// Copyright 2016 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. use std::fmt; pub trait MethodType { type GetProp: ?Sized; } pub struct MTFn; impl<'a> MethodType for MTFn { //~ ERROR E0207 //~| NOTE unconstrained lifetime parameter type GetProp = fmt::Debug + 'a; } fn bad(a: Box<::GetProp>) -> Box { a } fn dangling(a: &str) -> Box { bad(Box::new(a)) } fn main() { let mut s = "hello".to_string(); let x = dangling(&s); s = String::new(); println!("{:?}", x); }