// Copyright David Abrahams, Daniel Wallin 2003. Use, modification and 

// distribution is subject to 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)

#ifndef BOOST_PARAMETERS_031014_HPP

#define BOOST_PARAMETERS_031014_HPP

#include <boost/detail/is_xxx.hpp>

#include <boost/type_traits/is_const.hpp>

#include <boost/mpl/lambda.hpp>

#include <boost/mpl/apply.hpp>

#include <boost/mpl/always.hpp>

#include <boost/mpl/and.hpp>

#include <boost/mpl/or.hpp>

#include <boost/mpl/if.hpp>

#include <boost/mpl/identity.hpp>

#include <boost/mpl/not.hpp>

#include <boost/mpl/eval_if.hpp>

#include <boost/mpl/pair.hpp>

#include <boost/type_traits/is_same.hpp>

#include <boost/type_traits/remove_reference.hpp>

#include <boost/preprocessor/repetition/enum.hpp>

#include <boost/preprocessor/repetition/enum_params.hpp>

#include <boost/preprocessor/repetition/enum_trailing_params.hpp>

#include <boost/preprocessor/arithmetic/sub.hpp>

#include <boost/preprocessor/repetition/repeat.hpp>

#include <boost/preprocessor/repetition/enum_shifted.hpp>

#include <boost/preprocessor/repetition/enum_binary_params.hpp>

#include <boost/preprocessor/repetition/enum_shifted_params.hpp>

#include <boost/preprocessor/seq/elem.hpp>

#include <boost/preprocessor/iteration/iterate.hpp>

#include <boost/preprocessor/facilities/intercept.hpp>

#include <boost/preprocessor/cat.hpp>

#include <boost/parameter/aux_/arg_list.hpp>

#include <boost/parameter/aux_/yesno.hpp>

#include <boost/parameter/aux_/void.hpp>

#include <boost/parameter/aux_/default.hpp>

#include <boost/parameter/aux_/unwrap_cv_reference.hpp>

#include <boost/parameter/aux_/tagged_argument.hpp>

#include <boost/parameter/aux_/tag.hpp>

#include <boost/parameter/aux_/template_keyword.hpp>

#include <boost/parameter/aux_/set.hpp>

#include <boost/parameter/config.hpp>

namespace parameter_

{

  template <class T>

  struct unmatched_argument

  {

      BOOST_MPL_ASSERT((boost::is_same<T,void>));

      typedef int type;

  }; 

} // namespace parameter_

namespace boost {

template<class T> class reference_wrapper;

namespace parameter {

namespace aux { struct use_default {}; }

// These templates can be used to describe the treatment of particular

// named parameters for the purposes of overload elimination with

// SFINAE, by placing specializations in the parameters<...> list.  In

// order for a treated function to participate in overload resolution:

//

//   - all keyword tags wrapped in required<...> must have a matching

//     actual argument

//

//   - The actual argument type matched by every keyword tag

//     associated with a predicate must satisfy that predicate

//

// If a keyword k is specified without an optional<...> or

// required<...>, wrapper, it is treated as though optional<k> were

// specified.

//

// If a keyword k is specified with deduced<...>, that keyword

// will be automatically deduced from the argument list.

//

template <class Tag, class Predicate = aux::use_default>

struct required

{

    typedef Tag key_type;

    typedef Predicate predicate;

};

template <class Tag, class Predicate = aux::use_default>

struct optional

{

    typedef Tag key_type;

    typedef Predicate predicate;

};

template <class Tag>

struct deduced

{

    typedef Tag key_type;

};

namespace aux

{

  // Defines metafunctions, is_required and is_optional, that

  // identify required<...>, optional<...> and deduced<...> specializations.

  BOOST_DETAIL_IS_XXX_DEF(required, required, 2)

  BOOST_DETAIL_IS_XXX_DEF(optional, optional, 2)

  BOOST_DETAIL_IS_XXX_DEF(deduced_aux, deduced, 1)

  template <class S>

  struct is_deduced0

    : is_deduced_aux<

          typename S::key_type

      >::type

  {};

  template <class S>

  struct is_deduced

    : mpl::eval_if<

          mpl::or_<

              is_optional<S>, is_required<S>

          >

        , is_deduced0<S>

        , mpl::false_

      >::type

  {};

  //

  // key_type, has_default, and predicate --

  //

  // These metafunctions accept a ParameterSpec and extract the

  // keyword tag, whether or not a default is supplied for the

  // parameter, and the predicate that the corresponding actual

  // argument type is required match.

  //

  // a ParameterSpec is a specialization of either keyword<...>,

  // required<...>, optional<...>

  //

  // helper for key_type<...>, below.

  template <class T>

  struct get_tag_type0

  {

      typedef typename T::key_type type;

  };

  template <class T>

  struct get_tag_type

    : mpl::eval_if<

          is_deduced_aux<typename T::key_type>

        , get_tag_type0<typename T::key_type>

        , mpl::identity<typename T::key_type>

      >

  {};

  template <class T>

  struct tag_type

    : mpl::eval_if<

          mpl::or_<

              is_optional<T>

            , is_required<T>

          >

        , get_tag_type<T>

        , mpl::identity<T>

      >

  {};

  template <class T>

  struct has_default

    : mpl::not_<is_required<T> >

  {};

  // helper for get_predicate<...>, below

  template <class T>

  struct get_predicate_or_default

  {

      typedef T type;

  };

  template <>

  struct get_predicate_or_default<use_default>

  {

      typedef mpl::always<mpl::true_> type;

  };

  // helper for predicate<...>, below

  template <class T>

  struct get_predicate

  {

      typedef typename

          get_predicate_or_default<typename T::predicate>::type

      type;

  };

  template <class T>

  struct predicate

    : mpl::eval_if<

         mpl::or_<

              is_optional<T>

            , is_required<T>

          >

        , get_predicate<T>

        , mpl::identity<mpl::always<mpl::true_> >

      >

  {

  };

  // Converts a ParameterSpec into a specialization of

  // parameter_requirements.  We need to do this in order to get the

  // tag_type into the type in a way that can be conveniently matched

  // by a satisfies(...) member function in arg_list.

  template <class ParameterSpec>

  struct as_parameter_requirements

  {

      typedef parameter_requirements<

          typename tag_type<ParameterSpec>::type

        , typename predicate<ParameterSpec>::type

        , typename has_default<ParameterSpec>::type

      > type;

  };

  template <class T>

  struct is_named_argument

    : mpl::or_<

          is_template_keyword<T>

        , is_tagged_argument<T>

      >

  {};

  // Returns mpl::true_ iff the given ParameterRequirements are

  // satisfied by ArgList.

  template <class ArgList, class ParameterRequirements>

  struct satisfies

  {

#if BOOST_WORKAROUND(BOOST_MSVC, == 1310)

      // VC7.1 can't handle the sizeof() implementation below,

      // so we use this instead.

      typedef typename mpl::apply_wrap3<

          typename ArgList::binding

        , typename ParameterRequirements::keyword

        , void_

        , mpl::false_

      >::type bound;

      typedef typename mpl::eval_if<

          is_same<bound, void_>

        , typename ParameterRequirements::has_default

        , mpl::apply_wrap2<

              typename mpl::lambda<

                  typename ParameterRequirements::predicate, lambda_tag

              >::type

            , bound

            , ArgList

          >

      >::type type;

#else

      BOOST_STATIC_CONSTANT(

          bool, value = (

              sizeof(

                  aux::to_yesno(

                      ArgList::satisfies((ParameterRequirements*)0, (ArgList*)0)

                  )

              ) == sizeof(yes_tag)

          )

      );

      typedef mpl::bool_<satisfies::value> type;

#endif

  };

  // Returns mpl::true_ if the requirements of the given ParameterSpec

  // are satisfied by ArgList.

  template <class ArgList, class ParameterSpec>

  struct satisfies_requirements_of

    : satisfies<

          ArgList

        , typename as_parameter_requirements<ParameterSpec>::type

      >

  {};

  // Tags a deduced argument Arg with the keyword tag of Spec using TagFn.

  // Returns the tagged argument and the mpl::set<> UsedArgs with the

  // tag of Spec inserted.

  template <class UsedArgs, class Spec, class Arg, class TagFn>

  struct tag_deduced

  {

      typedef mpl::pair<

          typename mpl::apply_wrap2<TagFn, typename tag_type<Spec>::type, Arg>::type

        , typename aux::insert_<UsedArgs, typename tag_type<Spec>::type>::type

      > type;

  };

  template <

      class Argument

    , class ArgumentPack

    , class DeducedArgs

    , class UsedArgs

    , class TagFn

  >

  struct deduce_tag;

  // Tag type passed to MPL lambda.

  struct lambda_tag;

  // Helper for deduce_tag<> below.

  template <

      class Argument

    , class ArgumentPack

    , class DeducedArgs

    , class UsedArgs

    , class TagFn

  >

  struct deduce_tag0

  {

      typedef typename DeducedArgs::spec spec;

      typedef typename mpl::apply_wrap2<

          typename mpl::lambda<

              typename spec::predicate, lambda_tag

          >::type

        , Argument

        , ArgumentPack

      >::type condition;

      // Deduced parameter matches several arguments.

      BOOST_MPL_ASSERT((

          mpl::not_<mpl::and_<

              condition

            , aux::has_key_<UsedArgs, typename tag_type<spec>::type>

          > >

      ));

      typedef typename mpl::eval_if<

          condition

        , tag_deduced<UsedArgs, spec, Argument, TagFn>

        , deduce_tag<Argument, ArgumentPack, typename DeducedArgs::tail, UsedArgs, TagFn>

      >::type type;

  };

  // Tries to deduced a keyword tag for a given Argument.

  // Returns an mpl::pair<> consisting of the tagged_argument<>, 

  // and an mpl::set<> where the new tag has been inserted.

  //

  //  Argument: The argument type to be tagged.

  //

  //  ArgumentPack: The ArgumentPack built so far.

  //

  //  DeducedArgs: A specialization of deduced_item<> (see below).

  //               A list containing only the deduced ParameterSpecs.

  //

  //  UsedArgs: An mpl::set<> containing the keyword tags used so far.

  //

  //  TagFn: A metafunction class used to tag positional or deduced

  //         arguments with a keyword tag.

  template <

      class Argument

    , class ArgumentPack

    , class DeducedArgs

    , class UsedArgs

    , class TagFn

  >

  struct deduce_tag

  {

      typedef typename mpl::eval_if<

          is_same<DeducedArgs, void_>

        , mpl::pair<void_, UsedArgs>

        , deduce_tag0<Argument, ArgumentPack, DeducedArgs, UsedArgs, TagFn>

      >::type type;

  };

  template <

      class List

    , class DeducedArgs

    , class TagFn

    , class Positional

    , class UsedArgs

    , class ArgumentPack

    , class Error

  >

  struct make_arg_list_aux;

  // Inserts Tagged::key_type into the UserArgs set.

  // Extra indirection to lazily evaluate Tagged::key_type.

  template <class UsedArgs, class Tagged>

  struct insert_tagged

  {

      typedef typename aux::insert_<

          UsedArgs, typename Tagged::key_type

      >::type type;

  };

  // Borland needs the insane extra-indirection workaround below

  // so that it doesn't magically drop the const qualifier from

  // the argument type.

  template <

      class List

    , class DeducedArgs

    , class TagFn

    , class Positional

    , class UsedArgs

    , class ArgumentPack

#if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))

    , class argument

#endif

    , class Error

  >

#if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))

  struct make_arg_list00

#else

  struct make_arg_list0

#endif

  {

#if !BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))

      typedef typename List::arg argument;

#endif

      typedef typename List::spec parameter_spec;

      typedef typename tag_type<parameter_spec>::type tag_;

      typedef is_named_argument<argument> is_tagged;

      // If this argument is either explicitly tagged or a deduced

      // parameter, we turn off positional matching.

      typedef mpl::and_<

          mpl::not_<

              mpl::or_<is_deduced<parameter_spec>, is_tagged> 

          > 

        , Positional

      > positional;

      // If this parameter is explicitly tagged we add it to the

      // used-parmeters set. We only really need to add parameters

      // that are deduced, but we would need a way to check if

      // a given tag corresponds to a deduced parameter spec.

      typedef typename mpl::eval_if<

          is_tagged

        , insert_tagged<UsedArgs, argument>

        , mpl::identity<UsedArgs>

      >::type used_args;

      // If this parameter is neither explicitly tagged, nor

      // positionally matched; deduce the tag from the deduced

      // parameter specs.

      typedef typename mpl::eval_if<

          mpl::or_<is_tagged, positional>

        , mpl::pair<void_, used_args>

        , deduce_tag<argument, ArgumentPack, DeducedArgs, used_args, TagFn>

      >::type deduced_data;

      // If this parameter is explicitly tagged..

      typedef typename mpl::eval_if<

          is_tagged

        , mpl::identity<argument>                        // .. just use it

        , mpl::eval_if<                                  // .. else, if positional matching is turned on..

                positional

              , mpl::apply_wrap2<TagFn, tag_, argument>  // .. tag it positionally

              , mpl::first<deduced_data>                 // .. else, use the deduced tag

          >

      >::type tagged;

      // We build the arg_list incrementally as we go, prepending new

      // nodes.

      typedef typename mpl::if_<

          mpl::and_<

              is_same<Error, void_>

            , is_same<tagged, void_>

          >

        , parameter_::unmatched_argument<argument>

        , void_

      >::type error;

      typedef typename mpl::if_<

          is_same<tagged, void_>

        , ArgumentPack

        , arg_list<tagged, ArgumentPack>

      >::type argument_pack;

      typedef typename make_arg_list_aux<

          typename List::tail

        , DeducedArgs

        , TagFn

        , positional

        , typename deduced_data::second

        , argument_pack

        , error

      >::type type;

  };

#if BOOST_WORKAROUND(__BORLANDC__, BOOST_TESTED_AT(0x564))

  template <

      class List

    , class DeducedArgs

    , class TagFn

    , class Positional

    , class UsedArgs

    , class ArgumentPack

    , class Error

  >

  struct make_arg_list0

  {

      typedef typename mpl::eval_if<

          typename List::is_arg_const

        , make_arg_list00<

              List

            , DeducedArgs

            , TagFn

            , Positional

            , UsedArgs

            , ArgumentPack

            , typename List::arg const

            , Error

          >

        , make_arg_list00<

              List

            , DeducedArgs

            , TagFn

            , Positional

            , UsedArgs

            , ArgumentPack