Incorrect "non-exhaustive patterns" using @-binding in match

Binding a match arm using "as-patterns" ref x @ or ref mut x @ will emit an incorrect error message.

rusti:  match Some(1) { ref x@Some(*) => 1, None => 0 }
<anon>:5:10: 5:57 error: non-exhaustive patterns
<anon>:5           match Some(1) { ref x@Some(*) => 1, None => 0 }
                   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

rustc will be silent and happy if a third case _ => fail!() is provided.

Reproduced with 16b8a41 . Unfortunate, but not a milestone blocker IMO.

Not an issue any more. The following compiles happily:

pub fn main() {
  let _x = match Some(1) {
    _y @ Some(_) => 1,
    None => 2,
  };
}

Flagging as needstest

test: Add tests for closed issues

auto merge of #13811 : alexcrichton/rust/closed-issues, r=sfackler

@edwardw

I just hit this, and it is an issue which still fails. @edwardw, you missed the key fact in the initial report: the usage of ref as well as @. @ without ref or ref mut is fine.

Can we please reopen this issue?

Test case:

pub fn main() {
  let _x = match Some(1) {
    ref _y @ Some(_) => 1,
    None => 2,
  };
}

Ah, my bad to misread the original ticket. Obliged to fix it then :)

Fix rust-lang#8391

Auto merge of rust-lang#8441 - Jarcho:needless_borrow_temp, r=flip1995

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Incorrect "non-exhaustive patterns" using @-binding in match #8391

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Incorrect "non-exhaustive patterns" using @-binding in match #8391

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catamorphism commented on Oct 29, 2013

edwardw commented on Mar 23, 2014

alexcrichton commented on Mar 24, 2014

chris-morgan commented on May 12, 2014

huonw commented on May 12, 2014

edwardw commented on May 13, 2014

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