| //@ revisions: current next |
| //@[next] compile-flags: -Znext-solver |
| //@ ignore-compare-mode-next-solver (explicit revisions) |
| //@ check-pass |
| |
| // We've got `'0 member ['a, 'b, 'static]` and `'1 member ['a, 'b, 'static]`. |
| // |
| // As '0 gets outlived by 'a - its "upper bound" - the only applicable choice |
| // region is 'a. |
| // |
| // '1 has to outlive 'b so the only applicable choice regions are 'b and 'static. |
| // Considering this member constraint by itself would choose 'b as it is the |
| // smaller of the two regions. |
| // |
| // However, this is only the case when ignoring the member constraint on '0. |
| // After applying this constraint and requiring '0 to outlive 'a. As '1 outlives |
| // '0, the region 'b is no longer an applicable choice region for '1 as 'b does |
| // does not outlive 'a. We would therefore choose 'static. |
| // |
| // This means applying member constraints is order dependent. We handle this by |
| // first applying member constraints for regions 'x and then consider the resulting |
| // constraints when applying member constraints for regions 'y with 'y: 'x. |
| fn with_constraints<'r0, 'r1, 'a, 'b>() -> *mut (&'r0 (), &'r1 ()) |
| where |
| 'r1: 'r0, |
| 'a: 'r0, |
| 'r1: 'b, |
| { |
| loop {} |
| } |
| fn foo<'a, 'b>() -> impl Sized + use<'a, 'b> { |
| with_constraints::<'_, '_, 'a, 'b>() |
| } |
| fn main() {} |
