std::future::FutureObj - Rust
Description: API documentation for the Rust `FutureObj` struct in crate `std`.
Keywords: rust, rustlang, rust-lang, FutureObj

# Struct std::future::FutureObj[−][src]

    pub struct FutureObj<'a, T>(_);

🔬 This is a nightly-only experimental API. (`futures_api` #50547)

futures in libcore are unstable

A custom trait object for polling futures, roughly akin to `Box<dyn Future<Output = T> + Send + 'a>`.

This custom trait object was introduced for two reasons:

- Currently it is not possible to take `dyn Trait` by value and `Box<dyn Trait>` is not available in no_std contexts.
- The `Future` trait is currently not object safe: The `Future::poll` method makes uses the arbitrary self types feature and traits in which this feature is used are currently not object safe due to current compiler limitations. (See tracking issue for arbitray self types for more information #44874)

## Methods

###

`impl<'a, T> FutureObj<'a, T>`

[src]

####

`pub fn new<F>(f: F) -> FutureObj<'a, T> where F: Send + UnsafeFutureObj<'a, T>,`

[src]

🔬 This is a nightly-only experimental API. (`futures_api` #50547)

futures in libcore are unstable

Create a `FutureObj` from a custom trait object representation.

## Trait Implementations

###

`impl<'a, T> From<FutureObj<'a, T>> for LocalFutureObj<'a, T>`

[src]

####

`fn from(f: FutureObj<'a, T>) -> LocalFutureObj<'a, T>`

[src]

Performs the conversion.

###

`impl<'a, T> Debug for FutureObj<'a, T>`

[src]

####

`fn fmt(&self, f: &mut Formatter) -> Result<(), Error>`

[src]

Formats the value using the given formatter. Read more

###

`impl<'a, T> Future for FutureObj<'a, T>`

[src]

#### `type Output = T`

🔬 This is a nightly-only experimental API. (`futures_api` #50547)

futures in libcore are unstable

The result of the `Future`.

####

`fn poll(self: PinMut<FutureObj<'a, T>>, cx: &mut Context) -> Poll<T>`

[src]

🔬 This is a nightly-only experimental API. (`futures_api` #50547)

futures in libcore are unstable

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<'a, T> Send for FutureObj<'a, T>`

[src]

###

`impl<'a, F> From<Box<F>> for FutureObj<'a, ()> where F: 'a + Send + Future<Output = ()>,`

[src]

####

`fn from(boxed: Box<F>) -> FutureObj<'a, ()>`

[src]

Performs the conversion.

###

`impl<'a, F> From<PinBox<F>> for FutureObj<'a, ()> where F: 'a + Send + Future<Output = ()>,`

[src]

####

`fn from(boxed: PinBox<F>) -> FutureObj<'a, ()>`

[src]

Performs the conversion.

## Auto Trait Implementations

###

`impl<'a, T> !Sync for FutureObj<'a, T>`

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