Previously some code paths would fail to evaluate the rvalue, while
incorrectly indicating success with `Ok`. As a result the previous value
of lhs could have been incorrectly const propagated.
Suggest to specify a target triple when lang item is missing
It is very common for newbies to embedded to hit this confusing error when forgetting to specify the target.
Source: me googling this error many times.
## Possible changes
* We could possibly restrict the note+help to only be included on eh_personality lang item if that helped reduce false positives, but its also possible doing so would just increase false negatives
* Open to any suggestions on rewriting the messages
* We could possibly remove the `.cargo/config` alternative to avoid the message getting too noisy but I think its valuable to have as its the correct approach for most embedded projects so that `cargo build` just works.
r? rust-lang/diagnostics
add BinaryHeap::try_reserve and BinaryHeap::try_reserve_exact
`try_reserve` of many collections were stablized in https://github.com/rust-lang/rust/pull/87993 in 1.57.0. Add `try_reserve` for the rest collections such as `BinaryHeap` should be not controversial.
Use spare_capacity_mut instead of invalid unchecked indexing when joining str
This is a fix for https://github.com/rust-lang/rust/issues/91574
I think in general I'd prefer to see this code implemented with raw pointers or `MaybeUninit::write_slice`, but there's existing code in here based on copying from slice to slice, so converting everything from `&[T]` to `&[MaybeUninit<T>]` is less disruptive.
manually implement `Hash` for `DefId`
This might speed up hashing for hashers that can work on individual u64s. Just as an experiment, suggested in a reddit thread on `FxHasher`. cc `@nnethercote`
Note that this should not be merged as is without cfg-ing the code path for 64 bits.
This is a type for efficiently and easily constructing the part of a URL
after the domain: `nightly/core/str/struct.Bytes.html`.
It allows simplifying some code and avoiding some allocations in the
`href_*` functions.
It will also allow making `Cache.paths` et al. use `Symbol` without
having to allocate `String`s in the `href_*` functions. `String`s would
be necessary otherwise because `Symbol::as_str()` returns `SymbolStr`,
whose `Deref<Target = str>` impl requires the `str` to not outlive it.
This is the primary motivation for the addition of `UrlPartsBuilder`.
