Chris@16: #ifndef BORROWED_PTR_DWA20020601_HPP
Chris@16: # define BORROWED_PTR_DWA20020601_HPP
Chris@16: // Copyright David Abrahams 2002.
Chris@16: // Distributed under the Boost Software License, Version 1.0. (See
Chris@16: // accompanying file LICENSE_1_0.txt or copy at
Chris@16: // http://www.boost.org/LICENSE_1_0.txt)
Chris@16: 
Chris@16: # include <boost/config.hpp>
Chris@16: # include <boost/type.hpp>
Chris@16: # include <boost/mpl/if.hpp>
Chris@16: # include <boost/type_traits/object_traits.hpp>
Chris@16: # include <boost/type_traits/cv_traits.hpp>
Chris@16: # include <boost/python/tag.hpp>
Chris@16: 
Chris@16: namespace boost { namespace python { namespace detail {
Chris@16: 
Chris@16: template<class T> class borrowed
Chris@16: { 
Chris@16:     typedef T type;
Chris@16: };
Chris@16: 
Chris@16: # ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
Chris@16: template<typename T>
Chris@16: struct is_borrowed_ptr
Chris@16: {
Chris@16:     BOOST_STATIC_CONSTANT(bool, value = false); 
Chris@16: };
Chris@16: 
Chris@16: #  if !defined(__MWERKS__) || __MWERKS__ > 0x3000
Chris@16: template<typename T>
Chris@16: struct is_borrowed_ptr<borrowed<T>*>
Chris@16: {
Chris@16:     BOOST_STATIC_CONSTANT(bool, value = true);
Chris@16: };
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct is_borrowed_ptr<borrowed<T> const*>
Chris@16: {
Chris@16:     BOOST_STATIC_CONSTANT(bool, value = true);
Chris@16: };
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct is_borrowed_ptr<borrowed<T> volatile*>
Chris@16: {
Chris@16:     BOOST_STATIC_CONSTANT(bool, value = true);
Chris@16: };
Chris@16: 
Chris@16: template<typename T>
Chris@16: struct is_borrowed_ptr<borrowed<T> const volatile*>
Chris@16: {
Chris@16:     BOOST_STATIC_CONSTANT(bool, value = true);
Chris@16: };
Chris@16: #  else
Chris@16: template<typename T>
Chris@16: struct is_borrowed
Chris@16: {
Chris@16:     BOOST_STATIC_CONSTANT(bool, value = false);
Chris@16: };
Chris@16: template<typename T>
Chris@16: struct is_borrowed<borrowed<T> >
Chris@16: {
Chris@16:     BOOST_STATIC_CONSTANT(bool, value = true);
Chris@16: };
Chris@16: template<typename T>
Chris@16: struct is_borrowed_ptr<T*>
Chris@16:     : is_borrowed<typename remove_cv<T>::type>
Chris@16: {
Chris@16: };
Chris@16: #  endif 
Chris@16: 
Chris@16: # else // no partial specialization
Chris@16: 
Chris@16: typedef char (&yes_borrowed_ptr_t)[1];
Chris@16: typedef char (&no_borrowed_ptr_t)[2];
Chris@16: 
Chris@16: no_borrowed_ptr_t is_borrowed_ptr_test(...);
Chris@16: 
Chris@16: template <class T>
Chris@16: typename mpl::if_c<
Chris@16:     is_pointer<T>::value
Chris@16:     , T
Chris@16:     , int
Chris@16:     >::type
Chris@16: is_borrowed_ptr_test1(boost::type<T>);
Chris@16: 
Chris@16: template<typename T>
Chris@16: yes_borrowed_ptr_t is_borrowed_ptr_test(borrowed<T> const volatile*);
Chris@16: 
Chris@16: template<typename T>
Chris@16: class is_borrowed_ptr
Chris@16: {
Chris@16:  public:
Chris@16:     BOOST_STATIC_CONSTANT(
Chris@16:         bool, value = (
Chris@16:             sizeof(detail::is_borrowed_ptr_test(is_borrowed_ptr_test1(boost::type<T>())))
Chris@16:             == sizeof(detail::yes_borrowed_ptr_t)));
Chris@16: };
Chris@16: 
Chris@16: # endif // BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
Chris@16: 
Chris@16: }
Chris@16: 
Chris@16: template <class T>
Chris@16: inline T* get_managed_object(detail::borrowed<T> const volatile* p, tag_t)
Chris@16: {
Chris@16:     return (T*)p;
Chris@16: }
Chris@16: 
Chris@16: }} // namespace boost::python::detail
Chris@16: 
Chris@16: #endif // #ifndef BORROWED_PTR_DWA20020601_HPP