...one of the most highly
regarded and expertly designed C++ library projects in the
world.
— Herb Sutter and Andrei
Alexandrescu, C++
Coding Standards
boost::stl_interfaces::v1::v1_dtl::ra_iter<Iterator, void_t< typename Iterator::iterator_concept >>
// In header: <boost/stl_interfaces/iterator_interface.hpp> template<typename Iterator> struct ra_iter<Iterator, void_t< typename Iterator::iterator_concept >> : public std::integral_constant< bool, std::is_base_of< std::random_access_iterator_tag, Iterator::iterator_concept >::value > { };