Added thirdparty: boost library

thirdparty/include/boost/url/optional.hpp

@@ -0,0 +1,50 @@
+//
+// Copyright (c) 2022 Vinnie Falco (vinnie.falco@gmail.com)
+//
+// 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)
+//
+// Official repository: https://github.com/boostorg/url
+//
+
+#ifndef BOOST_URL_OPTIONAL_HPP
+#define BOOST_URL_OPTIONAL_HPP
+
+#include <boost/url/detail/config.hpp>
+#include <boost/optional.hpp>
+
+namespace boost {
+namespace urls {
+
+/** The type of optional used by the library
+
+    @note This alias is no longer supported and
+    should not be used in new code. Please use
+    `boost::optional` instead.
+
+    This alias is included for backwards
+    compatibility with earlier versions of the
+    library.
+
+    However, it will be removed in future releases,
+    and using it in new code is not recommended.
+
+    Please use the updated version instead to
+    ensure compatibility with future versions of
+    the library.
+
+*/
+#ifndef BOOST_URL_DOCS
+template<class T>
+using optional
+    BOOST_URL_DEPRECATED("Use boost::optional<T> instead") =
+    boost::optional<T>;
+#else
+template<class T>
+using optional = boost::optional<T>;
+#endif
+
+} // urls
+} // boost
+
+#endif