src/test/ui/associated-types/hr-associated-type-bound-param-5.rs

   1 trait Cycle: Sized {
   2     type Next: Cycle<Next = Self>;
   3 }
   4
   5 impl<T> Cycle for Box<T> {
   6     type Next = Vec<T>;
   7 }
   8
   9 impl<T> Cycle for Vec<T> {
  10     type Next = Box<T>;
  11 }
  12
  13 trait X<'a, T: Cycle + for<'b> X<'b, T>>
  14 where
  15     for<'b> <T as X<'b, T>>::U: Clone,
  16     for<'b> T::Next: X<'b, T::Next>,
  17     for<'b> <T::Next as X<'b, T::Next>>::U: Clone,
  18 {
  19     type U: ?Sized;
  20     fn f(x: &<T as X<'_, T>>::U) {
  21         <<T as X<'_, T>>::U>::clone(x);
  22     }
  23 }
  24
  25 impl<S, T> X<'_, Vec<T>> for S {
  26     type U = str;
  27     //~^ ERROR the trait bound `str: Clone` is not satisfied
  28 }
  29
  30 impl<S, T> X<'_, Box<T>> for S {
  31     type U = str;
  32     //~^ ERROR the trait bound `str: Clone` is not satisfied
  33 }
  34
  35 pub fn main() {
  36     <i32 as X<Box<i32>>>::f("abc");
  37 }