rust/compiler/rustc_middle
bors 7fc6365570 Auto merge of #116692 - Nadrieril:half-open-ranges, r=cjgillot
Match usize/isize exhaustively with half-open ranges

The long-awaited finale to the saga of [exhaustiveness checking for integers](https://github.com/rust-lang/rust/pull/50912)!

```rust
match 0usize {
    0.. => {} // exhaustive!
}
match 0usize {
    0..usize::MAX => {} // helpful error message!
}
```

Features:
- Half-open ranges behave as expected for `usize`/`isize`;
- Trying to use `0..usize::MAX` will tell you that `usize::MAX..` is missing and explain why. No more unhelpful "`_` is missing";
- Everything else stays the same.

This should unblock https://github.com/rust-lang/rust/issues/37854.

Review-wise:
- I recommend looking commit-by-commit;
- This regresses perf because of the added complexity in `IntRange`; hopefully not too much;
- I measured each `#[inline]`, they all help a bit with the perf regression (tho I don't get why);
- I did not touch MIR building; I expect there's an easy PR there that would skip unnecessary comparisons when the range is half-open.
2023-11-01 03:17:19 +00:00
..
src Auto merge of #116692 - Nadrieril:half-open-ranges, r=cjgillot 2023-11-01 03:17:19 +00:00
Cargo.toml Clean up rustc_*/Cargo.toml. 2023-10-30 08:46:02 +11:00
messages.ftl Add a custom panic message for resuming gen blocks after they panicked 2023-10-30 10:23:57 +00:00
README.md

For more information about how rustc works, see the rustc dev guide.