rust/src/test/compile-fail/issue-7061.rs

// Copyright 2014 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 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.

struct BarStruct;

impl<'a> BarStruct {
    fn foo(&'a mut self) -> Box<BarStruct> { self }
    //~^ ERROR mismatched types
    //~| expected `Box<BarStruct>`
    //~| found `&'a mut BarStruct`
    //~| expected box
    //~| found &-ptr
}

fn main() {}