// Copyright David Abrahams 2002.

// Distributed under 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 DATA_MEMBERS_DWA2002328_HPP

# define DATA_MEMBERS_DWA2002328_HPP



# include <boost/python/detail/prefix.hpp>



# include <boost/python/handle.hpp>



# include <boost/python/return_value_policy.hpp>

# include <boost/python/return_by_value.hpp>

# include <boost/python/return_internal_reference.hpp>

# include <boost/python/make_function.hpp>



# include <boost/python/converter/builtin_converters.hpp>



# include <boost/python/detail/indirect_traits.hpp>

# include <boost/python/detail/not_specified.hpp>

# include <boost/python/detail/value_arg.hpp>



# include <boost/type_traits/add_const.hpp>

# include <boost/type_traits/add_reference.hpp>

# include <boost/type_traits/is_member_pointer.hpp>



# if BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))

#  include <boost/type_traits/remove_cv.hpp>

# endif 



# include <boost/mpl/eval_if.hpp>

# include <boost/mpl/if.hpp>

# include <boost/mpl/vector/vector10.hpp>



# include <boost/detail/workaround.hpp>



namespace boost { namespace python { 



//

// This file defines the make_getter and make_setter function

// families, which are responsible for turning pointers, references,

// and pointers-to-data-members into callable Python objects which

// can be used for attribute access on wrapped classes.

//



namespace detail

{



  // A small function object which handles the getting and setting of

  // data members.

  template <class Data, class Class>

  struct member

  {

   public:      

      member(Data Class::*which) : m_which(which) {}

      

      Data& operator()(Class& c) const

      {

          return c.*m_which;

      }



      void operator()(Class& c, typename value_arg<Data>::type d) const

      {

          c.*m_which = d;

      }

   private:

      Data Class::*m_which;

  };



  // A small function object which handles the getting and setting of

  // non-member objects.

  template <class Data>

  struct datum

  {

   public:      

      datum(Data *which) : m_which(which) {}

      

      Data& operator()() const

      {

          return *m_which;

      }



      void operator()(typename value_arg<Data>::type d) const

      {

          *m_which = d;

      }

   private:

      Data *m_which;

  };

  

  //

  // Helper metafunction for determining the default CallPolicy to use

  // for attribute access.  If T is a [reference to a] class type X

  // whose conversion to python would normally produce a new copy of X

  // in a wrapped X class instance (as opposed to types such as

  // std::string, which are converted to native Python types, and

  // smart pointer types which produce a wrapped class instance of the

  // pointee type), to-python conversions will attempt to produce an

  // object which refers to the original C++ object, rather than a

  // copy.  See default_member_getter_policy for rationale.

  // 

  template <class T>

  struct default_getter_by_ref

      : mpl::and_<

          mpl::bool_<

              to_python_value<

                  typename value_arg<T>::type

              >::uses_registry

          >

        , indirect_traits::is_reference_to_class<

              typename value_arg<T>::type

          >

       >

  {

  };



  // Metafunction computing the default CallPolicy to use for reading

  // data members

  //

  // If it's a regular class type (not an object manager or other

  // type for which we have to_python specializations, use

  // return_internal_reference so that we can do things like

  //    x.y.z =  1

  // and get the right result.

  template <class T>

  struct default_member_getter_policy

    : mpl::if_<

          default_getter_by_ref<T>

        , return_internal_reference<>

        , return_value_policy<return_by_value>

      >

  {};



  // Metafunction computing the default CallPolicy to use for reading

  // non-member data.

  template <class T>

  struct default_datum_getter_policy

    : mpl::if_<

          default_getter_by_ref<T>

        , return_value_policy<reference_existing_object>

        , return_value_policy<return_by_value>

      >

  {};



  //

  // make_getter helper function family -- These helpers to

  // boost::python::make_getter are used to dispatch behavior.  The

  // third argument is a workaround for a CWPro8 partial ordering bug

  // with pointers to data members.  It should be convertible to

  // mpl::true_ iff the first argument is a pointer-to-member, and

  // mpl::false_ otherwise.  The fourth argument is for compilers

  // which don't support partial ordering at all and should always be

  // passed 0L.

  //



#if BOOST_WORKAROUND(__EDG_VERSION__, <= 238)

  template <class D, class P>

  inline object make_getter(D& d, P& p, mpl::false_, ...);

#endif



  // Handle non-member pointers with policies

  template <class D, class Policies>

  inline object make_getter(D* d, Policies const& policies, mpl::false_, int)

  {

      return python::make_function(

          detail::datum<D>(d), policies, mpl::vector1<D&>()

      );

  }

  

  // Handle non-member pointers without policies

  template <class D>

  inline object make_getter(D* d, not_specified, mpl::false_, long)

  {

      typedef typename default_datum_getter_policy<D>::type policies;

      return detail::make_getter(d, policies(), mpl::false_(), 0);

  }



  // Handle pointers-to-members with policies

  template <class C, class D, class Policies>

  inline object make_getter(D C::*pm, Policies const& policies, mpl::true_, int)

  {

#if BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3003))

      typedef typename remove_cv<C>::type Class;

#else

      typedef C Class;

#endif 

      return python::make_function(

          detail::member<D,Class>(pm)

        , policies

        , mpl::vector2<D&,Class&>()

      );

  }

      

  // Handle pointers-to-members without policies

  template <class C, class D>

  inline object make_getter(D C::*pm, not_specified, mpl::true_, long)

  {

      typedef typename default_member_getter_policy<D>::type policies;

      return detail::make_getter(pm, policies(), mpl::true_(), 0);

  }



  // Handle references

  template <class D, class P>

  inline object make_getter(D& d, P& p, mpl::false_, ...)

  {

      // Just dispatch to the handler for pointer types.

      return detail::make_getter(&d, p, mpl::false_(), 0L);

  }



  //

  // make_setter helper function family -- These helpers to

  // boost::python::make_setter are used to dispatch behavior.  The

  // third argument is for compilers which don't support partial

  // ordering at all and should always be passed 0.

  //



  

  // Handle non-member pointers

  template <class D, class Policies>

  inline object make_setter(D* p, Policies const& policies, mpl::false_, int)

  {

      return python::make_function(

          detail::datum<D>(p), policies, mpl::vector2<void,D const&>()

      );

  }



  // Handle pointers-to-members

  template <class C, class D, class Policies>

  inline object make_setter(D C::*pm, Policies const& policies, mpl::true_, int)

  {

      return python::make_function(

          detail::member<D,C>(pm)

        , policies

        , mpl::vector3<void, C&, D const&>()

      );

  }



  // Handle references

  template <class D, class Policies>

  inline object make_setter(D& x, Policies const& policies, mpl::false_, ...)

  {

      return detail::make_setter(&x, policies, mpl::false_(), 0L);

  }

}



//

// make_getter function family -- build a callable object which

// retrieves data through the first argument and is appropriate for

// use as the `get' function in Python properties .  The second,

// policies argument, is optional.  We need both D& and D const&

// overloads in order be able to handle rvalues.

//

template <class D, class Policies>

inline object make_getter(D& d, Policies const& policies)

{

    return detail::make_getter(d, policies, is_member_pointer<D>(), 0L);

}



template <class D, class Policies>

inline object make_getter(D const& d, Policies const& policies)

{

    return detail::make_getter(d, policies, is_member_pointer<D>(), 0L);

}



template <class D>

inline object make_getter(D& x)

{

    detail::not_specified policy;

    return detail::make_getter(x, policy, is_member_pointer<D>(), 0L);

}



#  if !BOOST_WORKAROUND(__EDG_VERSION__, <= 238) && !BOOST_WORKAROUND(BOOST_MSVC, <= 1300)

template <class D>

inline object make_getter(D const& d)

{

    detail::not_specified policy;

    return detail::make_getter(d, policy, is_member_pointer<D>(), 0L);

}

#  endif



//

// make_setter function family -- build a callable object which

// writes data through the first argument and is appropriate for

// use as the `set' function in Python properties .  The second,

// policies argument, is optional.  We need both D& and D const&

// overloads in order be able to handle rvalues.

//

template <class D, class Policies>

inline object make_setter(D& x, Policies const& policies)

{

    return detail::make_setter(x, policies, is_member_pointer<D>(), 0);

}



template <class D, class Policies>

inline object make_setter(D const& x, Policies const& policies)

{

    return detail::make_setter(x, policies, is_member_pointer<D>(), 0);

}



template <class D>

inline object make_setter(D& x)

{

    return detail::make_setter(x, default_call_policies(), is_member_pointer<D>(), 0);

}



# if !(BOOST_WORKAROUND(BOOST_MSVC, <= 1300) || BOOST_WORKAROUND(__EDG_VERSION__, <= 238))

template <class D>

inline object make_setter(D const& x)

{

    return detail::make_setter(x, default_call_policies(), is_member_pointer<D>(), 0);

}

# endif



}} // namespace boost::python



#endif // DATA_MEMBERS_DWA2002328_HPP

