Files
test/guide/language/floats.zig
2026-01-19 05:43:29 +09:00

40 lines
1.2 KiB
Zig

const expect = @import("std").testing.expect;
// Zig's floats are strictly IEEE-compliant unless `@setFloatMode(.Optimized)` is used,
// which is equivalent to GCC's `-ffast-math`.
// Floats coerce to larger float types.
test "float widening" {
const a: f16 = 0;
const b: f32 = a;
const c: f128 = b;
try expect(c == @as(f128, a));
}
// Floats support multiple kinds of literal.
const floating_point: f64 = 123.0E+77;
const another_float: f64 = 123.0;
const yet_another: f64 = 123.0e+77;
const hex_floating_point: f64 = 0x103.70p-5;
const another_hex_float: f64 = 0x103.70;
const yet_another_hex_float: f64 = 0x103.70P-5;
// Underscores may also be placed between digits.
const lightspeed: f64 = 299_792_458.000_000;
const nanosecond: f64 = 0.000_000_001;
const more_hex: f64 = 0x1234_5678.9ABC_CDEFp-10;
// Integers and floats may be converted using the built-in functions `@floatFromInt` and `@intFromFloat`.
// `@floatFromInt` is always safe, whereas `@intFromFloat` is detectable illegal behaviour
// if the float value cannot fit in the integer destination type.
test "int-float conversion" {
const a: i32 = 0;
const b = @as(f32, @floatFromInt(a));
const c = @as(i32, @intFromFloat(b));
try expect(c == a);
}