Overloaded function error not caught with multiple impls

[nrc]

E.g.,

struct Type;

impl Type {
  fn a(_x: (), _y: ()) -> () {
  }
}
impl Type {
  fn a(_x: ()) -> () {
  }
}

fn main() {
}

Putting the two as into the same impl gives the expected error.

From rust-lang/rfcs#1614

[nagisa]

I’m pretty sure we have a bug for this already, but my search skills fail me.

[Mark-Simulacrum]

@nagisa You were probably thinking of the rfcs#1614 issue (from which this was created). I couldn't find anything else similar either.

[durka]

There was #31925 but I guess that only caught duplicates with the same signature?

[Mark-Simulacrum]

This works today. I believe that src/test/ui/codemap_tests/overlapping_inherent_impls.rs tests this, so closing.

error[E0592]: duplicate definitions with name `a`
 --> test.rs:4:3
  |
4 | /   fn a(_x: (), _y: ()) -> () {
5 | |   }
  | |___^ duplicate definitions for `a`
...
8 | /   fn a(_x: ()) -> () {
9 | |   }
  | |___- other definition for `a`

error: aborting due to previous error