SequenceIterCompareFunc

A #GSequenceIterCompareFunc is a function used to compare iterators. It must return zero if the iterators compare equal, a negative value if @a comes before @b, and a positive value if @b comes before @a.

• param data user data

• return zero if the iterators are equal, a negative value if @a comes before @b, and a positive value if @b comes before @a.