cpp/ranges/split view/iterator

The return type of. The name is for exposition purposes only.

This is a, so it is expected that models at least.

Data members
Typical implementations of hold four non-static data members:
 * a pointer of type to the parent ranges object (shown here as  for exposition only),
 * an iterator of type (shown here as  for exposition only) into the underlying ;  points to the begin of a current subrange,
 * a subrange of type (shown here as  for exposition only) to the position of the pattern next to the current subrange, and
 * a boolean flag (shown here as for exposition only) that indicates whether an empty trailing subrange (if any) was reached.