src/test/ui/associated-type-bounds/assoc-type-eq-with-dyn-atb-fail.rs

   1 // This test documents that `type Out = Box<dyn Bar<Assoc: Copy>>;`
   2 // is allowed and will correctly reject an opaque `type Out` which
   3 // does not satisfy the bound `<TheType as Bar>::Assoc: Copy`.
   4 //
   5 // FIXME(rust-lang/lang): I think this behavior is logical if we want to allow
   6 // `dyn Trait<Assoc: Bound>` but we should decide if we want that. // Centril
   7 //
   8 // Additionally, as reported in https://github.com/rust-lang/rust/issues/63594,
   9 // we check that the spans for the error message are sane here.
  10
  11 #![feature(associated_type_bounds)]
  12
  13 fn main() {}
  14
  15 trait Bar {
  16     type Assoc;
  17 }
  18
  19 trait Thing {
  20     type Out;
  21     fn func() -> Self::Out;
  22 }
  23
  24 struct AssocNoCopy;
  25 impl Bar for AssocNoCopy {
  26     type Assoc = String;
  27 }
  28
  29 impl Thing for AssocNoCopy {
  30     type Out = Box<dyn Bar<Assoc: Copy>>;
  31
  32     fn func() -> Self::Out {
  33         //~^ ERROR the trait bound `String: Copy` is not satisfied
  34         Box::new(AssocNoCopy)
  35     }
  36 }