pub trait One {
fn one() -> Self;
}
macro_rules! impl_One {
(for $($t:ty),+) => {
$(impl One for $t {
fn one() -> $t {
1 as $t
}
})*
}
}
impl_One!(for u8, u16, u32, u64, u128, usize);
impl_One!(for i8, i16, i32, i64, i128, isize);
impl_One!(for f32, f64);