
         return FixedBufferAllocator {
             .allocator = Allocator {
                 .allocFn = alloc,
@@ -123,7 +123,7 @@ pub const FixedBufferAllocator = struct {
         };
     }
 
-    fn alloc(allocator: &Allocator, n: usize, alignment: u29) -> %[]u8 {
+    fn alloc(allocator: &Allocator, n: usize, alignment: u29) %[]u8 {
         const self = @fieldParentPtr(FixedBufferAllocator, "allocator", allocator);
         const addr = @ptrToInt(&self.buffer[self.end_index]);
         const rem = @rem(addr, alignment);
@@ -138,7 +138,7 @@ pub const FixedBufferAllocator = struct {
         return result;
     }
 
-    fn realloc(allocator: &Allocator, old_mem: []u8, new_size: usize, alignment: u29) -> %[]u8 {
+    fn realloc(allocator: &Allocator, old_mem: []u8, new_size: usize, alignment: u29) %[]u8 {
         if (new_size <= old_mem.len) {
             return old_mem[0..new_size];
         } else {
@@ -148,13 +148,13 @@ pub const FixedBufferAllocator = struct {
         }
     }
 
-    fn free(allocator: &Allocator, bytes: []u8) { }
+    fn free(allocator: &Allocator, bytes: []u8) void { }
 };
 
 
 /// Copy all of source into dest at position 0.
 /// dest.len must be >= source.len.
-pub fn copy(comptime T: type, dest: []T, source: []const T) {
+pub fn copy(comptime T: type, dest: []T, source: []const T) void {
     // TODO instead of manually doing this check for the whole array
     // and turning off runtime safety, the compiler should detect loops like
     // this and automatically omit safety checks for loops
@@ -163,12 +163,12 @@ pub fn copy(comptime T: type, dest: []T, source: []const T) {
     for (source) |s, i| dest[i] = s;
 }
 
-pub fn set(comptime T: type, dest: []T, value: T) {
+pub fn set(comptime T: type, dest: []T, value: T) void {
     for (dest) |*d| *d = value;
 }
 
 /// Returns true if lhs < rhs, false otherwise
-pub fn lessThan(comptime T: type, lhs: []const T, rhs: []const T) -> bool {
+pub fn lessThan(comptime T: type, lhs: []const T, rhs: []const T) bool {
     const n = math.min(lhs.len, rhs.len);
     var i: usize = 0;
     while (i < n) : (i += 1) {
@@ -188,7 +188,7 @@ test "mem.lessThan" {
 }
 
 /// Compares two slices and returns whether they are equal.
-pub fn eql(comptime T: type, a: []const T, b: []const T) -> bool {
+pub fn eql(comptime T: type, a: []const T, b: []const T) bool {
     if (a.len != b.len) return false;
     for (a) |item, index| {
         if (b[index] != item) return false;
@@ -197,14 +197,14 @@ pub fn eql(comptime T: type, a: []const T, b: []const T) -> bool {
 }
 
 /// Copies ::m to newly allocated memory. Caller is responsible to free it.
-pub fn dupe(allocator: &Allocator, comptime T: type, m: []const T) -> %[]T {
+pub fn dupe(allocator: &Allocator, comptime T: type, m: []const T) %[]T {
     const new_buf = try allocator.alloc(T, m.len);
     copy(T, new_buf, m);
     return new_buf;
 }
 
 /// Remove values from the beginning and end of a slice.
-pub fn trim(comptime T: type, slice: []const T, values_to_strip: []const T) -> []const T {
+pub fn trim(comptime T: type, slice: []const T, values_to_strip: []const T) []const T {
     var begin: usize = 0;
     var end: usize = slice.len;
     while (begin < end and indexOfScalar(T, values_to_strip, slice[begin]) != null) : (begin += 1) {}
@@ -218,11 +218,11 @@ test "mem.trim" {
 }
 
 /// Linear search for the index of a scalar value inside a slice.
-pub fn indexOfScalar(comptime T: type, slice: []const T, value: T) -> ?usize {
+pub fn indexOfScalar(comptime T: type, slice: []const T, value: T) ?usize {
     return indexOfScalarPos(T, slice, 0, value);
 }
 
-pub fn indexOfScalarPos(comptime T: type, slice: []const T, start_index: usize, value: T) -> ?usize {
+pub fn indexOfScalarPos(comptime T: type, slice: []const T, start_index: usize, value: T) ?usize {
     var i: usize = start_index;
     while (i < slice.len) : (i += 1) {
         if (slice[i] == value)
@@ -231,11 +231,11 @@ pub fn indexOfScalarPos(comptime T: type, slice: []const T, start_index: usize,
     return null;
 }
 
-pub fn indexOfAny(comptime T: type, slice: []const T, values: []const T) -> ?usize {
+pub fn indexOfAny(comptime T: type, slice: []const T, values: []const T) ?usize {
     return indexOfAnyPos(T, slice, 0, values);
 }
 
-pub fn indexOfAnyPos(comptime T: type, slice: []const T, start_index: usize, values: []const T) -> ?usize {
+pub fn indexOfAnyPos(comptime T: type, slice: []const T, start_index: usize, values: []const T) ?usize {
     var i: usize = start_index;
     while (i < slice.len) : (i += 1) {
         for (values) |value| {
@@ -246,12 +246,12 @@ pub fn indexOfAnyPos(comptime T: type, slice: []const T, start_index: usize, val
     return null;
 }
 
-pub fn indexOf(comptime T: type, haystack: []const T, needle: []const T) -> ?usize {
+pub fn indexOf(comptime T: type, haystack: []const T, needle: []const T) ?usize {
     return indexOfPos(T, haystack, 0, needle);
 }
 
 // TODO boyer-moore algorithm
-pub fn indexOfPos(comptime T: type, haystack: []const T, start_index: usize, needle: []const T) -> ?usize {
+pub fn indexOfPos(comptime T: type, haystack: []const T, start_index: usize, needle: []const T) ?usize {
     if (needle.len > haystack.len)
         return null;
 
@@ -275,7 +275,7 @@ test "mem.indexOf" {
 /// T specifies the return type, which must be large enough to store
 /// the result.
 /// See also ::readIntBE or ::readIntLE.
-pub fn readInt(bytes: []const u8, comptime T: type, endian: builtin.Endian) -> T {
+pub fn readInt(bytes: []const u8, comptime T: type, endian: builtin.Endian) T {
     if (T.bit_count == 8) {
         return bytes[0];
     }
@@ -298,7 +298,7 @@ pub fn readInt(bytes: []const u8, comptime T: type, endian: builtin.Endian) -> T
 
 /// Reads a big-endian int of type T from bytes.
 /// bytes.len must be exactly @sizeOf(T).
-pub fn readIntBE(comptime T: type, bytes: []const u8) -> T {
+pub fn readIntBE(comptime T: type, bytes: []const u8) T {
     if (T.is_signed) {
         return @bitCast(T, readIntBE(@IntType(false, T.bit_count), bytes));
     }
@@ -312,7 +312,7 @@ pub fn readIntBE(comptime T: type, bytes: []const u8) -> T {
 
 /// Reads a little-endian int of type T from bytes.
 /// bytes.len must be exactly @sizeOf(T).
-pub fn readIntLE(comptime T: type, bytes: []const u8) -> T {
+pub fn readIntLE(comptime T: type, bytes: []const u8) T {
     if (T.is_signed) {
         return @bitCast(T, readIntLE(@IntType(false, T.bit_count), bytes));
     }
@@ -327,7 +327,7 @@ pub fn readIntLE(comptime T: type, bytes: []const u8) -> T {
 /// Writes an integer to memory with size equal to bytes.len. Pads with zeroes
 /// to fill the entire buffer provided.
 /// value must be an integer.
-pub fn writeInt(buf: []u8, value: var, endian: builtin.Endian) {
+pub fn writeInt(buf: []u8, value: var, endian: builtin.Endian) void {
     const uint = @IntType(false, @typeOf(value).bit_count);
     var bits = @truncate(uint, value);
     switch (endian) {
@@ -351,7 +351,7 @@ pub fn writeInt(buf: []u8, value: var, endian: builtin.Endian) {
 }
 
 
-pub fn hash_slice_u8(k: []const u8) -> u32 {
+pub fn hash_slice_u8(k: []const u8) u32 {
     // FNV 32-bit hash
     var h: u32 = 2166136261;
     for (k) |b| {
@@ -360,7 +360,7 @@ pub fn hash_slice_u8(k: []const u8) -> u32 {
     return h;
 }
 
-pub fn eql_slice_u8(a: []const u8, b: []const u8) -> bool {
+pub fn eql_slice_u8(a: []const u8, b: []const u8) bool {
     return eql(u8, a, b);
 }
 
@@ -368,7 +368,7 @@ pub fn eql_slice_u8(a: []const u8, b: []const u8) -> bool {
 /// any of the bytes in `split_bytes`.
 /// split("   abc def    ghi  ", " ")
 /// Will return slices for "abc", "def", "ghi", null, in that order.
-pub fn split(buffer: []const u8, split_bytes: []const u8) -> SplitIterator {
+pub fn split(buffer: []const u8, split_bytes: []const u8) SplitIterator {
     return SplitIterator {
         .index = 0,
         .buffer = buffer,
@@ -384,7 +384,7 @@ test "mem.split" {
     assert(it.next() == null);
 }
 
-pub fn startsWith(comptime T: type, haystack: []const T, needle: []const T) -> bool {
+pub fn startsWith(comptime T: type, haystack: []const T, needle: []const T) bool {
     return if (needle.len > haystack.len) false else eql(T, haystack[0 .. needle.len], needle);
 }
 
@@ -393,7 +393,7 @@ const SplitIterator = struct {
     split_bytes: []const u8, 
     index: usize,
 
-    pub fn next(self: &SplitIterator) -> ?[]const u8 {
+    pub fn next(self: &SplitIterator) ?[]const u8 {
         // move to beginning of token
         while (self.index < self.buffer.len and self.isSplitByte(self.buffer[self.index])) : (self.index += 1) {}
         const start = self.index;
@@ -409,14 +409,14 @@ const SplitIterator = struct {
     }
 
     /// Returns a slice of the remaining bytes. Does not affect iterator state.
-    pub fn rest(self: &const SplitIterator) -> []const u8 {
+    pub fn rest(self: &const SplitIterator) []const u8 {
         // move to beginning of token
         var index: usize = self.index;
         while (index < self.buffer.len and self.isSplitByte(self.buffer[index])) : (index += 1) {}
         return self.buffer[index..];
     }
 
-    fn isSplitByte(self: &const SplitIterator, byte: u8) -> bool {
+    fn isSplitByte(self: &const SplitIterator, byte: u8) bool {
         for (self.split_bytes) |split_byte| {
             if (byte == split_byte) {
                 return true;
@@ -428,7 +428,7 @@ const SplitIterator = struct {
 
 /// Naively combines a series of strings with a separator.
 /// Allocates memory for the result, which must be freed by the caller.
-pub fn join(allocator: &Allocator, sep: u8, strings: ...) -> %[]u8 {
+pub fn join(allocator: &Allocator, sep: u8, strings: ...) %[]u8 {
     comptime assert(strings.len >= 1);
     var total_strings_len: usize = strings.len; // 1 sep per string
     {
@@ -474,7 +474,7 @@ test "testReadInt" {
     testReadIntImpl();
     comptime testReadIntImpl();
 }
-fn testReadIntImpl() {
+fn testReadIntImpl() void {
     {
         const bytes = []u8{ 0x12, 0x34, 0x56, 0x78 };
         assert(readInt(bytes, u32, builtin.Endian.Big)  == 0x12345678);
@@ -507,7 +507,7 @@ test "testWriteInt" {
     testWriteIntImpl();
     comptime testWriteIntImpl();
 }
-fn testWriteIntImpl() {
+fn testWriteIntImpl() void {
     var bytes: [4]u8 = undefined;
 
     writeInt(bytes[0..], u32(0x12345678), builtin.Endian.Big);
@@ -524,7 +524,7 @@ fn testWriteIntImpl() {
 }
 
 
-pub fn min(comptime T: type, slice: []const T) -> T {
+pub fn min(comptime T: type, slice: []const T) T {
     var best = slice[0];
     for (slice[1..]) |item| {
         best = math.min(best, item);
@@ -536,7 +536,7 @@ test "mem.min" {
     assert(min(u8, "abcdefg") == 'a');
 }
 
-pub fn max(comptime T: type, slice: []const T) -> T {
+pub fn max(comptime T: type, slice: []const T) T {
     var best = slice[0];
     for (slice[1..]) |item| {
         best = math.max(best, item);
@@ -548,14 +548,14 @@ test "mem.max" {
     assert(max(u8, "abcdefg") == 'g');
 }
 
-pub fn swap(comptime T: type, a: &T, b: &T) {
+pub fn swap(comptime T: type, a: &T, b: &T) void {
     const tmp = *a;
     *a = *b;
     *b = tmp;
 }
 
 /// In-place order reversal of a slice
-pub fn reverse(comptime T: type, items: []T) {
+pub fn reverse(comptime T: type, items: []T) void {
     var i: usize = 0;
     const end = items.len / 2;
     while (i < end) : (i += 1) {
@@ -572,7 +572,7 @@ test "std.mem.reverse" {
 
 /// In-place rotation of the values in an array ([0 1 2 3] becomes [1 2 3 0] if we rotate by 1)
 /// Assumes 0 <= amount <= items.len
-pub fn rotate(comptime T: type, items: []T, amount: usize) {
+pub fn rotate(comptime T: type, items: []T, amount: usize) void {
     reverse(T, items[0..amount]);
     reverse(T, items[amount..]);
     reverse(T, items);

std/net.zig

@@ -17,7 +17,7 @@ error BadFd;
 const Connection = struct {
     socket_fd: i32,
 
-    pub fn send(c: Connection, buf: []const u8) -> %usize {
+    pub fn send(c: Connection, buf: []const u8) %usize {
         const send_ret = linux.sendto(c.socket_fd, buf.ptr, buf.len, 0, null, 0);
         const send_err = linux.getErrno(send_ret);
         switch (send_err) {
@@ -31,7 +31,7 @@ const Connection = struct {
         }
     }
 
-    pub fn recv(c: Connection, buf: []u8) -> %[]u8 {
+    pub fn recv(c: Connection, buf: []u8) %[]u8 {
         const recv_ret = linux.recvfrom(c.socket_fd, buf.ptr, buf.len, 0, null, null);
         const recv_err = linux.getErrno(recv_ret);
         switch (recv_err) {
@@ -48,7 +48,7 @@ const Connection = struct {
         }
     }
 
-    pub fn close(c: Connection) -> %void {
+    pub fn close(c: Connection) %void {
         switch (linux.getErrno(linux.close(c.socket_fd))) {
             0 => return,
             linux.EBADF => unreachable,
@@ -66,7 +66,7 @@ const Address = struct {
     sort_key: i32,
 };
 
-pub fn lookup(hostname: []const u8, out_addrs: []Address) -> %[]Address {
+pub fn lookup(hostname: []const u8, out_addrs: []Address) %[]Address {
     if (hostname.len == 0) {
 
         unreachable; // TODO
@@ -75,7 +75,7 @@ pub fn lookup(hostname: []const u8, out_addrs: []Address) -> %[]Address {
     unreachable; // TODO
 }
 
-pub fn connectAddr(addr: &Address, port: u16) -> %Connection {
+pub fn connectAddr(addr: &Address, port: u16) %Connection {
     const socket_ret = linux.socket(addr.family, linux.SOCK_STREAM, linux.PROTO_tcp);
     const socket_err = linux.getErrno(socket_ret);
     if (socket_err > 0) {
@@ -118,7 +118,7 @@ pub fn connectAddr(addr: &Address, port: u16) -> %Connection {
     };
 }
 
-pub fn connect(hostname: []const u8, port: u16) -> %Connection {
+pub fn connect(hostname: []const u8, port: u16) %Connection {
     var addrs_buf: [1]Address = undefined;
     const addrs_slice = try lookup(hostname, addrs_buf[0..]);
     const main_addr = &addrs_slice[0];
@@ -128,12 +128,12 @@ pub fn connect(hostname: []const u8, port: u16) -> %Connection {
 
 error InvalidIpLiteral;
 
-pub fn parseIpLiteral(buf: []const u8) -> %Address {
+pub fn parseIpLiteral(buf: []const u8) %Address {
 
     return error.InvalidIpLiteral;
 }
 
-fn hexDigit(c: u8) -> u8 {
+fn hexDigit(c: u8) u8 {
     // TODO use switch with range
     if ('0' <= c and c <= '9') {
         return c - '0';
@@ -151,7 +151,7 @@ error Overflow;
 error JunkAtEnd;
 error Incomplete;
 
-fn parseIp6(buf: []const u8) -> %Address {
+fn parseIp6(buf: []const u8) %Address {
     var result: Address = undefined;
     result.family = linux.AF_INET6;
     result.scope_id = 0;
@@ -232,7 +232,7 @@ fn parseIp6(buf: []const u8) -> %Address {
     return error.Incomplete;
 }
 
-fn parseIp4(buf: []const u8) -> %u32 {
+fn parseIp4(buf: []const u8) %u32 {
     var result: u32 = undefined;
     const out_ptr = ([]u8)((&result)[0..1]);