1 files changed, 23 insertions, 0 deletions
diff --git a/src/test/ui/lazy-type-alias-impl-trait/recursion4.rs b/src/test/ui/lazy-type-alias-impl-trait/recursion4.rs
new file mode 100644
index 000000000..57dd7fb06
--- /dev/null
+++ b/src/test/ui/lazy-type-alias-impl-trait/recursion4.rs
@@ -0,0 +1,23 @@
+#![feature(type_alias_impl_trait)]
+
+type Foo = impl std::fmt::Debug;
+
+fn foo(b: bool) -> Foo {
+    if b {
+        return vec![];
+    }
+    let mut x = foo(false);
+    x = std::iter::empty().collect(); //~ ERROR `Foo` cannot be built from an iterator
+    vec![]
+}
+
+fn bar(b: bool) -> impl std::fmt::Debug {
+    if b {
+        return vec![];
+    }
+    let mut x = bar(false);
+    x = std::iter::empty().collect(); //~ ERROR `impl Debug` cannot be built from an iterator
+    vec![]
+}
+
+fn main() {}