Reduce use of deprecated IO types

Related: #4917

doc/docgen.zig

@@ -40,9 +40,9 @@ pub fn main() !void {
     var out_file = try fs.cwd().createFile(out_file_name, .{});
     defer out_file.close();
 
-    const input_file_bytes = try in_file.inStream().readAllAlloc(allocator, max_doc_file_size);
+    const input_file_bytes = try in_file.reader().readAllAlloc(allocator, max_doc_file_size);
 
-    var buffered_out_stream = io.bufferedOutStream(out_file.writer());
+    var buffered_writer = io.bufferedWriter(out_file.writer());
 
     var tokenizer = Tokenizer.init(in_file_name, input_file_bytes);
     var toc = try genToc(allocator, &tokenizer);
@@ -50,8 +50,8 @@ pub fn main() !void {
     try fs.cwd().makePath(tmp_dir_name);
     defer fs.cwd().deleteTree(tmp_dir_name) catch {};
 
-    try genHtml(allocator, &tokenizer, &toc, buffered_out_stream.writer(), zig_exe);
+    try genHtml(allocator, &tokenizer, &toc, buffered_writer.writer(), zig_exe);
-    try buffered_out_stream.flush();
+    try buffered_writer.flush();
 }
 
 const Token = struct {

lib/std/Progress.zig

@@ -271,7 +271,7 @@ fn refreshWithHeldLock(self: *Progress) void {
 pub fn log(self: *Progress, comptime format: []const u8, args: anytype) void {
     const file = self.terminal orelse return;
     self.refresh();
-    file.outStream().print(format, args) catch {
+    file.writer().print(format, args) catch {
         self.terminal = null;
         return;
     };

lib/std/atomic/queue.zig

@@ -122,7 +122,7 @@ pub fn Queue(comptime T: type) type {
 
         /// Dumps the contents of the queue to `stderr`.
         pub fn dump(self: *Self) void {
-            self.dumpToStream(std.io.getStdErr().outStream()) catch return;
+            self.dumpToStream(std.io.getStdErr().writer()) catch return;
         }
 
         /// Dumps the contents of the queue to `stream`.
@@ -351,7 +351,7 @@ test "std.atomic.Queue dump" {
 
     // Test empty stream
     fbs.reset();
-    try queue.dumpToStream(fbs.outStream());
+    try queue.dumpToStream(fbs.writer());
     expect(mem.eql(u8, buffer[0..fbs.pos],
         \\head: (null)
         \\tail: (null)
@@ -367,7 +367,7 @@ test "std.atomic.Queue dump" {
     queue.put(&node_0);
 
     fbs.reset();
-    try queue.dumpToStream(fbs.outStream());
+    try queue.dumpToStream(fbs.writer());
 
     var expected = try std.fmt.bufPrint(expected_buffer[0..],
         \\head: 0x{x}=1
@@ -387,7 +387,7 @@ test "std.atomic.Queue dump" {
     queue.put(&node_1);
 
     fbs.reset();
-    try queue.dumpToStream(fbs.outStream());
+    try queue.dumpToStream(fbs.writer());
 
     expected = try std.fmt.bufPrint(expected_buffer[0..],
         \\head: 0x{x}=1

lib/std/build.zig

@@ -1042,7 +1042,7 @@ pub const Builder = struct {
 
         try child.spawn();
 
-        const stdout = try child.stdout.?.inStream().readAllAlloc(self.allocator, max_output_size);
+        const stdout = try child.stdout.?.reader().readAllAlloc(self.allocator, max_output_size);
         errdefer self.allocator.free(stdout);
 
         const term = try child.wait();
@@ -1849,7 +1849,7 @@ pub const LibExeObjStep = struct {
     }
 
     pub fn addBuildOption(self: *LibExeObjStep, comptime T: type, name: []const u8, value: T) void {
-        const out = self.build_options_contents.outStream();
+        const out = self.build_options_contents.writer();
         switch (T) {
             []const []const u8 => {
                 out.print("pub const {z}: []const []const u8 = &[_][]const u8{{\n", .{name}) catch unreachable;
@@ -2295,16 +2295,16 @@ pub const LibExeObjStep = struct {
             } else {
                 var mcpu_buffer = std.ArrayList(u8).init(builder.allocator);
 
-                try mcpu_buffer.outStream().print("-mcpu={s}", .{cross.cpu.model.name});
+                try mcpu_buffer.writer().print("-mcpu={s}", .{cross.cpu.model.name});
 
                 for (all_features) |feature, i_usize| {
                     const i = @intCast(std.Target.Cpu.Feature.Set.Index, i_usize);
                     const in_cpu_set = populated_cpu_features.isEnabled(i);
                     const in_actual_set = cross.cpu.features.isEnabled(i);
                     if (in_cpu_set and !in_actual_set) {
-                        try mcpu_buffer.outStream().print("-{s}", .{feature.name});
+                        try mcpu_buffer.writer().print("-{s}", .{feature.name});
                     } else if (!in_cpu_set and in_actual_set) {
-                        try mcpu_buffer.outStream().print("+{s}", .{feature.name});
+                        try mcpu_buffer.writer().print("+{s}", .{feature.name});
                     }
                 }
 

lib/std/build/run.zig

@@ -200,7 +200,7 @@ pub const RunStep = struct {
 
         switch (self.stdout_action) {
             .expect_exact, .expect_matches => {
-                stdout = child.stdout.?.inStream().readAllAlloc(self.builder.allocator, max_stdout_size) catch unreachable;
+                stdout = child.stdout.?.reader().readAllAlloc(self.builder.allocator, max_stdout_size) catch unreachable;
             },
             .inherit, .ignore => {},
         }
@@ -210,7 +210,7 @@ pub const RunStep = struct {
 
         switch (self.stderr_action) {
             .expect_exact, .expect_matches => {
-                stderr = child.stderr.?.inStream().readAllAlloc(self.builder.allocator, max_stdout_size) catch unreachable;
+                stderr = child.stderr.?.reader().readAllAlloc(self.builder.allocator, max_stdout_size) catch unreachable;
             },
             .inherit, .ignore => {},
         }

lib/std/child_process.zig

@@ -922,7 +922,7 @@ fn writeIntFd(fd: i32, value: ErrInt) !void {
         .capable_io_mode = .blocking,
         .intended_io_mode = .blocking,
     };
-    file.outStream().writeIntNative(u64, @intCast(u64, value)) catch return error.SystemResources;
+    file.writer().writeIntNative(u64, @intCast(u64, value)) catch return error.SystemResources;
 }
 
 fn readIntFd(fd: i32) !ErrInt {

lib/std/coff.zig

@@ -127,7 +127,7 @@ pub const Coff = struct {
     pub fn loadHeader(self: *Coff) !void {
         const pe_pointer_offset = 0x3C;
 
-        const in = self.in_file.inStream();
+        const in = self.in_file.reader();
 
         var magic: [2]u8 = undefined;
         try in.readNoEof(magic[0..]);
@@ -163,7 +163,7 @@ pub const Coff = struct {
     }
 
     fn loadOptionalHeader(self: *Coff) !void {
-        const in = self.in_file.inStream();
+        const in = self.in_file.reader();
         self.pe_header.magic = try in.readIntLittle(u16);
         // For now we're only interested in finding the reference to the .pdb,
         // so we'll skip most of this header, which size is different in 32
@@ -206,7 +206,7 @@ pub const Coff = struct {
         const debug_dir = &self.pe_header.data_directory[DEBUG_DIRECTORY];
         const file_offset = debug_dir.virtual_address - header.virtual_address + header.pointer_to_raw_data;
 
-        const in = self.in_file.inStream();
+        const in = self.in_file.reader();
         try self.in_file.seekTo(file_offset);
 
         // Find the correct DebugDirectoryEntry, and where its data is stored.
@@ -257,7 +257,7 @@ pub const Coff = struct {
 
         try self.sections.ensureCapacity(self.coff_header.number_of_sections);
 
-        const in = self.in_file.inStream();
+        const in = self.in_file.reader();
 
         var name: [8]u8 = undefined;
 

lib/std/crypto/benchmark.zig

@@ -314,7 +314,7 @@ fn mode(comptime x: comptime_int) comptime_int {
 }
 
 pub fn main() !void {
-    const stdout = std.io.getStdOut().outStream();
+    const stdout = std.io.getStdOut().writer();
 
     var buffer: [1024]u8 = undefined;
     var fixed = std.heap.FixedBufferAllocator.init(buffer[0..]);

lib/std/debug.zig

@@ -517,15 +517,15 @@ fn populateModule(di: *ModuleDebugInfo, mod: *Module) !void {
 
     const modi = di.pdb.getStreamById(mod.mod_info.ModuleSymStream) orelse return error.MissingDebugInfo;
 
-    const signature = try modi.inStream().readIntLittle(u32);
+    const signature = try modi.reader().readIntLittle(u32);
     if (signature != 4)
         return error.InvalidDebugInfo;
 
     mod.symbols = try allocator.alloc(u8, mod.mod_info.SymByteSize - 4);
-    try modi.inStream().readNoEof(mod.symbols);
+    try modi.reader().readNoEof(mod.symbols);
 
     mod.subsect_info = try allocator.alloc(u8, mod.mod_info.C13ByteSize);
-    try modi.inStream().readNoEof(mod.subsect_info);
+    try modi.reader().readNoEof(mod.subsect_info);
 
     var sect_offset: usize = 0;
     var skip_len: usize = undefined;
@@ -704,11 +704,11 @@ fn readCoffDebugInfo(allocator: *mem.Allocator, coff_file: File) !ModuleDebugInf
         try di.pdb.openFile(di.coff, path);
 
         var pdb_stream = di.pdb.getStream(pdb.StreamType.Pdb) orelse return error.InvalidDebugInfo;
-        const version = try pdb_stream.inStream().readIntLittle(u32);
+        const version = try pdb_stream.reader().readIntLittle(u32);
-        const signature = try pdb_stream.inStream().readIntLittle(u32);
+        const signature = try pdb_stream.reader().readIntLittle(u32);
-        const age = try pdb_stream.inStream().readIntLittle(u32);
+        const age = try pdb_stream.reader().readIntLittle(u32);
         var guid: [16]u8 = undefined;
-        try pdb_stream.inStream().readNoEof(&guid);
+        try pdb_stream.reader().readNoEof(&guid);
         if (version != 20000404) // VC70, only value observed by LLVM team
             return error.UnknownPDBVersion;
         if (!mem.eql(u8, &di.coff.guid, &guid) or di.coff.age != age)
@@ -716,9 +716,9 @@ fn readCoffDebugInfo(allocator: *mem.Allocator, coff_file: File) !ModuleDebugInf
         // We validated the executable and pdb match.
 
         const string_table_index = str_tab_index: {
-            const name_bytes_len = try pdb_stream.inStream().readIntLittle(u32);
+            const name_bytes_len = try pdb_stream.reader().readIntLittle(u32);
             const name_bytes = try allocator.alloc(u8, name_bytes_len);
-            try pdb_stream.inStream().readNoEof(name_bytes);
+            try pdb_stream.reader().readNoEof(name_bytes);
 
             const HashTableHeader = packed struct {
                 Size: u32,
@@ -728,17 +728,17 @@ fn readCoffDebugInfo(allocator: *mem.Allocator, coff_file: File) !ModuleDebugInf
                     return cap * 2 / 3 + 1;
                 }
             };
-            const hash_tbl_hdr = try pdb_stream.inStream().readStruct(HashTableHeader);
+            const hash_tbl_hdr = try pdb_stream.reader().readStruct(HashTableHeader);
             if (hash_tbl_hdr.Capacity == 0)
                 return error.InvalidDebugInfo;
 
             if (hash_tbl_hdr.Size > HashTableHeader.maxLoad(hash_tbl_hdr.Capacity))
                 return error.InvalidDebugInfo;
 
-            const present = try readSparseBitVector(&pdb_stream.inStream(), allocator);
+            const present = try readSparseBitVector(&pdb_stream.reader(), allocator);
             if (present.len != hash_tbl_hdr.Size)
                 return error.InvalidDebugInfo;
-            const deleted = try readSparseBitVector(&pdb_stream.inStream(), allocator);
+            const deleted = try readSparseBitVector(&pdb_stream.reader(), allocator);
 
             const Bucket = struct {
                 first: u32,
@@ -746,8 +746,8 @@ fn readCoffDebugInfo(allocator: *mem.Allocator, coff_file: File) !ModuleDebugInf
             };
             const bucket_list = try allocator.alloc(Bucket, present.len);
             for (present) |_| {
-                const name_offset = try pdb_stream.inStream().readIntLittle(u32);
+                const name_offset = try pdb_stream.reader().readIntLittle(u32);
-                const name_index = try pdb_stream.inStream().readIntLittle(u32);
+                const name_index = try pdb_stream.reader().readIntLittle(u32);
                 const name = mem.spanZ(std.meta.assumeSentinel(name_bytes.ptr + name_offset, 0));
                 if (mem.eql(u8, name, "/names")) {
                     break :str_tab_index name_index;
@@ -762,7 +762,7 @@ fn readCoffDebugInfo(allocator: *mem.Allocator, coff_file: File) !ModuleDebugInf
         const dbi = di.pdb.dbi;
 
         // Dbi Header
-        const dbi_stream_header = try dbi.inStream().readStruct(pdb.DbiStreamHeader);
+        const dbi_stream_header = try dbi.reader().readStruct(pdb.DbiStreamHeader);
         if (dbi_stream_header.VersionHeader != 19990903) // V70, only value observed by LLVM team
             return error.UnknownPDBVersion;
         if (dbi_stream_header.Age != age)
@@ -776,7 +776,7 @@ fn readCoffDebugInfo(allocator: *mem.Allocator, coff_file: File) !ModuleDebugInf
         // Module Info Substream
         var mod_info_offset: usize = 0;
         while (mod_info_offset != mod_info_size) {
-            const mod_info = try dbi.inStream().readStruct(pdb.ModInfo);
+            const mod_info = try dbi.reader().readStruct(pdb.ModInfo);
             var this_record_len: usize = @sizeOf(pdb.ModInfo);
 
             const module_name = try dbi.readNullTermString(allocator);
@@ -814,14 +814,14 @@ fn readCoffDebugInfo(allocator: *mem.Allocator, coff_file: File) !ModuleDebugInf
         var sect_contribs = ArrayList(pdb.SectionContribEntry).init(allocator);
         var sect_cont_offset: usize = 0;
         if (section_contrib_size != 0) {
-            const ver = @intToEnum(pdb.SectionContrSubstreamVersion, try dbi.inStream().readIntLittle(u32));
+            const ver = @intToEnum(pdb.SectionContrSubstreamVersion, try dbi.reader().readIntLittle(u32));
             if (ver != pdb.SectionContrSubstreamVersion.Ver60)
                 return error.InvalidDebugInfo;
             sect_cont_offset += @sizeOf(u32);
         }
         while (sect_cont_offset != section_contrib_size) {
             const entry = try sect_contribs.addOne();
-            entry.* = try dbi.inStream().readStruct(pdb.SectionContribEntry);
+            entry.* = try dbi.reader().readStruct(pdb.SectionContribEntry);
             sect_cont_offset += @sizeOf(pdb.SectionContribEntry);
 
             if (sect_cont_offset > section_contrib_size)

lib/std/dwarf.zig

@@ -408,7 +408,7 @@ pub const DwarfInfo = struct {
 
     fn scanAllFunctions(di: *DwarfInfo) !void {
         var stream = io.fixedBufferStream(di.debug_info);
-        const in = &stream.inStream();
+        const in = &stream.reader();
         const seekable = &stream.seekableStream();
         var this_unit_offset: u64 = 0;
 
@@ -512,7 +512,7 @@ pub const DwarfInfo = struct {
 
     fn scanAllCompileUnits(di: *DwarfInfo) !void {
         var stream = io.fixedBufferStream(di.debug_info);
-        const in = &stream.inStream();
+        const in = &stream.reader();
         const seekable = &stream.seekableStream();
         var this_unit_offset: u64 = 0;
 
@@ -585,7 +585,7 @@ pub const DwarfInfo = struct {
             if (di.debug_ranges) |debug_ranges| {
                 if (compile_unit.die.getAttrSecOffset(AT_ranges)) |ranges_offset| {
                     var stream = io.fixedBufferStream(debug_ranges);
-                    const in = &stream.inStream();
+                    const in = &stream.reader();
                     const seekable = &stream.seekableStream();
 
                     // All the addresses in the list are relative to the value
@@ -640,7 +640,7 @@ pub const DwarfInfo = struct {
 
     fn parseAbbrevTable(di: *DwarfInfo, offset: u64) !AbbrevTable {
         var stream = io.fixedBufferStream(di.debug_abbrev);
-        const in = &stream.inStream();
+        const in = &stream.reader();
         const seekable = &stream.seekableStream();
 
         try seekable.seekTo(offset);
@@ -691,7 +691,7 @@ pub const DwarfInfo = struct {
 
     pub fn getLineNumberInfo(di: *DwarfInfo, compile_unit: CompileUnit, target_address: usize) !debug.LineInfo {
         var stream = io.fixedBufferStream(di.debug_line);
-        const in = &stream.inStream();
+        const in = &stream.reader();
         const seekable = &stream.seekableStream();
 
         const compile_unit_cwd = try compile_unit.die.getAttrString(di, AT_comp_dir);

lib/std/heap/logging_allocator.zig

@@ -89,7 +89,7 @@ test "LoggingAllocator" {
 
     var allocator_buf: [10]u8 = undefined;
     var fixedBufferAllocator = std.mem.validationWrap(std.heap.FixedBufferAllocator.init(&allocator_buf));
-    const allocator = &loggingAllocator(&fixedBufferAllocator.allocator, fbs.outStream()).allocator;
+    const allocator = &loggingAllocator(&fixedBufferAllocator.allocator, fbs.writer()).allocator;
 
     var a = try allocator.alloc(u8, 10);
     a = allocator.shrink(a, 5);

lib/std/io/buffered_atomic_file.zig

@@ -38,7 +38,7 @@ pub const BufferedAtomicFile = struct {
         self.atomic_file = try dir.atomicFile(dest_path, atomic_file_options);
         errdefer self.atomic_file.deinit();
 
-        self.file_stream = self.atomic_file.file.outStream();
+        self.file_stream = self.atomic_file.file.writer();
         self.buffered_stream = .{ .unbuffered_writer = self.file_stream };
         return self;
     }

lib/std/io/fixed_buffer_stream.zig

@@ -45,7 +45,7 @@ pub fn FixedBufferStream(comptime Buffer: type) type {
             return .{ .context = self };
         }
 
-        /// Deprecated: use `inStream`
+        /// Deprecated: use `reader`
         pub fn inStream(self: *Self) InStream {
             return .{ .context = self };
         }

lib/std/io/test.zig

@@ -30,8 +30,8 @@ test "write a file, read it, then delete it" {
         var file = try tmp.dir.createFile(tmp_file_name, .{});
         defer file.close();
 
-        var buf_stream = io.bufferedOutStream(file.outStream());
+        var buf_stream = io.bufferedWriter(file.writer());
-        const st = buf_stream.outStream();
+        const st = buf_stream.writer();
         try st.print("begin", .{});
         try st.writeAll(data[0..]);
         try st.print("end", .{});
@@ -72,7 +72,7 @@ test "BitStreams with File Stream" {
         var file = try tmp.dir.createFile(tmp_file_name, .{});
         defer file.close();
 
-        var bit_stream = io.bitOutStream(builtin.endian, file.outStream());
+        var bit_stream = io.bitWriter(builtin.endian, file.writer());
 
         try bit_stream.writeBits(@as(u2, 1), 1);
         try bit_stream.writeBits(@as(u5, 2), 2);

lib/std/json.zig

@@ -1323,31 +1323,31 @@ test "Value.jsonStringify" {
     {
         var buffer: [10]u8 = undefined;
         var fbs = std.io.fixedBufferStream(&buffer);
-        try @as(Value, .Null).jsonStringify(.{}, fbs.outStream());
+        try @as(Value, .Null).jsonStringify(.{}, fbs.writer());
         testing.expectEqualSlices(u8, fbs.getWritten(), "null");
     }
     {
         var buffer: [10]u8 = undefined;
         var fbs = std.io.fixedBufferStream(&buffer);
-        try (Value{ .Bool = true }).jsonStringify(.{}, fbs.outStream());
+        try (Value{ .Bool = true }).jsonStringify(.{}, fbs.writer());
         testing.expectEqualSlices(u8, fbs.getWritten(), "true");
     }
     {
         var buffer: [10]u8 = undefined;
         var fbs = std.io.fixedBufferStream(&buffer);
-        try (Value{ .Integer = 42 }).jsonStringify(.{}, fbs.outStream());
+        try (Value{ .Integer = 42 }).jsonStringify(.{}, fbs.writer());
         testing.expectEqualSlices(u8, fbs.getWritten(), "42");
     }
     {
         var buffer: [10]u8 = undefined;
         var fbs = std.io.fixedBufferStream(&buffer);
-        try (Value{ .Float = 42 }).jsonStringify(.{}, fbs.outStream());
+        try (Value{ .Float = 42 }).jsonStringify(.{}, fbs.writer());
         testing.expectEqualSlices(u8, fbs.getWritten(), "4.2e+01");
     }
     {
         var buffer: [10]u8 = undefined;
         var fbs = std.io.fixedBufferStream(&buffer);
-        try (Value{ .String = "weeee" }).jsonStringify(.{}, fbs.outStream());
+        try (Value{ .String = "weeee" }).jsonStringify(.{}, fbs.writer());
         testing.expectEqualSlices(u8, fbs.getWritten(), "\"weeee\"");
     }
     {
@@ -1360,7 +1360,7 @@ test "Value.jsonStringify" {
         };
         try (Value{
             .Array = Array.fromOwnedSlice(undefined, &vals),
-        }).jsonStringify(.{}, fbs.outStream());
+        }).jsonStringify(.{}, fbs.writer());
         testing.expectEqualSlices(u8, fbs.getWritten(), "[1,2,3]");
     }
     {
@@ -1369,7 +1369,7 @@ test "Value.jsonStringify" {
         var obj = ObjectMap.init(testing.allocator);
         defer obj.deinit();
         try obj.putNoClobber("a", .{ .String = "b" });
-        try (Value{ .Object = obj }).jsonStringify(.{}, fbs.outStream());
+        try (Value{ .Object = obj }).jsonStringify(.{}, fbs.writer());
         testing.expectEqualSlices(u8, fbs.getWritten(), "{\"a\":\"b\"}");
     }
 }
@@ -2223,7 +2223,7 @@ test "write json then parse it" {
     var out_buffer: [1000]u8 = undefined;
 
     var fixed_buffer_stream = std.io.fixedBufferStream(&out_buffer);
-    const out_stream = fixed_buffer_stream.outStream();
+    const out_stream = fixed_buffer_stream.writer();
     var jw = writeStream(out_stream, 4);
 
     try jw.beginObject();

lib/std/json/write_stream.zig

@@ -238,7 +238,7 @@ pub fn writeStream(
 test "json write stream" {
     var out_buf: [1024]u8 = undefined;
     var slice_stream = std.io.fixedBufferStream(&out_buf);
-    const out = slice_stream.outStream();
+    const out = slice_stream.writer();
 
     var arena_allocator = std.heap.ArenaAllocator.init(std.testing.allocator);
     defer arena_allocator.deinit();

lib/std/net.zig

@@ -1106,7 +1106,7 @@ fn linuxLookupNameFromHosts(
     };
     defer file.close();
 
-    const stream = std.io.bufferedInStream(file.inStream()).inStream();
+    const stream = std.io.bufferedReader(file.reader()).reader();
     var line_buf: [512]u8 = undefined;
     while (stream.readUntilDelimiterOrEof(&line_buf, '\n') catch |err| switch (err) {
         error.StreamTooLong => blk: {
@@ -1304,7 +1304,7 @@ fn getResolvConf(allocator: *mem.Allocator, rc: *ResolvConf) !void {
     };
     defer file.close();
 
-    const stream = std.io.bufferedInStream(file.inStream()).inStream();
+    const stream = std.io.bufferedReader(file.reader()).reader();
     var line_buf: [512]u8 = undefined;
     while (stream.readUntilDelimiterOrEof(&line_buf, '\n') catch |err| switch (err) {
         error.StreamTooLong => blk: {

lib/std/net/test.zig

@@ -249,6 +249,6 @@ fn testServer(server: *net.StreamServer) anyerror!void {
 
     var client = try server.accept();
 
-    const stream = client.file.outStream();
+    const stream = client.file.writer();
     try stream.print("hello from server\n", .{});
 }

lib/std/os.zig

@@ -191,7 +191,7 @@ fn getRandomBytesDevURandom(buf: []u8) !void {
         .capable_io_mode = .blocking,
         .intended_io_mode = .blocking,
     };
-    const stream = file.inStream();
+    const stream = file.reader();
     stream.readNoEof(buf) catch return error.Unexpected;
 }
 

lib/std/os/test.zig

@@ -475,7 +475,7 @@ test "mmap" {
         const file = try tmp.dir.createFile(test_out_file, .{});
         defer file.close();
 
-        const stream = file.outStream();
+        const stream = file.writer();
 
         var i: u32 = 0;
         while (i < alloc_size / @sizeOf(u32)) : (i += 1) {
@@ -499,7 +499,7 @@ test "mmap" {
         defer os.munmap(data);
 
         var mem_stream = io.fixedBufferStream(data);
-        const stream = mem_stream.inStream();
+        const stream = mem_stream.reader();
 
         var i: u32 = 0;
         while (i < alloc_size / @sizeOf(u32)) : (i += 1) {
@@ -523,7 +523,7 @@ test "mmap" {
         defer os.munmap(data);
 
         var mem_stream = io.fixedBufferStream(data);
-        const stream = mem_stream.inStream();
+        const stream = mem_stream.reader();
 
         var i: u32 = alloc_size / 2 / @sizeOf(u32);
         while (i < alloc_size / @sizeOf(u32)) : (i += 1) {

lib/std/special/build_runner.zig

@@ -57,8 +57,8 @@ pub fn main() !void {
 
     var targets = ArrayList([]const u8).init(allocator);
 
-    const stderr_stream = io.getStdErr().outStream();
+    const stderr_stream = io.getStdErr().writer();
-    const stdout_stream = io.getStdOut().outStream();
+    const stdout_stream = io.getStdOut().writer();
 
     while (nextArg(args, &arg_idx)) |arg| {
         if (mem.startsWith(u8, arg, "-D")) {

lib/std/unicode/throughput_test.zig

@@ -45,7 +45,7 @@ fn benchmarkCodepointCount(buf: []const u8) !ResultCount {
 }
 
 pub fn main() !void {
-    const stdout = std.io.getStdOut().outStream();
+    const stdout = std.io.getStdOut().writer();
 
     const args = try std.process.argsAlloc(std.heap.page_allocator);
 

lib/std/zig/cross_target.zig

@@ -519,29 +519,29 @@ pub const CrossTarget = struct {
         var result = std.ArrayList(u8).init(allocator);
         defer result.deinit();
 
-        try result.outStream().print("{s}-{s}", .{ arch_name, os_name });
+        try result.writer().print("{s}-{s}", .{ arch_name, os_name });
 
         // The zig target syntax does not allow specifying a max os version with no min, so
         // if either are present, we need the min.
         if (self.os_version_min != null or self.os_version_max != null) {
             switch (self.getOsVersionMin()) {
                 .none => {},
-                .semver => |v| try result.outStream().print(".{}", .{v}),
+                .semver => |v| try result.writer().print(".{}", .{v}),
-                .windows => |v| try result.outStream().print("{s}", .{v}),
+                .windows => |v| try result.writer().print("{s}", .{v}),
             }
         }
         if (self.os_version_max) |max| {
             switch (max) {
                 .none => {},
-                .semver => |v| try result.outStream().print("...{}", .{v}),
+                .semver => |v| try result.writer().print("...{}", .{v}),
-                .windows => |v| try result.outStream().print("..{s}", .{v}),
+                .windows => |v| try result.writer().print("..{s}", .{v}),
             }
         }
 
         if (self.glibc_version) |v| {
-            try result.outStream().print("-{s}.{}", .{ @tagName(self.getAbi()), v });
+            try result.writer().print("-{s}.{}", .{ @tagName(self.getAbi()), v });
         } else if (self.abi) |abi| {
-            try result.outStream().print("-{s}", .{@tagName(abi)});
+            try result.writer().print("-{s}", .{@tagName(abi)});
         }
 
         return result.toOwnedSlice();

lib/std/zig/parser_test.zig

@@ -3734,7 +3734,7 @@ const maxInt = std.math.maxInt;
 var fixed_buffer_mem: [100 * 1024]u8 = undefined;
 
 fn testParse(source: []const u8, allocator: *mem.Allocator, anything_changed: *bool) ![]u8 {
-    const stderr = io.getStdErr().outStream();
+    const stderr = io.getStdErr().writer();
 
     const tree = try std.zig.parse(allocator, source);
     defer tree.deinit();
@@ -3767,8 +3767,8 @@ fn testParse(source: []const u8, allocator: *mem.Allocator, anything_changed: *b
     var buffer = std.ArrayList(u8).init(allocator);
     errdefer buffer.deinit();
 
-    const outStream = buffer.outStream();
+    const writer = buffer.writer();
-    anything_changed.* = try std.zig.render(allocator, outStream, tree);
+    anything_changed.* = try std.zig.render(allocator, writer, tree);
     return buffer.toOwnedSlice();
 }
 fn testTransform(source: []const u8, expected_source: []const u8) !void {

lib/std/zig/perf_test.zig

@@ -29,7 +29,7 @@ pub fn main() !void {
     const mb_per_sec = bytes_per_sec / (1024 * 1024);
 
     var stdout_file = std.io.getStdOut();
-    const stdout = stdout_file.outStream();
+    const stdout = stdout_file.writer();
     try stdout.print("{:.3} MiB/s, {} KiB used \n", .{ mb_per_sec, memory_used / 1024 });
 }
 

lib/std/zig/render.zig

@@ -790,7 +790,7 @@ fn renderExpression(
                         const section_exprs = row_exprs[0..section_end];
 
                         // Null stream for counting the printed length of each expression
-                        var line_find_stream = std.io.findByteOutStream('\n', std.io.null_out_stream);
+                        var line_find_stream = std.io.findByteOutStream('\n', std.io.null_writer);
                         var counting_stream = std.io.countingOutStream(line_find_stream.writer());
                         var auto_indenting_stream = std.io.autoIndentingStream(indent_delta, counting_stream.writer());
 
@@ -954,7 +954,7 @@ fn renderExpression(
             const expr_outputs_one_line = blk: {
                 // render field expressions until a LF is found
                 for (field_inits) |field_init| {
-                    var find_stream = std.io.findByteOutStream('\n', std.io.null_out_stream);
+                    var find_stream = std.io.findByteOutStream('\n', std.io.null_writer);
                     var auto_indenting_stream = std.io.autoIndentingStream(indent_delta, find_stream.writer());
 
                     try renderExpression(allocator, &auto_indenting_stream, tree, field_init, Space.None);

src/Cache.zig

@@ -285,7 +285,7 @@ pub const Manifest = struct {
             };
         }
 
-        const file_contents = try self.manifest_file.?.inStream().readAllAlloc(self.cache.gpa, manifest_file_size_max);
+        const file_contents = try self.manifest_file.?.reader().readAllAlloc(self.cache.gpa, manifest_file_size_max);
         defer self.cache.gpa.free(file_contents);
 
         const input_file_count = self.files.items.len;

src/Compilation.zig

@@ -1820,7 +1820,7 @@ pub fn cImport(comp: *Compilation, c_src: []const u8) !CImportResult {
         var out_zig_file = try o_dir.createFile(cimport_zig_basename, .{});
         defer out_zig_file.close();
 
-        var bos = std.io.bufferedOutStream(out_zig_file.writer());
+        var bos = std.io.bufferedWriter(out_zig_file.writer());
         _ = try std.zig.render(comp.gpa, bos.writer(), tree);
         try bos.flush();
 
@@ -2750,7 +2750,7 @@ pub fn generateBuiltinZigSource(comp: *Compilation, allocator: *Allocator) ![]u8
 
     switch (target.os.getVersionRange()) {
         .none => try buffer.appendSlice(" .none = {} }\n"),
-        .semver => |semver| try buffer.outStream().print(
+        .semver => |semver| try buffer.writer().print(
             \\ .semver = .{{
             \\        .min = .{{
             \\            .major = {},
@@ -2773,7 +2773,7 @@ pub fn generateBuiltinZigSource(comp: *Compilation, allocator: *Allocator) ![]u8
             semver.max.minor,
             semver.max.patch,
         }),
-        .linux => |linux| try buffer.outStream().print(
+        .linux => |linux| try buffer.writer().print(
             \\ .linux = .{{
             \\        .range = .{{
             \\            .min = .{{
@@ -2807,7 +2807,7 @@ pub fn generateBuiltinZigSource(comp: *Compilation, allocator: *Allocator) ![]u8
             linux.glibc.minor,
             linux.glibc.patch,
         }),
-        .windows => |windows| try buffer.outStream().print(
+        .windows => |windows| try buffer.writer().print(
             \\ .windows = .{{
             \\        .min = {s},
             \\        .max = {s},

src/DepTokenizer.zig

@@ -910,7 +910,7 @@ fn depTokenizer(input: []const u8, expect: []const u8) !void {
             },
             else => {
                 try buffer.appendSlice("ERROR: ");
-                try token.printError(buffer.outStream());
+                try token.printError(buffer.writer());
                 break;
             },
         }

src/Module.zig

@@ -1649,7 +1649,7 @@ pub fn getAstTree(self: *Module, root_scope: *Scope.File) !*ast.Tree {
                 var msg = std.ArrayList(u8).init(self.gpa);
                 defer msg.deinit();
 
-                try parse_err.render(tree.token_ids, msg.outStream());
+                try parse_err.render(tree.token_ids, msg.writer());
                 const err_msg = try self.gpa.create(Compilation.ErrorMsg);
                 err_msg.* = .{
                     .msg = msg.toOwnedSlice(),

src/codegen/llvm.zig

@@ -200,7 +200,7 @@ pub const LLVMIRModule = struct {
         if (llvm.Target.getFromTriple(llvm_target_triple.ptr, &target, &error_message)) {
             defer llvm.disposeMessage(error_message);
 
-            const stderr = std.io.getStdErr().outStream();
+            const stderr = std.io.getStdErr().writer();
             try stderr.print(
                 \\Zig is expecting LLVM to understand this target: '{s}'
                 \\However LLVM responded with: "{s}"
@@ -268,7 +268,7 @@ pub const LLVMIRModule = struct {
             const dump = self.llvm_module.printToString();
             defer llvm.disposeMessage(dump);
 
-            const stderr = std.io.getStdErr().outStream();
+            const stderr = std.io.getStdErr().writer();
             try stderr.writeAll(std.mem.spanZ(dump));
         }
 
@@ -278,7 +278,7 @@ pub const LLVMIRModule = struct {
             defer llvm.disposeMessage(error_message);
 
             if (self.llvm_module.verify(.ReturnStatus, &error_message)) {
-                const stderr = std.io.getStdErr().outStream();
+                const stderr = std.io.getStdErr().writer();
                 try stderr.print("broken LLVM module found: {s}\nThis is a bug in the Zig compiler.", .{error_message});
                 return error.BrokenLLVMModule;
             }
@@ -296,7 +296,7 @@ pub const LLVMIRModule = struct {
         )) {
             defer llvm.disposeMessage(error_message);
 
-            const stderr = std.io.getStdErr().outStream();
+            const stderr = std.io.getStdErr().writer();
             try stderr.print("LLVM failed to emit file: {s}\n", .{error_message});
             return error.FailedToEmit;
         }

src/libc_installation.zig

@@ -338,7 +338,7 @@ pub const LibCInstallation = struct {
 
         for (searches) |search| {
             result_buf.shrinkAndFree(0);
-            try result_buf.outStream().print("{s}\\Include\\{s}\\ucrt", .{ search.path, search.version });
+            try result_buf.writer().print("{s}\\Include\\{s}\\ucrt", .{ search.path, search.version });
 
             var dir = fs.cwd().openDir(result_buf.items, .{}) catch |err| switch (err) {
                 error.FileNotFound,
@@ -384,7 +384,7 @@ pub const LibCInstallation = struct {
 
         for (searches) |search| {
             result_buf.shrinkAndFree(0);
-            try result_buf.outStream().print("{s}\\Lib\\{s}\\ucrt\\{s}", .{ search.path, search.version, arch_sub_dir });
+            try result_buf.writer().print("{s}\\Lib\\{s}\\ucrt\\{s}", .{ search.path, search.version, arch_sub_dir });
 
             var dir = fs.cwd().openDir(result_buf.items, .{}) catch |err| switch (err) {
                 error.FileNotFound,
@@ -438,7 +438,7 @@ pub const LibCInstallation = struct {
 
         for (searches) |search| {
             result_buf.shrinkAndFree(0);
-            const stream = result_buf.outStream();
+            const stream = result_buf.writer();
             try stream.print("{s}\\Lib\\{s}\\um\\{s}", .{ search.path, search.version, arch_sub_dir });
 
             var dir = fs.cwd().openDir(result_buf.items, .{}) catch |err| switch (err) {

src/main.zig

@@ -196,7 +196,7 @@ pub fn mainArgs(gpa: *Allocator, arena: *Allocator, args: []const []const u8) !v
         return cmdInit(gpa, arena, cmd_args, .Lib);
     } else if (mem.eql(u8, cmd, "targets")) {
         const info = try detectNativeTargetInfo(arena, .{});
-        const stdout = io.getStdOut().outStream();
+        const stdout = io.getStdOut().writer();
         return @import("print_targets.zig").cmdTargets(arena, cmd_args, stdout, info.target);
     } else if (mem.eql(u8, cmd, "version")) {
         try std.io.getStdOut().writeAll(build_options.version ++ "\n");
@@ -1944,8 +1944,8 @@ fn buildOutputType(
         }
     }
 
-    const stdin = std.io.getStdIn().inStream();
+    const stdin = std.io.getStdIn().reader();
-    const stderr = std.io.getStdErr().outStream();
+    const stderr = std.io.getStdErr().writer();
     var repl_buf: [1024]u8 = undefined;
 
     while (watch) {
@@ -2114,9 +2114,9 @@ fn cmdTranslateC(comp: *Compilation, arena: *Allocator, enable_cache: bool) !voi
         var zig_file = try o_dir.createFile(translated_zig_basename, .{});
         defer zig_file.close();
 
-        var bos = io.bufferedOutStream(zig_file.writer());
+        var bw = io.bufferedWriter(zig_file.writer());
-        _ = try std.zig.render(comp.gpa, bos.writer(), tree);
+        _ = try std.zig.render(comp.gpa, bw.writer(), tree);
-        try bos.flush();
+        try bw.flush();
 
         man.writeManifest() catch |err| warn("failed to write cache manifest: {s}", .{@errorName(err)});
 
@@ -2187,9 +2187,9 @@ pub fn cmdLibC(gpa: *Allocator, args: []const []const u8) !void {
         };
         defer libc.deinit(gpa);
 
-        var bos = io.bufferedOutStream(io.getStdOut().writer());
+        var bw = io.bufferedWriter(io.getStdOut().writer());
-        try libc.render(bos.writer());
+        try libc.render(bw.writer());
-        try bos.flush();
+        try bw.flush();
     }
 }
 
@@ -2570,7 +2570,7 @@ pub fn cmdFmt(gpa: *Allocator, args: []const []const u8) !void {
             const arg = args[i];
             if (mem.startsWith(u8, arg, "-")) {
                 if (mem.eql(u8, arg, "-h") or mem.eql(u8, arg, "--help")) {
-                    const stdout = io.getStdOut().outStream();
+                    const stdout = io.getStdOut().writer();
                     try stdout.writeAll(usage_fmt);
                     return cleanExit();
                 } else if (mem.eql(u8, arg, "--color")) {
@@ -2600,7 +2600,7 @@ pub fn cmdFmt(gpa: *Allocator, args: []const []const u8) !void {
             fatal("cannot use --stdin with positional arguments", .{});
         }
 
-        const stdin = io.getStdIn().inStream();
+        const stdin = io.getStdIn().reader();
 
         const source_code = try stdin.readAllAlloc(gpa, max_src_size);
         defer gpa.free(source_code);
@@ -2617,14 +2617,14 @@ pub fn cmdFmt(gpa: *Allocator, args: []const []const u8) !void {
             process.exit(1);
         }
         if (check_flag) {
-            const anything_changed = try std.zig.render(gpa, io.null_out_stream, tree);
+            const anything_changed = try std.zig.render(gpa, io.null_writer, tree);
             const code = if (anything_changed) @as(u8, 1) else @as(u8, 0);
             process.exit(code);
         }
 
-        var bos = io.bufferedOutStream(io.getStdOut().writer());
+        var bw = io.bufferedWriter(io.getStdOut().writer());
-        _ = try std.zig.render(gpa, bos.writer(), tree);
+        _ = try std.zig.render(gpa, bw.writer(), tree);
-        try bos.flush();
+        try bw.flush();
         return;
     }
 
@@ -2774,7 +2774,7 @@ fn fmtPathFile(
     }
 
     if (check_mode) {
-        const anything_changed = try std.zig.render(fmt.gpa, io.null_out_stream, tree);
+        const anything_changed = try std.zig.render(fmt.gpa, io.null_writer, tree);
         if (anything_changed) {
             const stdout = io.getStdOut().writer();
             try stdout.print("{s}\n", .{file_path});
@@ -2823,11 +2823,11 @@ fn printErrMsgToFile(
 
     var text_buf = std.ArrayList(u8).init(gpa);
     defer text_buf.deinit();
-    const out_stream = text_buf.outStream();
+    const writer = text_buf.writer();
-    try parse_error.render(tree.token_ids, out_stream);
+    try parse_error.render(tree.token_ids, writer);
     const text = text_buf.items;
 
-    const stream = file.outStream();
+    const stream = file.writer();
     try stream.print("{s}:{d}:{d}: error: {s}\n", .{ path, start_loc.line + 1, start_loc.column + 1, text });
 
     if (!color_on) return;

src/print_env.zig

@@ -20,10 +20,10 @@ pub fn cmdEnv(gpa: *Allocator, args: []const []const u8, stdout: std.fs.File.Wri
     const global_cache_dir = try introspect.resolveGlobalCacheDir(gpa);
     defer gpa.free(global_cache_dir);
 
-    var bos = std.io.bufferedOutStream(stdout);
+    var bw = std.io.bufferedWriter(stdout);
-    const bos_stream = bos.outStream();
+    const w = bw.writer();
 
-    var jws = std.json.WriteStream(@TypeOf(bos_stream), 6).init(bos_stream);
+    var jws = std.json.WriteStream(@TypeOf(w), 6).init(w);
     try jws.beginObject();
 
     try jws.objectField("zig_exe");
@@ -42,6 +42,6 @@ pub fn cmdEnv(gpa: *Allocator, args: []const []const u8, stdout: std.fs.File.Wri
     try jws.emitString(build_options.version);
 
     try jws.endObject();
-    try bos_stream.writeByte('\n');
+    try w.writeByte('\n');
-    try bos.flush();
+    try bw.flush();
 }

src/print_targets.zig

@@ -26,9 +26,9 @@ pub fn cmdTargets(
     const glibc_abi = try glibc.loadMetaData(allocator, zig_lib_directory.handle);
     defer glibc_abi.destroy(allocator);
 
-    var bos = io.bufferedOutStream(stdout);
+    var bw = io.bufferedWriter(stdout);
-    const bos_stream = bos.outStream();
+    const w = bw.writer();
-    var jws = std.json.WriteStream(@TypeOf(bos_stream), 6).init(bos_stream);
+    var jws = std.json.WriteStream(@TypeOf(w), 6).init(w);
 
     try jws.beginObject();
 
@@ -156,6 +156,6 @@ pub fn cmdTargets(
 
     try jws.endObject();
 
-    try bos_stream.writeByte('\n');
+    try w.writeByte('\n');
-    return bos.flush();
+    return bw.flush();
 }

src/test.zig

@@ -738,7 +738,7 @@ pub const TestContext = struct {
                     write_node.activate();
                     var out_zir = std.ArrayList(u8).init(allocator);
                     defer out_zir.deinit();
-                    try new_zir_module.writeToStream(allocator, out_zir.outStream());
+                    try new_zir_module.writeToStream(allocator, out_zir.writer());
                     write_node.end();
 
                     var test_node = update_node.start("assert", 0);

src/translate_c.zig

@@ -5268,7 +5268,7 @@ fn appendTokenFmt(c: *Context, token_id: Token.Id, comptime format: []const u8,
     try c.token_locs.ensureCapacity(c.gpa, c.token_locs.items.len + 1);
 
     const start_index = c.source_buffer.items.len;
-    try c.source_buffer.outStream().print(format ++ " ", args);
+    try c.source_buffer.writer().print(format ++ " ", args);
 
     c.token_ids.appendAssumeCapacity(token_id);
     c.token_locs.appendAssumeCapacity(.{

src/zir.zig

@@ -1116,7 +1116,7 @@ pub const Module = struct {
 
     /// This is a debugging utility for rendering the tree to stderr.
     pub fn dump(self: Module) void {
-        self.writeToStream(std.heap.page_allocator, std.io.getStdErr().outStream()) catch {};
+        self.writeToStream(std.heap.page_allocator, std.io.getStdErr().writer()) catch {};
     }
 
     const DeclAndIndex = struct {
@@ -3254,7 +3254,7 @@ pub fn dumpZir(allocator: *Allocator, kind: []const u8, decl_name: [*:0]const u8
 
     try write.inst_table.ensureCapacity(@intCast(u32, instructions.len));
 
-    const stderr = std.io.getStdErr().outStream();
+    const stderr = std.io.getStdErr().writer();
     try stderr.print("{s} {s} {{ // unanalyzed\n", .{ kind, decl_name });
 
     for (instructions) |inst| {

test/compare_output.zig

@@ -22,7 +22,7 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
             \\
             \\pub fn main() void {
             \\    privateFunction();
-            \\    const stdout = getStdOut().outStream();
+            \\    const stdout = getStdOut().writer();
             \\    stdout.print("OK 2\n", .{}) catch unreachable;
             \\}
             \\
@@ -37,7 +37,7 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
             \\// purposefully conflicting function with main.zig
             \\// but it's private so it should be OK
             \\fn privateFunction() void {
-            \\    const stdout = getStdOut().outStream();
+            \\    const stdout = getStdOut().writer();
             \\    stdout.print("OK 1\n", .{}) catch unreachable;
             \\}
             \\
@@ -63,7 +63,7 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
         tc.addSourceFile("foo.zig",
             \\usingnamespace @import("std").io;
             \\pub fn foo_function() void {
-            \\    const stdout = getStdOut().outStream();
+            \\    const stdout = getStdOut().writer();
             \\    stdout.print("OK\n", .{}) catch unreachable;
             \\}
         );
@@ -74,7 +74,7 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
             \\
             \\pub fn bar_function() void {
             \\    if (foo_function()) {
-            \\        const stdout = getStdOut().outStream();
+            \\        const stdout = getStdOut().writer();
             \\        stdout.print("OK\n", .{}) catch unreachable;
             \\    }
             \\}
@@ -106,7 +106,7 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
             \\pub const a_text = "OK\n";
             \\
             \\pub fn ok() void {
-            \\    const stdout = io.getStdOut().outStream();
+            \\    const stdout = io.getStdOut().writer();
             \\    stdout.print(b_text, .{}) catch unreachable;
             \\}
         );
@@ -124,7 +124,7 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
         \\const io = @import("std").io;
         \\
         \\pub fn main() void {
-        \\    const stdout = io.getStdOut().outStream();
+        \\    const stdout = io.getStdOut().writer();
         \\    stdout.print("Hello, world!\n{d:4} {x:3} {c}\n", .{@as(u32, 12), @as(u16, 0x12), @as(u8, 'a')}) catch unreachable;
         \\}
     , "Hello, world!\n  12  12 a\n");
@@ -267,7 +267,7 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
         \\    var x_local : i32 = print_ok(x);
         \\}
         \\fn print_ok(val: @TypeOf(x)) @TypeOf(foo) {
-        \\    const stdout = io.getStdOut().outStream();
+        \\    const stdout = io.getStdOut().writer();
         \\    stdout.print("OK\n", .{}) catch unreachable;
         \\    return 0;
         \\}
@@ -349,7 +349,7 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
         \\pub fn main() void {
         \\    const bar = Bar {.field2 = 13,};
         \\    const foo = Foo {.field1 = bar,};
-        \\    const stdout = io.getStdOut().outStream();
+        \\    const stdout = io.getStdOut().writer();
         \\    if (!foo.method()) {
         \\        stdout.print("BAD\n", .{}) catch unreachable;
         \\    }
@@ -363,7 +363,7 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
     cases.add("defer with only fallthrough",
         \\const io = @import("std").io;
         \\pub fn main() void {
-        \\    const stdout = io.getStdOut().outStream();
+        \\    const stdout = io.getStdOut().writer();
         \\    stdout.print("before\n", .{}) catch unreachable;
         \\    defer stdout.print("defer1\n", .{}) catch unreachable;
         \\    defer stdout.print("defer2\n", .{}) catch unreachable;
@@ -376,7 +376,7 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
         \\const io = @import("std").io;
         \\const os = @import("std").os;
         \\pub fn main() void {
-        \\    const stdout = io.getStdOut().outStream();
+        \\    const stdout = io.getStdOut().writer();
         \\    stdout.print("before\n", .{}) catch unreachable;
         \\    defer stdout.print("defer1\n", .{}) catch unreachable;
         \\    defer stdout.print("defer2\n", .{}) catch unreachable;
@@ -393,7 +393,7 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
         \\    do_test() catch return;
         \\}
         \\fn do_test() !void {
-        \\    const stdout = io.getStdOut().outStream();
+        \\    const stdout = io.getStdOut().writer();
         \\    stdout.print("before\n", .{}) catch unreachable;
         \\    defer stdout.print("defer1\n", .{}) catch unreachable;
         \\    errdefer stdout.print("deferErr\n", .{}) catch unreachable;
@@ -412,7 +412,7 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
         \\    do_test() catch return;
         \\}
         \\fn do_test() !void {
-        \\    const stdout = io.getStdOut().outStream();
+        \\    const stdout = io.getStdOut().writer();
         \\    stdout.print("before\n", .{}) catch unreachable;
         \\    defer stdout.print("defer1\n", .{}) catch unreachable;
         \\    errdefer stdout.print("deferErr\n", .{}) catch unreachable;
@@ -429,7 +429,7 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
             \\const io = @import("std").io;
             \\
             \\pub fn main() void {
-            \\    const stdout = io.getStdOut().outStream();
+            \\    const stdout = io.getStdOut().writer();
             \\    stdout.print(foo_txt, .{}) catch unreachable;
             \\}
         , "1234\nabcd\n");
@@ -448,7 +448,7 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
             \\
             \\pub fn main() !void {
             \\    var args_it = std.process.args();
-            \\    const stdout = io.getStdOut().outStream();
+            \\    const stdout = io.getStdOut().writer();
             \\    var index: usize = 0;
             \\    _ = args_it.skip();
             \\    while (args_it.next(allocator)) |arg_or_err| : (index += 1) {
@@ -487,7 +487,7 @@ pub fn addCases(cases: *tests.CompareOutputContext) void {
             \\
             \\pub fn main() !void {
             \\    var args_it = std.process.args();
-            \\    const stdout = io.getStdOut().outStream();
+            \\    const stdout = io.getStdOut().writer();
             \\    var index: usize = 0;
             \\    _ = args_it.skip();
             \\    while (args_it.next(allocator)) |arg_or_err| : (index += 1) {

test/stage1/behavior/bugs/5487.zig

@@ -3,10 +3,10 @@ const io = @import("std").io;
 pub fn write(_: void, bytes: []const u8) !usize {
     return 0;
 }
-pub fn outStream() io.OutStream(void, @typeInfo(@typeInfo(@TypeOf(write)).Fn.return_type.?).ErrorUnion.error_set, write) {
+pub fn writer() io.Writer(void, @typeInfo(@typeInfo(@TypeOf(write)).Fn.return_type.?).ErrorUnion.error_set, write) {
-    return io.OutStream(void, @typeInfo(@typeInfo(@TypeOf(write)).Fn.return_type.?).ErrorUnion.error_set, write){ .context = {} };
+    return io.Writer(void, @typeInfo(@typeInfo(@TypeOf(write)).Fn.return_type.?).ErrorUnion.error_set, write){ .context = {} };
 }
 
 test "crash" {
-    _ = io.multiOutStream(.{outStream()});
+    _ = io.multiWriter(.{writer()});
 }

test/tests.zig

@@ -652,9 +652,9 @@ pub const StackTracesContext = struct {
             }
             child.spawn() catch |err| debug.panic("Unable to spawn {s}: {s}\n", .{ full_exe_path, @errorName(err) });
 
-            const stdout = child.stdout.?.inStream().readAllAlloc(b.allocator, max_stdout_size) catch unreachable;
+            const stdout = child.stdout.?.reader().readAllAlloc(b.allocator, max_stdout_size) catch unreachable;
             defer b.allocator.free(stdout);
-            const stderrFull = child.stderr.?.inStream().readAllAlloc(b.allocator, max_stdout_size) catch unreachable;
+            const stderrFull = child.stderr.?.reader().readAllAlloc(b.allocator, max_stdout_size) catch unreachable;
             defer b.allocator.free(stderrFull);
             var stderr = stderrFull;
 
@@ -875,8 +875,8 @@ pub const CompileErrorContext = struct {
             var stdout_buf = ArrayList(u8).init(b.allocator);
             var stderr_buf = ArrayList(u8).init(b.allocator);
 
-            child.stdout.?.inStream().readAllArrayList(&stdout_buf, max_stdout_size) catch unreachable;
+            child.stdout.?.reader().readAllArrayList(&stdout_buf, max_stdout_size) catch unreachable;
-            child.stderr.?.inStream().readAllArrayList(&stderr_buf, max_stdout_size) catch unreachable;
+            child.stderr.?.reader().readAllArrayList(&stderr_buf, max_stdout_size) catch unreachable;
 
             const term = child.wait() catch |err| {
                 debug.panic("Unable to spawn {s}: {s}\n", .{ zig_args.items[0], @errorName(err) });

tools/update_clang_options.zig

@@ -388,8 +388,8 @@ pub fn main() anyerror!void {
     // "W" and "Wl,". So we sort this list in order of descending priority.
     std.sort.sort(*json.ObjectMap, all_objects.items, {}, objectLessThan);
 
-    var stdout_bos = std.io.bufferedOutStream(std.io.getStdOut().outStream());
+    var buffered_stdout = std.io.bufferedWriter(std.io.getStdOut().writer());
-    const stdout = stdout_bos.outStream();
+    const stdout = buffered_stdout.writer();
     try stdout.writeAll(
         \\// This file is generated by tools/update_clang_options.zig.
         \\// zig fmt: off
@@ -469,7 +469,7 @@ pub fn main() anyerror!void {
         \\
     );
 
-    try stdout_bos.flush();
+    try buffered_stdout.flush();
 }
 
 // TODO we should be able to import clang_options.zig but currently this is problematic because it will
@@ -611,7 +611,7 @@ fn objectLessThan(context: void, a: *json.ObjectMap, b: *json.ObjectMap) bool {
 }
 
 fn usageAndExit(file: fs.File, arg0: []const u8, code: u8) noreturn {
-    file.outStream().print(
+    file.writer().print(
         \\Usage: {} /path/to/llvm-tblgen /path/to/git/llvm/llvm-project
         \\Alternative Usage: zig run /path/to/git/zig/tools/update_clang_options.zig -- /path/to/llvm-tblgen /path/to/git/llvm/llvm-project
         \\

tools/update_glibc.zig

@@ -239,7 +239,7 @@ pub fn main() !void {
         const vers_txt_path = try fs.path.join(allocator, &[_][]const u8{ glibc_out_dir, "vers.txt" });
         const vers_txt_file = try fs.cwd().createFile(vers_txt_path, .{});
         defer vers_txt_file.close();
-        var buffered = std.io.bufferedOutStream(vers_txt_file.writer());
+        var buffered = std.io.bufferedWriter(vers_txt_file.writer());
         const vers_txt = buffered.writer();
         for (global_ver_list) |name, i| {
             _ = global_ver_set.put(name, i) catch unreachable;
@@ -251,7 +251,7 @@ pub fn main() !void {
         const fns_txt_path = try fs.path.join(allocator, &[_][]const u8{ glibc_out_dir, "fns.txt" });
         const fns_txt_file = try fs.cwd().createFile(fns_txt_path, .{});
         defer fns_txt_file.close();
-        var buffered = std.io.bufferedOutStream(fns_txt_file.writer());
+        var buffered = std.io.bufferedWriter(fns_txt_file.writer());
         const fns_txt = buffered.writer();
         for (global_fn_list) |name, i| {
             const entry = global_fn_set.getEntry(name).?;
@@ -282,7 +282,7 @@ pub fn main() !void {
         const abilist_txt_path = try fs.path.join(allocator, &[_][]const u8{ glibc_out_dir, "abi.txt" });
         const abilist_txt_file = try fs.cwd().createFile(abilist_txt_path, .{});
         defer abilist_txt_file.close();
-        var buffered = std.io.bufferedOutStream(abilist_txt_file.writer());
+        var buffered = std.io.bufferedWriter(abilist_txt_file.writer());
         const abilist_txt = buffered.writer();
 
         // first iterate over the abi lists