Sub in std::ops - Rust (original) (raw)

Trait std::ops::Sub

1.0.0· source · [−]

pub trait Sub<Rhs = Self> {
    type Output;
    fn sub(self, rhs: Rhs) -> Self::Output;
}

Expand description

The subtraction operator -.

Note that Rhs is Self by default, but this is not mandatory. For example, std::time::SystemTime implements Sub<Duration>, which permits operations of the form SystemTime = SystemTime - Duration.

use std::ops::Sub;

#[derive(Debug, Copy, Clone, PartialEq)]
struct Point {
    x: i32,
    y: i32,
}

impl Sub for Point {
    type Output = Self;

    fn sub(self, other: Self) -> Self::Output {
        Self {
            x: self.x - other.x,
            y: self.y - other.y,
        }
    }
}

assert_eq!(Point { x: 3, y: 3 } - Point { x: 2, y: 3 },
           Point { x: 1, y: 0 });

Run

Here is an example of the same Point struct implementing the Sub trait using generics.

use std::ops::Sub;

#[derive(Debug, PartialEq)]
struct Point<T> {
    x: T,
    y: T,
}

// Notice that the implementation uses the associated type `Output`.
impl<T: Sub<Output = T>> Sub for Point<T> {
    type Output = Self;

    fn sub(self, other: Self) -> Self::Output {
        Point {
            x: self.x - other.x,
            y: self.y - other.y,
        }
    }
}

assert_eq!(Point { x: 2, y: 3 } - Point { x: 1, y: 0 },
           Point { x: 1, y: 3 });

Run

The resulting type after applying the - operator.

Performs the - operation.

assert_eq!(12 - 1, 11);

Run

impl<'_, '_> Sub<&'_ i8> for &'_ i8

impl<'_, '_> Sub<&'_ u8> for &'_ u8

impl<'_, T, const LANES: usize> Sub<&'_ Simd<T, LANES>> for Simd<T, LANES> where

T: SimdElement,
Simd<T, LANES>: Sub<Simd<T, LANES>>,
LaneCount: SupportedLaneCount,
<Simd<T, LANES> as Sub<Simd<T, LANES>>>::Output == Simd<T, LANES>,

impl<'_, T, const LANES: usize> Sub<Simd<T, LANES>> for &'_ Simd<T, LANES> where

T: SimdElement,
Simd<T, LANES>: Sub<Simd<T, LANES>>,
LaneCount: SupportedLaneCount,
<Simd<T, LANES> as Sub<Simd<T, LANES>>>::Output == Simd<T, LANES>,

impl<'lhs, 'rhs, T, const LANES: usize> Sub<&'rhs Simd<T, LANES>> for &'lhs Simd<T, LANES> where

T: SimdElement,
Simd<T, LANES>: Sub<Simd<T, LANES>>,
LaneCount: SupportedLaneCount,
<Simd<T, LANES> as Sub<Simd<T, LANES>>>::Output == Simd<T, LANES>,