zig/std/math/isnormal.zig
Andrew Kelley 3671582c15 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.
2018-01-25 04:10:11 -05:00

28 lines
732 B
Zig

const std = @import("../index.zig");
const math = std.math;
const assert = std.debug.assert;
pub fn isNormal(x: var) bool {
const T = @typeOf(x);
switch (T) {
f32 => {
const bits = @bitCast(u32, x);
return (bits + 0x00800000) & 0x7FFFFFFF >= 0x01000000;
},
f64 => {
const bits = @bitCast(u64, x);
return (bits + (1 << 52)) & (@maxValue(u64) >> 1) >= (1 << 53);
},
else => {
@compileError("isNormal not implemented for " ++ @typeName(T));
},
}
}
test "math.isNormal" {
assert(!isNormal(math.nan(f32)));
assert(!isNormal(math.nan(f64)));
assert(isNormal(f32(1.0)));
assert(isNormal(f64(1.0)));
}