1 // Copyright 2016 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
11 // In contrast to `region-escape-via-bound-invariant`, in this case we
12 // *can* return a value of type `&'x u32`, even though `'x` does not
13 // appear in the bounds. This is because `&` is contravariant, and so
14 // we are *actually* returning a `&'y u32`.
16 // See https://github.com/rust-lang/rust/issues/46541 for more details.
21 #![feature(in_band_lifetimes)]
26 impl Trait<'b> for &'a u32 { }
28 fn foo(x: &'x u32) -> impl Trait<'y>