fixedpoint

具有基础类型和精度除数的定点数。

通常这是10的幂，但您也可以做其他事情，比如256来使用低字节等。大概编译器会优化操作以使用移位而不是除法/乘法。

// use it directly
let x = Fixed<u8, 10>::from(5.3f64);
println!("{}", x * 2); // 10.6

// have a wrapper that controls what operations can be done
// useful for units of measurement that have special semantics
// for example, multiplying lengths gives an area.
struct Length(Fixed<u16, 100>);
struct Area(Fixed<u32, 100>);

impl Mul for Length {
	type Output = Area;

	fn mul(self, rhs: Self) -> Area {
		Area((self.0 * rhs.0).into())
	}
}