mod private {
pub trait Sealed {}
impl Sealed for usize {}
impl Sealed for u8 {}
impl Sealed for u16 {}
impl Sealed for u32 {}
impl Sealed for u64 {}
impl Sealed for u128 {}
}
pub trait Unsigned: private::Sealed {}
impl Unsigned for usize {}
impl Unsigned for u8 {}
impl Unsigned for u16 {}
impl Unsigned for u32 {}
impl Unsigned for u64 {}
impl Unsigned for u128 {}