Chris@16: // Copyright David Abrahams, Daniel Wallin 2003. Use, modification and 
Chris@16: // distribution is subject to the Boost Software License, Version 1.0. 
Chris@16: // (See accompanying file LICENSE_1_0.txt or copy at 
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: #ifndef BOOST_PARAMETERS_031014_HPP
Chris@16: #define BOOST_PARAMETERS_031014_HPP
Chris@16: 
Chris@16: #include <boost/detail/is_xxx.hpp>
Chris@16: 
Chris@16: #include <boost/type_traits/is_const.hpp>
Chris@16: 
Chris@16: #include <boost/mpl/lambda.hpp>
Chris@16: #include <boost/mpl/apply.hpp>
Chris@16: #include <boost/mpl/always.hpp>
Chris@16: #include <boost/mpl/and.hpp>
Chris@16: #include <boost/mpl/or.hpp>
Chris@16: #include <boost/mpl/if.hpp>
Chris@16: #include <boost/mpl/identity.hpp>
Chris@16: #include <boost/mpl/not.hpp>
Chris@16: #include <boost/mpl/eval_if.hpp>
Chris@16: #include <boost/mpl/pair.hpp>
Chris@16: 
Chris@16: #include <boost/type_traits/is_same.hpp>
Chris@16: #include <boost/type_traits/remove_reference.hpp>
Chris@16: 
Chris@16: #include <boost/preprocessor/repetition/enum.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/arithmetic/sub.hpp>
Chris@16: #include <boost/preprocessor/repetition/repeat.hpp>
Chris@16: #include <boost/preprocessor/repetition/enum_shifted.hpp>
Chris@16: #include <boost/preprocessor/repetition/enum_binary_params.hpp>
Chris@16: #include <boost/preprocessor/repetition/enum_shifted_params.hpp>
Chris@16: #include <boost/preprocessor/seq/elem.hpp>
Chris@16: #include <boost/preprocessor/iteration/iterate.hpp>
Chris@16: #include <boost/preprocessor/facilities/intercept.hpp>
Chris@16: #include <boost/preprocessor/cat.hpp>
Chris@16: 
Chris@16: #include <boost/parameter/aux_/arg_list.hpp>
Chris@16: #include <boost/parameter/aux_/yesno.hpp>
Chris@16: #include <boost/parameter/aux_/void.hpp>
Chris@16: #include <boost/parameter/aux_/default.hpp>
Chris@16: #include <boost/parameter/aux_/unwrap_cv_reference.hpp>
Chris@16: #include <boost/parameter/aux_/tagged_argument.hpp>
Chris@16: #include <boost/parameter/aux_/tag.hpp>
Chris@16: #include <boost/parameter/aux_/template_keyword.hpp>
Chris@16: #include <boost/parameter/aux_/set.hpp>
Chris@16: #include <boost/parameter/config.hpp>
Chris@16: 
Chris@16: namespace parameter_
Chris@16: {
Chris@16:   template <class T>
Chris@16:   struct unmatched_argument
Chris@16:   {
Chris@16:       BOOST_MPL_ASSERT((boost::is_same<T,void>));
Chris@16:       typedef int type;
Chris@16:   }; 
Chris@16: } // namespace parameter_
Chris@16: 
Chris@16: namespace boost {
Chris@16: 
Chris@16: template<class T> class reference_wrapper;
Chris@16: 
Chris@16: namespace parameter {
Chris@16: 
Chris@16: namespace aux { struct use_default {}; }
Chris@16: 
Chris@16: // These templates can be used to describe the treatment of particular
Chris@16: // named parameters for the purposes of overload elimination with
Chris@16: // SFINAE, by placing specializations in the parameters<...> list.  In
Chris@16: // order for a treated function to participate in overload resolution:
Chris@16: //
Chris@16: //   - all keyword tags wrapped in required<...> must have a matching
Chris@16: //     actual argument
Chris@16: //
Chris@16: //   - The actual argument type matched by every keyword tag
Chris@16: //     associated with a predicate must satisfy that predicate
Chris@16: //
Chris@16: // If a keyword k is specified without an optional<...> or
Chris@16: // required<...>, wrapper, it is treated as though optional<k> were
Chris@16: // specified.
Chris@16: //
Chris@16: // If a keyword k is specified with deduced<...>, that keyword
Chris@16: // will be automatically deduced from the argument list.
Chris@16: //
Chris@16: template <class Tag, class Predicate = aux::use_default>
Chris@16: struct required
Chris@16: {
Chris@16:     typedef Tag key_type;
Chris@16:     typedef Predicate predicate;
Chris@16: };
Chris@16: 
Chris@16: template <class Tag, class Predicate = aux::use_default>
Chris@16: struct optional
Chris@16: {
Chris@16:     typedef Tag key_type;
Chris@16:     typedef Predicate predicate;
Chris@16: };
Chris@16: 
Chris@16: template <class Tag>
Chris@16: struct deduced
Chris@16: {
Chris@16:     typedef Tag key_type;
Chris@16: };
Chris@16: 
Chris@16: namespace aux
Chris@16: {
Chris@16:   // Defines metafunctions, is_required and is_optional, that
Chris@16:   // identify required<...>, optional<...> and deduced<...> specializations.
Chris@16:   BOOST_DETAIL_IS_XXX_DEF(required, required, 2)
Chris@16:   BOOST_DETAIL_IS_XXX_DEF(optional, optional, 2)
Chris@16:   BOOST_DETAIL_IS_XXX_DEF(deduced_aux, deduced, 1)
Chris@16: 
Chris@16:   template <class S>
Chris@16:   struct is_deduced0
Chris@16:     : is_deduced_aux<
Chris@16:           typename S::key_type
Chris@16:       >::type
Chris@16:   {};
Chris@16: 
Chris@16:   template <class S>
Chris@16:   struct is_deduced
Chris@16:     : mpl::eval_if<
Chris@16:           mpl::or_<
Chris@16:               is_optional<S>, is_required<S>
Chris@16:           >
Chris@16:         , is_deduced0<S>
Chris@16:         , mpl::false_
Chris@16:       >::type
Chris@16:   {};
Chris@16: 
Chris@16:   //
Chris@16:   // key_type, has_default, and predicate --
Chris@16:   //
Chris@16:   // These metafunctions accept a ParameterSpec and extract the
Chris@16:   // keyword tag, whether or not a default is supplied for the
Chris@16:   // parameter, and the predicate that the corresponding actual
Chris@16:   // argument type is required match.
Chris@16:   //
Chris@16:   // a ParameterSpec is a specialization of either keyword<...>,
Chris@16:   // required<...>, optional<...>
Chris@16:   //
Chris@16: 
Chris@16:   // helper for key_type<...>, below.
Chris@16:   template <class T>
Chris@16:   struct get_tag_type0
Chris@16:   {
Chris@16:       typedef typename T::key_type type;
Chris@16:   };
Chris@16: 
Chris@16:   template <class T>
Chris@16:   struct get_tag_type
Chris@16:     : mpl::eval_if<
Chris@16:           is_deduced_aux<typename T::key_type>
Chris@16:         , get_tag_type0<typename T::key_type>
Chris@16:         , mpl::identity<typename T::key_type>
Chris@16:       >
Chris@16:   {};
Chris@16: 
Chris@16:   template <class T>
Chris@16:   struct tag_type
Chris@16:     : mpl::eval_if<
Chris@16:           mpl::or_<
Chris@16:               is_optional<T>
Chris@16:             , is_required<T>
Chris@16:           >
Chris@16:         , get_tag_type<T>
Chris@16:         , mpl::identity<T>
Chris@16:       >
Chris@16:   {};
Chris@16: 
Chris@16:   template <class T>
Chris@16:   struct has_default
Chris@16:     : mpl::not_<is_required<T> >
Chris@16:   {};
Chris@16: 
Chris@16:   // helper for get_predicate<...>, below
Chris@16:   template <class T>
Chris@16:   struct get_predicate_or_default
Chris@16:   {
Chris@16:       typedef T type;
Chris@16:   };
Chris@16: 
Chris@16:   template <>
Chris@16:   struct get_predicate_or_default<use_default>
Chris@16:   {
Chris@16:       typedef mpl::always<mpl::true_> type;
Chris@16:   };
Chris@16: 
Chris@16:   // helper for predicate<...>, below
Chris@16:   template <class T>
Chris@16:   struct get_predicate
Chris@16:   {
Chris@16:       typedef typename
Chris@16:           get_predicate_or_default<typename T::predicate>::type
Chris@16:       type;
Chris@16:   };
Chris@16: 
Chris@16:   template <class T>
Chris@16:   struct predicate
Chris@16:     : mpl::eval_if<
Chris@16:          mpl::or_<
Chris@16:               is_optional<T>
Chris@16:             , is_required<T>
Chris@16:           >
Chris@16:         , get_predicate<T>
Chris@16:         , mpl::identity<mpl::always<mpl::true_> >
Chris@16:       >
Chris@16:   {
Chris@16:   };
Chris@16: 
Chris@16: 
Chris@16:   // Converts a ParameterSpec into a specialization of
Chris@16:   // parameter_requirements.  We need to do this in order to get the
Chris@16:   // tag_type into the type in a way that can be conveniently matched
Chris@16:   // by a satisfies(...) member function in arg_list.
Chris@16:   template <class ParameterSpec>
Chris@16:   struct as_parameter_requirements
Chris@16:   {
Chris@16:       typedef parameter_requirements<
Chris@16:           typename tag_type<ParameterSpec>::type
Chris@16:         , typename predicate<ParameterSpec>::type
Chris@16:         , typename has_default<ParameterSpec>::type
Chris@16:       > type;
Chris@16:   };
Chris@16: 
Chris@16:   template <class T>
Chris@16:   struct is_named_argument
Chris@16:     : mpl::or_<
Chris@16:           is_template_keyword<T>
Chris@16:         , is_tagged_argument<T>
Chris@16:       >
Chris@16:   {};
Chris@16:   
Chris@16:   // Returns mpl::true_ iff the given ParameterRequirements are
Chris@16:   // satisfied by ArgList.
Chris@16:   template <class ArgList, class ParameterRequirements>
Chris@16:   struct satisfies
Chris@16:   {
Chris@16: #if BOOST_WORKAROUND(BOOST_MSVC, == 1310)
Chris@16:       // VC7.1 can't handle the sizeof() implementation below,
Chris@16:       // so we use this instead.
Chris@16:       typedef typename mpl::apply_wrap3<
Chris@16:           typename ArgList::binding
Chris@16:         , typename ParameterRequirements::keyword
Chris@16:         , void_
Chris@16:         , mpl::false_
Chris@16:       >::type bound;
Chris@16: 
Chris@16:       typedef typename mpl::eval_if<
Chris@16:           is_same<bound, void_>
Chris@16:         , typename ParameterRequirements::has_default
Chris@16:         , mpl::apply_wrap2<
Chris@16:               typename mpl::lambda<
Chris@16:                   typename ParameterRequirements::predicate, lambda_tag
Chris@16:               >::type
Chris@16:             , bound
Chris@16:             , ArgList
Chris@16:           >
Chris@16:       >::type type;
Chris@16: #else
Chris@16:       BOOST_STATIC_CONSTANT(
Chris@16:           bool, value = (
Chris@16:               sizeof(
Chris@16:                   aux::to_yesno(
Chris@16:                       ArgList::satisfies((ParameterRequirements*)0, (ArgList*)0)
Chris@16:                   )
Chris@16:               ) == sizeof(yes_tag)
Chris@16:           )
Chris@16:       );
Chris@16: 
Chris@16:       typedef mpl::bool_<satisfies::value> type;
Chris@16: #endif
Chris@16:   };
Chris@16: 
Chris@16:   // Returns mpl::true_ if the requirements of the given ParameterSpec
Chris@16:   // are satisfied by ArgList.
Chris@16:   template <class ArgList, class ParameterSpec>
Chris@16:   struct satisfies_requirements_of
Chris@16:     : satisfies<
Chris@16:           ArgList
Chris@16:         , typename as_parameter_requirements<ParameterSpec>::type
Chris@16:       >
Chris@16:   {};
Chris@16: 
Chris@16:   // Tags a deduced argument Arg with the keyword tag of Spec using TagFn.
Chris@16:   // Returns the tagged argument and the mpl::set<> UsedArgs with the
Chris@16:   // tag of Spec inserted.
Chris@16:   template <class UsedArgs, class Spec, class Arg, class TagFn>
Chris@16:   struct tag_deduced
Chris@16:   {
Chris@16:       typedef mpl::pair<
Chris@16:           typename mpl::apply_wrap2<TagFn, typename tag_type<Spec>::type, Arg>::type
Chris@16:         , typename aux::insert_<UsedArgs, typename tag_type<Spec>::type>::type
Chris@16:       > type;
Chris@16:   };
Chris@16: 
Chris@16:   template <
Chris@16:       class Argument
Chris@16:     , class ArgumentPack
Chris@16:     , class DeducedArgs
Chris@16:     , class UsedArgs
Chris@16:     , class TagFn
Chris@16:   >
Chris@16:   struct deduce_tag;
Chris@16: 
Chris@16:   // Tag type passed to MPL lambda.
Chris@16:   struct lambda_tag;
Chris@16: 
Chris@16:   // Helper for deduce_tag<> below.
Chris@16:   template <
Chris@16:       class Argument
Chris@16:     , class ArgumentPack
Chris@16:     , class DeducedArgs
Chris@16:     , class UsedArgs
Chris@16:     , class TagFn
Chris@16:   >
Chris@16:   struct deduce_tag0
Chris@16:   {
Chris@16:       typedef typename DeducedArgs::spec spec;
Chris@16: 
Chris@16:       typedef typename mpl::apply_wrap2<
Chris@16:           typename mpl::lambda<
Chris@16:               typename spec::predicate, lambda_tag
Chris@16:           >::type
Chris@16:         , Argument
Chris@16:         , ArgumentPack
Chris@16:       >::type condition;
Chris@16: 
Chris@16:       // Deduced parameter matches several arguments.
Chris@16: 
Chris@16:       BOOST_MPL_ASSERT((
Chris@16:           mpl::not_<mpl::and_<
Chris@16:               condition
Chris@16:             , aux::has_key_<UsedArgs, typename tag_type<spec>::type>
Chris@16:           > >
Chris@16:       ));
Chris@16: 
Chris@16:       typedef typename mpl::eval_if<
Chris@16:           condition
Chris@16:         , tag_deduced<UsedArgs, spec, Argument, TagFn>
Chris@16:         , deduce_tag<Argument, ArgumentPack, typename DeducedArgs::tail, UsedArgs, TagFn>
Chris@16:       >::type type;
Chris@16:   };
Chris@16: 
Chris@16:   // Tries to deduced a keyword tag for a given Argument.
Chris@16:   // Returns an mpl::pair<> consisting of the tagged_argument<>, 
Chris@16:   // and an mpl::set<> where the new tag has been inserted.
Chris@16:   //
Chris@16:   //  Argument: The argument type to be tagged.
Chris@16:   //
Chris@16:   //  ArgumentPack: The ArgumentPack built so far.
Chris@16:   //
Chris@16:   //  DeducedArgs: A specialization of deduced_item<> (see below).
Chris@16:   //               A list containing only the deduced ParameterSpecs.
Chris@16:   //
Chris@16:   //  UsedArgs: An mpl::set<> containing the keyword tags used so far.
Chris@16:   //
Chris@16:   //  TagFn: A metafunction class used to tag positional or deduced
Chris@16:   //         arguments with a keyword tag.
Chris@16: 
Chris@16:   template <
Chris@16:       class Argument
Chris@16:     , class ArgumentPack
Chris@16:     , class DeducedArgs
Chris@16:     , class UsedArgs
Chris@16:     , class TagFn
Chris@16:   >
Chris@16:   struct deduce_tag
Chris@16:   {
Chris@16:       typedef typename mpl::eval_if<
Chris@16:           is_same<DeducedArgs, void_>
Chris@16:         , mpl::pair<void_, UsedArgs>
Chris@16:         , deduce_tag0<Argument, ArgumentPack, DeducedArgs, UsedArgs, TagFn>
Chris@16:       >::type type;
Chris@16:   };
Chris@16: 
Chris@16:   template <
Chris@16:       class List
Chris@16:     , class DeducedArgs
Chris@16:     , class TagFn
Chris@16:     , class Positional
Chris@16:     , class UsedArgs
Chris@16:     , class ArgumentPack
Chris@16:     , class Error
Chris@16:   >
Chris@16:   struct make_arg_list_aux;
Chris@16: 
Chris@16:   // Inserts Tagged::key_type into the UserArgs set.
Chris@16:   // Extra indirection to lazily evaluate Tagged::key_type.
Chris@16:   template <class UsedArgs, class Tagged>
Chris@16:   struct insert_tagged
Chris@16:   {
Chris@16:       typedef typename aux::insert_<
Chris@16:           UsedArgs, typename Tagged::key_type
Chris@16:       >::type type;
Chris@16:   };
Chris@16: 
Chris@16:   // Borland needs the insane extra-indirection workaround below
Chris@16:   // so that it doesn't magically drop the const qualifier from
Chris@16:   // the argument type.
Chris@16: 
Chris@16:   template <
Chris@16:       class List
Chris@16:     , class DeducedArgs
Chris@16:     , class TagFn
Chris@16:     , class Positional
Chris@16:     , class UsedArgs
Chris@16:     , class ArgumentPack
Chris@16: #if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
Chris@16:     , class argument
Chris@16: #endif
Chris@16:     , class Error
Chris@16:   >
Chris@16: #if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
Chris@16:   struct make_arg_list00
Chris@16: #else
Chris@16:   struct make_arg_list0
Chris@16: #endif
Chris@16:   {
Chris@16: #if !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
Chris@16:       typedef typename List::arg argument;
Chris@16: #endif
Chris@16:       typedef typename List::spec parameter_spec;
Chris@16:       typedef typename tag_type<parameter_spec>::type tag_;
Chris@16: 
Chris@16:       typedef is_named_argument<argument> is_tagged;
Chris@16: 
Chris@16:       // If this argument is either explicitly tagged or a deduced
Chris@16:       // parameter, we turn off positional matching.
Chris@16:       typedef mpl::and_<
Chris@16:           mpl::not_<
Chris@16:               mpl::or_<is_deduced<parameter_spec>, is_tagged> 
Chris@16:           > 
Chris@16:         , Positional
Chris@16:       > positional;
Chris@16: 
Chris@16:       // If this parameter is explicitly tagged we add it to the
Chris@16:       // used-parmeters set. We only really need to add parameters
Chris@16:       // that are deduced, but we would need a way to check if
Chris@16:       // a given tag corresponds to a deduced parameter spec.
Chris@16:       typedef typename mpl::eval_if<
Chris@16:           is_tagged
Chris@16:         , insert_tagged<UsedArgs, argument>
Chris@16:         , mpl::identity<UsedArgs>
Chris@16:       >::type used_args;
Chris@16: 
Chris@16:       // If this parameter is neither explicitly tagged, nor
Chris@16:       // positionally matched; deduce the tag from the deduced
Chris@16:       // parameter specs.
Chris@16:       typedef typename mpl::eval_if<
Chris@16:           mpl::or_<is_tagged, positional>
Chris@16:         , mpl::pair<void_, used_args>
Chris@16:         , deduce_tag<argument, ArgumentPack, DeducedArgs, used_args, TagFn>
Chris@16:       >::type deduced_data;
Chris@16: 
Chris@16:       // If this parameter is explicitly tagged..
Chris@16:       typedef typename mpl::eval_if<
Chris@16:           is_tagged
Chris@16:         , mpl::identity<argument>                        // .. just use it
Chris@16:         , mpl::eval_if<                                  // .. else, if positional matching is turned on..
Chris@16:                 positional
Chris@16:               , mpl::apply_wrap2<TagFn, tag_, argument>  // .. tag it positionally
Chris@16:               , mpl::first<deduced_data>                 // .. else, use the deduced tag
Chris@16:           >
Chris@16:       >::type tagged;
Chris@16: 
Chris@16:       // We build the arg_list incrementally as we go, prepending new
Chris@16:       // nodes.
Chris@16: 
Chris@16:       typedef typename mpl::if_<
Chris@16:           mpl::and_<
Chris@16:               is_same<Error, void_>
Chris@16:             , is_same<tagged, void_>
Chris@16:           >
Chris@16:         , parameter_::unmatched_argument<argument>
Chris@16:         , void_
Chris@16:       >::type error;
Chris@16: 
Chris@16:       typedef typename mpl::if_<
Chris@16:           is_same<tagged, void_>
Chris@16:         , ArgumentPack
Chris@16:         , arg_list<tagged, ArgumentPack>
Chris@16:       >::type argument_pack;
Chris@16: 
Chris@16:       typedef typename make_arg_list_aux<
Chris@16:           typename List::tail
Chris@16:         , DeducedArgs
Chris@16:         , TagFn
Chris@16:         , positional
Chris@16:         , typename deduced_data::second
Chris@16:         , argument_pack
Chris@16:         , error
Chris@16:       >::type type;
Chris@16:   };
Chris@16: 
Chris@16: #if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
Chris@16:   template <
Chris@16:       class List
Chris@16:     , class DeducedArgs
Chris@16:     , class TagFn
Chris@16:     , class Positional
Chris@16:     , class UsedArgs
Chris@16:     , class ArgumentPack
Chris@16:     , class Error
Chris@16:   >
Chris@16:   struct make_arg_list0
Chris@16:   {
Chris@16:       typedef typename mpl::eval_if<
Chris@16:           typename List::is_arg_const
Chris@16:         , make_arg_list00<
Chris@16:               List
Chris@16:             , DeducedArgs
Chris@16:             , TagFn
Chris@16:             , Positional
Chris@16:             , UsedArgs
Chris@16:             , ArgumentPack
Chris@16:             , typename List::arg const
Chris@16:             , Error
Chris@16:           >
Chris@16:         , make_arg_list00<
Chris@16:               List
Chris@16:             , DeducedArgs
Chris@16:             , TagFn
Chris@16:             , Positional
Chris@16:             , UsedArgs
Chris@16:             , ArgumentPack
Chris@16:             , typename List::arg
Chris@16:             , Error
Chris@16:           >
Chris@16:       >::type type;
Chris@16:   };
Chris@16: #endif
Chris@16: 
Chris@16:   // Returns an ArgumentPack where the list of arguments has
Chris@16:   // been tagged with keyword tags.
Chris@16:   //
Chris@16:   //   List: A specialization of item<> (see below). Contains
Chris@16:   //         both the ordered ParameterSpecs, and the given arguments.
Chris@16:   //
Chris@16:   //   DeducedArgs: A specialization of deduced_item<> (see below).
Chris@16:   //                A list containing only the deduced ParameterSpecs.
Chris@16:   //
Chris@16:   //   TagFn: A metafunction class used to tag positional or deduced
Chris@16:   //          arguments with a keyword tag.
Chris@16:   //
Chris@16:   //   Position: An mpl::bool_<> specialization indicating if positional
Chris@16:   //             matching is to be performed.
Chris@16:   //
Chris@16:   //   DeducedSet: An mpl::set<> containing the keyword tags used so far.
Chris@16:   //
Chris@16:   //   ArgumentPack: The ArgumentPack built so far. This is initially an
Chris@16:   //                 empty_arg_list and is built incrementally.
Chris@16:   //
Chris@16: 
Chris@16:   template <
Chris@16:       class List
Chris@16:     , class DeducedArgs
Chris@16:     , class TagFn
Chris@16:     , class Positional
Chris@16:     , class DeducedSet
Chris@16:     , class ArgumentPack
Chris@16:     , class Error
Chris@16:   >
Chris@16:   struct make_arg_list_aux
Chris@16:   {
Chris@16:       typedef typename mpl::eval_if<
Chris@16:           is_same<List, void_>
Chris@16:         , mpl::identity<mpl::pair<ArgumentPack, Error> >
Chris@16:         , make_arg_list0<List, DeducedArgs, TagFn, Positional, DeducedSet, ArgumentPack, Error>
Chris@16:       >::type type;
Chris@16:   };
Chris@16: 
Chris@16:   // VC6.5 was choking on the default parameters for make_arg_list_aux, so
Chris@16:   // this just forwards to that adding in the defaults.
Chris@16:   template <
Chris@16:       class List
Chris@16:     , class DeducedArgs
Chris@16:     , class TagFn
Chris@16:     , class EmitErrors = mpl::true_
Chris@16:   >
Chris@16:   struct make_arg_list
Chris@16:   {
Chris@16:       typedef typename make_arg_list_aux<
Chris@16:           List, DeducedArgs, TagFn, mpl::true_, aux::set0, empty_arg_list, void_
Chris@16:       >::type type;
Chris@16:   };
Chris@16: 
Chris@16:   // A parameter spec item typelist.
Chris@16:   template <class Spec, class Arg, class Tail = void_>
Chris@16:   struct item
Chris@16:   {
Chris@16:       typedef Spec spec;
Chris@16: 
Chris@16: #if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
Chris@16:       typedef is_const<Arg> is_arg_const;
Chris@16: #endif
Chris@16: 
Chris@16:       typedef Arg arg;
Chris@16:       typedef Tail tail;
Chris@16:   };
Chris@16: 
Chris@16:   template <class Spec, class Arg, class Tail>
Chris@16:   struct make_item
Chris@16:   {
Chris@16:       typedef item<Spec, Arg, typename Tail::type> type;
Chris@16:   };
Chris@16: 
Chris@16:   // Creates a item typelist.
Chris@16:   template <class Spec, class Arg, class Tail>
Chris@16:   struct make_items
Chris@16:   {
Chris@16:       typedef typename mpl::eval_if<
Chris@16:           is_same<Arg, void_>
Chris@16:         , mpl::identity<void_>
Chris@16:         , make_item<Spec, Arg, Tail>
Chris@16:       >::type type;
Chris@16:   };
Chris@16: 
Chris@16:   // A typelist that stored deduced parameter specs.
Chris@16:   template <class ParameterSpec, class Tail = void_>
Chris@16:   struct deduced_item
Chris@16:   {
Chris@16:       typedef ParameterSpec spec;
Chris@16:       typedef Tail tail;
Chris@16:   };
Chris@16: 
Chris@16:   // Evaluate Tail and construct deduced_item list.
Chris@16:   template <class Spec, class Tail>
Chris@16:   struct make_deduced_item
Chris@16:   {
Chris@16:       typedef deduced_item<Spec, typename Tail::type> type;
Chris@16:   };
Chris@16: 
Chris@16:   template <class Spec, class Tail>
Chris@16:   struct make_deduced_items
Chris@16:   {
Chris@16:       typedef typename mpl::eval_if<
Chris@16:           is_same<Spec, void_>
Chris@16:         , mpl::identity<void_>
Chris@16:         , mpl::eval_if<
Chris@16:               is_deduced<Spec>
Chris@16:             , make_deduced_item<Spec, Tail>
Chris@16:             , Tail
Chris@16:           >
Chris@16:       >::type type;
Chris@16:   };
Chris@16: 
Chris@16:   // Generates:
Chris@16:   //
Chris@16:   //   make<
Chris@16:   //       parameter_spec#0, argument_type#0
Chris@16:   //     , make<
Chris@16:   //           parameter_spec#1, argument_type#1
Chris@16:   //         , ... mpl::identity<aux::empty_arg_list>
Chris@16:   //    ...>
Chris@16:   //   >
Chris@16: #define BOOST_PARAMETER_make_arg_list(z, n, names)      \
Chris@16:       BOOST_PP_SEQ_ELEM(0,names)<                       \
Chris@16:           BOOST_PP_CAT(BOOST_PP_SEQ_ELEM(1,names), n),  \
Chris@16:           BOOST_PP_CAT(BOOST_PP_SEQ_ELEM(2,names), n), 
Chris@16: 
Chris@16: #define BOOST_PARAMETER_right_angle(z, n, text) >
Chris@16: 
Chris@16: #define BOOST_PARAMETER_build_arg_list(n, make, parameter_spec, argument_type)      \
Chris@16:   BOOST_PP_REPEAT(                                                                  \
Chris@16:       n, BOOST_PARAMETER_make_arg_list, (make)(parameter_spec)(argument_type))      \
Chris@16:       mpl::identity<void_>                                                          \
Chris@16:   BOOST_PP_REPEAT(n, BOOST_PARAMETER_right_angle, _)
Chris@16: 
Chris@16: #define BOOST_PARAMETER_make_deduced_list(z, n, names)  \
Chris@16:       BOOST_PP_SEQ_ELEM(0,names)<                       \
Chris@16:           BOOST_PP_CAT(BOOST_PP_SEQ_ELEM(1,names), n),
Chris@16: 
Chris@16: #define BOOST_PARAMETER_build_deduced_list(n, make, parameter_spec)                 \
Chris@16:   BOOST_PP_REPEAT(                                                                  \
Chris@16:       n, BOOST_PARAMETER_make_deduced_list, (make)(parameter_spec))                 \
Chris@16:   mpl::identity<void_>                                                              \
Chris@16:   BOOST_PP_REPEAT(n, BOOST_PARAMETER_right_angle, _)
Chris@16: 
Chris@16:   struct tag_keyword_arg
Chris@16:   {
Chris@16:       template <class K, class T>
Chris@16:       struct apply
Chris@16:         : tag<K,T>
Chris@16:       {};
Chris@16:   };
Chris@16: 
Chris@16:   struct tag_template_keyword_arg
Chris@16:   {
Chris@16:       template <class K, class T>
Chris@16:       struct apply
Chris@16:       {
Chris@16:           typedef template_keyword<K,T> type;
Chris@16:       };
Chris@16:   };
Chris@16: 
Chris@16: } // namespace aux
Chris@16: 
Chris@16: #define BOOST_PARAMETER_FORWARD_TYPEDEF(z, i, names) \
Chris@16:     typedef BOOST_PP_CAT(BOOST_PP_SEQ_ELEM(0,names),i) BOOST_PP_CAT(BOOST_PP_SEQ_ELEM(1,names),i);
Chris@16: 
Chris@16: #define BOOST_PARAMETER_FORWARD_TYPEDEFS(n, src, dest) \
Chris@16:     BOOST_PP_REPEAT(n, BOOST_PARAMETER_FORWARD_TYPEDEF, (src)(dest))
Chris@16: 
Chris@16: 
Chris@16: #define BOOST_PARAMETER_TEMPLATE_ARGS(z, n, text) class BOOST_PP_CAT(PS, n) = void_
Chris@16: 
Chris@16: template<
Chris@16:      class PS0
Chris@16:    , BOOST_PP_ENUM_SHIFTED(BOOST_PARAMETER_MAX_ARITY, BOOST_PARAMETER_TEMPLATE_ARGS, _)
Chris@16: >
Chris@16: struct parameters
Chris@16: {
Chris@16: #undef BOOST_PARAMETER_TEMPLATE_ARGS
Chris@16: 
Chris@16:     typedef typename BOOST_PARAMETER_build_deduced_list(
Chris@16:         BOOST_PARAMETER_MAX_ARITY, aux::make_deduced_items, PS
Chris@16:     )::type deduced_list;
Chris@16: 
Chris@16:     // if the elements of NamedList match the criteria of overload
Chris@16:     // resolution, returns a type which can be constructed from
Chris@16:     // parameters.  Otherwise, this is not a valid metafunction (no nested
Chris@16:     // ::type).
Chris@16: 
Chris@16: 
Chris@16: #if ! defined(BOOST_NO_SFINAE) && ! BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x592))
Chris@16:     // If NamedList satisfies the PS0, PS1, ..., this is a
Chris@16:     // metafunction returning parameters.  Otherwise it 
Chris@16:     // has no nested ::type.
Chris@16:     template <class ArgumentPackAndError>
Chris@16:     struct match_base
Chris@16:       : mpl::if_<
Chris@16:             // mpl::and_<
Chris@16:             //    aux::satisfies_requirements_of<NamedList,PS0>
Chris@16:             //  , mpl::and_<
Chris@16:             //       aux::satisfies_requirements_of<NamedList,PS1>...
Chris@16:             //           ..., mpl::true_
Chris@16:             // ...> >
Chris@16:             
Chris@16: # define BOOST_PARAMETER_satisfies(z, n, text)                                      \
Chris@16:             mpl::and_<                                                              \
Chris@16:                 aux::satisfies_requirements_of<                                     \
Chris@16:                     typename mpl::first<ArgumentPackAndError>::type                 \
Chris@16:                   , BOOST_PP_CAT(PS, n)>                                            \
Chris@16:                   ,
Chris@16:             mpl::and_<
Chris@16:                 is_same<typename mpl::second<ArgumentPackAndError>::type, void_>
Chris@16:               , BOOST_PP_REPEAT(BOOST_PARAMETER_MAX_ARITY, BOOST_PARAMETER_satisfies, _)
Chris@16:                 mpl::true_
Chris@16:                 BOOST_PP_REPEAT(BOOST_PARAMETER_MAX_ARITY, BOOST_PARAMETER_right_angle, _)
Chris@16:             >
Chris@16: 
Chris@16: # undef BOOST_PARAMETER_satisfies
Chris@16: 
Chris@16:           , mpl::identity<parameters>
Chris@16:           , void_
Chris@16:         >
Chris@16:     {};
Chris@16: #endif
Chris@16:     
Chris@16:     // Specializations are to be used as an optional argument to
Chris@16:     // eliminate overloads via SFINAE
Chris@16:     template<
Chris@16: #if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
Chris@16:         // Borland simply can't handle default arguments in member
Chris@16:         // class templates.  People wishing to write portable code can
Chris@16:         // explicitly specify BOOST_PARAMETER_MAX_ARITY arguments
Chris@16:         BOOST_PP_ENUM_PARAMS(BOOST_PARAMETER_MAX_ARITY, class A)
Chris@16: #else 
Chris@16:         BOOST_PP_ENUM_BINARY_PARAMS(
Chris@16:             BOOST_PARAMETER_MAX_ARITY, class A, = void_ BOOST_PP_INTERCEPT
Chris@16:         )
Chris@16: #endif
Chris@16:     >
Chris@16:     struct match
Chris@16: # if ! defined(BOOST_NO_SFINAE) && ! BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x592))
Chris@16:       : match_base<
Chris@16:             typename aux::make_arg_list<
Chris@16:                 typename BOOST_PARAMETER_build_arg_list(
Chris@16:                     BOOST_PARAMETER_MAX_ARITY, aux::make_items, PS, A
Chris@16:                 )::type
Chris@16:               , deduced_list
Chris@16:               , aux::tag_keyword_arg
Chris@16:               , mpl::false_ // Don't emit errors when doing SFINAE
Chris@16:             >::type
Chris@16:         >::type
Chris@16:     {};
Chris@16: # else
Chris@16:     { 
Chris@16:         typedef parameters<
Chris@16:             BOOST_PP_ENUM_PARAMS(BOOST_PARAMETER_MAX_ARITY, PS)
Chris@16:         > type; 
Chris@16:     };
Chris@16: # endif
Chris@16: 
Chris@16:     // Metafunction that returns an ArgumentPack.
Chris@16: 
Chris@16:     // TODO, bind has to instantiate the error type in the result
Chris@16:     // of make_arg_list.
Chris@16: 
Chris@16:     template <
Chris@16: #if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))
Chris@16:         // Borland simply can't handle default arguments in member
Chris@16:         // class templates.  People wishing to write portable code can
Chris@16:         // explicitly specify BOOST_PARAMETER_MAX_ARITY arguments
Chris@16:         BOOST_PP_ENUM_PARAMS(BOOST_PARAMETER_MAX_ARITY, class A)
Chris@16: #else 
Chris@16:         BOOST_PP_ENUM_BINARY_PARAMS(
Chris@16:             BOOST_PARAMETER_MAX_ARITY, class A, = void_ BOOST_PP_INTERCEPT
Chris@16:         )
Chris@16: #endif            
Chris@16:     >
Chris@16:     struct bind
Chris@16:     {
Chris@16:         typedef typename aux::make_arg_list<
Chris@16:             typename BOOST_PARAMETER_build_arg_list(
Chris@16:                 BOOST_PARAMETER_MAX_ARITY, aux::make_items, PS, A
Chris@16:             )::type
Chris@16:           , deduced_list
Chris@16:           , aux::tag_template_keyword_arg
Chris@16:         >::type result;
Chris@16: 
Chris@16:         typedef typename mpl::first<result>::type type;
Chris@16:     };
Chris@16: 
Chris@16:     BOOST_PARAMETER_FORWARD_TYPEDEFS(BOOST_PARAMETER_MAX_ARITY, PS, parameter_spec)
Chris@16: 
Chris@16:     //
Chris@16:     // The function call operator is used to build an arg_list that
Chris@16:     // labels the positional parameters and maintains whatever other
Chris@16:     // tags may have been specified by the caller.
Chris@16:     //
Chris@16:     // !!!NOTE!!!
Chris@16:     //
Chris@16:     // The make_arg_list<> produces a reversed arg_list, so
Chris@16:     // we need to pass the arguments to its constructor
Chris@16:     // reversed.
Chris@16:     //
Chris@16:     aux::empty_arg_list operator()() const
Chris@16:     {
Chris@16:        return aux::empty_arg_list();
Chris@16:     }
Chris@16: 
Chris@16:     template<class A0>
Chris@16:     typename mpl::first<
Chris@16:         typename aux::make_arg_list<
Chris@16:             aux::item<
Chris@16:                 PS0,A0
Chris@16:             >
Chris@16:           , deduced_list
Chris@16:           , aux::tag_keyword_arg
Chris@16:         >::type
Chris@16:     >::type
Chris@16:     operator()(A0& a0) const
Chris@16:     {
Chris@16:         typedef typename aux::make_arg_list<
Chris@16:             aux::item<
Chris@16:                 PS0,A0
Chris@16:             >
Chris@16:           , deduced_list
Chris@16:           , aux::tag_keyword_arg
Chris@16:         >::type result;
Chris@16: 
Chris@16:         typedef typename mpl::first<result>::type result_type;
Chris@16:         typedef typename mpl::second<result>::type error;
Chris@16:         error();
Chris@16: 
Chris@16:         return result_type(
Chris@16:             a0
Chris@16:             // , void_(), void_(), void_() ...
Chris@16:             BOOST_PP_ENUM_TRAILING_PARAMS(
Chris@16:                 BOOST_PP_SUB(BOOST_PARAMETER_MAX_ARITY, 1)
Chris@16:               , aux::void_reference() BOOST_PP_INTERCEPT)
Chris@16:         );
Chris@16:     }
Chris@16: 
Chris@16:     template<class A0, class A1>
Chris@16:     typename mpl::first<
Chris@16:         typename aux::make_arg_list<
Chris@16:             aux::item<
Chris@16:                 PS0,A0
Chris@16:               , aux::item<
Chris@16:                     PS1,A1
Chris@16:                 >
Chris@16:             >
Chris@16:           , deduced_list
Chris@16:           , aux::tag_keyword_arg
Chris@16:         >::type
Chris@16:     >::type
Chris@16:     operator()(A0& a0, A1& a1) const
Chris@16:     {
Chris@16:         typedef typename aux::make_arg_list<
Chris@16:             aux::item<
Chris@16:                 PS0,A0
Chris@16:               , aux::item<
Chris@16:                     PS1,A1
Chris@16:                 >
Chris@16:             >
Chris@16:           , deduced_list
Chris@16:           , aux::tag_keyword_arg
Chris@16:         >::type result;
Chris@16: 
Chris@16:         typedef typename mpl::first<result>::type result_type;
Chris@16:         typedef typename mpl::second<result>::type error;
Chris@16:         error();
Chris@16: 
Chris@16:         return result_type(
Chris@16:             a1,a0
Chris@16:             // , void_(), void_() ...
Chris@16:             BOOST_PP_ENUM_TRAILING_PARAMS(
Chris@16:                 BOOST_PP_SUB(BOOST_PARAMETER_MAX_ARITY, 2)
Chris@16:               , aux::void_reference() BOOST_PP_INTERCEPT)
Chris@16:         );
Chris@16:     }
Chris@16: 
Chris@16:     // Higher arities are handled by the preprocessor
Chris@16: #define BOOST_PP_ITERATION_PARAMS_1 (3,( \
Chris@16:         3,BOOST_PARAMETER_MAX_ARITY,<boost/parameter/aux_/overloads.hpp> \
Chris@16:     ))
Chris@16: #include BOOST_PP_ITERATE()
Chris@16: 
Chris@16: };
Chris@16: 
Chris@16: } // namespace parameter
Chris@16: 
Chris@16: } // namespace boost
Chris@16: 
Chris@16: #endif // BOOST_PARAMETERS_031014_HPP
Chris@16: