src/test/ui/rfc1445/cant-hide-behind-doubly-indirect-embedded.rs

   1 // This is part of a set of tests exploring the different ways a
   2 // structural-match ADT might try to hold a
   3 // non-structural-match in hidden manner that lets matches
   4 // through that we had intended to reject.
   5 //
   6 // See discussion on rust-lang/rust#62307 and rust-lang/rust#62339
   7 #![warn(indirect_structural_match)]
   8 // run-pass
   9
  10 struct NoDerive(i32);
  11
  12 // This impl makes NoDerive irreflexive.
  13 impl PartialEq for NoDerive { fn eq(&self, _: &Self) -> bool { false } }
  14
  15 impl Eq for NoDerive { }
  16
  17 #[derive(PartialEq, Eq)]
  18 struct WrapInline<'a>(&'a &'a NoDerive);
  19
  20 const WRAP_DOUBLY_INDIRECT_INLINE: & &WrapInline = & &WrapInline(& & NoDerive(0));
  21
  22 fn main() {
  23     match WRAP_DOUBLY_INDIRECT_INLINE {
  24         WRAP_DOUBLY_INDIRECT_INLINE => { panic!("WRAP_DOUBLY_INDIRECT_INLINE matched itself"); }
  25         //~^ WARN must be annotated with `#[derive(PartialEq, Eq)]`
  26         //~| WARN this was previously accepted
  27         _ => { println!("WRAP_DOUBLY_INDIRECT_INLINE correctly did not match itself"); }
  28     }
  29 }