title: Error arising when assigning window .load and .unload functions
body: <p>I'm working on a multi-window application and on my second window, I call this init() function</p>
  <pre><code>static struct MessageUI {
      Window *window;
      MenuLayer *menu_layer;
  } ui;
  
  ...
  ...
  ...
  
  void messages_init(void) {
      ui.window = window_create();
  
      window_set_window_handlers(ui.window, (WindowHandlers) {
          .load = window_load,
          .unload = window_unload
      });
  }
  </code></pre>
  <p>When I run the code, I'm getting this error pertaining to the .load and .unload assignment operators.</p>
  <pre><code>../src/messages.c: In function 'messages_init':
  ../src/messages.c:63:3: error: initialization from incompatible pointer type [-Werror]
  ../src/messages.c:63:3: error: (near initialization for 'handlers.load') [-Werror]
  ../src/messages.c:65:2: error: initialization from incompatible pointer type [-Werror]
  ../src/messages.c:65:2: error: (near initialization for 'handlers.unload') [-Werror]
  </code></pre>
  <p>Any idea why this error is arising?</p>
  <p><strong>EDIT</strong></p>
  <p>Here are my window_load and window_unload functions</p>
  <pre><code>static void window_load(void) {
      // Create it - 12 is approx height of the top bar
      ui.menu_layer = menu_layer_create(GRect(0,0,144,168-16));
      menu_layer_set_click_config_onto_window(ui.menu_layer,ui.window);
  
      MenuLayerCallbacks callbacks = { 
          .draw_row = (MenuLayerDrawRowCallback) draw_row_callback,
          .get_num_rows = (MenuLayerGetNumberOfRowsInSectionsCallback) num_rows_callback,
          .select_click = (MenuLayerSelectCallback) select_click_callback
      };
      menu_layer_set_callbacks(ui.menu_layer, NULL, callbacks);
  
      //Add to window
      layer_add_child(window_get_root_layer(ui.window), menu_layer_get_layer(ui.menu_layer));
  }
  
  static void window_unload(void) {
      APP_LOG(APP_LOG_LEVEL_DEBUG, &quot;unloading message UI&quot;);
  }
  </code></pre>