src/test/compile-fail/unboxed-closure-sugar-equiv.rs

   1 // Copyright 2014 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 that the unboxed closure sugar can be used with an arbitrary
  12 // struct type and that it is equivalent to the same syntax using
  13 // angle brackets. This test covers only simple types and in
  14 // particular doesn't test bound regions.
  15
  16 #![feature(unboxed_closures)]
  17 #![allow(dead_code)]
  18
  19 trait Foo<T> {
  20     type Output;
  21     fn dummy(&self, t: T, u: Self::Output);
  22 }
  23
  24 trait Eq<X: ?Sized> { }
  25 impl<X: ?Sized> Eq<X> for X { }
  26 fn eq<A: ?Sized,B: ?Sized +Eq<A>>() { }
  27
  28 fn test<'a,'b>() {
  29     // No errors expected:
  30     eq::< Foo<(),Output=()>,                       Foo()                         >();
  31     eq::< Foo<(isize,),Output=()>,                 Foo(isize)                      >();
  32     eq::< Foo<(isize,usize),Output=()>,            Foo(isize,usize)                 >();
  33     eq::< Foo<(isize,usize),Output=usize>,         Foo(isize,usize) -> usize         >();
  34     eq::< Foo<(&'a isize,&'b usize),Output=usize>, Foo(&'a isize,&'b usize) -> usize >();
  35
  36     // Test that anonymous regions in `()` form are equivalent
  37     // to fresh bound regions, and that we can intermingle
  38     // named and anonymous as we choose:
  39     eq::< for<'x,'y> Foo<(&'x isize,&'y usize),Output=usize>,
  40           for<'x,'y> Foo(&'x isize,&'y usize) -> usize            >();
  41     eq::< for<'x,'y> Foo<(&'x isize,&'y usize),Output=usize>,
  42           for<'x> Foo(&'x isize,&usize) -> usize                  >();
  43     eq::< for<'x,'y> Foo<(&'x isize,&'y usize),Output=usize>,
  44           for<'y> Foo(&isize,&'y usize) -> usize                  >();
  45     eq::< for<'x,'y> Foo<(&'x isize,&'y usize),Output=usize>,
  46           Foo(&isize,&usize) -> usize                             >();
  47
  48     // lifetime elision
  49     eq::< for<'x> Foo<(&'x isize,), Output=&'x isize>,
  50           Foo(&isize) -> &isize                                   >();
  51
  52     // Errors expected:
  53     eq::< Foo<(),Output=()>,
  54           Foo(char)                                               >();
  55     //~^^ ERROR E0277
  56 }
  57
  58 fn main() { }