a function to create a hash value from a key. Hash values are used to determine where keys are stored within the GHashTable data structure. The g_direct_hash(), g_int_hash(), g_int64_hash(), g_double_hash() and g_str_hash() functions are provided for some common types of keys. If hash_func is NULL, g_direct_hash() is used.
a function to check two keys for equality. This is used when looking up keys in the GHashTable. The g_direct_equal(), g_int_equal(), g_int64_equal(), g_double_equal() and g_str_equal() functions are provided for the most common types of keys. If key_equal_func is NULL, keys are compared directly in a similar fashion to g_direct_equal(), but without the overhead of a function call.
ConstructionException GTK+ fails to create the object.
Creates a new GHashTable with a reference count of 1.