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.
aliasGSequenceIterCompareFunc = intfunction(GSequenceIter* a, GSequenceIter* b, void* data)
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.