src/test/compile-fail/coherence-overlap-issue-23516.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 // Tests that we consider `Box<U>: !Sugar` to be ambiguous, even
  12 // though we see no impl of `Sugar` for `Box`. Therefore, an overlap
  13 // error is reported for the following pair of impls (#23516).
  14
  15 pub trait Sugar { fn dummy(&self) { } }
  16 pub trait Sweet { fn dummy(&self) { } }
  17 impl<T:Sugar> Sweet for T { }
  18 impl<U:Sugar> Sweet for Box<U> { } //~ ERROR E0119
  19 fn main() { }