The function ch_nswe_point finds the four extreme points of a given set of input points using a linear scan of the input points. That is, it determines the points with maximal , minimal , minimal , and maximal coordinates.
|traverses the range [first,beyond). After execution, the value of n is an iterator in the range such that *n *it for all iterators it in the range. Similarly, for s, w, and e the inequalities *s *it, *w *it, and *e *it hold for all iterators it in the range.|
The default traits class Default_traits is the kernel in which the type ForwardIterator::value_type is defined.