rust/tests/ui/nll/member-constraints/min-choice.rs
Ali MJ Al-Nasrawy 837c1aff05 rework min_choice algorithm of member constraints
See the inline comments for the description of the new algorithm.
2023-01-17 18:38:49 +03:00

35 lines
849 B
Rust

// Assuming that the hidden type in these tests is `&'_#15r u8`,
// we have a member constraint: `'_#15r member ['static, 'a, 'b, 'c]`.
//
// Make sure we pick up the minimum non-ambiguous region among them.
// We will have to exclude `['b, 'c]` because they're incomparable,
// and then we should pick `'a` because we know `'static: 'a`.
// check-pass
trait Cap<'a> {}
impl<T> Cap<'_> for T {}
fn type_test<'a, T: 'a>() -> &'a u8 { &0 }
// Basic test: make sure we don't bail out because 'b and 'c are incomparable.
fn basic<'a, 'b, 'c>() -> impl Cap<'a> + Cap<'b> + Cap<'c>
where
'a: 'b,
'a: 'c,
{
&0
}
// Make sure we don't pick `'static`.
fn test_static<'a, 'b, 'c, T>() -> impl Cap<'a> + Cap<'b> + Cap<'c>
where
'a: 'b,
'a: 'c,
T: 'a,
{
type_test::<'_, T>() // This will fail if we pick 'static
}
fn main() {}