Avoid erase_regions_ty queries if there are no regions to erase
It's overall faster to perform this extra check than to perform the
query, even if the result is already in the query cache.
Kill remaining uses of mem::uninitialized in libcore, liballoc
Kill remaining uses of mem::uninitialized in libcore and liballoc, and enable a lint that will warn when uses are added again in the future.
To avoid casting raw pointers around (which is always very dangerous because it is not typechecked at all -- it doesn't even get the "same size" sanity check that `transmute` gets), I also added two new functions to `MaybeUninit`:
```rust
/// Get a pointer to the first contained values.
pub fn first_ptr(this: &[MaybeUninit<T>]) -> *const T {
this as *const [MaybeUninit<T>] as *const T
}
/// Get a mutable pointer to the first contained values.
pub fn first_mut_ptr(this: &mut [MaybeUninit<T>]) -> *mut T {
this as *mut [MaybeUninit<T>] as *mut T
}
```
I changed some of the existing code to use array-of-`MaybeUninit` instead of `MaybeUninit`-of-array, successfully removing raw pointer casts there as well.
Using CC, CFLAGS, CXX, CXXFLAGS, AR and RANLIB breaks cross compilation
because host is built first and has correct values. The same
values are incorrect for the target however.
Use pinning for generators to make trait safe
I'm unsure whether there needs to be any changes to the actual generator transform. Tests are passing so the fact that `Pin<&mut T>` is fundamentally the same as `&mut T` seems to allow it to still work, but maybe there's something subtle here that could go wrong.
This is specified in [RFC 2349 § Immovable generators](https://github.com/rust-lang/rfcs/blob/master/text/2349-pin.md#immovable-generators) (although, since that RFC it has become safe to create an immovable generator, and instead it's unsafe to resume any generator; with these changes both are now safe and instead the unsafety is moved to creating a `Pin<&mut [static generator]>` which there are safe APIs for).
CC #43122
Unused variable suggestions apply on all patterns.
Fixes#56685.
This PR extends existing suggestions to prefix unused variable bindings in match arms with an underscore so that it applies to all patterns in a match arm.
r? @estebank
cc @alexcrichton (since you filed the issue)
This commit extends existing suggestions to prefix unused variable
bindings in match arms with an underscore so that it applies to all
patterns in a match arm.
Simplify `ConstValue::ScalarPair`
While looking at #57432 I realized that some of our types for representing constants are very big. This reduces `LazyConst` to 3/4th of its original size and simplifies some code around slices at the same time.
r? @RalfJung
Refactor core::iter module
A while back, I refactored `core::ops` in #42523 because the module had become a giant mess and was difficult to modify. Now, I'm doing the same with the `core::iter` module.
Like the `core::ops` refactor, things have been split up into multiple commits to make rebasing easier, and so that you can follow changes. Although the diffs are hard to decipher, the only actual code changes I've made in the first few commits are to modify exports and imports. I save all of the actual code refactoring, e.g. modifying what methods are called, for the end.
When mentioning lifetimes, only invert wording between the expected trait and the self type when the self type has the vid.
This way, the lifetimes always stay close to the self type or trait ref that actually contains them.
