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: #ifndef HANDLE_DWA200269_HPP
Chris@16: # define HANDLE_DWA200269_HPP
Chris@16: 
Chris@16: # include <boost/python/detail/prefix.hpp>
Chris@16: 
Chris@16: # include <boost/python/cast.hpp>
Chris@16: # include <boost/python/errors.hpp>
Chris@16: # include <boost/python/borrowed.hpp>
Chris@16: # include <boost/python/handle_fwd.hpp>
Chris@16: # include <boost/python/refcount.hpp>
Chris@16: # include <boost/python/tag.hpp>
Chris@16: # include <boost/python/detail/raw_pyobject.hpp>
Chris@16: 
Chris@16: namespace boost { namespace python { 
Chris@16: 
Chris@16: template <class T> struct null_ok;
Chris@16: 
Chris@16: template <class T>
Chris@16: inline null_ok<T>* allow_null(T* p)
Chris@16: {
Chris@16:     return (null_ok<T>*)p;
Chris@16: }
Chris@16: 
Chris@16: namespace detail
Chris@16: {
Chris@16:   template <class T>
Chris@16:   inline T* manage_ptr(detail::borrowed<null_ok<T> >* p, int)
Chris@16:   {
Chris@16:       return python::xincref((T*)p);
Chris@16:   }
Chris@16:   
Chris@16:   template <class T>
Chris@16:   inline T* manage_ptr(null_ok<detail::borrowed<T> >* p, int)
Chris@16:   {
Chris@16:       return python::xincref((T*)p);
Chris@16:   }
Chris@16:   
Chris@16:   template <class T>
Chris@16:   inline T* manage_ptr(detail::borrowed<T>* p, long)
Chris@16:   {
Chris@16:       return python::incref(expect_non_null((T*)p));
Chris@16:   }
Chris@16:   
Chris@16:   template <class T>
Chris@16:   inline T* manage_ptr(null_ok<T>* p, long)
Chris@16:   {
Chris@16:       return (T*)p;
Chris@16:   }
Chris@16:   
Chris@16:   template <class T>
Chris@16:   inline T* manage_ptr(T* p, ...)
Chris@16:   {
Chris@16:       return expect_non_null(p);
Chris@16:   }
Chris@16: }
Chris@16: 
Chris@16: template <class T>
Chris@16: class handle
Chris@16: {
Chris@16:     typedef T* (handle::* bool_type )() const;
Chris@16: 
Chris@16:  public: // types
Chris@16:     typedef T element_type;
Chris@16:     
Chris@16:  public: // member functions
Chris@16:     handle();
Chris@16:     ~handle();
Chris@16: 
Chris@16:     template <class Y>
Chris@16:     explicit handle(Y* p)
Chris@16:         : m_p(
Chris@16:             python::upcast<T>(
Chris@16:                 detail::manage_ptr(p, 0)
Chris@16:                 )
Chris@16:             )
Chris@16:     {
Chris@16:     }
Chris@16: 
Chris@16:     handle& operator=(handle const& r)
Chris@16:     {
Chris@16:         python::xdecref(m_p);
Chris@16:         m_p = python::xincref(r.m_p);
Chris@16:         return *this;
Chris@16:     }
Chris@16: 
Chris@16: #if !defined(BOOST_MSVC) || (BOOST_MSVC >= 1300)
Chris@16: 
Chris@16:     template<typename Y>
Chris@16:     handle& operator=(handle<Y> const & r) // never throws
Chris@16:     {
Chris@16:         python::xdecref(m_p);
Chris@16:         m_p = python::xincref(python::upcast<T>(r.get()));
Chris@16:         return *this;
Chris@16:     }
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16:     template <typename Y>
Chris@16:     handle(handle<Y> const& r)
Chris@16:         : m_p(python::xincref(python::upcast<T>(r.get())))
Chris@16:     {
Chris@16:     }
Chris@16:     
Chris@16:     handle(handle const& r)
Chris@16:         : m_p(python::xincref(r.m_p))
Chris@16:     {
Chris@16:     }
Chris@16:     
Chris@16:     T* operator-> () const;
Chris@16:     T& operator* () const;
Chris@16:     T* get() const;
Chris@16:     T* release();
Chris@16:     void reset();
Chris@16:     
Chris@16:     operator bool_type() const // never throws
Chris@16:     {
Chris@16:         return m_p ? &handle<T>::get : 0;
Chris@16:     }
Chris@16:     bool operator! () const; // never throws
Chris@16: 
Chris@16:  public: // implementation details -- do not touch
Chris@16:     // Defining this in the class body suppresses a VC7 link failure
Chris@16:     inline handle(detail::borrowed_reference x)
Chris@16:         : m_p(
Chris@16:             python::incref(
Chris@16:                 downcast<T>((PyObject*)x)
Chris@16:                 ))
Chris@16:     {
Chris@16:     }
Chris@16:     
Chris@16:  private: // data members
Chris@16:     T* m_p;
Chris@16: };
Chris@16: 
Chris@16: #ifdef BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP
Chris@16: } // namespace python
Chris@16: #endif
Chris@16: 
Chris@16: template<class T> inline T * get_pointer(python::handle<T> const & p)
Chris@16: {
Chris@16:     return p.get();
Chris@16: }
Chris@16: 
Chris@16: #ifdef BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP
Chris@16: namespace python {
Chris@16: #else
Chris@16: 
Chris@16: // We don't want get_pointer above to hide the others
Chris@16: using boost::get_pointer;
Chris@16: 
Chris@16: #endif
Chris@16: 
Chris@16: typedef handle<PyTypeObject> type_handle;
Chris@16: 
Chris@16: //
Chris@16: // Compile-time introspection
Chris@16: //
Chris@16: # ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
Chris@16: template<typename T>
Chris@16: class is_handle
Chris@16: {
Chris@16:  public:
Chris@16:     BOOST_STATIC_CONSTANT(bool, value = false); 
Chris@16: };
Chris@16: 
Chris@16: template<typename T>
Chris@16: class is_handle<handle<T> >
Chris@16: {
Chris@16:  public:
Chris@16:     BOOST_STATIC_CONSTANT(bool, value = true);
Chris@16: };
Chris@16: # else
Chris@16: namespace detail
Chris@16: {
Chris@16:   typedef char (&yes_handle_t)[1];
Chris@16:   typedef char (&no_handle_t)[2];
Chris@16:       
Chris@16:   no_handle_t is_handle_test(...);
Chris@16: 
Chris@16:   template<typename T>
Chris@16:   yes_handle_t is_handle_test(boost::type< handle<T> >);
Chris@16: }
Chris@16: 
Chris@16: template<typename T>
Chris@16: class is_handle
Chris@16: {
Chris@16:  public:
Chris@16:     BOOST_STATIC_CONSTANT(
Chris@16:         bool, value = (
Chris@16:             sizeof(detail::is_handle_test(boost::type<T>()))
Chris@16:             == sizeof(detail::yes_handle_t)));
Chris@16: };
Chris@16: # endif
Chris@16: 
Chris@16: //
Chris@16: // implementations
Chris@16: //
Chris@16: template <class T>
Chris@16: inline handle<T>::handle()
Chris@16:     : m_p(0)
Chris@16: {
Chris@16: }
Chris@16: 
Chris@16: template <class T>
Chris@16: inline handle<T>::~handle()
Chris@16: {
Chris@16:     python::xdecref(m_p);
Chris@16: }
Chris@16: 
Chris@16: template <class T>
Chris@16: inline T* handle<T>::operator->() const
Chris@16: {
Chris@16:     return m_p;
Chris@16: }
Chris@16: 
Chris@16: template <class T>
Chris@16: inline T& handle<T>::operator*() const
Chris@16: {
Chris@16:     return *m_p;
Chris@16: }
Chris@16: 
Chris@16: template <class T>
Chris@16: inline T* handle<T>::get() const
Chris@16: {
Chris@16:     return m_p;
Chris@16: }
Chris@16:     
Chris@16: template <class T>
Chris@16: inline bool handle<T>::operator!() const
Chris@16: {
Chris@16:     return m_p == 0;
Chris@16: }
Chris@16: 
Chris@16: template <class T>
Chris@16: inline T* handle<T>::release()
Chris@16: {
Chris@16:     T* result = m_p;
Chris@16:     m_p = 0;
Chris@16:     return result;
Chris@16: }
Chris@16: 
Chris@16: template <class T>
Chris@16: inline void handle<T>::reset()
Chris@16: {
Chris@16:     python::xdecref(m_p);
Chris@16:     m_p = 0;
Chris@16: }
Chris@16: 
Chris@16: // Because get_managed_object must return a non-null PyObject*, we
Chris@16: // return Py_None if the handle is null.
Chris@16: template <class T>
Chris@16: inline PyObject* get_managed_object(handle<T> const& h, tag_t)
Chris@16: {
Chris@16:     return h.get() ? python::upcast<PyObject>(h.get()) : Py_None;
Chris@16: }
Chris@16: 
Chris@16: }} // namespace boost::python
Chris@16: 
Chris@16: 
Chris@16: #endif // HANDLE_DWA200269_HPP