Chris@16: // Copyright David Abrahams 2004. Distributed under the Boost
Chris@16: // Software License, Version 1.0. (See accompanying
Chris@16: // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
Chris@16: #ifndef CLASS_METADATA_DWA2004719_HPP
Chris@16: # define CLASS_METADATA_DWA2004719_HPP
Chris@16: # include <boost/python/converter/shared_ptr_from_python.hpp>
Chris@16: 
Chris@16: # include <boost/python/object/inheritance.hpp>
Chris@16: # include <boost/python/object/class_wrapper.hpp>
Chris@16: # include <boost/python/object/make_instance.hpp>
Chris@16: # include <boost/python/object/value_holder.hpp>
Chris@16: # include <boost/python/object/pointer_holder.hpp>
Chris@16: # include <boost/python/object/make_ptr_instance.hpp>
Chris@16: 
Chris@16: # include <boost/python/detail/force_instantiate.hpp>
Chris@16: # include <boost/python/detail/not_specified.hpp>
Chris@16: 
Chris@16: # include <boost/python/has_back_reference.hpp>
Chris@16: # include <boost/python/bases.hpp>
Chris@16: 
Chris@16: # include <boost/type_traits/add_pointer.hpp>
Chris@16: # include <boost/type_traits/is_convertible.hpp>
Chris@16: # include <boost/type_traits/is_polymorphic.hpp>
Chris@16: 
Chris@16: # include <boost/mpl/if.hpp>
Chris@16: # include <boost/mpl/eval_if.hpp>
Chris@16: # include <boost/mpl/bool.hpp>
Chris@16: # include <boost/mpl/or.hpp>
Chris@16: # include <boost/mpl/identity.hpp>
Chris@16: # include <boost/mpl/for_each.hpp>
Chris@16: # include <boost/mpl/placeholders.hpp>
Chris@16: # include <boost/mpl/single_view.hpp>
Chris@16: 
Chris@16: # include <boost/mpl/assert.hpp>
Chris@16: # include <boost/type_traits/is_same.hpp>
Chris@16: 
Chris@16: # include <boost/type_traits/is_convertible.hpp>
Chris@16: 
Chris@16: # include <boost/noncopyable.hpp>
Chris@16: # include <boost/detail/workaround.hpp>
Chris@16: 
Chris@16: namespace boost { namespace python { namespace objects { 
Chris@16: 
Chris@16: BOOST_PYTHON_DECL
Chris@16: void copy_class_object(type_info const& src, type_info const& dst);
Chris@16: 
Chris@16: //
Chris@16: // Support for registering base/derived relationships
Chris@16: //
Chris@16: template <class Derived>
Chris@16: struct register_base_of
Chris@16: {
Chris@16:     template <class Base>
Chris@16:     inline void operator()(Base*) const
Chris@16:     {
Chris@16: # if !BOOST_WORKAROUND(BOOST_MSVC, == 1200)
Chris@16:         BOOST_MPL_ASSERT_NOT((is_same<Base,Derived>));
Chris@16: # else
Chris@16:         BOOST_STATIC_ASSERT(!(is_same<Base,Derived>::value));
Chris@16: # endif 
Chris@16:         
Chris@16:         // Register the Base class
Chris@16:         register_dynamic_id<Base>();
Chris@16: 
Chris@16:         // Register the up-cast
Chris@16:         register_conversion<Derived,Base>(false);
Chris@16: 
Chris@16:         // Register the down-cast, if appropriate.
Chris@16:         this->register_downcast((Base*)0, is_polymorphic<Base>());
Chris@16:     }
Chris@16: 
Chris@16:  private:
Chris@16:     static inline void register_downcast(void*, mpl::false_) {}
Chris@16:     
Chris@16:     template <class Base>
Chris@16:     static inline void register_downcast(Base*, mpl::true_)
Chris@16:     {
Chris@16:         register_conversion<Base, Derived>(true);
Chris@16:     }
Chris@16: 
Chris@16: };
Chris@16: 
Chris@16: //
Chris@16: // Preamble of register_class.  Also used for callback classes, which
Chris@16: // need some registration of their own.
Chris@16: //
Chris@16: template <class T, class Bases>
Chris@16: inline void register_shared_ptr_from_python_and_casts(T*, Bases)
Chris@16: {
Chris@16:     // Constructor performs registration
Chris@16:     python::detail::force_instantiate(converter::shared_ptr_from_python<T>());
Chris@16: 
Chris@16:     //
Chris@16:     // register all up/downcasts here.  We're using the alternate
Chris@16:     // interface to mpl::for_each to avoid an MSVC 6 bug.
Chris@16:     //
Chris@16:     register_dynamic_id<T>();
Chris@16:     mpl::for_each(register_base_of<T>(), (Bases*)0, (add_pointer<mpl::_>*)0);
Chris@16: }
Chris@16: 
Chris@16: //
Chris@16: // Helper for choosing the unnamed held_type argument
Chris@16: //
Chris@16: template <class T, class Prev>
Chris@16: struct select_held_type
Chris@16:   : mpl::if_<
Chris@16:         mpl::or_<
Chris@16:             python::detail::specifies_bases<T>
Chris@16:           , is_same<T,noncopyable>
Chris@16:         >
Chris@16:       , Prev
Chris@16:       , T
Chris@16:     >
Chris@16: {
Chris@16: };
Chris@16: 
Chris@16: template <
Chris@16:     class T // class being wrapped
Chris@16:   , class X1 // = detail::not_specified
Chris@16:   , class X2 // = detail::not_specified
Chris@16:   , class X3 // = detail::not_specified
Chris@16: >
Chris@16: struct class_metadata
Chris@16: {
Chris@16:     //
Chris@16:     // Calculate the unnamed template arguments
Chris@16:     //
Chris@16:     
Chris@16:     // held_type_arg -- not_specified, [a class derived from] T or a
Chris@16:     // smart pointer to [a class derived from] T.  Preserving
Chris@16:     // not_specified allows us to give class_<T,T> a back-reference.
Chris@16:     typedef typename select_held_type<
Chris@16:         X1
Chris@16:       , typename select_held_type<
Chris@16:             X2
Chris@16:           , typename select_held_type<
Chris@16:                 X3
Chris@16:               , python::detail::not_specified
Chris@16:             >::type
Chris@16:         >::type
Chris@16:     >::type held_type_arg;
Chris@16: 
Chris@16:     // bases
Chris@16:     typedef typename python::detail::select_bases<
Chris@16:         X1
Chris@16:       , typename python::detail::select_bases<
Chris@16:             X2
Chris@16:           , typename python::detail::select_bases<
Chris@16:                 X3
Chris@16:               , python::bases<>
Chris@16:             >::type
Chris@16:         >::type
Chris@16:     >::type bases;
Chris@16: 
Chris@16:     typedef mpl::or_<
Chris@16:         is_same<X1,noncopyable>
Chris@16:       , is_same<X2,noncopyable>
Chris@16:       , is_same<X3,noncopyable>
Chris@16:     > is_noncopyable;
Chris@16:     
Chris@16:     //
Chris@16:     // Holder computation.
Chris@16:     //
Chris@16:     
Chris@16:     // Compute the actual type that will be held in the Holder.
Chris@16:     typedef typename mpl::if_<
Chris@16:         is_same<held_type_arg,python::detail::not_specified>, T, held_type_arg
Chris@16:     >::type held_type;
Chris@16: 
Chris@16:     // Determine if the object will be held by value
Chris@16:     typedef is_convertible<held_type*,T*> use_value_holder;
Chris@16:     
Chris@16:     // Compute the "wrapped type", that is, if held_type is a smart
Chris@16:     // pointer, we're talking about the pointee.
Chris@16:     typedef typename mpl::eval_if<
Chris@16:         use_value_holder
Chris@16:       , mpl::identity<held_type>
Chris@16:       , pointee<held_type>
Chris@16:     >::type wrapped;
Chris@16: 
Chris@16:     // Determine whether to use a "back-reference holder"
Chris@16:     typedef mpl::or_<
Chris@16:         has_back_reference<T>
Chris@16:       , is_same<held_type_arg,T>
Chris@16:       , is_base_and_derived<T,wrapped>
Chris@16:     > use_back_reference;
Chris@16: 
Chris@16:     // Select the holder.
Chris@16:     typedef typename mpl::eval_if<
Chris@16:         use_back_reference
Chris@16:       , mpl::if_<
Chris@16:             use_value_holder
Chris@16:           , value_holder_back_reference<T, wrapped>
Chris@16:           , pointer_holder_back_reference<held_type,T>
Chris@16:         >
Chris@16:       , mpl::if_<
Chris@16:             use_value_holder
Chris@16:           , value_holder<T>
Chris@16:           , pointer_holder<held_type,wrapped>
Chris@16:         >
Chris@16:     >::type holder;
Chris@16:     
Chris@16:     inline static void register_() // Register the runtime metadata.
Chris@16:     {
Chris@16:         class_metadata::register_aux((T*)0);
Chris@16:     }
Chris@16: 
Chris@16:  private:
Chris@16:     template <class T2>
Chris@16:     inline static void register_aux(python::wrapper<T2>*) 
Chris@16:     {
Chris@16:         typedef typename mpl::not_<is_same<T2,wrapped> >::type use_callback;
Chris@16:         class_metadata::register_aux2((T2*)0, use_callback());
Chris@16:     }
Chris@16: 
Chris@16:     inline static void register_aux(void*) 
Chris@16:     {
Chris@16:         typedef typename is_base_and_derived<T,wrapped>::type use_callback;
Chris@16:         class_metadata::register_aux2((T*)0, use_callback());
Chris@16:     }
Chris@16: 
Chris@16:     template <class T2, class Callback>
Chris@16:     inline static void register_aux2(T2*, Callback) 
Chris@16:     {
Chris@16:         objects::register_shared_ptr_from_python_and_casts((T2*)0, bases());
Chris@16:         
Chris@16:         class_metadata::maybe_register_callback_class((T2*)0, Callback());
Chris@16: 
Chris@16:         class_metadata::maybe_register_class_to_python((T2*)0, is_noncopyable());
Chris@16:         
Chris@16:         class_metadata::maybe_register_pointer_to_python(
Chris@16:             (T2*)0, (use_value_holder*)0, (use_back_reference*)0);
Chris@16:     }
Chris@16: 
Chris@16: 
Chris@16:     //
Chris@16:     // Support for converting smart pointers to python
Chris@16:     //
Chris@16:     inline static void maybe_register_pointer_to_python(...) {}
Chris@16: 
Chris@16: #ifndef BOOST_PYTHON_NO_PY_SIGNATURES
Chris@16:     inline static void maybe_register_pointer_to_python(void*,void*,mpl::true_*) 
Chris@16:     {
Chris@16:         objects::copy_class_object(python::type_id<T>(), python::type_id<back_reference<T const &> >());
Chris@16:         objects::copy_class_object(python::type_id<T>(), python::type_id<back_reference<T &> >());
Chris@16:     }
Chris@16: #endif
Chris@16: 
Chris@16:     template <class T2>
Chris@16:     inline static void maybe_register_pointer_to_python(T2*, mpl::false_*, mpl::false_*)
Chris@16:     {
Chris@16:         python::detail::force_instantiate(
Chris@16:             objects::class_value_wrapper<
Chris@16:                 held_type
Chris@16:               , make_ptr_instance<T2, pointer_holder<held_type, T2> >
Chris@16:             >()
Chris@16:         );
Chris@16: #ifndef BOOST_PYTHON_NO_PY_SIGNATURES
Chris@16:         // explicit qualification of type_id makes msvc6 happy
Chris@16:         objects::copy_class_object(python::type_id<T2>(), python::type_id<held_type>());
Chris@16: #endif
Chris@16:     }
Chris@16:     //
Chris@16:     // Support for registering to-python converters
Chris@16:     //
Chris@16:     inline static void maybe_register_class_to_python(void*, mpl::true_) {}
Chris@16:     
Chris@16: 
Chris@16:     template <class T2>
Chris@16:     inline static void maybe_register_class_to_python(T2*, mpl::false_)
Chris@16:     {
Chris@16:         python::detail::force_instantiate(class_cref_wrapper<T2, make_instance<T2, holder> >());
Chris@16: #ifndef BOOST_PYTHON_NO_PY_SIGNATURES
Chris@16:         // explicit qualification of type_id makes msvc6 happy
Chris@16:         objects::copy_class_object(python::type_id<T2>(), python::type_id<held_type>());
Chris@16: #endif
Chris@16:     }
Chris@16: 
Chris@16:     //
Chris@16:     // Support for registering callback classes
Chris@16:     //
Chris@16:     inline static void maybe_register_callback_class(void*, mpl::false_) {}
Chris@16: 
Chris@16:     template <class T2>
Chris@16:     inline static void maybe_register_callback_class(T2*, mpl::true_)
Chris@16:     {
Chris@16:         objects::register_shared_ptr_from_python_and_casts(
Chris@16:             (wrapped*)0, mpl::single_view<T2>());
Chris@16: 
Chris@16:         // explicit qualification of type_id makes msvc6 happy
Chris@16:         objects::copy_class_object(python::type_id<T2>(), python::type_id<wrapped>());
Chris@16:     }
Chris@16: };
Chris@16: 
Chris@16: }}} // namespace boost::python::object
Chris@16: 
Chris@16: #endif // CLASS_METADATA_DWA2004719_HPP