// Copyright 2013 The Rust Project Developers. See the COPYRIGHT // file at the top-level directory of this distribution and at // http://rust-lang.org/COPYRIGHT. // // Licensed under the Apache License, Version 2.0 or the MIT license // , at your // option. This file may not be copied, modified, or distributed // except according to those terms. trait T { fn foo(@mut self); } struct S { unused: int } impl T for S { fn foo(@mut self) { } } fn main() { let s = @S { unused: 0 }; let _s2 = s as @mut T; //~ error: types differ in mutability let _s3 = &s as &mut T; //~ error: types differ in mutability }