Build error: `address of ‘Gtk::Dialog::<anonymous>’ will never be NULL`
file-chooser.cpp: In member function ‘virtual void utsushi::gtkmm::file_chooser::on_response(int)’:
file-chooser.cpp:271:13: error: the address of ‘Gtk::Dialog::<anonymous>’ will never be NULL [-Werror=address]
271 | if (dynamic_cast< Gtk::Window * > (this))
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
In file included from file-chooser.hpp:24,
from file-chooser.cpp:25:
/app/include/gtkmm-2.4/gtkmm/dialog.h:125:7: note: ‘Gtk::Dialog::<anonymous>’ declared here
125 | class Dialog : public Window
| ^~~~~~
file-chooser.cpp:296:15: error: the address of ‘Gtk::Dialog::<anonymous>’ will never be NULL [-Werror=address]
296 | if (dynamic_cast< Gtk::Window * > (this))
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/app/include/gtkmm-2.4/gtkmm/dialog.h:125:7: note: ‘Gtk::Dialog::<anonymous>’ declared here
125 | class Dialog : public Window
| ^~~~~~
file-chooser.cpp:349:7: error: the address of ‘Gtk::Dialog::<anonymous>’ will never be NULL [-Werror=address]
349 | if (dynamic_cast< Gtk::Window * > (this))
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
/app/include/gtkmm-2.4/gtkmm/dialog.h:125:7: note: ‘Gtk::Dialog::<anonymous>’ declared here
125 | class Dialog : public Window
| ^~~~~~
cc1plus: all warnings being treated as errors
GCC 12.1.0 gtkmm 2.24.5