| // edition:2018 |
| // build-pass (FIXME(62277): could be check-pass?) |
| // revisions: migrate mir |
| //[mir]compile-flags: -Z borrowck=mir |
| |
| #![feature(member_constraints)] |
| |
| trait Trait<'a, 'b> { } |
| impl<T> Trait<'_, '_> for T { } |
| |
| // Here we wind up selecting `'a` and `'b` in the hidden type because |
| // those are the types that appear in the original values. |
| |
| fn upper_bounds<'a, 'b>(a: &'a u8, b: &'b u8) -> impl Trait<'a, 'b> { |
| // In this simple case, you have a hidden type `(&'0 u8, &'1 u8)` and constraints like |
| // |
| // ``` |
| // 'a: '0 |
| // 'b: '1 |
| // '0 in ['a, 'b] |
| // '1 in ['a, 'b] |
| // ``` |
| // |
| // We use the fact that `'a: 0'` must hold (combined with the in |
| // constraint) to determine that `'0 = 'a` must be the answer. |
| (a, b) |
| } |
| |
| fn main() { } |
