Add unstable Iterator::copied()
Initially suggested at https://github.com/bluss/rust-itertools/pull/289, however the maintainers of itertools suggested this may be better of in a standard library.
The intent of `copied` is to avoid accidentally cloning iterator elements after doing a code refactoring which causes a structure to be no longer `Copy`. This is a relatively common pattern, as it can be seen by calling `rg --pcre2 '[.]map[(][|](?:(\w+)[|] [*]\1|&(\w+)[|] \2)[)]'` on Rust main repository. Additionally, many uses of `cloned` actually want to simply `Copy`, and changing something to be no longer copyable may introduce unnoticeable performance penalty.
Also, this makes sense because the standard library includes `[T].copy_from_slice` to pair with `[T].clone_from_slice`.
This also adds `Option::copied`, because it makes sense to pair it with `Iterator::copied`. I don't think this feature is particularly important, but it makes sense to update `Option` along with `Iterator` for consistency.
Update the stdsimd submodule
This brings in a few updates:
* Update wasm intrinsic naming for atomics
* Update and reimplement most simd128 wasm intrinsics
* Other misc improvements here and there, including a small start to
AVX-512 intrinsics
Pin stabilization
This implements the changes suggested in https://github.com/rust-lang/rust/issues/55766#issue-378417538 and stabilizes the `pin` feature. @alexcrichton also listed several "blockers" in that issue, but then in [this comment](https://github.com/rust-lang/rust/issues/55766#issuecomment-445074980) mentioned that they're more "TODO items":
> In that vein I think it's fine for a stabilization PR to be posted at any time now with FCP lapsed for a week or so now. The final points about self/pin/pinned can be briefly discussed there (if even necessary, they could be left as the proposal above).
Let's settle these last bits here and get this thing stabilized! :)
r? @alexcrichton
cc @withoutboats
Changes the original example to use more idiomatic formatting as well
as `.checked_add`. Also adds a second example to show a case where the
`.collect` returns `None`.
Mem uninit doc ptr drop
Extend the mem::uninitialized documentation to account for partially initialized arrays and how to correctly handle these. These are used in some datastructures (trees for example) or in FFI.
r? @Manishearth
deny intra-doc link resolution failures in libstd
Fixes#56693.
Until we land a fix for the underlying issue (#56922), we can at least fix the failures in libstd so they don't propagate to downstream crates.
rename div_euc -> div_euclid, and mod_euc -> rem_euclid
logic is written up in #49048
Also, update the documentation slightly.
cc @alexcrichton @clarcharr @varkor
Add DoubleEndedIterator::nth_back
As suggested by #54054. This doesn't fix that issue, as this doesn't add enough implementations to optimise that specific use case, but it adds the method and a few (relatively) trivial overrides to work as an initial implementation.
It's probably going to be a lot of work adding `nth_back` implementations everywhere, and I don't have the time to include it all in this commit. But, it's a start. :)
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)
This lets you write methods using `self: Rc<Self>`, `self: Arc<Self>`, `self: Pin<&mut Self>`, `self: Pin<Box<Self>`, and other combinations involving `Pin` and another stdlib receiver type, without needing the `arbitrary_self_types`. Other user-created receiver types can be used, but they still require the feature flag to use.
This is implemented by introducing a new trait, `Receiver`, which the method receiver's type must implement if the `arbitrary_self_types` feature is not enabled. To keep composed receiver types such as `&Arc<Self>` unstable, the receiver type is also required to implement `Deref<Target=Self>` when the feature flag is not enabled.
This lets you use `self: Rc<Self>` and `self: Arc<Self>` in stable Rust, which was not allowed previously. It was agreed that they would be stabilized in #55786. `self: Pin<&Self>` and other pinned receiver types do not require the `arbitrary_self_types` feature, but they cannot be used on stable because `Pin` still requires the `pin` feature.
Fix grammar in compiler error for array iterators
This fixes a small grammatical mistake in the message the compiler gives when attempting to iterate directly over an array `arr` without calling `arr.iter()` or borrowing `&arr`.
Fix various aspects around `let` bindings inside const functions
* forbid `let` bindings in const contexts that use short circuiting operators
* harden analysis code against derefs of mutable references
Initially this PR was about stabilizing `let` bindings, but too many flaws were exposed that need some more testing on nightly
This brings in a few updates:
* Update wasm intrinsic naming for atomics
* Update and reimplement most simd128 wasm intrinsics
* Other misc improvements here and there, including a small start to
AVX-512 intrinsics
Remove u8 cttz hack
This issue has since been fixed in LLVM: 1886c8e29a
Furthermore this code doesn't actually work, because the 8 literal does not match the $BITS provided from the macro invocation, so effectively this was just dead code. Ref #43024.
What LLVM does is still not ideal for CPUs that only have bsf but not tzcnt, will create a patch for that later.
r? @nagisa
