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//! Combines common [operators](https://doc.rust-lang.org/book/appendix-02-operators.html)
//! and constants `0`, `1` and `10` to enable generic methods on integer types.
use std::cmp::{PartialEq, PartialOrd};
use std::ops::{Add, BitAnd, Div, Mul, Neg, Rem, Shr, Sub};

pub trait Integer<T>:
Copy
+ From<u8>
+ PartialEq
+ PartialOrd
+ Add<Output = T>
+ BitAnd<Output = T>
+ Div<Output = T>
+ Mul<Output = T>
+ Rem<Output = T>
+ Shr<Output = T>
+ Sub<Output = T>
{
    const ZERO: T;
    const ONE: T;
    const TEN: T;
}

pub trait Unsigned<T>: Integer<T> {}

pub trait Signed<T>: Integer<T> + Neg<Output = T> {}

macro_rules! integer {
    ($($t:ty)*) => ($(
        impl Integer<$t> for $t {
            const ZERO: $t = 0;
            const ONE: $t = 1;
            const TEN: $t = 10;
        }
    )*)
}

macro_rules! empty_trait {
    ($name:ident for $($t:ty)*) => ($(
        impl $name<$t> for $t {}
    )*)
}

integer!(u8 u16 u32 u64 u128 usize i16 i32 i64 i128);
empty_trait!(Unsigned for u8 u16 u32 u64 u128 usize);
empty_trait!(Signed for i16 i32 i64 i128);