enable align_to tests in Miri
With https://github.com/rust-lang/miri/issues/1074 resolved, we can enable these tests in Miri.
I also tweaked the test sized to get reasonable execution times with decent test coverage.
Use min_specialization in libcore
Getting `TrustedRandomAccess` to work is the main interesting thing here.
- `get_unchecked` is now an unstable, hidden method on `Iterator`
- The contract for `TrustedRandomAccess` is made clearer in documentation
- Fixed a bug where `Debug` would create aliasing references when using the specialized zip impl
- Added tests for the side effects of `next_back` and `nth`.
closes#68536
Switch from indexing to zip, and also use `write` on `MaybeUninit`.
Add array_map feature to core/src/lib
Attempt to fix issue of no such feature
Update w/ pickfire's review
This changes a couple of names around, adds another small test of variable size,
and hides the rustdoc #![feature(..)].
Fmt doctest
Add suggestions from lcnr
Add basic test
And also run fmt which is where the other changes are from
Fix mut issues
These only appear when running tests, so resolved by adding mut
Swap order of forget
Add pub and rm guard impl
Add explicit type to guard
Add safety note
Change guard type from T to S
It should never have been T, as it guards over [MaybeUninit<S>; N]
Also add feature to test
Stabilize `Result::as_deref` and `as_deref_mut`
FCP completed in https://github.com/rust-lang/rust/issues/50264#issuecomment-645681400.
This PR stabilizes two new APIs for `std::result::Result`:
```rust
fn as_deref(&self) -> Result<&T::Target, &E> where T: Deref;
fn as_deref_mut(&mut self) -> Result<&mut T::Target, &mut E> where T: DerefMut;
```
This PR also removes two rarely used unstable APIs from `Result`:
```rust
fn as_deref_err(&self) -> Result<&T, &E::Target> where E: Deref;
fn as_deref_mut_err(&mut self) -> Result<&mut T, &mut E::Target> where E: DerefMut;
```
Closes#50264
