# Trait core::ops::FnOnce [−] [src]

    pub trait FnOnce<Args> {
        type Output;
        extern "rust-call" fn call_once(self, args: Args) -> Self::Output;
    }

A version of the call operator that takes a by-value receiver.

## Associated Types

### `type Output`

Unstable (`fn_traits` #29625)

The returned type after the call operator is used.

## Required Methods

### `extern "rust-call" fn call_once(self, args: Args) -> Self::Output`

Unstable (`fn_traits` #29625)

This is called when the call operator is used.

## Implementors

- `impl<'a, A, F: ?Sized> FnOnce<A> for &'a F where F: Fn<A>`
- `impl<'a, A, F: ?Sized> FnOnce<A> for &'a mut F where F: FnMut<A>`

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