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-rw-r--r--tests/ui/variance/variance-contravariant-arg-trait-match.rs28
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() { }