rust/src/test/run-pass/issue-21726.rs
2017-07-08 01:56:27 +03:00

47 lines
1.2 KiB
Rust

// Copyright 2015 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.
// Regression test for #21726: an issue arose around the rules for
// subtyping of projection types that resulted in an unconstrained
// region, yielding region inference failures.
// pretty-expanded FIXME #23616
fn main() { }
fn foo<'a>(s: &'a str) {
let b: B<()> = B::new(s, ());
b.get_short();
}
trait IntoRef<'a> {
type T: Clone;
fn into_ref(self, _: &'a str) -> Self::T;
}
impl<'a> IntoRef<'a> for () {
type T = &'a str;
fn into_ref(self, s: &'a str) -> &'a str {
s
}
}
struct B<'a, P: IntoRef<'a>>(P::T);
impl<'a, P: IntoRef<'a>> B<'a, P> {
fn new(s: &'a str, i: P) -> B<'a, P> {
B(i.into_ref(s))
}
fn get_short(&self) -> P::T {
self.0.clone()
}
}