Trait UpcastSub

pub trait UpcastSub<H: Sub<Output = H> + Rem<Output = H>>:
    Upcast<Higher = H>
    + CheckedSub
    + Copy {
    // Provided methods
    fn upcast_sub(self, rhs: Self) -> H { ... }
    fn upcast_sub_mod(self, rhs: Self, modulo: Self) -> Self { ... }
}

Trait to implement upcast sub. (Casting up when type bounds are hit during arithmetic)

Provided Methods

fn upcast_sub(self, rhs: Self) -> H

performs the operatoin self - rhs and returns value as type H.

let a = i8::MIN;
let b = 10;

let expected = i8::MIN as i16 - 10;

let res = a.upcast_sub(b);
assert_eq!(res, expected);

Panics

Panics if the operation still exceeds the higher types limit.

let a = 1u8;
let b = 2u8;

let _ = a.upcast_sub(b);

fn upcast_sub_mod(self, rhs: Self, modulo: Self) -> Self

performs the operation (self - rhs) % modulo and returns value as type Self.

let a = i8::MIN;
let b = 10;
let modulo = i8::MIN;

let expected = -10;

let res = a.upcast_sub_mod(b, modulo);
assert_eq!(res, expected);

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety", so this trait is not object safe.

Implementations on Foreign Types

impl UpcastSub<i16> for i8

impl UpcastSub<i32> for i16

impl UpcastSub<i64> for i32

impl UpcastSub<i128> for i64

impl UpcastSub<u16> for u8

impl UpcastSub<u32> for u16

impl UpcastSub<u64> for u32

impl UpcastSub<u128> for u64

Implementors