rust/src/test/compile-fail/regions-infer-paramd-indirect.rs

// Copyright 2012 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.


// Check that we correctly infer that b and c must be region
// parameterized because they reference a which requires a region.

type a<'a> = &'a int;
type b<'a> = Box<a<'a>>;

struct c<'a> {
    f: Box<b<'a>>
}

trait set_f<'a> {
    fn set_f_ok(&mut self, b: Box<b<'a>>);
    fn set_f_bad(&mut self, b: Box<b>);
}

impl<'a> set_f<'a> for c<'a> {
    fn set_f_ok(&mut self, b: Box<b<'a>>) {
        self.f = b;
    }

    fn set_f_bad(&mut self, b: Box<b>) {
        self.f = b; //~ ERROR mismatched types: expected `Box<Box<&'a int>>`, found `Box<Box<&int>>`
    }
}

fn main() {}