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https://github.com/bolero-MURAKAMI/Sprout.git
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105 lines
2.9 KiB
C++
105 lines
2.9 KiB
C++
#ifndef SPROUT_CSTRING_MEMCHR_HPP
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#define SPROUT_CSTRING_MEMCHR_HPP
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#include <cstddef>
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#include <type_traits>
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#include <utility>
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#include <sprout/config.hpp>
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#include <sprout/type_traits/enabler_if.hpp>
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#include <sprout/iterator/ptr_index_iterator.hpp>
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#include <sprout/algorithm/find.hpp>
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namespace sprout {
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namespace detail {
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inline SPROUT_CONSTEXPR unsigned char const*
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memchr_impl(unsigned char const* found, unsigned char const* last) {
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return found == last ? nullptr
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: found
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;
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}
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inline SPROUT_CONSTEXPR unsigned char*
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memchr_impl(unsigned char* found, unsigned char* last) {
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return found == last ? nullptr
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: found
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;
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}
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template<typename T>
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struct memchr_result {
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private:
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static void const* check(void const*);
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static void* check(void*);
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static void check(...);
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public:
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typedef decltype(check(std::declval<T>())) type;
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};
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} // namespace detail
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// 7.21.5.1 memchr ŠÖ<C5A0>”
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//
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// recursion depth:
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// O(log N)
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//
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#if 0
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inline SPROUT_CONSTEXPR void const*
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memchr(void const* s, int c, std::size_t n) {
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return sprout::detail::memchr_impl(
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sprout::ptr_unindex(
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sprout::find(
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sprout::ptr_index(static_cast<unsigned char const*>(s)), sprout::ptr_index(static_cast<unsigned char const*>(s), n),
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static_cast<unsigned char>(c)
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)
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),
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static_cast<unsigned char const*>(s) + n
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);
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}
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inline SPROUT_CONSTEXPR void*
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memchr(void* s, int c, std::size_t n) {
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return sprout::detail::memchr_impl(
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sprout::ptr_unindex(
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sprout::find(
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sprout::ptr_index(static_cast<unsigned char*>(s)), sprout::ptr_index(static_cast<unsigned char*>(s), n),
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static_cast<unsigned char>(c)
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)
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),
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static_cast<unsigned char*>(s) + n
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);
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}
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#endif
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template<
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typename T,
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typename sprout::enabler_if<std::is_same<typename sprout::detail::memchr_result<T>::type, void const*>::value>::type = sprout::enabler
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>
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inline SPROUT_CONSTEXPR void const*
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memchr(T s, int c, std::size_t n) {
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return sprout::detail::memchr_impl(
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sprout::ptr_unindex(
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sprout::find(
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sprout::ptr_index(static_cast<unsigned char const*>(s)), sprout::ptr_index(static_cast<unsigned char const*>(s), n),
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static_cast<unsigned char>(c)
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)
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),
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static_cast<unsigned char const*>(s) + n
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);
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}
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template<
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typename T,
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typename sprout::enabler_if<std::is_same<typename sprout::detail::memchr_result<T>::type, void*>::value>::type = sprout::enabler
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>
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inline SPROUT_CONSTEXPR void*
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memchr(T s, int c, std::size_t n) {
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return sprout::detail::memchr_impl(
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sprout::ptr_unindex(
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sprout::find(
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sprout::ptr_index(static_cast<unsigned char*>(s)), sprout::ptr_index(static_cast<unsigned char*>(s), n),
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static_cast<unsigned char>(c)
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)
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),
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static_cast<unsigned char*>(s) + n
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);
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}
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} // namespace sprout
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#endif // #ifndef SPROUT_CSTRING_MEMCHR_HPP
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