Added thirdparty: boost library

thirdparty/include/boost/url/rfc/pchars.hpp

@@ -0,0 +1,51 @@
+//
+// Copyright (c) 2016-2019 Vinnie Falco (vinnie dot falco at gmail dot 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_RFC_PCHARS_HPP
+#define BOOST_URL_RFC_PCHARS_HPP
+
+#include <boost/url/detail/config.hpp>
+#include <boost/url/rfc/sub_delim_chars.hpp>
+#include <boost/url/rfc/unreserved_chars.hpp>
+
+namespace boost {
+namespace urls {
+
+/** The path character set
+
+    @par Example
+    Character sets are used with rules and
+    the functions @ref grammar::find_if and
+    @ref grammar::find_if_not.
+    @code
+    system::result< decode_view > rv = grammar::parse( "Program%20Files", pchars );
+    @endcode
+
+    @par BNF
+    @code
+    pchar         = unreserved / pct-encoded / sub-delims / ":" / "@"
+    @endcode
+
+    @par Specification
+    @li <a href="https://datatracker.ietf.org/doc/html/rfc3986#section-3.3"
+        >3.3. Path (rfc3986)</a>
+
+    @see
+        @ref grammar::find_if,
+        @ref grammar::find_if_not,
+        @ref grammar::parse,
+        @ref pct_encoded_rule.
+*/
+constexpr auto pchars =
+    unreserved_chars + sub_delim_chars + ':' + '@';
+
+} // urls
+} // boost
+
+#endif