# futures_util::future::MaybeDone - Rust
API documentation for the Rust `MaybeDone` enum in crate `futures_util`.
Keywords: rust, rustlang, rust-lang, MaybeDone

# Enum futures_util::future::MaybeDone [−] [src]

    pub enum MaybeDone<Fut: Future> {
        Future(Fut),
        Done(Fut::Output),
        Gone,
    }

A future that may have completed.

This is created by the `maybe_done()` function.

## Variants

`Future(Fut)`

A not-yet-completed future

`Done(Fut::Output)`

The output of the completed future

`Gone`

The empty variant after the result of a `MaybeDone` has been taken using the `take_output` method.

## Implementations

### `impl<Fut: Future> MaybeDone<Fut>` [src]

#### `pub fn output_mut(self: Pin<&mut Self>) -> Option<&mut Fut::Output>` [src]

Returns an `Option` containing a mutable reference to the output of the future. The output of this method will be `Some` if and only if the inner future has been completed and `take_output` has not yet been called.

#### `pub fn take_output(self: Pin<&mut Self>) -> Option<Fut::Output>` [src]

Attempt to take the output of a `MaybeDone` without driving it towards completion.

## Trait Implementations

### `impl<Fut: Debug + Future> Debug for MaybeDone<Fut> where
Fut::Output: Debug,` [src]

#### `fn fmt(&self, f: &mut Formatter<'_>) -> Result` [src]

Formats the value using the given formatter. Read more

### `impl<Fut: Future> FusedFuture for MaybeDone<Fut>` [src]

#### `fn is_terminated(&self) -> bool` [src]

Returns `true` if the underlying future should no longer be polled.

### `impl<Fut: Future> Future for MaybeDone<Fut>` [src]

#### `type Output = ()`

The type of value produced on completion.

#### `fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output>` [src]

Attempt to resolve the future to a final value, registering the current task for wakeup if the value is not yet available. Read more

### `impl<Fut: Future + Unpin> Unpin for MaybeDone<Fut>` [src]

## Auto Trait Implementations

### `impl<Fut> RefUnwindSafe for MaybeDone<Fut> where
Fut: RefUnwindSafe,
<Fut as Future>::Output: RefUnwindSafe,` [src]

### `impl<Fut> Send for MaybeDone<Fut> where
Fut: Send,
<Fut as Future>::Output: Send,` [src]

### `impl<Fut> Sync for MaybeDone<Fut> where
Fut: Sync,
<Fut as Future>::Output: Sync,` [src]

### `impl<Fut> UnwindSafe for MaybeDone<Fut> where
Fut: UnwindSafe,
<Fut as Future>::Output: UnwindSafe,` [src]

## Blanket Implementations

### `impl<T> Any for T where
T: 'static + ?Sized,` [src]

#### `pub fn type_id(&self) -> TypeId` [src]

Gets the `TypeId` of `self`. Read more

### `impl<T> Borrow<T> for T where
T: ?Sized,` [src]

#### `pub fn borrow(&self) -> &T` [src]

Immutably borrows from an owned value. Read more

### `impl<T> BorrowMut<T> for T where
T: ?Sized,` [src]

#### `pub fn borrow_mut(&mut self) -> &mut T` [src]

Mutably borrows from an owned value. Read more

### `impl<T> From<T> for T` [src]

#### `pub fn from(t: T) -> T` [src]

Performs the conversion.

### `impl<T, U> Into<U> for T where
U: From<T>,` [src]

#### `pub fn into(self) -> U` [src]

Performs the conversion.

### `impl<F> IntoFuture for F where
F: Future,` [src]

#### `type Output = <F as Future>::Output`

🔬 This is a nightly-only experimental API. (`into_future`)

The output that the future will produce on completion.

#### `type Future = F`

🔬 This is a nightly-only experimental API. (`into_future`)

Which kind of future are we turning this into?

#### `pub fn into_future(self) -> <F as IntoFuture>::Future` [src]

🔬 This is a nightly-only experimental API. (`into_future`)

Creates a future from a value.

### `impl<T, U> TryFrom<U> for T where
U: Into<T>,` [src]

#### `type Error = Infallible`

The type returned in the event of a conversion error.

#### `pub fn try_from(value: U) -> Result<T, <T as TryFrom<U>>::Error>` [src]

Performs the conversion.

### `impl<T, U> TryInto<U> for T where
U: TryFrom<T>,` [src]

#### `type Error = <U as TryFrom<T>>::Error`

The type returned in the event of a conversion error.

#### `pub fn try_into(self) -> Result<U, <U as TryFrom<T>>::Error>` [src]

Performs the conversion.