Trait num_traits::ops::checked::CheckedNeg [−] [src]

pub trait CheckedNeg: Sized {
    fn checked_neg(&self) -> Option<Self>;
}

Performs negation that returns None if the result can't be represented.

Required Methods

`fn checked_neg(&self) -> Option<Self>`

Negates a number, returning None for results that can't be represented, like signed MIN values that can't be positive, or non-zero unsigned values that can't be negative.

Examples

use num_traits::CheckedNeg;
use std::i32::MIN;

assert_eq!(CheckedNeg::checked_neg(&1_i32), Some(-1));
assert_eq!(CheckedNeg::checked_neg(&-1_i32), Some(1));
assert_eq!(CheckedNeg::checked_neg(&MIN), None);

assert_eq!(CheckedNeg::checked_neg(&0_u32), Some(0));
assert_eq!(CheckedNeg::checked_neg(&1_u32), None);