Make fire_event_callback take a std::function instead of function pointer

src/input_common.cpp

@@ -37,8 +37,7 @@ static int wait_on_escape_ms = WAIT_ON_ESCAPE_DEFAULT;
 static std::deque<wchar_t> lookahead_list;
 
 // Queue of pairs of (function pointer, argument) to be invoked. Expected to be mostly empty.
-typedef std::pair<void (*)(void *), void *> callback_info_t;
-typedef std::queue<callback_info_t, std::list<callback_info_t> > callback_queue_t;
+typedef std::list<std::function<void(void)>> callback_queue_t;
 static callback_queue_t callback_queue;
 static void input_flush_callbacks(void);
 
@@ -237,22 +236,18 @@ void input_common_queue_ch(wint_t ch) { lookahead_push_back(ch); }
 
 void input_common_next_ch(wint_t ch) { lookahead_push_front(ch); }
 
-void input_common_add_callback(void (*callback)(void *), void *arg) {
+void input_common_add_callback(std::function<void(void)> callback) {
     ASSERT_IS_MAIN_THREAD();
-    callback_queue.push(callback_info_t(callback, arg));
+    callback_queue.push_back(std::move(callback));
 }
 
 static void input_flush_callbacks(void) {
-    // Nothing to do if nothing to do.
-    if (callback_queue.empty()) return;
-
     // We move the queue into a local variable, so that events queued up during a callback don't get
     // fired until next round.
+    ASSERT_IS_MAIN_THREAD();
     callback_queue_t local_queue;
     std::swap(local_queue, callback_queue);
-    while (!local_queue.empty()) {
-        const callback_info_t &callback = local_queue.front();
-        callback.first(callback.second);  // cute
-        local_queue.pop();
+    for (auto &f : local_queue) {
+        f();
     }
 }