Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: // extractor.hpp
Chris@16: //
Chris@16: //  Copyright 2005 Eric Niebler. Distributed under the Boost
Chris@16: //  Software License, Version 1.0. (See accompanying file
Chris@16: //  LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_ACCUMULATORS_FRAMEWORK_EXTRACTOR_HPP_EAN_28_10_2005
Chris@16: #define BOOST_ACCUMULATORS_FRAMEWORK_EXTRACTOR_HPP_EAN_28_10_2005
Chris@16: 
Chris@16: #include <boost/preprocessor/tuple/rem.hpp>
Chris@16: #include <boost/preprocessor/array/size.hpp>
Chris@16: #include <boost/preprocessor/array/data.hpp>
Chris@16: #include <boost/preprocessor/array/elem.hpp>
Chris@16: #include <boost/preprocessor/seq/to_array.hpp>
Chris@16: #include <boost/preprocessor/seq/transform.hpp>
Chris@16: #include <boost/preprocessor/repetition/enum_params.hpp>
Chris@16: #include <boost/preprocessor/repetition/enum_trailing_params.hpp>
Chris@16: #include <boost/preprocessor/repetition/enum_trailing_binary_params.hpp>
Chris@16: #include <boost/parameter/binding.hpp>
Chris@16: #include <boost/mpl/apply.hpp>
Chris@16: #include <boost/mpl/eval_if.hpp>
Chris@16: #include <boost/type_traits/remove_reference.hpp>
Chris@16: #include <boost/accumulators/accumulators_fwd.hpp>
Chris@16: #include <boost/accumulators/framework/parameters/accumulator.hpp>
Chris@16: 
Chris@16: namespace boost { namespace accumulators
Chris@16: {
Chris@16: 
Chris@16: namespace detail
Chris@16: {
Chris@16:     template<typename AccumulatorSet, typename Feature>
Chris@16:     struct accumulator_set_result
Chris@16:     {
Chris@16:         typedef typename as_feature<Feature>::type feature_type;
Chris@16:         typedef typename mpl::apply<AccumulatorSet, feature_type>::type::result_type type;
Chris@16:     };
Chris@16: 
Chris@16:     template<typename Args, typename Feature>
Chris@16:     struct argument_pack_result
Chris@16:       : accumulator_set_result<
Chris@16:             typename remove_reference<
Chris@16:                 typename parameter::binding<Args, tag::accumulator>::type
Chris@16:             >::type
Chris@16:           , Feature
Chris@16:         >
Chris@16:     {
Chris@16:     };
Chris@16: 
Chris@16:     template<typename A, typename Feature>
Chris@16:     struct extractor_result
Chris@16:       : mpl::eval_if<
Chris@16:             detail::is_accumulator_set<A>
Chris@16:           , accumulator_set_result<A, Feature>
Chris@16:           , argument_pack_result<A, Feature>
Chris@16:         >
Chris@16:     {
Chris@16:     };
Chris@16: 
Chris@16:     template<typename Feature, typename AccumulatorSet>
Chris@16:     typename extractor_result<AccumulatorSet, Feature>::type
Chris@16:     do_extract(AccumulatorSet const &acc, mpl::true_)
Chris@16:     {
Chris@16:         typedef typename as_feature<Feature>::type feature_type;
Chris@16:         return extract_result<feature_type>(acc);
Chris@16:     }
Chris@16: 
Chris@16:     template<typename Feature, typename Args>
Chris@16:     typename extractor_result<Args, Feature>::type
Chris@16:     do_extract(Args const &args, mpl::false_)
Chris@16:     {
Chris@16:         typedef typename as_feature<Feature>::type feature_type;
Chris@16:         return find_accumulator<feature_type>(args[accumulator]).result(args);
Chris@16:     }
Chris@16: 
Chris@16: } // namespace detail
Chris@16: 
Chris@16: 
Chris@16: ///////////////////////////////////////////////////////////////////////////////
Chris@16: /// Extracts the result associated with Feature from the specified accumulator_set.
Chris@16: template<typename Feature>
Chris@16: struct extractor
Chris@16: {
Chris@16:     typedef extractor<Feature> this_type;
Chris@16: 
Chris@16:     /// The result meta-function for determining the return type of the extractor
Chris@16:     template<typename F>
Chris@16:     struct result;
Chris@16: 
Chris@16:     template<typename A1>
Chris@16:     struct result<this_type(A1)>
Chris@16:       : detail::extractor_result<A1, Feature>
Chris@16:     {
Chris@16:     };
Chris@16: 
Chris@16:     /// Extract the result associated with Feature from the accumulator set
Chris@16:     /// \param acc The accumulator set object from which to extract the result
Chris@16:     template<typename Arg1>
Chris@16:     typename detail::extractor_result<Arg1, Feature>::type
Chris@16:     operator ()(Arg1 const &arg1) const
Chris@16:     {
Chris@16:         // Arg1 could be an accumulator_set or an argument pack containing
Chris@16:         // an accumulator_set. Dispatch accordingly.
Chris@16:         return detail::do_extract<Feature>(arg1, detail::is_accumulator_set<Arg1>());
Chris@16:     }
Chris@16: 
Chris@16:     /// \overload
Chris@16:     ///
Chris@16:     /// \param a1 Optional named parameter to be passed to the accumulator's result() function.
Chris@16:     template<typename AccumulatorSet, typename A1>
Chris@16:     typename detail::extractor_result<AccumulatorSet, Feature>::type
Chris@16:     operator ()(AccumulatorSet const &acc, A1 const &a1) const
Chris@16:     {
Chris@16:         BOOST_MPL_ASSERT((detail::is_accumulator_set<AccumulatorSet>));
Chris@16:         typedef typename as_feature<Feature>::type feature_type;
Chris@16:         return extract_result<feature_type>(acc, a1);
Chris@16:     }
Chris@16: 
Chris@16:     // ... other overloads generated by Boost.Preprocessor:
Chris@16: 
Chris@16:     /// INTERNAL ONLY
Chris@16:     ///
Chris@16: #define BOOST_ACCUMULATORS_EXTRACTOR_FUN_OP(z, n, _)                                    \
Chris@16:     template<BOOST_PP_ENUM_PARAMS_Z(z, n, typename A)>                                  \
Chris@16:     struct result<this_type(BOOST_PP_ENUM_PARAMS_Z(z, n, A))>                           \
Chris@16:       : detail::extractor_result<A1, Feature>                                           \
Chris@16:     {};                                                                                 \
Chris@16:     template<                                                                           \
Chris@16:         typename AccumulatorSet                                                         \
Chris@16:         BOOST_PP_ENUM_TRAILING_PARAMS_Z(z, n, typename A)                               \
Chris@16:     >                                                                                   \
Chris@16:     typename detail::extractor_result<AccumulatorSet, Feature>::type                    \
Chris@16:     operator ()(                                                                        \
Chris@16:         AccumulatorSet const &acc                                                       \
Chris@16:         BOOST_PP_ENUM_TRAILING_BINARY_PARAMS_Z(z, n, A, const &a)                       \
Chris@16:     ) const                                                                             \
Chris@16:     {                                                                                   \
Chris@16:         BOOST_MPL_ASSERT((detail::is_accumulator_set<AccumulatorSet>));                 \
Chris@16:         typedef typename as_feature<Feature>::type feature_type;                        \
Chris@16:         return extract_result<feature_type>(acc BOOST_PP_ENUM_TRAILING_PARAMS_Z(z, n, a));\
Chris@16:     }
Chris@16: 
Chris@16:     BOOST_PP_REPEAT_FROM_TO(
Chris@16:         2
Chris@16:       , BOOST_PP_INC(BOOST_ACCUMULATORS_MAX_ARGS)
Chris@16:       , BOOST_ACCUMULATORS_EXTRACTOR_FUN_OP
Chris@16:       , _
Chris@16:     )
Chris@16: 
Chris@16:     #ifdef BOOST_ACCUMULATORS_DOXYGEN_INVOKED
Chris@16:     /// \overload
Chris@16:     ///
Chris@16:     template<typename AccumulatorSet, typename A1, typename A2, ...>
Chris@16:     typename detail::extractor_result<AccumulatorSet, Feature>::type
Chris@16:     operator ()(AccumulatorSet const &acc, A1 const &a1, A2 const &a2, ...);
Chris@16:     #endif
Chris@16: };
Chris@16: 
Chris@16: /// INTERNAL ONLY
Chris@16: ///
Chris@16: #define BOOST_ACCUMULATORS_ARRAY_REM(Array)                                                         \
Chris@16:     BOOST_PP_TUPLE_REM_CTOR(BOOST_PP_ARRAY_SIZE(Array), BOOST_PP_ARRAY_DATA(Array))
Chris@16: 
Chris@16: /// INTERNAL ONLY
Chris@16: ///
Chris@16: #define BOOST_ACCUMULATORS_SEQ_REM(Seq)                                                             \
Chris@16:     BOOST_ACCUMULATORS_ARRAY_REM(BOOST_PP_SEQ_TO_ARRAY(Seq))
Chris@16: 
Chris@16: /// INTERNAL ONLY
Chris@16: ///
Chris@16: #define BOOST_ACCUMULATORS_ARGS_OP(s, data, elem)                                                   \
Chris@16:     T ## s
Chris@16: 
Chris@16: /// INTERNAL ONLY
Chris@16: ///
Chris@16: #define BOOST_ACCUMULATORS_PARAMS_OP(s, data, elem)                                                 \
Chris@16:     elem T ## s
Chris@16: 
Chris@16: /// INTERNAL ONLY
Chris@16: ///
Chris@16: #define BOOST_ACCUMULATORS_MAKE_FEATURE(Tag, Feature, ParamsSeq)                                    \
Chris@16:     Tag::Feature<                                                                                   \
Chris@16:         BOOST_ACCUMULATORS_SEQ_REM(                                                                 \
Chris@16:             BOOST_PP_SEQ_TRANSFORM(BOOST_ACCUMULATORS_ARGS_OP, ~, ParamsSeq)                        \
Chris@16:         )                                                                                           \
Chris@16:     >
Chris@16: 
Chris@16: /// INTERNAL ONLY
Chris@16: ///
Chris@16: #define BOOST_ACCUMULATORS_DEFINE_EXTRACTOR_FUN_IMPL(z, n, Tag, Feature, ParamsSeq)                 \
Chris@16:     template<                                                                                       \
Chris@16:         BOOST_ACCUMULATORS_SEQ_REM(                                                                 \
Chris@16:             BOOST_PP_SEQ_TRANSFORM(BOOST_ACCUMULATORS_PARAMS_OP, ~, ParamsSeq)                      \
Chris@16:         )                                                                                           \
Chris@16:       , typename Arg1                                                                               \
Chris@16:         BOOST_PP_ENUM_TRAILING_PARAMS_Z(z, n, typename A)                                           \
Chris@16:     >                                                                                               \
Chris@16:     typename boost::accumulators::detail::extractor_result<                                         \
Chris@16:         Arg1                                                                                        \
Chris@16:       , BOOST_ACCUMULATORS_MAKE_FEATURE(Tag, Feature, ParamsSeq)                                    \
Chris@16:     >::type                                                                                         \
Chris@16:     Feature(Arg1 const &arg1 BOOST_PP_ENUM_TRAILING_BINARY_PARAMS_Z(z, n, A, const &a) )            \
Chris@16:     {                                                                                               \
Chris@16:         typedef BOOST_ACCUMULATORS_MAKE_FEATURE(Tag, Feature, ParamsSeq) feature_type;              \
Chris@16:         return boost::accumulators::extractor<feature_type>()(                                      \
Chris@16:             arg1 BOOST_PP_ENUM_TRAILING_PARAMS_Z(z, n, a));                                         \
Chris@16:     }
Chris@16: 
Chris@16: /// INTERNAL ONLY
Chris@16: ///
Chris@16: #define BOOST_ACCUMULATORS_DEFINE_EXTRACTOR_FUN(z, n, _)                                            \
Chris@16:     BOOST_ACCUMULATORS_DEFINE_EXTRACTOR_FUN_IMPL(                                                   \
Chris@16:         z                                                                                           \
Chris@16:       , n                                                                                           \
Chris@16:       , BOOST_PP_ARRAY_ELEM(0, _)                                                                   \
Chris@16:       , BOOST_PP_ARRAY_ELEM(1, _)                                                                   \
Chris@16:       , BOOST_PP_ARRAY_ELEM(2, _)                                                                   \
Chris@16:     )
Chris@16: 
Chris@16: #define BOOST_ACCUMULATORS_DEFINE_EXTRACTOR(Tag, Feature, ParamSeq)                                 \
Chris@16:     BOOST_PP_REPEAT(                                                                                \
Chris@16:         BOOST_PP_INC(BOOST_ACCUMULATORS_MAX_ARGS)                                                   \
Chris@16:       , BOOST_ACCUMULATORS_DEFINE_EXTRACTOR_FUN                                                     \
Chris@16:       , (3, (Tag, Feature, ParamSeq))                                                               \
Chris@16:     )
Chris@16: 
Chris@16: }} // namespace boost::accumulators
Chris@16: 
Chris@16: #endif