| //@ run-pass |
| // 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 |
| |
| pub fn main() { |
| fn explicit() { |
| fn test<F>(_x: Option<Box<F>>) where F: FnMut(Box<dyn for<'a> FnMut(&'a isize)>) {} |
| test(Some(Box::new(|_f: Box<dyn 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<dyn FnMut(& isize)>) {} |
| test(Some(Box::new(|_f: Box<dyn FnMut(& isize)>| {}))); |
| } |
| |
| explicit(); |
| implicit(); |
| } |
