1 files changed, 26 insertions, 0 deletions
diff --git a/src/test/ui/type-alias-impl-trait/argument-types.rs b/src/test/ui/type-alias-impl-trait/argument-types.rs
new file mode 100644
index 000000000..185207b98
--- /dev/null
+++ b/src/test/ui/type-alias-impl-trait/argument-types.rs
@@ -0,0 +1,26 @@
+#![feature(type_alias_impl_trait)]
+#![allow(dead_code)]
+// check-pass
+use std::fmt::Debug;
+
+type Foo = impl Debug;
+
+fn foo1(mut x: Foo) {
+    x = 22_u32;
+}
+
+fn foo2(mut x: Foo) {
+    // no constraint on x
+}
+
+fn foo3(x: Foo) {
+    println!("{:?}", x);
+}
+
+fn foo_value() -> Foo {
+    11_u32
+}
+
+fn main() {
+    foo3(foo_value());
+}