Sprout/sprout/cstring/memcmp.hpp
2015-01-10 19:13:57 +09:00

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/*=============================================================================
Copyright (c) 2011-2015 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_MEMCMP_HPP
#define SPROUT_CSTRING_MEMCMP_HPP
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/workaround/std/cstddef.hpp>
#include <sprout/type_traits/enabler_if.hpp>
#include <sprout/iterator/ptr_index_iterator.hpp>
#include <sprout/algorithm/tristate_lexicographical_compare.hpp>
namespace sprout {
namespace detail {
template<typename PtrIterator>
inline SPROUT_CONSTEXPR int
memcmp(PtrIterator s1, PtrIterator s2, std::size_t n) {
return sprout::tristate_lexicographical_compare(
sprout::ptr_index(s1), sprout::ptr_index(s1, n),
sprout::ptr_index(s2), sprout::ptr_index(s2, n)
);
}
} // namespace detail
// 7.21.4.1 memcmp ŠÖ<C5A0>
//
// recursion depth:
// O(log(N1+N2))
//
#if 0
inline SPROUT_CONSTEXPR int
memcmp(void const* s1, void const* s2, std::size_t n) {
return sprout::detail::memcmp(static_cast<unsigned char const*>(s1), static_cast<unsigned char const*>(s2), n);
}
#endif
template<
typename T,
typename sprout::enabler_if<std::is_convertible<T, void const*>::value>::type = sprout::enabler
>
inline SPROUT_CONSTEXPR int
memcmp(T s1, T s2, std::size_t n) {
return sprout::detail::memcmp(static_cast<unsigned char const*>(s1), static_cast<unsigned char const*>(s2), n);
}
} // namespace sprout
#endif // #ifndef SPROUT_CSTRING_MEMCMP_HPP