Sprout/sprout/cstring/strncmp.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_STRNCMP_HPP
#define SPROUT_CSTRING_STRNCMP_HPP
#include <type_traits>
#include <sprout/config.hpp>
#include <sprout/workaround/std/cstddef.hpp>
#include <sprout/iterator/ptr_index_iterator.hpp>
#include <sprout/type_traits/is_char_type.hpp>
#include <sprout/algorithm/tristate_lexicographical_compare.hpp>
namespace sprout {
// 7.21.4.4 strncmp ŠÖ<C5A0>
//
// recursion depth:
// O(log(N1+N2))
//
inline SPROUT_CONSTEXPR int
strncmp(char const* s1, char const* s2, std::size_t n) {
return sprout::tristate_lexicographical_compare(
sprout::ptr_index(s1), sprout::ptr_index(s1, n), '\0',
sprout::ptr_index(s2), sprout::ptr_index(s2, n), '\0'
);
}
template<typename Elem>
inline SPROUT_CONSTEXPR typename std::enable_if<
sprout::is_char_type<Elem>::value,
int
>::type
strncmp(Elem* s1, Elem* s2, std::size_t n) {
typedef typename std::decay<Elem>::type type;
return sprout::tristate_lexicographical_compare(
sprout::ptr_index(s1), sprout::ptr_index(s1, n), type(),
sprout::ptr_index(s2), sprout::ptr_index(s2, n), type()
);
}
} // namespace sprout
#endif // #ifndef SPROUT_CSTRING_STRNCMP_HPP