diff --git a/src/libcore/future/into_future.rs b/src/libcore/future/into_future.rs new file mode 100644 index 0000000000000..4020c254446e3 --- /dev/null +++ b/src/libcore/future/into_future.rs @@ -0,0 +1,27 @@ +use crate::future::Future; + +/// Conversion into a `Future`. +#[unstable(feature = "into_future", issue = "67644")] +pub trait IntoFuture { + /// The output that the future will produce on completion. + #[unstable(feature = "into_future", issue = "67644")] + type Output; + + /// Which kind of future are we turning this into? + #[unstable(feature = "into_future", issue = "67644")] + type Future: Future; + + /// Creates a future from a value. + #[unstable(feature = "into_future", issue = "67644")] + fn into_future(self) -> Self::Future; +} + +#[unstable(feature = "into_future", issue = "67644")] +impl IntoFuture for F { + type Output = F::Output; + type Future = F; + + fn into_future(self) -> Self::Future { + self + } +} diff --git a/src/libcore/future/mod.rs b/src/libcore/future/mod.rs index b5a102916a07e..6f6009b47e672 100644 --- a/src/libcore/future/mod.rs +++ b/src/libcore/future/mod.rs @@ -10,12 +10,16 @@ use crate::{ }; mod future; +mod into_future; mod pending; mod ready; #[stable(feature = "futures_api", since = "1.36.0")] pub use self::future::Future; +#[unstable(feature = "into_future", issue = "67644")] +pub use into_future::IntoFuture; + #[unstable(feature = "future_readiness_fns", issue = "70921")] pub use pending::{pending, Pending}; #[unstable(feature = "future_readiness_fns", issue = "70921")] diff --git a/src/libstd/future.rs b/src/libstd/future.rs index e2092cfefa369..89dd9fb9b2cd5 100644 --- a/src/libstd/future.rs +++ b/src/libstd/future.rs @@ -2,4 +2,16 @@ #[doc(inline)] #[stable(feature = "futures_api", since = "1.36.0")] -pub use core::future::*; +pub use core::future::Future; + +#[doc(inline)] +#[unstable(feature = "gen_future", issue = "50547")] +pub use core::future::{from_generator, get_context, ResumeTy}; + +#[doc(inline)] +#[unstable(feature = "future_readiness_fns", issue = "70921")] +pub use core::future::{pending, ready, Pending, Ready}; + +#[doc(inline)] +#[unstable(feature = "into_future", issue = "67644")] +pub use core::future::IntoFuture; diff --git a/src/libstd/lib.rs b/src/libstd/lib.rs index ac07af5e278fb..cc3e613fa3d60 100644 --- a/src/libstd/lib.rs +++ b/src/libstd/lib.rs @@ -266,12 +266,15 @@ #![feature(external_doc)] #![feature(fn_traits)] #![feature(format_args_nl)] +#![feature(future_readiness_fns)] +#![feature(gen_future)] #![feature(generator_trait)] #![feature(global_asm)] #![feature(hash_raw_entry)] #![feature(hashmap_internals)] #![feature(int_error_internals)] #![feature(int_error_matching)] +#![feature(into_future)] #![feature(integer_atomics)] #![feature(lang_items)] #![feature(libc)]