| // Test that a type which is covariant with respect to its region |
| // parameter yields an error when used in a contravariant way. |
| // |
| // Note: see variance-regions-*.rs for the tests that check that the |
| // variance inference works in the first place. |
| |
| use std::marker; |
| |
| struct Covariant<'a> { |
| marker: marker::PhantomData<fn(&'a ())> |
| } |
| |
| fn use_<'short,'long>(c: Covariant<'long>, |
| s: &'short isize, |
| l: &'long isize, |
| _where:Option<&'short &'long ()>) { |
| |
| // Test whether Covariant<'long> <: Covariant<'short>. Since |
| // 'short <= 'long, this would be true if the Covariant type were |
| // contravariant with respect to its parameter 'a. |
| |
| let _: Covariant<'short> = c; //~ ERROR E0623 |
| } |
| |
| fn main() {} |
