1 files changed, 31 insertions, 0 deletions
diff --git a/tests/ui/nll/type-alias-free-regions.rs b/tests/ui/nll/type-alias-free-regions.rs
new file mode 100644
index 000000000..fd5566f35
--- /dev/null
+++ b/tests/ui/nll/type-alias-free-regions.rs
@@ -0,0 +1,31 @@
+// Test that we don't assume that type aliases have the same type parameters
+// as the type they alias and then panic when we see this.
+
+type A<'a> = &'a isize;
+type B<'a> = Box<A<'a>>;
+
+struct C<'a> {
+    f: Box<B<'a>>
+}
+
+trait FromBox<'a> {
+    fn from_box(b: Box<B>) -> Self;
+}
+
+impl<'a> FromBox<'a> for C<'a> {
+    fn from_box(b: Box<B>) -> Self {
+        C { f: b } //~ ERROR
+    }
+}
+
+trait FromTuple<'a> {
+    fn from_tuple( b: (B,)) -> Self;
+}
+
+impl<'a> FromTuple<'a> for C<'a> {
+    fn from_tuple(b: (B,)) -> Self {
+        C { f: Box::new(b.0) } //~ ERROR
+    }
+}
+
+fn main() {}