Registers a private class structure for a classed type;
when the class is allocated, the private structures for
the class and all of its parent types are allocated
sequentially in the same memory block as the public
structures. This function should be called in the
type's get_type() function after the type is registered.
The private structure can be retrieved using the
G_TYPE_CLASS_GET_PRIVATE() macro.
Since 2.24
Registers a private class structure for a classed type; when the class is allocated, the private structures for the class and all of its parent types are allocated sequentially in the same memory block as the public structures. This function should be called in the type's get_type() function after the type is registered. The private structure can be retrieved using the G_TYPE_CLASS_GET_PRIVATE() macro. Since 2.24