Boost C++ Libraries

...one of the most highly regarded and expertly designed C++ library projects in the world. — Herb Sutter and Andrei Alexandrescu, C++ Coding Standards

View on a range, reversing direction if necessary.

template<typename Range, iterate_direction Direction>
struct reversible_view
{
  // ...
};

Parameter	Description
typename Range	original range
iterate_direction Direction	direction of iteration

Either

#include <boost/geometry.hpp>

#include <boost/geometry/views/reversible_view.hpp>