src/test/ui/self/where-for-self.rs

   1 // run-pass
   2 // Test that we can quantify lifetimes outside a constraint (i.e., including
   3 // the self type) in a where clause.
   4
   5
   6 static mut COUNT: u32 = 1;
   7
   8 trait Bar<'a> {
   9     fn bar(&self);
  10 }
  11
  12 trait Baz<'a>
  13 {
  14     fn baz(&self);
  15 }
  16
  17 impl<'a, 'b> Bar<'b> for &'a u32 {
  18     fn bar(&self) {
  19         unsafe { COUNT *= 2; }
  20     }
  21 }
  22
  23 impl<'a, 'b> Baz<'b> for &'a u32 {
  24     fn baz(&self) {
  25         unsafe { COUNT *= 3; }
  26     }
  27 }
  28
  29 // Test we can use the syntax for HRL including the self type.
  30 fn foo1<T>(x: &T)
  31     where for<'a, 'b> &'a T: Bar<'b>
  32 {
  33     x.bar()
  34 }
  35
  36 // Test we can quantify multiple bounds (i.e., the precedence is sensible).
  37 fn foo2<T>(x: &T)
  38     where for<'a, 'b> &'a T: Bar<'b> + Baz<'b>
  39 {
  40     x.baz();
  41     x.bar()
  42 }
  43
  44 fn main() {
  45     let x = 42;
  46     foo1(&x);
  47     foo2(&x);
  48     unsafe {
  49         assert_eq!(COUNT, 12);
  50     }
  51 }