\skip userdata_new
\until userdata_new
+BEWARE, the gras_userdata_new expects the pointed type, not the
+pointer type. As you can see, in our example, you should pass
+server_data_t to the macro, even if the global variable is later
+defined as being of type server_data_t*.
+
Once you declared a global that way, retriving this (for example in a
callback) is really easy:
\dontinclude 05-globals.c
