// Copyright 2017 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. #![feature(rustc_attrs)] use std::mem; trait Trait1 {} trait Trait2<'a> { type Ty; } fn _ice(param: Box Trait1<<() as Trait2<'a>>::Ty>>) { let _e: (usize, usize) = unsafe{mem::transmute(param)}; } trait Lifetime<'a> { type Out; } impl<'a> Lifetime<'a> for () { type Out = &'a (); } fn foo<'a>(x: &'a ()) -> <() as Lifetime<'a>>::Out { x } fn takes_lifetime(_f: for<'a> fn(&'a ()) -> <() as Lifetime<'a>>::Out) { } #[rustc_error] fn main() { //~ ERROR compilation successful takes_lifetime(foo); }