1 /////////////////////////////////////////////////////////////////////////////// 2 // regex_byref_matcher.hpp 3 // 4 // Copyright 2008 Eric Niebler. Distributed under the Boost 5 // Software License, Version 1.0. (See accompanying file 6 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) 7 8 #ifndef BOOST_XPRESSIVE_DETAIL_CORE_MATCHER_REGEX_BYREF_MATCHER_HPP_EAN_10_04_2005 9 #define BOOST_XPRESSIVE_DETAIL_CORE_MATCHER_REGEX_BYREF_MATCHER_HPP_EAN_10_04_2005 10 11 // MS compatible compilers support #pragma once 12 #if defined(_MSC_VER) 13 # pragma once 14 #endif 15 16 #include <boost/assert.hpp> 17 #include <boost/mpl/assert.hpp> 18 #include <boost/shared_ptr.hpp> 19 #include <boost/xpressive/regex_error.hpp> 20 #include <boost/xpressive/regex_constants.hpp> 21 #include <boost/xpressive/detail/detail_fwd.hpp> 22 #include <boost/xpressive/detail/core/quant_style.hpp> 23 #include <boost/xpressive/detail/core/state.hpp> 24 #include <boost/xpressive/detail/core/regex_impl.hpp> 25 #include <boost/xpressive/detail/core/adaptor.hpp> 26 27 namespace boost { namespace xpressive { namespace detail 28 { 29 /////////////////////////////////////////////////////////////////////////////// 30 // regex_byref_matcher 31 // 32 template<typename BidiIter> 33 struct regex_byref_matcher 34 : quant_style<quant_variable_width, unknown_width::value, false> 35 { 36 // avoid cyclic references by holding a weak_ptr to the 37 // regex_impl struct 38 weak_ptr<regex_impl<BidiIter> > wimpl_; 39 40 // the basic_regex object holds a ref-count to this regex_impl, so 41 // we don't have to worry about it going away. 42 regex_impl<BidiIter> const *pimpl_; 43 regex_byref_matcherboost::xpressive::detail::regex_byref_matcher44 regex_byref_matcher(shared_ptr<regex_impl<BidiIter> > const &impl) 45 : wimpl_(impl) 46 , pimpl_(impl.get()) 47 { 48 BOOST_ASSERT(this->pimpl_); 49 } 50 51 template<typename Next> matchboost::xpressive::detail::regex_byref_matcher52 bool match(match_state<BidiIter> &state, Next const &next) const 53 { 54 BOOST_ASSERT(this->pimpl_ == this->wimpl_.lock().get()); 55 BOOST_XPR_ENSURE_(this->pimpl_->xpr_, regex_constants::error_badref, "bad regex reference"); 56 57 return push_context_match(*this->pimpl_, state, this->wrap_(next, is_static_xpression<Next>())); 58 } 59 60 private: 61 template<typename Next> wrap_boost::xpressive::detail::regex_byref_matcher62 static xpression_adaptor<reference_wrapper<Next const>, matchable<BidiIter> > wrap_(Next const &next, mpl::true_) 63 { 64 // wrap the static xpression in a matchable interface 65 return xpression_adaptor<reference_wrapper<Next const>, matchable<BidiIter> >(boost::cref(next)); 66 } 67 68 template<typename Next> wrap_boost::xpressive::detail::regex_byref_matcher69 static Next const &wrap_(Next const &next, mpl::false_) 70 { 71 return next; 72 } 73 }; 74 75 }}} 76 77 #endif 78