Sprout/sprout/algorithm/includes.hpp
2013-01-11 02:55:19 +09:00

94 lines
3.4 KiB
C++

#ifndef SPROUT_ALGORITHM_INCLUDES_HPP
#define SPROUT_ALGORITHM_INCLUDES_HPP
#include <iterator>
#include <sprout/config.hpp>
#include <sprout/iterator/operation.hpp>
#include <sprout/functional/less.hpp>
namespace sprout {
namespace detail {
template<typename RandomAccessIterator1, typename RandomAccessIterator2, typename Compare>
inline SPROUT_CONSTEXPR RandomAccessIterator2
includes_impl_ra(
RandomAccessIterator1 first1, RandomAccessIterator1 last1, RandomAccessIterator2 first2, RandomAccessIterator2 last2, Compare comp,
typename std::iterator_traits<RandomAccessIterator1>::difference_type pivot
)
{
return first2 == last2 ? first2
: pivot == 0 ? (!comp(*first1, *first2) && !comp(*first2, *first1) ? sprout::next(first2) : first2)
: sprout::detail::includes_impl_ra(
sprout::next(first1, pivot), last1,
sprout::detail::includes_impl_ra(
first1, sprout::next(first1, pivot),
first2,
last2, comp,
pivot / 2
),
last2, comp,
(sprout::distance(first1, last1) - pivot) / 2
)
;
}
template<typename RandomAccessIterator1, typename RandomAccessIterator2, typename Compare>
inline SPROUT_CONSTEXPR bool
includes(
RandomAccessIterator1 first1, RandomAccessIterator1 last1, RandomAccessIterator2 first2, RandomAccessIterator2 last2, Compare comp,
std::random_access_iterator_tag*
)
{
return first1 == last1 ? first2 == last2
: sprout::detail::includes_impl_ra(
first1, last1, first2, last2, comp,
sprout::distance(first1, last1) / 2
)
== last2
;
}
// Copyright (C) 2011 RiSK (sscrisk)
template<typename InputIterator1, typename InputIterator2, typename Compare>
inline SPROUT_CONSTEXPR bool
includes_impl(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, Compare comp) {
return first2 == last2 ? true
: first1 == last1 ? false
: !comp(*first1, *first2) && !comp(*first2, *first1)
? sprout::detail::includes_impl(sprout::next(first1), last1, sprout::next(first2), last2)
: sprout::detail::includes_impl(sprout::next(first1), last1, first2, last2)
;
}
template<typename InputIterator1, typename InputIterator2, typename Compare>
inline SPROUT_CONSTEXPR bool
includes(
InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, Compare comp,
void*
)
{
return sprout::detail::includes_impl(first1, last1, first2, comp);
}
} // namespace detail
// 25.4.5.1 includes
//
// recursion depth:
// [first, last) is RandomAccessIterator -> O(log N)
// otherwise -> O(N)
//
template<typename InputIterator1, typename InputIterator2, typename Compare>
inline SPROUT_CONSTEXPR bool
includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2, Compare comp) {
typedef typename std::iterator_traits<InputIterator1>::iterator_category* category;
return sprout::detail::includes(first1, last1, first2, last2, comp, category());
}
template<typename InputIterator1, typename InputIterator2>
inline SPROUT_CONSTEXPR bool
includes(InputIterator1 first1, InputIterator1 last1, InputIterator2 first2, InputIterator2 last2) {
return sprout::includes(
first1, last1, first2, last2,
sprout::less<>()
);
}
} // namespace sprout
#endif // #ifndef SPROUT_ALGORITHM_INCLUDES_HPP