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authorMatthias Krüger <matthias.krueger@famsik.de>2024-11-20 20:10:12 +0100
committerGitHub <noreply@github.com>2024-11-20 20:10:12 +0100
commit7fc2b337229dfb4bc2e410317af271c1b8dbfe6b (patch)
tree08d5c5b85c484deb0435fe99ea5bcbef2f3bc217 /library/alloc/src/lib.rs
parent71d3c7790f7bcbfc254270ef76c3d772104321e1 (diff)
parent29acf8b422ab446fa4cd51fbb0e5a145f30c1cfc (diff)
downloadrust-7fc2b337229dfb4bc2e410317af271c1b8dbfe6b.tar.gz
rust-7fc2b337229dfb4bc2e410317af271c1b8dbfe6b.zip
Rollup merge of #132708 - estebank:const-as-binding, r=Nadrieril
Point at `const` definition when used instead of a binding in a `let` statement

Modify `PatKind::InlineConstant` to be `ExpandedConstant` standing in not only for inline `const` blocks but also for `const` items. This allows us to track named `const`s used in patterns when the pattern is a single binding. When we detect that there is a refutable pattern involving a `const` that could have been a binding instead, we point at the `const` item, and suggest renaming. We do this for both `let` bindings and `match` expressions missing a catch-all arm if there's at least one single binding pattern referenced.

After:

```
error[E0005]: refutable pattern in local binding
  --> $DIR/bad-pattern.rs:19:13
   |
LL |     const PAT: u32 = 0;
   |     -------------- missing patterns are not covered because `PAT` is interpreted as a constant pattern, not a new variable
...
LL |         let PAT = v1;
   |             ^^^ pattern `1_u32..=u32::MAX` not covered
   |
   = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
   = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html
   = note: the matched value is of type `u32`
help: introduce a variable instead
   |
LL |         let PAT_var = v1;
   |             ~~~~~~~
```

Before:

```
error[E0005]: refutable pattern in local binding
  --> $DIR/bad-pattern.rs:19:13
   |
LL |         let PAT = v1;
   |             ^^^
   |             |
   |             pattern `1_u32..=u32::MAX` not covered
   |             missing patterns are not covered because `PAT` is interpreted as a constant pattern, not a new variable
   |             help: introduce a variable instead: `PAT_var`
   |
   = note: `let` bindings require an "irrefutable pattern", like a `struct` or an `enum` with only one variant
   = note: for more information, visit https://doc.rust-lang.org/book/ch18-02-refutability.html
   = note: the matched value is of type `u32`
```

CC #132582.
Diffstat (limited to 'library/alloc/src/lib.rs')
0 files changed, 0 insertions, 0 deletions