// 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