src/test/run-pass/issue-38091.rs

   1 // Copyright 2018 The Rust Project Developers. See the COPYRIGHT
   2 // file at the top-level directory of this distribution and at
   3 // http://rust-lang.org/COPYRIGHT.
   4 //
   5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
   6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
   7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
   8 // option. This file may not be copied, modified, or distributed
   9 // except according to those terms.
  10
  11 #![feature(specialization)]
  12
  13 trait Iterate<'a> {
  14     type Ty: Valid;
  15     fn iterate(self);
  16 }
  17 impl<'a, T> Iterate<'a> for T where T: Check {
  18     default type Ty = ();
  19     default fn iterate(self) {}
  20 }
  21
  22 trait Check {}
  23 impl<'a, T> Check for T where <T as Iterate<'a>>::Ty: Valid {}
  24
  25 trait Valid {}
  26
  27 fn main() {
  28     Iterate::iterate(0);
  29 }