Cannot access gdkpixbuf?

["S. Wittenberg" <wittenb informatik uni-freiburg de>]

Hi there!

I tried to access the wrapped gdkpixbuf inside the Gdk::Pixbuf, but i 
get this, even if i #include the right header file (just to be sure):

connection.cpp: In member function ‘Glib::RefPtr<Gdk::Pixbuf> 
Connection::getBuffer()’:
connection.cpp:336: error: invalid use of incomplete type ‘struct 
_GdkPixbuf’
/usr/include/gtk-2.0/gdk-pixbuf/gdk-pixbuf-core.h:55: error: forward 
declaration of ‘struct _GdkPixbuf’

My code looks like this:

frame_buffer = Gdk::Pixbuf::create_from_data(....);
frame_buffer->gobj()->n_channels = 4;


Any help or advice how to proceed will be appreciated!

thanks in advance

Simon