rust/tests/ui/mir/issue-112269.stderr
许杰友 Jieyou Xu (Joe) 55b4549602
Show note for type ascription interpreted as a constant pattern, not a new variable
Given the code

```rust
pub fn main() {
    const y: i32 = 4;
    let y: i32 = 3;
}
```

`y` in the let binding is actually interpreted as a constant pattern
and is not a new variable, causing confusing diagnostics about
refutable patterns in local binding.

This commit extends the note for type ascription as a constant pattern
to `AscribeUserType` patterns as well.
2023-06-04 20:49:30 +08:00

32 lines
1.4 KiB
Plaintext

error[E0005]: refutable pattern in local binding
--> $DIR/issue-112269.rs:3:9
|
LL | let x: i32 = 3;
| ^
| |
| patterns `i32::MIN..=3_i32` and `5_i32..=i32::MAX` not covered
| missing patterns are not covered because `x` is interpreted as a constant pattern, not a new variable
| help: introduce a variable instead: `x_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 `i32`
error[E0005]: refutable pattern in local binding
--> $DIR/issue-112269.rs:7:9
|
LL | let y = 4;
| ^
| |
| patterns `i32::MIN..=2_i32` and `4_i32..=i32::MAX` not covered
| missing patterns are not covered because `y` is interpreted as a constant pattern, not a new variable
| help: introduce a variable instead: `y_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 `i32`
error: aborting due to 2 previous errors
For more information about this error, try `rustc --explain E0005`.