/=Operator

Explanation

/= divides the left operand by the right in place, overloadable via std::ops::DivAssign.

Usage examples

Dividing a mutable binding in place

let mut x = 7;
x /= 2; // <- `/=` divides `x` in place, truncating toward zero

Numeric computation

Turning a running sum into a running average is a one-line job for /= once the count is known — dividing the accumulator in place instead of introducing a second variable to hold the averaged result.

let samples = [18.0, 22.0, 19.5, 24.5];

let mut average = samples.iter().sum::<f64>();
average /= samples.len() as f64; // <- `/=` turns the sum into an average in place

assert_eq!(average, 21.0);

Dividing the same binding in place with /= reads as "this value, adjusted," matching the general in-place-assignment case made for +=; watch the integer-truncation caveat this page's Explanation calls out if average were an integer type instead of f64.

Explanation

Embedded support: Full

DivAssign lives in core::ops, so /= behaves identically under #![no_std], including the integer-truncation caveat this page's classic Explanation notes. It shares /'s hardware nuance directly: on a microcontroller with no hardware integer divider, /= lowers to the same software division routine / does. When the divisor is a compile-time-known power of two — a common choice for a sample count or buffer length precisely because of this — the compiler turns /= into a shift for you, making it effectively free; a divisor that only becomes known at runtime doesn't get that optimization and pays the software division cost.

Usage examples

Averaging accumulated ADC samples in place

let mut sum: u32 = adc_samples.iter().map(|&s| s as u32).sum();
sum /= adc_samples.len() as u32; // <- `/=` divides in place; a software routine unless the divisor is a compile-time power of two

Choosing a power-of-two sample count so `/=` compiles to a shift

const SAMPLE_COUNT: u32 = 8; // power of two: `/=` by this constant compiles to a shift, not a divide

fn average_in_place(sum: &mut u32) {
    *sum /= SAMPLE_COUNT; // <- `/=` here is free: division by a power-of-two constant lowers to a shift
}