| // Copyright 2014 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. |
| |
| // This is a regression test for the ICE from issue #10846. |
| // |
| // The original issue causing the ICE: the LUB-computations during |
| // type inference were encountering late-bound lifetimes, and |
| // asserting that such lifetimes should have already been substituted |
| // with a concrete lifetime. |
| // |
| // However, those encounters were occurring within the lexical scope |
| // of the binding for the late-bound lifetime; that is, the late-bound |
| // lifetimes were perfectly valid. The core problem was that the type |
| // folding code was over-zealously passing back all lifetimes when |
| // doing region-folding, when really all clients of the region-folding |
| // case only want to see FREE lifetime variables, not bound ones. |
| |
| // pretty-expanded FIXME #23616 |
| |
| #![allow(unknown_features)] |
| #![feature(box_syntax)] |
| |
| pub fn main() { |
| fn explicit() { |
| fn test<F>(_x: Option<Box<F>>) where F: FnMut(Box<for<'a> FnMut(&'a isize)>) {} |
| test(Some(box |_f: Box<for<'a> FnMut(&'a isize)>| {})); |
| } |
| |
| // The code below is shorthand for the code above (and more likely |
| // to represent what one encounters in practice). |
| fn implicit() { |
| fn test<F>(_x: Option<Box<F>>) where F: FnMut(Box< FnMut(& isize)>) {} |
| test(Some(box |_f: Box< FnMut(& isize)>| {})); |
| } |
| |
| explicit(); |
| implicit(); |
| } |