整理

include/boost/core/size.hpp

@@ -0,0 +1,45 @@
+/*
+Copyright 2023 Glen Joseph Fernandes
+(glenjofe@gmail.com)
+
+Distributed under the Boost Software License, Version 1.0.
+(http://www.boost.org/LICENSE_1_0.txt)
+*/
+#ifndef BOOST_CORE_SIZE_HPP
+#define BOOST_CORE_SIZE_HPP
+
+#include <iterator>
+
+// Note: MSVC doesn't define __cpp_lib_nonmember_container_access but supports the feature even in C++14 mode
+#if (defined(__cpp_lib_nonmember_container_access) && (__cpp_lib_nonmember_container_access >= 201411l)) || \
+    (defined(_MSC_VER) && (_MSC_VER >= 1900))
+
+namespace boost {
+using std::size;
+} /* boost */
+
+#else // (defined(__cpp_lib_nonmember_container_access) ...
+
+#include <cstddef>
+
+namespace boost {
+
+template<class C>
+inline constexpr auto
+size(const C& c) noexcept(noexcept(c.size())) -> decltype(c.size())
+{
+    return c.size();
+}
+
+template<class T, std::size_t N>
+inline constexpr std::size_t
+size(T(&)[N]) noexcept
+{
+    return N;
+}
+
+} /* boost */
+
+#endif // (defined(__cpp_lib_nonmember_container_access) ...
+
+#endif