/Rust

# Trait std::ops::Div

#[lang = "div"]pub trait Div<Rhs = Self> {
type Output;
fn div(self, rhs: Rhs) -> Self::Output;
}

The division operator /.

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

## Examples

### Dividable rational numbers

use std::ops::Div;

// 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);
Rational {
numerator: numerator / gcd,
denominator: denominator / gcd,
}
}
}

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

fn div(self, rhs: Self) -> Self::Output {
if rhs.numerator == 0 {
panic!("Cannot divide by zero-valued `Rational`!");
}

let numerator = self.numerator * rhs.denominator;
let denominator = self.denominator * rhs.numerator;
Rational::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(1, 2) / Rational::new(3, 4),
Rational::new(2, 3));

### Dividing vectors by scalars as in linear algebra

use std::ops::Div;

struct Scalar { value: f32 }

#[derive(Debug, PartialEq)]
struct Vector { value: Vec<f32> }

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

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

let scalar = Scalar { value: 2f32 };
let vector = Vector { value: vec![2f32, 4f32, 6f32] };
assert_eq!(vector / scalar, Vector { value: vec![1f32, 2f32, 3f32] });

## Associated Types

### type Output

The resulting type after applying the / operator.

## Required methods

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

Performs the / operation.

## Implementors

### impl Div<i8> for i8[src]

This operation rounds towards zero, truncating any fractional part of the exact result.

### impl Div<i16> for i16[src]

This operation rounds towards zero, truncating any fractional part of the exact result.

### impl Div<i32> for i32[src]

This operation rounds towards zero, truncating any fractional part of the exact result.

### impl Div<i64> for i64[src]

This operation rounds towards zero, truncating any fractional part of the exact result.

### impl Div<i128> for i128[src]

This operation rounds towards zero, truncating any fractional part of the exact result.

### impl Div<isize> for isize[src]

This operation rounds towards zero, truncating any fractional part of the exact result.

### impl Div<u8> for u8[src]

This operation rounds towards zero, truncating any fractional part of the exact result.

### impl Div<u16> for u16[src]

This operation rounds towards zero, truncating any fractional part of the exact result.

### impl Div<u32> for u32[src]

This operation rounds towards zero, truncating any fractional part of the exact result.

### impl Div<u64> for u64[src]

This operation rounds towards zero, truncating any fractional part of the exact result.

### impl Div<u128> for u128[src]

This operation rounds towards zero, truncating any fractional part of the exact result.

### impl Div<usize> for usize[src]

This operation rounds towards zero, truncating any fractional part of the exact result.