Added thirdparty: boost library

thirdparty/include/boost/json/detail/charconv/impl/from_chars.ipp

@@ -0,0 +1,47 @@
+// Copyright 2022 Peter Dimov
+// Copyright 2023 Matt Borland
+// Distributed under the Boost Software License, Version 1.0.
+// https://www.boost.org/LICENSE_1_0.txt
+
+// https://stackoverflow.com/questions/38060411/visual-studio-2015-wont-suppress-error-c4996
+#ifndef _SCL_SECURE_NO_WARNINGS
+# define _SCL_SECURE_NO_WARNINGS
+#endif
+#ifndef NO_WARN_MBCS_MFC_DEPRECATION
+# define NO_WARN_MBCS_MFC_DEPRECATION
+#endif
+
+#include <boost/json/detail/charconv/detail/fast_float/fast_float.hpp>
+#include <boost/json/detail/charconv/detail/from_chars_float_impl.hpp>
+#include <boost/json/detail/charconv/from_chars.hpp>
+#include <system_error>
+#include <string>
+#include <cstdlib>
+#include <cerrno>
+#include <cstring>
+
+#if defined(__GNUC__) && __GNUC__ < 5
+# pragma GCC diagnostic ignored "-Wmissing-field-initializers"
+#endif
+
+std::errc boost::json::detail::charconv::detail::errno_to_errc(int errno_value) noexcept
+{
+    switch (errno_value)
+    {
+        case EINVAL:
+            return std::errc::invalid_argument;
+        case ERANGE:
+            return std::errc::result_out_of_range;
+        default:
+            return std::errc();
+    }
+}
+
+boost::json::detail::charconv::from_chars_result boost::json::detail::charconv::from_chars(const char* first, const char* last, double& value, boost::json::detail::charconv::chars_format fmt) noexcept
+{
+    if (fmt != boost::json::detail::charconv::chars_format::hex)
+    {
+        return boost::json::detail::charconv::detail::fast_float::from_chars(first, last, value, fmt);
+    }
+    return boost::json::detail::charconv::detail::from_chars_float_impl(first, last, value, fmt);
+}