    const std = @import("../../std.zig");
    const testing = std.testing;
    const math = std.math;
    const cmath = math.complex;
    const Complex = cmath.Complex;

    /// Returns the angular component (in radians) of z.
    pub fn arg(z: anytype) @TypeOf(z.re) {
        const T = @TypeOf(z.re);
        return math.atan2(T, z.im, z.re);
    }

    const epsilon = 0.0001;

    test "complex.carg" {
        const a = Complex(f32).init(5, 3);
        const c = arg(a);
        try testing.expect(math.approxEqAbs(f32, c, 0.540420, epsilon));
    }