Added thirdparty: boost library

thirdparty/include/boost/url/grammar/variant_rule.hpp

@@ -0,0 +1,131 @@
+//
+// 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_GRAMMAR_VARIANT_RULE_HPP
+#define BOOST_URL_GRAMMAR_VARIANT_RULE_HPP
+
+#include <boost/url/detail/config.hpp>
+#include <boost/url/error_types.hpp>
+#include <boost/url/variant.hpp>
+#include <boost/url/grammar/detail/tuple.hpp>
+
+namespace boost {
+namespace urls {
+namespace grammar {
+
+/** Match one of a set of rules
+
+    Each specified rule is tried in sequence.
+    When the first match occurs, the result
+    is stored and returned in the variant. If
+    no match occurs, an error is returned.
+
+    @par Value Type
+    @code
+    using value_type = variant< typename Rules::value_type... >;
+    @endcode
+
+    @par Example
+    Rules are used with the function @ref parse.
+    @code
+    // request-target = origin-form
+    //                / absolute-form
+    //                / authority-form
+    //                / asterisk-form
+
+    system::result< variant< url_view, url_view, authority_view, core::string_view > > rv = grammar::parse(
+        "/index.html?width=full",
+        variant_rule(
+            origin_form_rule,
+            absolute_uri_rule,
+            authority_rule,
+            delim_rule('*') ) );
+    @endcode
+
+    @par BNF
+    @code
+    variant     = rule1 / rule2 / rule3...
+    @endcode
+
+    @par Specification
+    @li <a href="https://datatracker.ietf.org/doc/html/rfc5234#section-3.2"
+        >3.2.  Alternatives (rfc5234)</a>
+    @li <a href="https://datatracker.ietf.org/doc/html/rfc7230#section-5.3"
+        >5.3.  Request Target (rfc7230)</a>
+
+    @see
+        @ref absolute_uri_rule,
+        @ref authority_rule,
+        @ref delim_rule,
+        @ref parse,
+        @ref origin_form_rule,
+        @ref url_view.
+*/
+#ifdef BOOST_URL_DOCS
+template<class... Rules>
+constexpr
+__implementation_defined__
+variant_rule( Rules... rn ) noexcept;
+#else
+template<
+    class R0, class... Rn>
+class variant_rule_t
+{
+public:
+    using value_type = variant<
+        typename R0::value_type,
+        typename Rn::value_type...>;
+
+    auto
+    parse(
+        char const*& it,
+        char const* end) const ->
+            system::result<value_type>;
+
+    template<
+        class R0_,
+        class... Rn_>
+    friend
+    constexpr
+    auto
+    variant_rule(
+        R0_ const& r0,
+        Rn_ const&... rn) noexcept ->
+            variant_rule_t<R0_, Rn_...>;
+
+private:
+    constexpr
+    variant_rule_t(
+        R0 const& r0,
+        Rn const&... rn) noexcept
+        : rn_(r0, rn...)
+    {
+    }
+
+    detail::tuple<R0, Rn...> rn_;
+};
+
+template<
+    class R0,
+    class... Rn>
+constexpr
+auto
+variant_rule(
+    R0 const& r0,
+    Rn const&... rn) noexcept ->
+        variant_rule_t<R0, Rn...>;
+#endif
+
+} // grammar
+} // urls
+} // boost
+
+#include <boost/url/grammar/impl/variant_rule.hpp>
+
+#endif