deref patterns: impl `DerefPure` for more std types
Context: [deref patterns](https://github.com/rust-lang/rust/issues/87121). The requirements of `DerefPure` aren't precise yet, but these types unambiguously satisfy them.
Interestingly, a hypothetical `impl DerefMut for Cow` that does a `Clone` would *not* be eligible for `DerefPure` if we allow mixing deref patterns with normal patterns. If the following is exhaustive then the `DerefMut` would cause UB:
```rust
match &mut Cow::Borrowed(&()) {
Cow::Owned(_) => ..., // Doesn't match
deref!(_x) if false => ..., // Causes the variant to switch to `Owned`
Cow::Borrowed(_) => ..., // Doesn't match
// We reach unreachable
}
```
Document never type fallback in `!`'s docs
Pulled the documentation I've written for #123939.
I want a single place where never type fallback is explained, which can be referred in all the lints and migration materials.
Use `target_vendor = "apple"` instead of `target_os = "..."`
Use `target_vendor = "apple"` instead of `all(target_os = "macos", target_os = "ios", target_os = "tvos", target_os = "watchos", target_os = "visionos")`.
The apple targets are quite close to being identical, with iOS, tvOS, watchOS and visionOS being even closer, so using `target_vendor` when possible makes it clearer when something is actually OS-specific, or just Apple-specific.
Note that `target_vendor` will [be deprecated in the future](https://github.com/rust-lang/rust/issues/100343), but not before an alternative (like `target_family = "apple"`) is available.
While doing this, I found various inconsistencies and small mistakes in the standard library, see the commits for details. Will follow-up with an extra PR for a similar issue that need a bit more discussion. EDIT: https://github.com/rust-lang/rust/pull/124494
Since you've talked about using `target_vendor = "apple"` in the past:
r? workingjubilee
CC `@simlay,` `@thomcc`
`@rustbot` label O-macos O-ios O-tvos O-watchos O-visionos
Fix#124478 - offset_of! returns a temporary
This was due to the must_use() call. Adding HIR's `OffsetOf` to the must_use checking within the compiler avoids this issue while maintaining the lint output.
Fixes#124478. `@tgross35`
Update `is_val_statically_known` Docs
* Add `Type Requirements` section, listing the allowed inputs, as requested by #121115
* Add `Pointers` subsection, explaining is_val_statically_known handles pointers.
* Add `Stability concerns` section, referring to other documentation relating to consistency in `const` functions.
Fixes#121115
Sorry this took so long.
Abort a process when FD ownership is violated
When an owned FD has already been closed before it's dropped that means something else touched an FD in ways it is not allowed to. At that point things can already be arbitrarily bad, e.g. clobbered mmaps. Recovery is not possible.
All we can do is hasten the fire.
Unlike the previous attempt in #124130 this shouldn't suffer from the possibility that FUSE filesystems can return arbitrary errors.
Convert some iter macros to normal functions
With all the MIR optimization changes that have happened since these were written, let's see if they still actually matter.
\*perf comes back\*
Well, it looks like it's not longer relevant for instruction, cycle, nor wall-time perf. Looks like a bunch of things are maybe 10kb bigger in debug, but some are also 50k *smaller* in debug.
So I think they should switch to being normal functions as the "greatly improves performance" justification for them being macros seems to no longer be true -- probably thanks to us always building `core` with `-Z inline-mir` so the difference is negligible.
Add diagnostic item for `std::iter::Enumerate`
This adds a diagnostic item for `std::iter::Enumerate`. The change will be used by the clippy `unused_enumerate_index` lint to move away from type paths to using diagnostic items.
see: https://github.com/rust-lang/rust-clippy/issues/5393
Rollup of 3 pull requests
Successful merges:
- #124003 (Dellvmize some intrinsics (use `u32` instead of `Self` in some integer intrinsics))
- #124169 (Don't fatal when calling `expect_one_of` when recovering arg in `parse_seq`)
- #124286 (Subtree sync for rustc_codegen_cranelift)
r? `@ghost`
`@rustbot` modify labels: rollup
Dellvmize some intrinsics (use `u32` instead of `Self` in some integer intrinsics)
This implements https://github.com/rust-lang/compiler-team/issues/693 minus what was implemented in #123226.
Note: I decided to _not_ change `shl`/... builder methods, as it just doesn't seem worth it.
r? ``@scottmcm``
alloc::Layout: explicitly document size invariant on the type level
https://github.com/rust-lang/rust/pull/95295 added this to the constructor, but it seems worth documenting the type invariant at the type level.
panic_str only exists for the migration to 2021 panic macros
The only caller is `expect_failed`, which is already a cold inline(never) function, so inlining into that function should be fine. (And indeed `panic_str` was `#[inline]` anyway.)
The existence of panic_str risks someone calling it when they should call `panic` instead, and I can't see a reason why this footgun should exist.
I also extended the comment in `panic` to explain why it needs a `'static` string -- I know I've wondered about this in the past and it took me quite a while to understand.
