zig/std/math/isfinite.zig

31 lines
825 B
Zig

const math = @import("index.zig");
const assert = @import("../debug.zig").assert;
pub fn isFinite(x: var) -> bool {
const T = @typeOf(x);
switch (T) {
f32 => {
const bits = @bitCast(u32, x);
bits & 0x7FFFFFFF < 0x7F800000
},
f64 => {
const bits = @bitCast(u64, x);
bits & (@maxValue(u64) >> 1) < (0x7FF << 52)
},
else => {
@compileError("isFinite not implemented for " ++ @typeName(T));
},
}
}
test "math.isFinite" {
assert(isFinite(f32(0.0)));
assert(isFinite(f32(-0.0)));
assert(isFinite(f64(0.0)));
assert(isFinite(f64(-0.0)));
assert(!isFinite(math.inf(f32)));
assert(!isFinite(-math.inf(f32)));
assert(!isFinite(math.inf(f64)));
assert(!isFinite(-math.inf(f64)));
}