[GtkGLExt] ambiguities when compiling with gtkglextmm

[dagecko free fr]

Hello,

I'm using gtkmm along with gtkglextmm.
When trying to get the size of a widget (which inherits from 
Gtk::GL::DrawingArea), I have the following error:

interface.cc:112: error: request for member ‘get_size’ is ambiguous
/usr/include/gtkglextmm-1.2/gdkmm/gl/drawable.h:169: error: candidates are: void Gdk::GL::Drawable::get_size(int&, int&)
/usr/include/gdkmm-2.4/gdkmm/drawable.h:186: error:                 void Gdk::Drawable::get_size(int&, int&) const
/usr/include/gdkmm-2.4/gdkmm/drawable.h:173: error:                 void Gdk::Drawable::get_size(int&, int&)