Have remote commands return a success/failure message

util/src/lib.rs

@@ -16,6 +16,13 @@ pub fn opt_contains<T: PartialEq>(o: &Option<T>, v: &T) -> bool {
     o.as_ref().filter(|ov| ov == &v).is_some()
 }
 
+pub fn result_contains<T: PartialEq, E>(res: &Result<T, E>, v: &T) -> bool {
+    match res {
+        Ok(ok) if ok == v => true,
+        _ => false,
+    }
+}
+
 pub fn create_atom(conn: &xcb::Connection, name: &[u8]) -> xcb::Result<x::Atom> {
     let cookie = conn.send_request(&x::InternAtom {
         only_if_exists: false,