1 2 #ifndef BOOST_MPL_AUX_ITER_FOLD_IF_IMPL_HPP_INCLUDED 3 #define BOOST_MPL_AUX_ITER_FOLD_IF_IMPL_HPP_INCLUDED 4 5 // Copyright Aleksey Gurtovoy 2001-2004 6 // Copyright David Abrahams 2001-2002 7 // 8 // Distributed under the Boost Software License, Version 1.0. 9 // (See accompanying file LICENSE_1_0.txt or copy at 10 // http://www.boost.org/LICENSE_1_0.txt) 11 // 12 // See http://www.boost.org/libs/mpl for documentation. 13 14 // $Id: iter_fold_if_impl.hpp 49267 2008-10-11 06:19:02Z agurtovoy $ 15 // $Date: 2008-10-10 23:19:02 -0700 (Fri, 10 Oct 2008) $ 16 // $Revision: 49267 $ 17 18 #if !defined(BOOST_MPL_PREPROCESSING_MODE) 19 # include <boost/mpl/identity.hpp> 20 # include <boost/mpl/next.hpp> 21 # include <boost/mpl/if.hpp> 22 # include <boost/mpl/apply.hpp> 23 # include <boost/mpl/aux_/value_wknd.hpp> 24 #endif 25 26 #include <boost/mpl/aux_/config/use_preprocessed.hpp> 27 28 #if !defined(BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS) \ 29 && !defined(BOOST_MPL_PREPROCESSING_MODE) 30 31 # define BOOST_MPL_PREPROCESSED_HEADER iter_fold_if_impl.hpp 32 # include <boost/mpl/aux_/include_preprocessed.hpp> 33 34 #else 35 36 # include <boost/mpl/limits/unrolling.hpp> 37 # include <boost/preprocessor/arithmetic/sub.hpp> 38 # include <boost/preprocessor/repeat.hpp> 39 # include <boost/preprocessor/inc.hpp> 40 # include <boost/preprocessor/dec.hpp> 41 # include <boost/preprocessor/cat.hpp> 42 43 namespace boost { namespace mpl { namespace aux { 44 45 template< typename Iterator, typename State > 46 struct iter_fold_if_null_step 47 { 48 typedef State state; 49 typedef Iterator iterator; 50 }; 51 52 template< bool > 53 struct iter_fold_if_step_impl 54 { 55 template< 56 typename Iterator 57 , typename State 58 , typename StateOp 59 , typename IteratorOp 60 > 61 struct result_ 62 { 63 typedef typename apply2<StateOp,State,Iterator>::type state; 64 typedef typename IteratorOp::type iterator; 65 }; 66 }; 67 68 template<> 69 struct iter_fold_if_step_impl<false> 70 { 71 template< 72 typename Iterator 73 , typename State 74 , typename StateOp 75 , typename IteratorOp 76 > 77 struct result_ 78 { 79 typedef State state; 80 typedef Iterator iterator; 81 }; 82 }; 83 84 // agurt, 25/jun/02: MSVC 6.5 workaround, had to get rid of inheritance 85 // here and in 'iter_fold_if_backward_step', because sometimes it interfered 86 // with the "early template instantiation bug" in _really_ ugly ways 87 template< 88 typename Iterator 89 , typename State 90 , typename ForwardOp 91 , typename Predicate 92 > 93 struct iter_fold_if_forward_step 94 { 95 typedef typename apply2<Predicate,State,Iterator>::type not_last; 96 typedef typename iter_fold_if_step_impl< 97 BOOST_MPL_AUX_MSVC_VALUE_WKND(not_last)::value 98 >::template result_< Iterator,State,ForwardOp,mpl::next<Iterator> > impl_; 99 100 typedef typename impl_::state state; 101 typedef typename impl_::iterator iterator; 102 }; 103 104 template< 105 typename Iterator 106 , typename State 107 , typename BackwardOp 108 , typename Predicate 109 > 110 struct iter_fold_if_backward_step 111 { 112 typedef typename apply2<Predicate,State,Iterator>::type not_last; 113 typedef typename iter_fold_if_step_impl< 114 BOOST_MPL_AUX_MSVC_VALUE_WKND(not_last)::value 115 >::template result_< Iterator,State,BackwardOp,identity<Iterator> > impl_; 116 117 typedef typename impl_::state state; 118 typedef typename impl_::iterator iterator; 119 }; 120 121 122 // local macros, #undef-ined at the end of the header 123 124 # define AUX_ITER_FOLD_FORWARD_STEP(unused, i, unused2) \ 125 typedef iter_fold_if_forward_step< \ 126 typename BOOST_PP_CAT(forward_step,i)::iterator \ 127 , typename BOOST_PP_CAT(forward_step,i)::state \ 128 , ForwardOp \ 129 , ForwardPredicate \ 130 > BOOST_PP_CAT(forward_step, BOOST_PP_INC(i)); \ 131 /**/ 132 133 # define AUX_ITER_FOLD_BACKWARD_STEP_FUNC(i) \ 134 typedef iter_fold_if_backward_step< \ 135 typename BOOST_PP_CAT(forward_step,BOOST_PP_DEC(i))::iterator \ 136 , typename BOOST_PP_CAT(backward_step,i)::state \ 137 , BackwardOp \ 138 , BackwardPredicate \ 139 > BOOST_PP_CAT(backward_step,BOOST_PP_DEC(i)); \ 140 /**/ 141 142 # define AUX_ITER_FOLD_BACKWARD_STEP(unused, i, unused2) \ 143 AUX_ITER_FOLD_BACKWARD_STEP_FUNC( \ 144 BOOST_PP_SUB_D(1,BOOST_MPL_LIMIT_UNROLLING,i) \ 145 ) \ 146 /**/ 147 148 # define AUX_LAST_FORWARD_STEP \ 149 BOOST_PP_CAT(forward_step, BOOST_MPL_LIMIT_UNROLLING) \ 150 /**/ 151 152 # define AUX_LAST_BACKWARD_STEP \ 153 BOOST_PP_CAT(backward_step, BOOST_MPL_LIMIT_UNROLLING) \ 154 /**/ 155 156 template< 157 typename Iterator 158 , typename State 159 , typename ForwardOp 160 , typename ForwardPredicate 161 , typename BackwardOp 162 , typename BackwardPredicate 163 > 164 struct iter_fold_if_impl 165 { 166 private: 167 typedef iter_fold_if_null_step<Iterator,State> forward_step0; 168 BOOST_PP_REPEAT( 169 BOOST_MPL_LIMIT_UNROLLING 170 , AUX_ITER_FOLD_FORWARD_STEP 171 , unused 172 ) 173 174 typedef typename if_< 175 typename AUX_LAST_FORWARD_STEP::not_last 176 , iter_fold_if_impl< 177 typename AUX_LAST_FORWARD_STEP::iterator 178 , typename AUX_LAST_FORWARD_STEP::state 179 , ForwardOp 180 , ForwardPredicate 181 , BackwardOp 182 , BackwardPredicate 183 > 184 , iter_fold_if_null_step< 185 typename AUX_LAST_FORWARD_STEP::iterator 186 , typename AUX_LAST_FORWARD_STEP::state 187 > 188 >::type AUX_LAST_BACKWARD_STEP; 189 190 BOOST_PP_REPEAT( 191 BOOST_MPL_LIMIT_UNROLLING 192 , AUX_ITER_FOLD_BACKWARD_STEP 193 , unused 194 ) 195 196 public: 197 typedef typename backward_step0::state state; 198 typedef typename AUX_LAST_BACKWARD_STEP::iterator iterator; 199 }; 200 201 # undef AUX_LAST_BACKWARD_STEP 202 # undef AUX_LAST_FORWARD_STEP 203 # undef AUX_ITER_FOLD_BACKWARD_STEP 204 # undef AUX_ITER_FOLD_BACKWARD_STEP_FUNC 205 # undef AUX_ITER_FOLD_FORWARD_STEP 206 207 }}} 208 209 #endif // BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS 210 #endif // BOOST_MPL_AUX_ITER_FOLD_IF_IMPL_HPP_INCLUDED 211
