# Trait std::ops::Neg 1.0.0 [−] [src]

    #[lang = "neg"]
    pub trait Neg {
        type Output;
        fn neg(self) -> Self::Output;
    }

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 = Sign;

        fn neg(self) -> Sign {
            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);Run

## Associated Types

### `type Output`

The resulting type after applying the `-` operator

## Required Methods

### `fn neg(self) -> Self::Output`

The method for the unary `-` operator

## Implementors

- `impl<'a> Neg for &'a Wrapping<i128> type Output = <Wrapping<i128> as Neg>::Output;`
- `impl<'a> Neg for &'a Wrapping<u8> type Output = <Wrapping<u8> as Neg>::Output;`
- `impl<'a> Neg for &'a Wrapping<u64> type Output = <Wrapping<u64> as Neg>::Output;`
- `impl Neg for Wrapping<i64> type Output = Wrapping<i64>;`
- `impl<'a> Neg for &'a Wrapping<i8> type Output = <Wrapping<i8> as Neg>::Output;`
- `impl Neg for Wrapping<usize> type Output = Wrapping<usize>;`
- `impl<'a> Neg for &'a Wrapping<i32> type Output = <Wrapping<i32> as Neg>::Output;`
- `impl Neg for Wrapping<i8> type Output = Wrapping<i8>;`
- `impl<'a> Neg for &'a Wrapping<i16> type Output = <Wrapping<i16> as Neg>::Output;`
- `impl<'a> Neg for &'a Wrapping<u16> type Output = <Wrapping<u16> as Neg>::Output;`
- `impl<'a> Neg for &'a i8 type Output = <i8 as Neg>::Output;`
- `impl Neg for i128 type Output = i128;`
- `impl<'a> Neg for &'a Wrapping<i64> type Output = <Wrapping<i64> as Neg>::Output;`
- `impl Neg for i8 type Output = i8;`
- `impl<'a> Neg for &'a f64 type Output = <f64 as Neg>::Output;`
- `impl Neg for f32 type Output = f32;`
- `impl<'a> Neg for &'a Wrapping<usize> type Output = <Wrapping<usize> as Neg>::Output;`
- `impl Neg for Wrapping<u16> type Output = Wrapping<u16>;`
- `impl Neg for Wrapping<i128> type Output = Wrapping<i128>;`
- `impl Neg for i16 type Output = i16;`
- `impl Neg for isize type Output = isize;`
- `impl Neg for Wrapping<u128> type Output = Wrapping<u128>;`
- `impl<'a> Neg for &'a Wrapping<u32> type Output = <Wrapping<u32> as Neg>::Output;`
- `impl Neg for i32 type Output = i32;`
- `impl Neg for i64 type Output = i64;`
- `impl<'a> Neg for &'a i16 type Output = <i16 as Neg>::Output;`
- `impl<'a> Neg for &'a Wrapping<isize> type Output = <Wrapping<isize> as Neg>::Output;`
- `impl Neg for Wrapping<u8> type Output = Wrapping<u8>;`
- `impl<'a> Neg for &'a i64 type Output = <i64 as Neg>::Output;`
- `impl Neg for Wrapping<i16> type Output = Wrapping<i16>;`
- `impl Neg for Wrapping<u32> type Output = Wrapping<u32>;`
- `impl Neg for Wrapping<i32> type Output = Wrapping<i32>;`
- `impl<'a> Neg for &'a Wrapping<u128> type Output = <Wrapping<u128> as Neg>::Output;`
- `impl<'a> Neg for &'a isize type Output = <isize as Neg>::Output;`
- `impl Neg for Wrapping<isize> type Output = Wrapping<isize>;`
- `impl Neg for Wrapping<u64> type Output = Wrapping<u64>;`
- `impl<'a> Neg for &'a i128 type Output = <i128 as Neg>::Output;`
- `impl Neg for f64 type Output = f64;`
- `impl<'a> Neg for &'a i32 type Output = <i32 as Neg>::Output;`
- `impl<'a> Neg for &'a f32 type Output = <f32 as Neg>::Output;`

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