Fixed outdated reference to `waker` argument; now futures are passed a
`Context`, from which one can obtain a `waker`.
Cleaned up explanation of what happens when you call `poll` on a completed
future. It doesn't make sense to say that `poll` implementations can't cause
memory unsafety; no safe function is ever allowed to cause memory unsafety, so
why mention it here? It seems like the intent is to say that the `Future` trait
doesn't say what the consequences of excess polls will be, and they might be
bad; but that the usual constraints that Rust imposes on any non-`unsafe`
function still apply. It's also oddly specific to say 'memory corruption'
instead of just 'undefined behavior'; UB is a bit jargony, so the text should
provide examples.
Fix typo in std::future::Future docs
I am not quite sure if this is actually a typo but
1. to me the sentence doesn't make sense if it says "expect"
2. I hope that `Future`s are not really allowed to cause memory unsafety if they are polled after completion.
There are two big categories of changes in here
- Removing lifetimes from common traits that can essentially never user a lifetime from an input (particularly `Drop` & `Debug`)
- Forwarding impls that are only possible because the lifetime doesn't matter (like `impl<R: Read + ?Sized> Read for &mut R`)
I omitted things that seemed like they could be more controversial, like the handful of iterators that have a `Item: 'static` despite the iterator having a lifetime or the `PartialEq` implementations where the flipped one cannot elide the lifetime.
This change updates the future and task API as discussed in the stabilization RFC at https://github.com/rust-lang/rfcs/pull/2592.
Changes:
- Replacing UnsafeWake with RawWaker and RawWakerVtable
- Removal of LocalWaker
- Removal of Arc-based Wake trait
Remove pin::Unpin reexport and add Unpin to the prelude.
Change Pin associated functions to methods.
Rename get_mut_unchecked_ to get_unchecked_mut
Remove impl Unpin for Pin
Mark Pin repr(transparent)
