Currently, g_object_ref() and g_object_ref_sink() return a
gpointer which can mask issues when assigning to fields or
returning from a function.
To help catch these type of programming errors, we can propagate
the type of the parameter through the function call on GCC
using the typeof() C language extension.
This will cause offending code to have a warning, but will
continue to be source and binary compatible.
This is only enabled when GLIB_VERSION_MAX_ALLOWED is 2.56 or greater.
https://bugzilla.gnome.org/show_bug.cgi?id=790697
3fae39a5d7