Get rid of bounds check in slice::chunks_exact() and related function…
…s during construction
LLVM can't figure out in
let rem = self.len() % chunk_size;
let len = self.len() - rem;
let (fst, snd) = self.split_at(len);
and
let rem = self.len() % chunk_size;
let (fst, snd) = self.split_at(rem);
that the index passed to split_at() is smaller than the slice length and
adds a bounds check plus panic for it.
Apart from removing the overhead of the bounds check this also allows
LLVM to optimize code around the ChunksExact iterator better.
Use intra-doc links for `core/src/slice.mod.rs`
partial help in #75080
r? @jyn514
- most are using primitive types links, which cannot be used with intra links at the moment
- also `std` cannot be referenced in any link, `std::ptr::NonNull` and `std::slice` could not be referenced
Make some Ordering methods const
Constify the following methods of `core::cmp::Ordering`:
- `reverse`
- `then`
Possible because of #49146 (Allow `if` and `match` in constants).
Tracking issue: #76113
LLVM can't figure out in
let rem = self.len() % chunk_size;
let len = self.len() - rem;
let (fst, snd) = self.split_at(len);
and
let rem = self.len() % chunk_size;
let (fst, snd) = self.split_at(rem);
that the index passed to split_at() is smaller than the slice length and
adds a bounds check plus panic for it.
Apart from removing the overhead of the bounds check this also allows
LLVM to optimize code around the ChunksExact iterator better.
These are unsafe variants of the non-unchecked functions and don't do
any bounds checking.
For the time being these are not public and only a preparation for the
following commit. Making it public and stabilization can follow later
and be discussed in https://github.com/rust-lang/rust/issues/76014 .
`alloc::slice` uses `core::slice` functions, documentation are copied
from there and the links as well without resolution. `crate::ptr...`
cannot be resolved in `alloc::slice`, but `ptr` itself is imported in
both `alloc::slice` and `core::slice`, so we used that instead.
Move to intra-doc links for library/core/src/sync/atomic.rs
Helps with #75080.
@rustbot modify labels: T-doc, A-intra-doc-links, T-rustdoc
Known issues:
* Link from core to std:
[`Arc`]
[`std:🧵:yield_now`]
[`std:🧵:sleep`]
[`std::sync::Mutex`]
Fix potential UB in align_offset doc examples
Currently it takes a pointer only to the first element in the array, this changes the code to take a pointer to the whole array.
miri can't catch this right now because it later calls `x.len()` which re-tags the pointer for the whole array.
https://github.com/rust-lang/miri/issues/1526#issuecomment-680897144
Unconfuse Unpin docs a bit
* Don't say that Unpin is used to prevent moves, because it is used
to *allow* moves
* Be more precise about kindedness of things, it is
`Pin<Pointer<Data>>`, rather than just `Pin<Pointer>`.
I would like to propose these two simple methods for stabilization:
- Knowing that a range is exhaused isn't otherwise trivial
- Clippy would like to suggest them, but had to do extra work to disable that path <https://github.com/rust-lang/rust-clippy/issues/3807> because they're unstable
- These work on `PartialOrd`, consistently with now-stable `contains`, and are thus more general than iterator-based approaches that need `Step`
- They've been unchanged for some time, and have picked up uses in the compiler
- Stabilizing them doesn't block any future iterator-based is_empty plans, as the inherent ones are preferred in name resolution
* Don't say that Unpin is used to prevent moves, because it is used
to *allow* moves
* Be more precise about kindedness of things, it is
`Pin<Pointer<Data>>`, rather than just `Pin<Pointer>`.
Report an ambiguity if both modules and primitives are in scope for intra-doc links
Closes https://github.com/rust-lang/rust/issues/75381
- Add a new `prim@` disambiguator, since both modules and primitives are in the same namespace
- Refactor `report_ambiguity` into a closure
Additionally, I noticed that rustdoc would previously allow `[struct@char]` if `char` resolved to a primitive (not if it had a DefId). I fixed that and added a test case.
I also need to update libstd to use `prim@char` instead of `type@char`. If possible I would also like to refactor `ambiguity_error` to use `Disambiguator` instead of its own hand-rolled match - that ran into issues with `prim@` (I updated one and not the other) and it would be better for them to be in sync.
Use allow(unused_imports) instead of cfg(doc) for imports used only for intra-doc links
This prevents links from breaking when items are re-exported in a
different crate and the original isn't being documented.
Spotted in https://github.com/rust-lang/rust/pull/75832#discussion_r475275837 (thanks ollie!)
r? @ollie27
