1 files changed, 17 insertions, 0 deletions
diff --git a/tests/ui/inference/ambiguous_type_parameter.rs b/tests/ui/inference/ambiguous_type_parameter.rs
new file mode 100644
index 000000000..dc70ed661
--- /dev/null
+++ b/tests/ui/inference/ambiguous_type_parameter.rs
@@ -0,0 +1,17 @@
+use std::collections::HashMap;
+
+trait Store<K, V> {
+    fn get_raw(&self, key: &K) -> Option<()>;
+}
+
+struct InMemoryStore;
+
+impl<K> Store<String, HashMap<K, String>> for InMemoryStore {
+    fn get_raw(&self, key: &String) -> Option<()> {
+        None
+    }
+}
+
+fn main() {
+    InMemoryStore.get_raw(&String::default()); //~ ERROR type annotations needed
+}