tests/ui/associated-types/defaults-cyclic-fail-2.rs

   1 #![feature(associated_type_defaults)]
   2
   3 // A more complex version of `defaults-cyclic-fail-1.rs`, with non-trivial defaults.
   4
   5 // Having a cycle in assoc. type defaults is okay...
   6 trait Tr {
   7     type A = Vec<Self::B>;
   8     type B = Box<Self::A>;
   9 }
  10
  11 impl Tr for () {}
  12
  13 impl Tr for u8 {
  14     type A = u8;
  15 }
  16
  17 impl Tr for u16 {
  18     type B = ();
  19 }
  20
  21 impl Tr for u32 {
  22     type A = ();
  23     type B = u8;
  24 }
  25
  26 impl Tr for bool {
  27     type A = Box<Self::B>;
  28     //~^ ERROR overflow evaluating the requirement `<bool as Tr>::B == _`
  29 }
  30 // (the error is shown twice for some reason)
  31
  32 impl Tr for usize {
  33     type B = &'static Self::A;
  34     //~^ ERROR overflow evaluating the requirement `<usize as Tr>::A == _`
  35 }
  36
  37 fn main() {
  38     // We don't check that the types project correctly because the cycle errors stop compilation
  39     // before `main` is type-checked.
  40     // `defaults-cyclic-pass-2.rs` does this.
  41 }