[futures] add a few blanket impls to std
these were defined in the futures crate, but with the core definitions moving to std these would need to move too.
Add Future and task system to the standard library
This adds preliminary versions of the `std::future` and `std::task` modules in order to unblock development of async/await (https://github.com/rust-lang/rust/issues/50547). These shouldn't be considered as final forms of these libraries-- design questions about the libraries should be left on https://github.com/rust-lang/rfcs/pull/2418. Once that RFC (or a successor) is merged, these APIs will be adjusted as necessary.
r? @aturon
Clarify the difference between get_mut and into_mut for OccupiedEntry
The examples for both hash_map::OccupiedEntry::get_mut and
hash_map::OccupiedEntry::into_mut were almost identical. This led to some
confusion over the difference, namely why you would ever use get_mut when
into_mut gives alonger lifetime. Reddit thread:
https://www.reddit.com/r/rust/comments/8a5swr/why_does_hashmaps
This commit adds two lines and a comment to the example, to show that the
entry object can be re-used after calling get_mut.
Closes https://github.com/rust-lang/rust/issues/49745
old tests cover the new fast path of str joining already
this adds tests for joining into Strings with long separators (>4 byte) and
for joining into Vec<T>, T: Clone + !Copy. Vec<T: Copy> will be
specialised when specialisation type inference bugs are fixed.
for both Vec<T> and String
- eliminates the boolean first flag in fn join()
for String only
- eliminates repeated bounds checks in join(), concat()
- adds fast paths for small string separators up to a len of 4 bytes
We only need to implement it for `Any + Send + Sync` because in practice
that's the only useful combination for `Arc` and `Any`.
Implementation for #44608 under the `rc_downcast` feature.
As discussed in
https://github.com/rust-lang/rust/issues/49668#issuecomment-384893456
and subsequent, there are use-cases where the OOM handler needs to know
the size of the allocation that failed. The alignment might also be a
cause for allocation failure, so providing it as well can be useful.
Rollup of 11 pull requests
Successful merges:
- #50987 (Underline multiple suggested replacements in the same line)
- #51014 (Add documentation about env! second argument)
- #51034 (Remove unused lowering field and method)
- #51047 (Use AllFacts from polonius-engine)
- #51048 (Add more missing examples for Formatter)
- #51056 (Mention and use `Once::new` instead of `ONCE_INIT`)
- #51059 (What does an expression look like, that consists only of special characters?)
- #51065 (Update nomicon link in transmute docs)
- #51067 (Add inner links in documentation)
- #51070 (Fail typecheck if we encounter a bogus break)
- #51073 (Rename TokenStream::empty to TokenStream::new)
Failed merges:
Add inner links in documentation
From [this SO question](https://stackoverflow.com/q/50518757/2733851) it looks like this page isn't really clear.
I personally do think this page is quite clear, the only think I could think of was adding some references.
std: Ensure OOM is classified as `nounwind`
OOM can't unwind today, and historically it's been optimized as if it can't
unwind. This accidentally regressed with recent changes to the OOM handler, so
this commit adds in a codegen test to assert that everything gets optimized away
after the OOM function is approrpiately classified as nounwind
Closes#50925
stabilize RangeBounds collections_range #30877
The FCP for #30877 closed last month, with the decision to:
1. move from `collections::range::RangeArgument` to `ops::RangeBounds`, and
2. rename `start()` and `end()` to `start_bounds()` and `end_bounds()`.
Simon Sapin already moved it to `ops::RangeBounds` in #49163.
I renamed the functions, and removed the old `collections::range::RangeArgument` alias.
This is my first Rust PR, please let me know if I can improve anything. This passes all tests for me, except the `clippy` tool (which uses `RangeArgument::start()`).
I considered deprecating `start()` and `end()` instead of removing them, but the contribution guidelines indicate we can break `clippy` temporarily. I thought it was best to remove the functions, since we're worried about name collisions with `Range::start` and `end`.
Closes#30877.
From [this SO question](https://stackoverflow.com/q/50518757/2733851) it looks like this page isn't really clear.
I personally do think this page is quite clear, the only think I could think of was adding some references.
OOM can't unwind today, and historically it's been optimized as if it can't
unwind. This accidentally regressed with recent changes to the OOM handler, so
this commit adds in a codegen test to assert that everything gets optimized away
after the OOM function is approrpiately classified as nounwind
Closes#50925
Escape combining characters in char::Debug
Although combining characters are technically printable, they make little sense to print on their own with `Debug`: it'd be better to escape them like non-printable characters.
This is a breaking change, but I imagine the fact `escape_debug` is rare and almost certainly primarily used for debugging that this is an acceptable change.
Resolves#41922.
r? @alexcrichton
cc @clarcharr
