Remove spawning from task::Context

[rust.git] / src / liballoc / boxed.rs

diff --git a/src/liballoc/boxed.rs b/src/liballoc/boxed.rs
index 29ba433bec7f52ed8a9791baf2a0c176e14c8856..d4cca387f0689ae43135f7c678a7e3580ef001d9 100644 (file)
--- a/src/liballoc/boxed.rs
+++ b/src/liballoc/boxed.rs
@@ -60,18 +60,17 @@
 use core::cmp::Ordering;
 use core::convert::From;
 use core::fmt;
-use core::future::{Future, FutureObj, LocalFutureObj, UnsafeFutureObj};
+use core::future::Future;
 use core::hash::{Hash, Hasher};
 use core::iter::FusedIterator;
 use core::marker::{Unpin, Unsize};
 use core::mem;
-use core::pin::PinMut;
+use core::pin::Pin;
 use core::ops::{CoerceUnsized, Deref, DerefMut, Generator, GeneratorState};
 use core::ptr::{self, NonNull, Unique};
-use core::task::{Context, Poll, Spawn, SpawnErrorKind, SpawnObjError};
+use core::task::{LocalWaker, Poll};
 
 use raw_vec::RawVec;
-use pin::PinBox;
 use str::from_boxed_utf8_unchecked;
 
 /// A pointer type for heap allocation.
@@ -97,6 +96,12 @@ impl<T> Box<T> {
     pub fn new(x: T) -> Box<T> {
         box x
     }
+
+    #[unstable(feature = "pin", issue = "49150")]
+    #[inline(always)]
+    pub fn pinned(x: T) -> Pin<Box<T>> {
+        (box x).into()
+    }
 }
 
 impl<T: ?Sized> Box<T> {
@@ -427,6 +432,16 @@ fn from(t: T) -> Self {
     }
 }
 
+#[unstable(feature = "pin", issue = "49150")]
+impl<T> From<Box<T>> for Pin<Box<T>> {
+    fn from(boxed: Box<T>) -> Self {
+        // It's not possible to move or replace the insides of a `Pin<Box<T>>`
+        // when `T: !Unpin`,  so it's safe to pin it directly without any
+        // additional requirements.
+        unsafe { Pin::new_unchecked(boxed) }
+    }
+}
+
 #[stable(feature = "box_from_slice", since = "1.17.0")]
 impl<'a, T: Copy> From<&'a [T]> for Box<[T]> {
     fn from(slice: &'a [T]) -> Box<[T]> {
@@ -789,63 +804,7 @@ unsafe fn resume(&mut self) -> GeneratorState<Self::Yield, Self::Return> {
 impl<F: ?Sized + Future + Unpin> Future for Box<F> {
     type Output = F::Output;
 
-    fn poll(mut self: PinMut<Self>, cx: &mut Context) -> Poll<Self::Output> {
-        PinMut::new(&mut **self).poll(cx)
-    }
-}
-
-#[unstable(feature = "futures_api", issue = "50547")]
-unsafe impl<'a, T, F> UnsafeFutureObj<'a, T> for Box<F>
-    where F: Future<Output = T> + 'a
-{
-    fn into_raw(self) -> *mut () {
-        Box::into_raw(self) as *mut ()
-    }
-
-    unsafe fn poll(ptr: *mut (), cx: &mut Context) -> Poll<T> {
-        let ptr = ptr as *mut F;
-        let pin: PinMut<F> = PinMut::new_unchecked(&mut *ptr);
-        pin.poll(cx)
-    }
-
-    unsafe fn drop(ptr: *mut ()) {
-        drop(Box::from_raw(ptr as *mut F))
-    }
-}
-
-#[unstable(feature = "futures_api", issue = "50547")]
-impl<Sp> Spawn for Box<Sp>
-    where Sp: Spawn + ?Sized
-{
-    fn spawn_obj(
-        &mut self,
-        future: FutureObj<'static, ()>,
-    ) -> Result<(), SpawnObjError> {
-        (**self).spawn_obj(future)
-    }
-
-    fn status(&self) -> Result<(), SpawnErrorKind> {
-        (**self).status()
-    }
-}
-
-#[unstable(feature = "futures_api", issue = "50547")]
-impl<'a, F: Future<Output = ()> + Send + 'a> From<Box<F>> for FutureObj<'a, ()> {
-    fn from(boxed: Box<F>) -> Self {
-        FutureObj::new(boxed)
-    }
-}
-
-#[unstable(feature = "futures_api", issue = "50547")]
-impl<'a, F: Future<Output = ()> + 'a> From<Box<F>> for LocalFutureObj<'a, ()> {
-    fn from(boxed: Box<F>) -> Self {
-        LocalFutureObj::new(boxed)
-    }
-}
-
-#[unstable(feature = "pin", issue = "49150")]
-impl<T: Unpin + ?Sized> From<PinBox<T>> for Box<T> {
-    fn from(pinned: PinBox<T>) -> Box<T> {
-        unsafe { PinBox::unpin(pinned) }
+    fn poll(mut self: Pin<&mut Self>, lw: &LocalWaker) -> Poll<Self::Output> {
+        F::poll(Pin::new(&mut *self), lw)
     }
 }