Trait Mul

1.0.0 · Source

pub trait Mul<Rhs = Self> {
    type Output;

    // Required method
    fn mul(self, rhs: Rhs) -> Self::Output;
}

Expand description

The multiplication operator *.

Note that Rhs is Self by default, but this is not mandatory.

§Examples

§`Mul`tipliable rational numbers

use std::ops::Mul;

// By the fundamental theorem of arithmetic, rational numbers in lowest
// terms are unique. So, by keeping `Rational`s in reduced form, we can
// derive `Eq` and `PartialEq`.
#[derive(Debug, Eq, PartialEq)]
struct Rational {
    numerator: usize,
    denominator: usize,
}

impl Rational {
    fn new(numerator: usize, denominator: usize) -> Self {
        if denominator == 0 {
            panic!("Zero is an invalid denominator!");
        }

        // Reduce to lowest terms by dividing by the greatest common
        // divisor.
        let gcd = gcd(numerator, denominator);
        Self {
            numerator: numerator / gcd,
            denominator: denominator / gcd,
        }
    }
}

impl Mul for Rational {
    // The multiplication of rational numbers is a closed operation.
    type Output = Self;

    fn mul(self, rhs: Self) -> Self {
        let numerator = self.numerator * rhs.numerator;
        let denominator = self.denominator * rhs.denominator;
        Self::new(numerator, denominator)
    }
}

// Euclid's two-thousand-year-old algorithm for finding the greatest common
// divisor.
fn gcd(x: usize, y: usize) -> usize {
    let mut x = x;
    let mut y = y;
    while y != 0 {
        let t = y;
        y = x % y;
        x = t;
    }
    x
}

assert_eq!(Rational::new(1, 2), Rational::new(2, 4));
assert_eq!(Rational::new(2, 3) * Rational::new(3, 4),
           Rational::new(1, 2));

§Multiplying vectors by scalars as in linear algebra

use std::ops::Mul;

struct Scalar { value: usize }

#[derive(Debug, PartialEq)]
struct Vector { value: Vec<usize> }

impl Mul<Scalar> for Vector {
    type Output = Self;

    fn mul(self, rhs: Scalar) -> Self::Output {
        Self { value: self.value.iter().map(|v| v * rhs.value).collect() }
    }
}

let vector = Vector { value: vec![2, 4, 6] };
let scalar = Scalar { value: 3 };
assert_eq!(vector * scalar, Vector { value: vec![6, 12, 18] });

Perform elementwise multiplication between self and rhs, and return the result.

self must be an Array or ArcArray.

If their shapes disagree, self is broadcast to their broadcast shape.

Panics if broadcasting isn’t possible.

Source §

impl<const N: usize> Mul for Simd<usize, N>
where usize: SimdElement, LaneCount<N>: SupportedLaneCount,

Source §

Trait MulCopy item path

§Examples

§Multipliable rational numbers

§Multiplying vectors by scalars as in linear algebra

Required Associated Types§

type Output

Required Methods§

fn mul(self, rhs: Rhs) -> Self::Output

§Example

Implementors§

impl Mul for &JsValue

type Output = JsValue

impl Mul for f16

type Output = f16

impl Mul for f32

type Output = f32

impl Mul for f64

type Output = f64

impl Mul for f128

type Output = f128

impl Mul for i8

type Output = i8

impl Mul for i16

type Output = i16

impl Mul for i32

type Output = i32

impl Mul for i64

type Output = i64

impl Mul for i128

type Output = i128

impl Mul for isize

type Output = isize

impl Mul for u8

type Output = u8

impl Mul for u16

type Output = u16

impl Mul for u32

type Output = u32

impl Mul for u64

type Output = u64

impl Mul for u128

type Output = u128

impl Mul for usize

type Output = usize

impl Mul for BigInt

type Output = <&'static BigInt as Mul>::Output

impl Mul for Number

type Output = <&'static Number as Mul>::Output

impl Mul for Saturating<i8>

type Output = Saturating<i8>

impl Mul for Saturating<i16>

type Output = Saturating<i16>

impl Mul for Saturating<i32>

type Output = Saturating<i32>

impl Mul for Saturating<i64>

type Output = Saturating<i64>

impl Mul for Saturating<i128>

type Output = Saturating<i128>

impl Mul for Saturating<isize>

type Output = Saturating<isize>

impl Mul for Saturating<u8>

type Output = Saturating<u8>

impl Mul for Saturating<u16>

type Output = Saturating<u16>

impl Mul for Saturating<u32>

type Output = Saturating<u32>

impl Mul for Saturating<u64>

type Output = Saturating<u64>

impl Mul for Saturating<u128>

type Output = Saturating<u128>

impl Mul for Saturating<usize>

type Output = Saturating<usize>

impl Mul for Wrapping<i8>

type Output = Wrapping<i8>

impl Mul for Wrapping<i16>

type Output = Wrapping<i16>

impl Mul for Wrapping<i32>

type Output = Wrapping<i32>

impl Mul for Wrapping<i64>

type Output = Wrapping<i64>

Trait Mul

§`Mul`tipliable rational numbers