pub trait Neg {
type Output;
// Required method
fn neg(self) -> Self::Output;
}Expand description
The unary negation operator -.
§Examples
An implementation of Neg for Sign, which allows the use of - to
negate its value.
use std::ops::Neg;
#[derive(Debug, PartialEq)]
enum Sign {
Negative,
Zero,
Positive,
}
impl Neg for Sign {
type Output = Self;
fn neg(self) -> Self::Output {
match self {
Sign::Negative => Sign::Positive,
Sign::Zero => Sign::Zero,
Sign::Positive => Sign::Negative,
}
}
}
// A negative positive is a negative.
assert_eq!(-Sign::Positive, Sign::Negative);
// A double negative is a positive.
assert_eq!(-Sign::Negative, Sign::Positive);
// Zero is its own negation.
assert_eq!(-Sign::Zero, Sign::Zero);