mirror of
https://github.com/bolero-MURAKAMI/Sprout
synced 2024-11-12 21:09:01 +00:00
116 lines
3.8 KiB
C++
116 lines
3.8 KiB
C++
/*=============================================================================
|
|
Copyright (c) 2011-2016 Bolero MURAKAMI
|
|
https://github.com/bolero-MURAKAMI/Sprout
|
|
|
|
Distributed under the Boost Software License, Version 1.0. (See accompanying
|
|
file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
|
|
=============================================================================*/
|
|
#ifndef SPROUT_ALGORITHM_FIND_HPP
|
|
#define SPROUT_ALGORITHM_FIND_HPP
|
|
|
|
#include <iterator>
|
|
#include <type_traits>
|
|
#include <sprout/config.hpp>
|
|
#include <sprout/iterator/operation.hpp>
|
|
#include <sprout/iterator/type_traits/category.hpp>
|
|
#include <sprout/utility/pair/pair.hpp>
|
|
|
|
namespace sprout {
|
|
namespace detail {
|
|
template<typename RandomAccessIterator, typename T>
|
|
inline SPROUT_CONSTEXPR RandomAccessIterator
|
|
find_impl_ra(
|
|
RandomAccessIterator first, RandomAccessIterator last, T const& value,
|
|
typename std::iterator_traits<RandomAccessIterator>::difference_type pivot, RandomAccessIterator found
|
|
)
|
|
{
|
|
return found != first ? found
|
|
: pivot == 0 ? (*first == value ? first : last)
|
|
: sprout::detail::find_impl_ra(
|
|
sprout::next(first, pivot), last, value,
|
|
(sprout::distance(first, last) - pivot) / 2,
|
|
sprout::detail::find_impl_ra(
|
|
first, sprout::next(first, pivot), value,
|
|
pivot / 2,
|
|
first
|
|
)
|
|
)
|
|
;
|
|
}
|
|
template<typename RandomAccessIterator, typename T>
|
|
inline SPROUT_CONSTEXPR typename std::enable_if<
|
|
sprout::is_constant_distance_iterator<RandomAccessIterator>::value,
|
|
RandomAccessIterator
|
|
>::type
|
|
find(
|
|
RandomAccessIterator first, RandomAccessIterator last, T const& value,
|
|
std::random_access_iterator_tag*
|
|
)
|
|
{
|
|
return first == last ? last
|
|
: sprout::detail::find_impl_ra(first, last, value, sprout::distance(first, last) / 2, first)
|
|
;
|
|
}
|
|
|
|
template<typename InputIterator, typename T>
|
|
inline SPROUT_CONSTEXPR sprout::pair<InputIterator, bool>
|
|
find_impl_1(
|
|
sprout::pair<InputIterator, bool> const& current,
|
|
InputIterator last, T const& value, typename std::iterator_traits<InputIterator>::difference_type n
|
|
)
|
|
{
|
|
typedef sprout::pair<InputIterator, bool> type;
|
|
return current.second || current.first == last ? current
|
|
: n == 1 ? *current.first == value ? type(current.first, true) : type(sprout::next(current.first), false)
|
|
: sprout::detail::find_impl_1(
|
|
sprout::detail::find_impl_1(
|
|
current,
|
|
last, value, n / 2
|
|
),
|
|
last, value, n - n / 2
|
|
)
|
|
;
|
|
}
|
|
template<typename InputIterator, typename T>
|
|
inline SPROUT_CONSTEXPR sprout::pair<InputIterator, bool>
|
|
find_impl(
|
|
sprout::pair<InputIterator, bool> const& current,
|
|
InputIterator last, T const& value, typename std::iterator_traits<InputIterator>::difference_type n
|
|
)
|
|
{
|
|
return current.second || current.first == last ? current
|
|
: sprout::detail::find_impl(
|
|
sprout::detail::find_impl_1(
|
|
current,
|
|
last, value, n
|
|
),
|
|
last, value, n * 2
|
|
)
|
|
;
|
|
}
|
|
template<typename InputIterator, typename T>
|
|
inline SPROUT_CONSTEXPR InputIterator
|
|
find(
|
|
InputIterator first, InputIterator last, T const& value,
|
|
std::input_iterator_tag*
|
|
)
|
|
{
|
|
typedef sprout::pair<InputIterator, bool> type;
|
|
return sprout::detail::find_impl(type(first, false), last, value, 1).first;
|
|
}
|
|
} // namespace detail
|
|
|
|
// 25.2.5 Find
|
|
//
|
|
// recursion depth:
|
|
// O(log N)
|
|
//
|
|
template<typename InputIterator, typename T>
|
|
inline SPROUT_CONSTEXPR InputIterator
|
|
find(InputIterator first, InputIterator last, T const& value) {
|
|
typedef typename std::iterator_traits<InputIterator>::iterator_category* category;
|
|
return sprout::detail::find(first, last, value, category());
|
|
}
|
|
} // namespace sprout
|
|
|
|
#endif // #ifndef SPROUT_ALGORITHM_FIND_HPP
|