src/test/compile-fail/on-unimplemented/multiple-impls.rs

   1 // Copyright 2016 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 // Test if the on_unimplemented message override works
  12
  13 #![feature(on_unimplemented)]
  14 #![feature(rustc_attrs)]
  15
  16 struct Foo<T>(T);
  17 struct Bar<T>(T);
  18
  19 #[rustc_on_unimplemented = "trait message"]
  20 trait Index<Idx: ?Sized> {
  21     type Output: ?Sized;
  22     fn index(&self, index: Idx) -> &Self::Output;
  23 }
  24
  25 #[rustc_on_unimplemented = "on impl for Foo"]
  26 impl Index<Foo<usize>> for [i32] {
  27     type Output = i32;
  28     fn index(&self, _index: Foo<usize>) -> &i32 {
  29         loop {}
  30     }
  31 }
  32
  33 #[rustc_on_unimplemented = "on impl for Bar"]
  34 impl Index<Bar<usize>> for [i32] {
  35     type Output = i32;
  36     fn index(&self, _index: Bar<usize>) -> &i32 {
  37         loop {}
  38     }
  39 }
  40
  41 #[rustc_error]
  42 fn main() {
  43     Index::index(&[] as &[i32], 2u32);
  44     //~^ ERROR E0277
  45     //~| NOTE trait message
  46     //~| NOTE required by
  47     Index::index(&[] as &[i32], Foo(2u32));
  48     //~^ ERROR E0277
  49     //~| NOTE on impl for Foo
  50     //~| NOTE required by
  51     Index::index(&[] as &[i32], Bar(2u32));
  52     //~^ ERROR E0277
  53     //~| NOTE on impl for Bar
  54     //~| NOTE required by
  55 }