Rollup of 13 pull requests
Successful merges:
- #72734 (Reduce duplicate in liballoc reserve error handling)
- #76131 (Don't use `zip` to compare iterators during pretty-print hack)
- #76150 (Don't recommend ManuallyDrop to customize drop order)
- #76275 (Implementation of Write for some immutable ref structs)
- #76489 (Add explanation for E0756)
- #76581 (do not ICE on bound variables, return `TooGeneric` instead)
- #76655 (Make some methods of `Pin` unstable const)
- #76783 (Only get ImplKind::Impl once)
- #76807 (Use const-checking to forbid use of unstable features in const-stable functions)
- #76888 (use if let instead of single match arm expressions)
- #76914 (extend `Ty` and `TyCtxt` lints to self types)
- #77022 (Reduce boilerplate for BytePos and CharPos)
- #77032 (lint missing docs for extern items)
Failed merges:
r? `@ghost`
use if let instead of single match arm expressions
use if let instead of single match arm expressions to compact code and reduce nesting (clippy::single_match)
Use const-checking to forbid use of unstable features in const-stable functions
First step towards #76618.
Currently this code isn't ever hit because `qualify_min_const_fn` runs first and catches pretty much everything. One exception is `const_precise_live_drops`, which does not use the newly added code since it runs as part of a separate pass.
Also contains some unrelated refactoring, which is split into separate commits.
r? @oli-obk
Make some methods of `Pin` unstable const
Make the following methods unstable const under the `const_pin` feature:
- `new`
- `new_unchecked`
- `into_inner`
- `into_inner_unchecked`
- `get_ref`
- `into_ref`
- `get_mut`
- `get_unchecked_mut`
Of these, `into_inner` and `into_inner_unchecked` require the unstable `const_precise_live_drops`.
Also adds tests for these methods in a const context.
Tracking issue: #76654
r? @ecstatic-morse
Don't recommend ManuallyDrop to customize drop order
See
https://internals.rust-lang.org/t/need-for-controlling-drop-order-of-fields/12914/21
for the discussion.
TL;DR: ManuallyDrop is unsafe and footguny, but you can just ask the compiler to do all the work for you by re-ordering declarations.
Specifically, the original example from the docs is much better written as
```rust
struct Peach;
struct Banana;
struct Melon;
struct FruitBox {
melon: Melon,
// XXX: mind the relative drop order of the fields below
peach: Peach,
banana: Banana,
}
```
Don't use `zip` to compare iterators during pretty-print hack
If the right-hand iterator has exactly one more element than the
left-hand iterator, then both iterators will be fully consumed, but
the extra element will never be compared.
Split out from https://github.com/rust-lang/rust/pull/76130
Add optimization to avoid load of address
Look for the sequence
```rust
_2 = &_1;
...
_5 = (*_2)
```
in which we can replace the last statement with `_5 = _1` to avoid the load of _2
Remove duplicated library links between std and libc
The libc crate is already responsible for linking in the appropriate
libraries, and std doing the same thing results in duplicated library
names on the linker command line. Removing this duplication slightly
reduces linker time, and makes it simpler to adjust the set or order of
linked libraries in one place (such as to add static linking support).
If the right-hand iterator has exactly one more element than the
left-hand iterator, then both iterators will be fully consumed, but
the extra element will never be compared.
