src/test/ui/nll/relate_tys/hr-fn-aau-eq-abu.rs

   1 // Test an interesting corner case that ought to be legal (though the
   2 // current code actually gets it wrong, see below): a fn that takes
   3 // two arguments that are references with the same lifetime is in fact
   4 // equivalent to a fn that takes two references with distinct
   5 // lifetimes. This is true because the two functions can call one
   6 // another -- effectively, the single lifetime `'a` is just inferred
   7 // to be the intersection of the two distinct lifetimes.
   8 //
   9 // check-pass
  10 // compile-flags:-Zno-leak-check
  11
  12 use std::cell::Cell;
  13
  14 fn make_cell_aa() -> Cell<for<'a> fn(&'a u32, &'a u32)> {
  15     panic!()
  16 }
  17
  18 fn aa_eq_ab() {
  19     let a: Cell<for<'a, 'b> fn(&'a u32, &'b u32)> = make_cell_aa();
  20     drop(a);
  21 }
  22
  23 fn main() { }