iter_cmp is called with two iterators pointing into the #GSequence that
iter points into. It should
return 0 if the iterators are equal, a negative value if the first
iterator comes before the second, and a positive value if the second
iterator comes before the first.
Like glib.sequence.Sequence.sortChanged, but uses a #GSequenceIterCompareFunc instead of a #GCompareDataFunc as the compare function.
iter_cmp is called with two iterators pointing into the #GSequence that iter points into. It should return 0 if the iterators are equal, a negative value if the first iterator comes before the second, and a positive value if the second iterator comes before the first.