Advances @iter and retrieves the key and/or value that are now pointed to as a result of this advancement. If %FALSE is returned, @key and @value are not set, and the iterator becomes invalid.
a location to store the key, or %NULL
a location to store the value, or %NULL
Return: %FALSE if the end of the #GHashTable has been reached.
2.16
See Implementation
Advances @iter and retrieves the key and/or value that are now pointed to as a result of this advancement. If %FALSE is returned, @key and @value are not set, and the iterator becomes invalid.