classic/dynamic/stored_rule.hpp

0001 /*=============================================================================
0002     Copyright (c) 1998-2003 Joel de Guzman
0003     http://spirit.sourceforge.net/
0004
0005   Distributed under the Boost Software License, Version 1.0. (See accompanying
0006   file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0007 =============================================================================*/
0008 #if !defined(BOOST_SPIRIT_STORED_RULE_HPP)
0009 #define BOOST_SPIRIT_STORED_RULE_HPP
0010
0011 ///////////////////////////////////////////////////////////////////////////////
0012 #include <boost/spirit/home/classic/namespace.hpp>
0013 #include <boost/spirit/home/classic/core/non_terminal/impl/rule.ipp>
0014 #include <boost/spirit/home/classic/dynamic/rule_alias.hpp>
0015 #include <boost/shared_ptr.hpp>
0016
0017 #include <boost/spirit/home/classic/dynamic/stored_rule_fwd.hpp>
0018
0019 ///////////////////////////////////////////////////////////////////////////////
0020 namespace boost { namespace spirit {
0021
0022 BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN
0023
0024     ///////////////////////////////////////////////////////////////////////////
0025     //
0026     //  stored_rule class
0027     //
0028     ///////////////////////////////////////////////////////////////////////////
0029     template <
0030         typename T0
0031       , typename T1
0032       , typename T2
0033       , bool EmbedByValue
0034     >
0035     class stored_rule
0036         : public impl::rule_base<
0037             stored_rule<T0, T1, T2, EmbedByValue>
0038           , typename mpl::if_c<
0039                 EmbedByValue
0040               , stored_rule<T0, T1, T2, true>
0041               , stored_rule<T0, T1, T2> const&>::type
0042           , T0, T1, T2>
0043     {
0044     public:
0045
0046         typedef stored_rule<T0, T1, T2, EmbedByValue> self_t;
0047         typedef impl::rule_base<
0048             self_t
0049           , typename mpl::if_c<
0050                 EmbedByValue
0051               , stored_rule<T0, T1, T2, true>
0052               , self_t const&>::type
0053           , T0, T1, T2>
0054         base_t;
0055
0056         typedef typename base_t::scanner_t scanner_t;
0057         typedef typename base_t::attr_t attr_t;
0058         typedef impl::abstract_parser<scanner_t, attr_t> abstract_parser_t;
0059         typedef rule_alias<self_t> alias_t;
0060
0061         stored_rule() : ptr() {}
0062         ~stored_rule() {}
0063
0064         stored_rule(stored_rule const& r)
0065         : ptr(r.ptr) {}
0066
0067         template <typename ParserT>
0068         stored_rule(ParserT const& p)
0069         : ptr(new impl::concrete_parser<ParserT, scanner_t, attr_t>(p)) {}
0070
0071         template <typename ParserT>
0072         stored_rule& operator=(ParserT const& p)
0073         {
0074             ptr.reset(new impl::concrete_parser<ParserT, scanner_t, attr_t>(p));
0075             return *this;
0076         }
0077
0078         stored_rule& operator=(stored_rule const& r)
0079         {
0080             //  If this is placed above the templatized assignment
0081             //  operator, VC6 incorrectly complains ambiguity with
0082             //  r1 = r2, where r1 and r2 are both rules.
0083             ptr = r.ptr;
0084             return *this;
0085         }
0086
0087         stored_rule<T0, T1, T2, true>
0088         copy() const
0089         {
0090             return stored_rule<T0, T1, T2, true>(ptr);
0091         }
0092
0093         alias_t
0094         alias() const
0095         {
0096             return alias_t(*this);
0097         }
0098
0099     private:
0100
0101         friend class impl::rule_base_access;
0102         friend class stored_rule<T0, T1, T2, !EmbedByValue>;
0103
0104         abstract_parser_t*
0105         get() const
0106         {
0107             return ptr.get();
0108         }
0109
0110         stored_rule(shared_ptr<abstract_parser_t> const& ptr)
0111         : ptr(ptr) {}
0112
0113         shared_ptr<abstract_parser_t> ptr;
0114     };
0115
0116 ///////////////////////////////////////////////////////////////////////////////
0117 BOOST_SPIRIT_CLASSIC_NAMESPACE_END
0118
0119 }} // namespace BOOST_SPIRIT_CLASSIC_NS
0120
0121 #endif