Add safety section to `NonNull::as_*` method docs
This basically adds the safety section of `*mut T::as_{ref,mut}` to the
same methods on `NonNull` with minor modifications to fit the
differences.
Part of #48929.
Simplify array::IntoIter
- Initialization can use `transmute_copy` to do the bitwise copy.
- `as_slice` can use `get_unchecked` and `MaybeUninit::slice_get_ref`,
and `as_mut_slice` can do similar.
- `next` and `next_back` can use the corresponding `Range` methods.
- `Clone` doesn't need any unsafety, and we can dynamically update the
new range to get partial drops if `T::clone` panics.
r? @LukasKalbertodt
Implement `into_keys` and `into_values` for associative maps
This PR implements `into_keys` and `into_values` for HashMap and BTreeMap types. They are implemented as unstable, under `map_into_keys_values` feature.
Fixes#55214.
r? @dtolnay
polymorphize: unevaluated constants
This PR makes polymorphization visit the promoted MIR of unevaluated constants with available promoted MIR instead of visiting the substitutions of that constant - which will mark all of the generic parameters as used; in addition polymorphization will now visit non-promoted unevaluated constants rather than visit their substs.
r? @lcnr
Emit == null instead of <= null for niche check
When the niche maximum is zero, emit a "== zero" check instead of a "<= zero" check. In particular, this avoids the awkward case of "<= null". While LLVM does canonicalize this to "== null", this apparently doesn't happen for constant expressions, leading to the issue in #74425. While that can be addressed on the LLVM side, it still seems prudent to emit sensible IR here, because this will allow null checks to be optimized earlier in the pipeline.
Fixes#74425.
This basically adds the safety section of `*mut T::as_{ref,mut}` to the
same methods on `NonNull` with minor modifications to fit the
differences.
Part of #48929.
When the niche maximum is zero, emit a "== zero" check instead of
a "<= zero" check. In particular, this avoid the awkward case of
"<= null". While LLVM does canonicalize this to "!= null", this
appently doesn't happen for constant expressions, leading to the
issue in #74425. While that can be addressed on the LLVM side, it
still seems prudent to emit sensible IR here, because this will
allow null checks to be optimized earlier in the pipeline.
Fixes#74425.
make MaybeUninit::as_(mut_)ptr const
I think it was just an oversight that they are not const yet.
I also changed their implementation as the old one created references to uninitialized memory.^^
Display elided lifetime for non-reference type in doc
In edition 2018 we encourage writing `<'_>` explicitly, so rustdoc should display like such as well.
Fixes#75225
~~Somehow when I run the compiled rustdoc using `cargo +stage2 doc` on other crates, it correctly produces `<'_>`, but I couldn't get the std doc to do the same with `./x.py doc --stage 2`. Might this be related to the recent change to x.py about how the doc is built?~~
Don't call a function in function-arguments-naked.rs
Fixes#75096
It's U.B. to use anything other than inline assmebling in a naked
function. Fortunately, the `#break` directive works fine without
anything in the function body.
