整理

include/boost/core/first_scalar.hpp

@@ -0,0 +1,45 @@
+/*
+Copyright 2019 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_FIRST_SCALAR_HPP
+#define BOOST_CORE_FIRST_SCALAR_HPP
+
+#include <boost/config.hpp>
+#include <cstddef>
+
+namespace boost {
+namespace detail {
+
+template<class T>
+struct make_scalar {
+    typedef T type;
+};
+
+template<class T, std::size_t N>
+struct make_scalar<T[N]> {
+    typedef typename make_scalar<T>::type type;
+};
+
+} /* detail */
+
+template<class T>
+BOOST_CONSTEXPR inline T*
+first_scalar(T* p) BOOST_NOEXCEPT
+{
+    return p;
+}
+
+template<class T, std::size_t N>
+BOOST_CONSTEXPR inline typename detail::make_scalar<T>::type*
+first_scalar(T (*p)[N]) BOOST_NOEXCEPT
+{
+    return boost::first_scalar(&(*p)[0]);
+}
+
+} /* boost */
+
+#endif