# [−][src]Trait subtle::ConstantTimeEq

pub trait ConstantTimeEq {
fn ct_eq(&self, other: &Self) -> Choice;
}

An Eq-like trait that produces a Choice instead of a bool.

# Example

use subtle::ConstantTimeEq;
let x: u8 = 5;
let y: u8 = 13;

assert_eq!(x.ct_eq(&y).unwrap_u8(), 0);
assert_eq!(x.ct_eq(&x).unwrap_u8(), 1);

## Required methods

### fn ct_eq(&self, other: &Self) -> Choice

Determine if two items are equal.

The ct_eq function should execute in constant time.

# Returns

• Choice(1u8) if self == other;
• Choice(0u8) if self != other.
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## Implementations on Foreign Types

### impl<T: ConstantTimeEq> ConstantTimeEq for [T][src]

#### fn ct_eq(&self, _rhs: &[T]) -> Choice[src]

Check whether two slices of ConstantTimeEq types are equal.

# Note

This function short-circuits if the lengths of the input slices are different. Otherwise, it should execute in time independent of the slice contents.

Since arrays coerce to slices, this function works with fixed-size arrays:

let a: [u8; 8] = [0,1,2,3,4,5,6,7];
let b: [u8; 8] = [0,1,2,3,0,1,2,3];

let a_eq_a = a.ct_eq(&a);
let a_eq_b = a.ct_eq(&b);

assert_eq!(a_eq_a.unwrap_u8(), 1);
assert_eq!(a_eq_b.unwrap_u8(), 0);

### impl ConstantTimeEq for isize[src]

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## Implementors

### impl<T: ConstantTimeEq> ConstantTimeEq for CtOption<T>[src]

#### fn ct_eq(&self, rhs: &CtOption<T>) -> Choice[src]

Two CtOption<T>s are equal if they are both Some and their values are equal, or both None.

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