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Sprout/sprout/cstring/strcspn.hpp
bolero-MURAKAMI 8dc640a6e2 fix comments
2016-04-05 18:21:13 +09:00

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3.2 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_CSTRING_STRCSPN_HPP
#define SPROUT_CSTRING_STRCSPN_HPP
#include <iterator>
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/workaround/std/cstddef.hpp>
#include <sprout/iterator/operation.hpp>
#include <sprout/tuple/tuple/tuple.hpp>
#include <sprout/tuple/tuple/get.hpp>
#include <sprout/type_traits/is_char_type.hpp>
#include <sprout/cstring/strchr.hpp>
namespace sprout {
namespace detail {
template<typename InputIterator1, typename ForwardIterator2>
inline SPROUT_CONSTEXPR sprout::tuples::tuple<InputIterator1, std::size_t, bool>
strcspn_impl_1(
sprout::tuples::tuple<InputIterator1, std::size_t, bool> const& current,
ForwardIterator2 first2, typename std::iterator_traits<InputIterator1>::difference_type n
)
{
typedef sprout::tuples::tuple<InputIterator1, std::size_t, bool> type;
return sprout::tuples::get<2>(current) || !*sprout::tuples::get<0>(current) ? current
: n == 1 ? !*sprout::detail::strchr(first2, *sprout::tuples::get<0>(current))
? type(sprout::next(sprout::tuples::get<0>(current)), sprout::tuples::get<1>(current) + 1, false)
: type(sprout::tuples::get<0>(current), sprout::tuples::get<1>(current), true)
: sprout::detail::strcspn_impl_1(
sprout::detail::strcspn_impl_1(
current,
first2, n / 2
),
first2, n - n / 2
)
;
}
template<typename InputIterator1, typename ForwardIterator2>
inline SPROUT_CONSTEXPR sprout::tuples::tuple<InputIterator1, std::size_t, bool>
strcspn_impl(
sprout::tuples::tuple<InputIterator1, std::size_t, bool> const& current,
ForwardIterator2 first2, typename std::iterator_traits<InputIterator1>::difference_type n
)
{
return sprout::tuples::get<2>(current) || !*sprout::tuples::get<0>(current) ? current
: sprout::detail::strcspn_impl(
sprout::detail::strcspn_impl_1(
current,
first2, n
),
first2, n * 2
)
;
}
template<typename InputIterator1, typename ForwardIterator2>
inline SPROUT_CONSTEXPR std::size_t
strcspn(InputIterator1 first1, ForwardIterator2 first2) {
typedef sprout::tuples::tuple<InputIterator1, std::size_t, bool> type;
return sprout::tuples::get<1>(sprout::detail::strcspn_impl(type(first1, 0, false), first2, 1));
}
} // namespace detail
// 7.21.5.3 strcspn function
//
// recursion depth:
// O(log(N1+N2))
//
inline SPROUT_CONSTEXPR std::size_t
strcspn(char const* s1, char const* s2) {
return sprout::detail::strcspn(s1, s2);
}
template<typename Elem>
inline SPROUT_CONSTEXPR typename std::enable_if<
sprout::is_char_type<Elem>::value,
std::size_t
>::type
strcspn(Elem* s1, Elem* s2) {
return sprout::detail::strcspn(s1, s2);
}
} // namespace sprout
#endif // #ifndef SPROUT_CSTRING_STRCSPN_HPP