Zig 0.17.0-dev (Split by item)

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frexpGeneric

math.frexpGeneric

fn frexpGeneric(comptime T: type, x: T, e: *c_int) T

File

lib/c/math.zig:203

Code

fn frexpGeneric(comptime T: type, x: T, e: *c_int) T {
    // libc expects `*e` to be unspecified in this case; an unspecified C value
    // should be a valid value of the relevant type, yet Zig's std
    // implementation sets it to `undefined` -- which can even be nonsense
    // according to the type (int). Therefore, we're setting it to a valid
    // int value in Zig -- a zero.
    //
    // This mirrors the handling of infinities, where libc also expects
    // unspecified for the value of `*e` and Zig std sets it to a zero.
    if (math.isNan(x)) {
        e.* = 0;
        return x;
    }

    const r = math.frexp(x);
    e.* = r.exponent;
    return r.significand;
}