src/test/run-pass/specialization/specialization-projection.rs

   1 // Copyright 2015 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 // Make sure we *can* project non-defaulted associated types
  14 // cf compile-fail/specialization-default-projection.rs
  15
  16 // First, do so without any use of specialization
  17
  18 trait Foo {
  19     type Assoc;
  20 }
  21
  22 impl<T> Foo for T {
  23     type Assoc = ();
  24 }
  25
  26 fn generic_foo<T>() -> <T as Foo>::Assoc {
  27     ()
  28 }
  29
  30 // Next, allow for one layer of specialization
  31
  32 trait Bar {
  33     type Assoc;
  34 }
  35
  36 impl<T> Bar for T {
  37     default type Assoc = ();
  38 }
  39
  40 impl<T: Clone> Bar for T {
  41     type Assoc = u8;
  42 }
  43
  44 fn generic_bar_clone<T: Clone>() -> <T as Bar>::Assoc {
  45     0u8
  46 }
  47
  48 fn main() {
  49 }