/*============================================================================= 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_ONE_OF_EQUAL_HPP #define SPROUT_ALGORITHM_ONE_OF_EQUAL_HPP #include #include #include #include #include #include namespace sprout { namespace detail { template inline SPROUT_CONSTEXPR bool one_of_equal_impl_ra_1( RandomAccessIterator const& first, RandomAccessIterator const& last, T const& value, typename std::iterator_traits::difference_type pivot ) { return pivot == 0 ? !(*first == value) : sprout::detail::one_of_equal_impl_ra_1( first, sprout::next(first, pivot), value, pivot / 2 ) && sprout::detail::one_of_equal_impl_ra_1( sprout::next(first, pivot), last, value, (sprout::distance(first, last) - pivot) / 2 ) ; } template inline SPROUT_CONSTEXPR bool one_of_equal_impl_ra( RandomAccessIterator const& first, RandomAccessIterator const& last, T const& value, typename std::iterator_traits::difference_type pivot ) { return pivot == 0 ? *first == value : sprout::detail::one_of_equal_impl_ra( first, sprout::next(first, pivot), value, pivot / 2 ) ? sprout::detail::one_of_equal_impl_ra_1( sprout::next(first, pivot), last, value, (sprout::distance(first, last) - pivot) / 2 ) : sprout::detail::one_of_equal_impl_ra( sprout::next(first, pivot), last, value, (sprout::distance(first, last) - pivot) / 2 ) ; } template inline SPROUT_CONSTEXPR typename std::enable_if< sprout::is_constant_distance_iterator::value, bool >::type one_of_equal( RandomAccessIterator const& first, RandomAccessIterator const& last, T const& value, std::random_access_iterator_tag* ) { return first == last ? false : sprout::detail::one_of_equal_impl_ra(first, last, value, sprout::distance(first, last) / 2) ; } template inline SPROUT_CONSTEXPR sprout::pair::difference_type> one_of_equal_impl_1( sprout::pair::difference_type> const& current, InputIterator const& last, T const& value, typename std::iterator_traits::difference_type n ) { typedef sprout::pair::difference_type> type; return current.second > 1 || current.first == last ? current : n == 1 ? current.second == 0 ? !(*current.first == value) ? type(sprout::next(current.first), 0) : type(sprout::next(current.first), 1) : !(*current.first == value) ? type(sprout::next(current.first), 1) : type(current.first, 2) : sprout::detail::one_of_equal_impl_1( sprout::detail::one_of_equal_impl_1( current, last, value, n / 2 ), last, value, n - n / 2 ) ; } template inline SPROUT_CONSTEXPR sprout::pair::difference_type> one_of_equal_impl( sprout::pair::difference_type> const& current, InputIterator const& last, T const& value, typename std::iterator_traits::difference_type n ) { return current.second > 1 || current.first == last ? current : sprout::detail::one_of_equal_impl( sprout::detail::one_of_equal_impl_1( current, last, value, n ), last, value, n * 2 ) ; } template inline SPROUT_CONSTEXPR bool one_of_equal( InputIterator const& first, InputIterator const& last, T const& value, std::input_iterator_tag* ) { typedef sprout::pair::difference_type> type; return sprout::detail::one_of_equal_impl(type(first, 0), last, value, 1).second == 1; } } // namespace detail // // one_of_equal // // recursion depth: // O(log N) // template inline SPROUT_CONSTEXPR bool one_of_equal(InputIterator first, InputIterator last, T const& value) { typedef typename std::iterator_traits::iterator_category* category; return sprout::detail::one_of_equal(first, last, value, category()); } } // namespace sprout #endif // #ifndef SPROUT_ALGORITHM_ONE_OF_EQUAL_HPP