Sprout/sprout/iterator/distance.hpp

42 lines
1.3 KiB
C++

#ifndef SPROUT_ITERATOR_DISTANCE_HPP
#define SPROUT_ITERATOR_DISTANCE_HPP
#include <iterator>
#include <sprout/config.hpp>
#include <sprout/iterator/next.hpp>
namespace sprout {
namespace iterator_detail {
// Copyright (C) 2011 RiSK (sscrisk)
template<typename InputIterator>
inline SPROUT_CONSTEXPR typename std::iterator_traits<InputIterator>::difference_type
iterator_distance(InputIterator first, InputIterator last) {
return first == last ? 0
: 1 + sprout::iterator_detail::iterator_distance(sprout::next(first), last)
;
}
} // namespace iterator_detail
} // namespace sprout
namespace sprout_iterator_detail {
template<typename InputIterator>
inline SPROUT_CONSTEXPR typename std::iterator_traits<InputIterator>::difference_type
distance(InputIterator first, InputIterator last) {
using sprout::iterator_detail::iterator_distance;
return iterator_distance(first, last);
}
} // namespace sprout_iterator_detail
namespace sprout {
//
// distance
//
template<typename InputIterator>
inline SPROUT_CONSTEXPR typename std::iterator_traits<InputIterator>::difference_type
distance(InputIterator first, InputIterator last) {
return sprout_iterator_detail::distance(first, last);
}
} // namespace sprout
#endif // #ifndef SPROUT_ITERATOR_DISTANCE_HPP