define mem history feature dependencies

src/app/browser/main/tab/page/navbar/history.hpp

@@ -1,8 +1,10 @@
 #ifndef APP_BROWSER_MAIN_TAB_PAGE_NAVBAR_HISTORY_HPP
 #define APP_BROWSER_MAIN_TAB_PAGE_NAVBAR_HISTORY_HPP
 
+#include "glibmm/ustring.h"
 #include <glibmm/i18n.h>
 #include <gtkmm/box.h>
+#include <vector>
 
 namespace app::browser::main::tab::page::navbar
 {
@@ -14,6 +16,11 @@ namespace app::browser::main::tab::page::navbar
 
     class History : public Gtk::Box
     {
+        // Memory
+        std::vector<Glib::ustring> history;
+        std::vector<Glib::ustring>::iterator index;
+
+        // Components
         history::Back * back;
         history::Forward * forward;