G_DEFINE_TYPE_WITH_PRIVATE triggers -Wzero-as-null-pointer-constant when called from C++
I do this in OSM2go:
G_DEFINE_TYPE_WITH_PRIVATE (OsmGpsMap, osm_gps_map, GTK_TYPE_DRAWING_AREA);
This causes the following warning when compiled with gcc 9 or later:
/.../osm2go/src/platforms/gtk/osm-gps-map/osm-gps-map.cpp: In function 'GType osm_gps_map_get_type()':
src/platforms/gtk/osm-gps-map/osm-gps-map.cpp:184:1: warning: zero as null pointer constant [-Wzero-as-null-pointer-constant]