1 files changed, 13 insertions, 0 deletions
diff --git a/src/test/ui/type-alias-impl-trait/issue-52843-closure-constrain.rs b/src/test/ui/type-alias-impl-trait/issue-52843-closure-constrain.rs
new file mode 100644
index 000000000..50eeff0b1
--- /dev/null
+++ b/src/test/ui/type-alias-impl-trait/issue-52843-closure-constrain.rs
@@ -0,0 +1,13 @@
+// Checks to ensure that we properly detect when a closure constrains an opaque type
+
+#![feature(type_alias_impl_trait)]
+
+use std::fmt::Debug;
+
+fn main() {
+    type Opaque = impl Debug;
+    fn _unused() -> Opaque { String::new() }
+    let null = || -> Opaque { 0 };
+    //~^ ERROR: concrete type differs from previous defining opaque type use
+    println!("{:?}", null());
+}