zig/lib/std/math/isinf.zig
mlugg 0fe3fd01dd
std: update std.builtin.Type fields to follow naming conventions
The compiler actually doesn't need any functional changes for this: Sema
does reification based on the tag indices of `std.builtin.Type` already!
So, no zig1.wasm update is necessary.

This change is necessary to disallow name clashes between fields and
decls on a type, which is a prerequisite of #9938.
2024-08-28 08:39:59 +01:00

55 lines
1.7 KiB
Zig

const std = @import("../std.zig");
const math = std.math;
const expect = std.testing.expect;
/// Returns whether x is an infinity, ignoring sign.
pub inline fn isInf(x: anytype) bool {
const T = @TypeOf(x);
const TBits = std.meta.Int(.unsigned, @typeInfo(T).float.bits);
const remove_sign = ~@as(TBits, 0) >> 1;
return @as(TBits, @bitCast(x)) & remove_sign == @as(TBits, @bitCast(math.inf(T)));
}
/// Returns whether x is an infinity with a positive sign.
pub inline fn isPositiveInf(x: anytype) bool {
return x == math.inf(@TypeOf(x));
}
/// Returns whether x is an infinity with a negative sign.
pub inline fn isNegativeInf(x: anytype) bool {
return x == -math.inf(@TypeOf(x));
}
test isInf {
inline for ([_]type{ f16, f32, f64, f80, f128 }) |T| {
try expect(!isInf(@as(T, 0.0)));
try expect(!isInf(@as(T, -0.0)));
try expect(isInf(math.inf(T)));
try expect(isInf(-math.inf(T)));
try expect(!isInf(math.nan(T)));
try expect(!isInf(-math.nan(T)));
}
}
test isPositiveInf {
inline for ([_]type{ f16, f32, f64, f80, f128 }) |T| {
try expect(!isPositiveInf(@as(T, 0.0)));
try expect(!isPositiveInf(@as(T, -0.0)));
try expect(isPositiveInf(math.inf(T)));
try expect(!isPositiveInf(-math.inf(T)));
try expect(!isInf(math.nan(T)));
try expect(!isInf(-math.nan(T)));
}
}
test isNegativeInf {
inline for ([_]type{ f16, f32, f64, f80, f128 }) |T| {
try expect(!isNegativeInf(@as(T, 0.0)));
try expect(!isNegativeInf(@as(T, -0.0)));
try expect(!isNegativeInf(math.inf(T)));
try expect(isNegativeInf(-math.inf(T)));
try expect(!isInf(math.nan(T)));
try expect(!isInf(-math.nan(T)));
}
}