impl f32 { // also f16, f64, f128
	fn classify(self) -> FpCategory;
	fn next_up(self) -> Self;
	fn next_down(self) -> Self;
	fn midpoint(self, other: Self) -> Self;
        fn sin_cos(self) -> (Self, Self);
}

#[must_use]
#[must_use = "method returns a new number and does not mutate the original value"]
#[must_use = "this returns the clamped value and does not modify the original"]
#[must_use = "this returns the result of the comparison, without modifying either input"]
#[must_use = "this returns the result of the operation, without modifying the original"]