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Diffstat (limited to 'tests/ui/variance/variance-contravariant-arg-trait-match.rs')
-rw-r--r-- | tests/ui/variance/variance-contravariant-arg-trait-match.rs | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/tests/ui/variance/variance-contravariant-arg-trait-match.rs b/tests/ui/variance/variance-contravariant-arg-trait-match.rs new file mode 100644 index 000000000..e0b280105 --- /dev/null +++ b/tests/ui/variance/variance-contravariant-arg-trait-match.rs @@ -0,0 +1,28 @@ +#![allow(dead_code)] + +// Test that even when `T` is only used in contravariant position, it +// is treated as invariant. + +trait Get<T> { + fn get(&self, t: T); +} + +fn get_min_from_max<'min, 'max, G>() + where 'max : 'min, G : Get<&'max i32> +{ + impls_get::<G,&'min i32>() + //~^ ERROR lifetime may not live long enough +} + +fn get_max_from_min<'min, 'max, G>() + where 'max : 'min, G : Get<&'min i32> +{ + // Previously OK, but now an error because traits are invariant: + + impls_get::<G,&'max i32>() + //~^ ERROR lifetime may not live long enough +} + +fn impls_get<G,T>() where G : Get<T> { } + +fn main() { } |