On Tue, Dec 24, 2013 at 8:48 PM, Takatoshi Kondo <redboltz@gmail.com> wrote:
typedef boost::any_range<int, boost::random_access_traversal_tag, int, std::ptrdiff_t> int_range;
I realized the problem in my code. int_range doesn't support a reference. It should be typedef boost::any_range<int, boost::random_access_traversal_tag, int&, std::ptrdiff_t> int_range; If the boost::iterator_facade is passed the template arguments boost::random_access_traversal_tag as Traversal and no reference type as Reference, the iterator_category is input_iterator due to a lack of reference support. I checked facade_iterator_category.hpp and wrote the following test code to clarify my understanding. #include <boost/iterator/iterator_facade.hpp> struct my_iter:boost::iterator_facade<my_iter, int, boost::random_access_traversal_tag, int&> {}; struct my_iter_noref:boost::iterator_facade<my_iter, int, boost::random_access_traversal_tag, int> {}; int main() { // has reference static_assert( std::is_convertible< std::iterator_traits<my_iter>::iterator_category, std::random_access_iterator_tag >::value, ""); // no reference static_assert( !std::is_convertible< std::iterator_traits<my_iter_noref>::iterator_category, std::random_access_iterator_tag >::value, ""); static_assert( std::is_convertible< std::iterator_traits<my_iter_noref>::iterator_category, std::input_iterator_tag >::value, ""); } Takatoshi Kondo