use crate::future::Future;
use crate::marker::Tuple;
#[unstable(feature = "async_closure", issue = "62290")]
#[rustc_paren_sugar]
#[fundamental]
#[must_use = "async closures are lazy and do nothing unless called"]
#[lang = "async_fn"]
pub trait AsyncFn<Args: Tuple>: AsyncFnMut<Args> {
#[unstable(feature = "async_fn_traits", issue = "none")]
extern "rust-call" fn async_call(&self, args: Args) -> Self::CallRefFuture<'_>;
}
#[unstable(feature = "async_closure", issue = "62290")]
#[rustc_paren_sugar]
#[fundamental]
#[must_use = "async closures are lazy and do nothing unless called"]
#[lang = "async_fn_mut"]
pub trait AsyncFnMut<Args: Tuple>: AsyncFnOnce<Args> {
#[unstable(feature = "async_fn_traits", issue = "none")]
#[lang = "call_ref_future"]
type CallRefFuture<'a>: Future<Output = Self::Output>
where
Self: 'a;
#[unstable(feature = "async_fn_traits", issue = "none")]
extern "rust-call" fn async_call_mut(&mut self, args: Args) -> Self::CallRefFuture<'_>;
}
#[unstable(feature = "async_closure", issue = "62290")]
#[rustc_paren_sugar]
#[fundamental]
#[must_use = "async closures are lazy and do nothing unless called"]
#[lang = "async_fn_once"]
pub trait AsyncFnOnce<Args: Tuple> {
#[unstable(feature = "async_fn_traits", issue = "none")]
#[lang = "call_once_future"]
type CallOnceFuture: Future<Output = Self::Output>;
#[unstable(feature = "async_fn_traits", issue = "none")]
#[lang = "async_fn_once_output"]
type Output;
#[unstable(feature = "async_fn_traits", issue = "none")]
extern "rust-call" fn async_call_once(self, args: Args) -> Self::CallOnceFuture;
}
mod impls {
use super::{AsyncFn, AsyncFnMut, AsyncFnOnce};
use crate::marker::Tuple;
#[unstable(feature = "async_fn_traits", issue = "none")]
impl<A: Tuple, F: ?Sized> AsyncFn<A> for &F
where
F: AsyncFn<A>,
{
extern "rust-call" fn async_call(&self, args: A) -> Self::CallRefFuture<'_> {
F::async_call(*self, args)
}
}
#[unstable(feature = "async_fn_traits", issue = "none")]
impl<A: Tuple, F: ?Sized> AsyncFnMut<A> for &F
where
F: AsyncFn<A>,
{
type CallRefFuture<'a> = F::CallRefFuture<'a> where Self: 'a;
extern "rust-call" fn async_call_mut(&mut self, args: A) -> Self::CallRefFuture<'_> {
F::async_call(*self, args)
}
}
#[unstable(feature = "async_fn_traits", issue = "none")]
impl<'a, A: Tuple, F: ?Sized> AsyncFnOnce<A> for &'a F
where
F: AsyncFn<A>,
{
type Output = F::Output;
type CallOnceFuture = F::CallRefFuture<'a>;
extern "rust-call" fn async_call_once(self, args: A) -> Self::CallOnceFuture {
F::async_call(self, args)
}
}
#[unstable(feature = "async_fn_traits", issue = "none")]
impl<A: Tuple, F: ?Sized> AsyncFnMut<A> for &mut F
where
F: AsyncFnMut<A>,
{
type CallRefFuture<'a> = F::CallRefFuture<'a> where Self: 'a;
extern "rust-call" fn async_call_mut(&mut self, args: A) -> Self::CallRefFuture<'_> {
F::async_call_mut(*self, args)
}
}
#[unstable(feature = "async_fn_traits", issue = "none")]
impl<'a, A: Tuple, F: ?Sized> AsyncFnOnce<A> for &'a mut F
where
F: AsyncFnMut<A>,
{
type Output = F::Output;
type CallOnceFuture = F::CallRefFuture<'a>;
extern "rust-call" fn async_call_once(self, args: A) -> Self::CallOnceFuture {
F::async_call_mut(self, args)
}
}
}
mod internal_implementation_detail {
#[lang = "async_fn_kind_helper"]
trait AsyncFnKindHelper<GoalKind> {
#[lang = "async_fn_kind_upvars"]
type Upvars<'closure_env, Inputs, Upvars, BorrowedUpvarsAsFnPtr>;
}
}