Trait futures_core::future::UnsafeFutureObj

pub unsafe trait UnsafeFutureObj<'a, T>: 'a {
    fn into_raw(self) -> *mut ();
    unsafe fn poll(ptr: *mut (), lw: &LocalWaker) -> Poll<T>;
    unsafe fn drop(ptr: *mut ());
}

A custom implementation of a future trait object for FutureObj, providing a hand-rolled vtable.

This custom representation is typically used only in no_std contexts, where the default Box-based implementation is not available.

The implementor must guarantee that it is safe to call poll repeatedly (in a non-concurrent fashion) with the result of into_raw until drop is called.

Required Methods

fn into_raw(self) -> *mut ()

Convert an owned instance into a (conceptually owned) void pointer.

unsafe fn poll(ptr: *mut (), lw: &LocalWaker) -> Poll<T>

Poll the future represented by the given void pointer.

Safety

The trait implementor must guarantee that it is safe to repeatedly call poll with the result of into_raw until drop is called; such calls are not, however, allowed to race with each other or with calls to drop.

unsafe fn drop(ptr: *mut ())

Drops the future represented by the given void pointer.

Safety

The trait implementor must guarantee that it is safe to call this function once per into_raw invocation; that call cannot race with other calls to drop or poll.

Implementations on Foreign Types

impl<'a, T, F> UnsafeFutureObj<'a, T> for &'a mut F where     F: Future<Output = T> + Unpin + 'a,

fn into_raw(self) -> *mut ()

unsafe fn poll(ptr: *mut (), lw: &LocalWaker) -> Poll<T>

unsafe fn drop(_ptr: *mut ())

impl<'a, T, F> UnsafeFutureObj<'a, T> for Pin<&'a mut F> where     F: Future<Output = T> + 'a,

fn into_raw(self) -> *mut ()

unsafe fn poll(ptr: *mut (), lw: &LocalWaker) -> Poll<T>

unsafe fn drop(_ptr: *mut ())

impl<'a, T, F> UnsafeFutureObj<'a, T> for Box<F> where     F: Future<Output = T> + 'a,

fn into_raw(self) -> *mut ()

unsafe fn poll(ptr: *mut (), lw: &LocalWaker) -> Poll<T>

unsafe fn drop(ptr: *mut ())

impl<'a, T, F> UnsafeFutureObj<'a, T> for Pin<Box<F>> where     F: Future<Output = T> + 'a,

fn into_raw(self) -> *mut ()

unsafe fn poll(ptr: *mut (), lw: &LocalWaker) -> Poll<T>

unsafe fn drop(ptr: *mut ())

Implementors