The GValue structure is basically a variable container that consists of a type identifier and a specific value of that type. The type identifier within a GValue structure always determines the type of the associated value. To create a undefined GValue structure, simply create a zero-filled GValue structure. To initialize the GValue, use the g_value_init() function. A GValue cannot be used until it is initialized. The basic type operations (such as freeing and copying) are determined by the GTypeValueTable associated with the type ID stored in the GValue. Other GValue operations (such as converting values between types) are provided by this interface.