commit 15f566626170d6a30dd606c4271445d26230dc74
author Stuart Cook <Zalathar@users.noreply.github.com> Tue Apr 15 15:47:25 2025 +1000
committer GitHub <noreply@github.com> Tue Apr 15 15:47:25 2025 +1000
tree ef774195e2de028a435a102296fdce93dbedd36f
parent 49f45981bf39b779d0ea8f8b3ba8947d47d31fa9
parent 3c7cbc98d1ddb01f57e24232406787008827bd46

Rollup merge of #138393 - oli-obk:pattern-type-in-pattern, r=BoxyUwU

Allow const patterns of matches to contain pattern types

Trying to pattern match on a type containing a pattern type will currently fail with an ICE

```rust
error: internal compiler error: compiler/rustc_mir_build/src/builder/matches/test.rs:459:18: invalid type for non-scalar compare: (u32) is 1..
  --> src/main.rs:22:5
   |
22 |     TWO => {}
   |     ^^^
```

because the compiler tries to generate a MIR `BinOp(Eq)` operation on a pattern type, which is not supported. While we could support that, there are side effects of allowing this (none that would compile, but the compiler would simultaneously think it could `==` pattern types and that it could not because `PartialEq` is not implemented. So instead I change the logic for pattern matching to transmute pattern types to their base type before comparing.

r? ```@BoxyUwU```

cc #123646 ```@scottmcm``` ```@joshtriplett```