use num_traits::Num;
pub trait AbsDiff {
type Abs: Num + PartialOrd + Copy + std::fmt::Debug + Send + Sync;
fn max_abs_diff() -> Self::Abs;
fn abs_diff(self, other: Self) -> Self::Abs;
}
macro_rules! impl_trivial_abs_diff {
($T: ty, $max: expr) => {
impl AbsDiff for $T {
type Abs = $T;
fn max_abs_diff() -> Self::Abs {
$max
}
fn abs_diff(self, other: Self) -> Self::Abs {
if self > other {
self - other
} else {
other - self
}
}
}
};
}
macro_rules! impl_signed_abs_diff {
($T: ty, $U: ty) => {
impl AbsDiff for $T {
type Abs = $U;
fn max_abs_diff() -> Self::Abs {
<$U>::MAX
}
fn abs_diff(self, other: Self) -> Self::Abs {
self.abs_diff(other)
}
}
};
}
impl_trivial_abs_diff!(u8, u8::MAX);
impl_trivial_abs_diff!(u16, u16::MAX);
impl_trivial_abs_diff!(u32, u32::MAX);
impl_trivial_abs_diff!(u64, u64::MAX);
impl_trivial_abs_diff!(u128, u128::MAX);
impl_trivial_abs_diff!(usize, usize::MAX);
impl_trivial_abs_diff!(f32, f32::INFINITY);
impl_trivial_abs_diff!(f64, f64::INFINITY);
impl_signed_abs_diff!(i8, u8);
impl_signed_abs_diff!(i16, u16);
impl_signed_abs_diff!(i32, u32);
impl_signed_abs_diff!(i64, u64);
impl_signed_abs_diff!(i128, u128);
impl_signed_abs_diff!(isize, usize);