data to lookup
the GCompareDataFunc used to compare items in the sequence. It is called with two items of the seq and user_data. It should return 0 if the items are equal, a negative value if the first item comes before the second, and a positive value if the second item comes before the first.
user data passed to cmp_func.
an GSequenceIter pointing to the position of the first item found equal to data according to cmp_func and cmp_data.
Returns an iterator pointing to the position of the first item found equal to data according to cmp_func and cmp_data. If more than one item is equal, it is not guaranteed that it is the first which is returned. In that case, you can use g_sequence_iter_next() and g_sequence_iter_prev() to get others. Since 2.28