1 files changed, 19 insertions, 0 deletions
diff --git a/src/test/ui/coercion/coerce-unify-return.rs b/src/test/ui/coercion/coerce-unify-return.rs
new file mode 100644
index 000000000..95a7ee8fe
--- /dev/null
+++ b/src/test/ui/coercion/coerce-unify-return.rs
@@ -0,0 +1,19 @@
+// run-pass
+// Check that coercions unify the expected return type of a polymorphic
+// function call, instead of leaving the type variables as they were.
+
+// pretty-expanded FIXME #23616
+
+struct Foo;
+impl Foo {
+    fn foo<T>(self, x: T) -> Option<T> { Some(x) }
+}
+
+pub fn main() {
+    let _: Option<fn()> = Some(main);
+    let _: Option<fn()> = Foo.foo(main);
+
+    // The same two cases, with implicit type variables made explicit.
+    let _: Option<fn()> = Some::<_>(main);
+    let _: Option<fn()> = Foo.foo::<_>(main);
+}