src/test/ui/associated-type-bounds/implied-region-constraints.rs

   1 #![feature(associated_type_bounds)]
   2
   3 trait Tr1 { type As1; }
   4 trait Tr2 { type As2; }
   5
   6 struct St<'a, 'b, T: Tr1<As1: Tr2>> { // `T: 'b` is *not* implied!
   7     f0: &'a T, // `T: 'a` is implied.
   8     f1: &'b <T::As1 as Tr2>::As2, // `<T::As1 as Tr2>::As2: 'a` is implied.
   9 }
  10
  11 fn _bad_st<'a, 'b, T>(x: St<'a, 'b, T>)
  12 where
  13     T: Tr1,
  14     T::As1: Tr2,
  15 {
  16     // This should fail because `T: 'b` is not implied from `WF(St<'a, 'b, T>)`.
  17     let _failure_proves_not_implied_outlives_region_b: &'b T = &x.f0;
  18     //~^ ERROR lifetime may not live long enough
  19 }
  20
  21 enum En7<'a, 'b, T> // `<T::As1 as Tr2>::As2: 'a` is implied.
  22 where
  23     T: Tr1,
  24     T::As1: Tr2,
  25 {
  26     V0(&'a T),
  27     V1(&'b <T::As1 as Tr2>::As2),
  28 }
  29
  30 fn _bad_en7<'a, 'b, T>(x: En7<'a, 'b, T>)
  31 where
  32     T: Tr1,
  33     T::As1: Tr2,
  34 {
  35     match x {
  36         En7::V0(x) => {
  37             // Also fails for the same reason as above:
  38             let _failure_proves_not_implied_outlives_region_b: &'b T = &x;
  39             //~^ ERROR lifetime may not live long enough
  40         },
  41         En7::V1(_) => {},
  42     }
  43 }
  44
  45 fn main() {}