| /*============================================================================= | |
| Copyright (c) 1998-2003 Joel de Guzman | |
| http://spirit.sourceforge.net/ | |
| 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) | |
| =============================================================================*/ | |
| #if !defined(BOOST_SPIRIT_RULE_ALIAS_HPP) | |
| #define BOOST_SPIRIT_RULE_ALIAS_HPP | |
| #include <boost/spirit/home/classic/namespace.hpp> | |
| #include <boost/spirit/home/classic/core/parser.hpp> | |
| namespace boost { namespace spirit { | |
| BOOST_SPIRIT_CLASSIC_NAMESPACE_BEGIN | |
| /////////////////////////////////////////////////////////////////////////// | |
| // | |
| // rule_alias class | |
| // | |
| /////////////////////////////////////////////////////////////////////////// | |
| template <typename ParserT> | |
| class rule_alias : | |
| public parser<rule_alias<ParserT> > | |
| { | |
| public: | |
| typedef rule_alias<ParserT> self_t; | |
| template <typename ScannerT> | |
| struct result | |
| { | |
| typedef typename parser_result<ParserT, ScannerT>::type type; | |
| }; | |
| rule_alias() | |
| : ptr(0) {} | |
| rule_alias(ParserT const& p) | |
| : ptr(&p) {} | |
| rule_alias& | |
| operator=(ParserT const& p) | |
| { | |
| ptr = &p; | |
| return *this; | |
| } | |
| template <typename ScannerT> | |
| typename parser_result<ParserT, ScannerT>::type | |
| parse(ScannerT const& scan) const | |
| { | |
| if (ptr) | |
| return ptr->parse(scan); | |
| else | |
| return scan.no_match(); | |
| } | |
| ParserT const& | |
| get() const | |
| { | |
| BOOST_ASSERT(ptr != 0); | |
| return *ptr; | |
| } | |
| private: | |
| ParserT const* ptr; // hold it by pointer | |
| }; | |
| BOOST_SPIRIT_CLASSIC_NAMESPACE_END | |
| }} // namespace BOOST_SPIRIT_CLASSIC_NS | |
| #endif |