// 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. trait Stream { type Item; } impl<'a> Stream for &'a str { type Item = u8; } fn f<'s>(s: &'s str) -> (&'s str, <&'s str as Stream>::Item) { (s, 42) } fn main() { let fx = f as for<'t> fn(&'t str) -> (&'t str, <&'t str as Stream>::Item); assert_eq!(fx("hi"), ("hi", 42)); }