add a test for #103095

src/test/ui/borrowck/issue-103095.rs

@@ -0,0 +1,30 @@
+// check-pass
+
+trait FnOnceForGenericRef<T>: FnOnce(&T) -> Self::FnOutput {
+    type FnOutput;
+}
+
+impl<T, R, F: FnOnce(&T) -> R> FnOnceForGenericRef<T> for F {
+    type FnOutput = R;
+}
+
+struct Data<T, D: FnOnceForGenericRef<T>> {
+    value: Option<T>,
+    output: Option<D::FnOutput>,
+}
+
+impl<T, D: FnOnceForGenericRef<T>> Data<T, D> {
+    fn new(value: T, f: D) -> Self {
+        let output = f(&value);
+        Self {
+            value: Some(value),
+            output: Some(output),
+        }
+    }
+}
+
+fn test() {
+    Data::new(String::new(), |_| {});
+}
+
+fn main() {}