sl@0: // Copyright David Abrahams 2002.
sl@0: // Distributed under the Boost Software License, Version 1.0. (See
sl@0: // accompanying file LICENSE_1_0.txt or copy at
sl@0: // http://www.boost.org/LICENSE_1_0.txt)
sl@0: #ifndef HANDLE_DWA200269_HPP
sl@0: # define HANDLE_DWA200269_HPP
sl@0: 
sl@0: # include <boost/python/detail/prefix.hpp>
sl@0: 
sl@0: # include <boost/python/cast.hpp>
sl@0: # include <boost/python/errors.hpp>
sl@0: # include <boost/python/borrowed.hpp>
sl@0: # include <boost/python/handle_fwd.hpp>
sl@0: # include <boost/python/refcount.hpp>
sl@0: # include <boost/python/tag.hpp>
sl@0: # include <boost/python/detail/raw_pyobject.hpp>
sl@0: 
sl@0: namespace boost { namespace python { 
sl@0: 
sl@0: template <class T> struct null_ok;
sl@0: 
sl@0: template <class T>
sl@0: inline null_ok<T>* allow_null(T* p)
sl@0: {
sl@0:     return (null_ok<T>*)p;
sl@0: }
sl@0: 
sl@0: namespace detail
sl@0: {
sl@0:   template <class T>
sl@0:   inline T* manage_ptr(detail::borrowed<null_ok<T> >* p, int)
sl@0:   {
sl@0:       return python::xincref((T*)p);
sl@0:   }
sl@0:   
sl@0:   template <class T>
sl@0:   inline T* manage_ptr(null_ok<detail::borrowed<T> >* p, int)
sl@0:   {
sl@0:       return python::xincref((T*)p);
sl@0:   }
sl@0:   
sl@0:   template <class T>
sl@0:   inline T* manage_ptr(detail::borrowed<T>* p, long)
sl@0:   {
sl@0:       return python::incref(expect_non_null((T*)p));
sl@0:   }
sl@0:   
sl@0:   template <class T>
sl@0:   inline T* manage_ptr(null_ok<T>* p, long)
sl@0:   {
sl@0:       return (T*)p;
sl@0:   }
sl@0:   
sl@0:   template <class T>
sl@0:   inline T* manage_ptr(T* p, ...)
sl@0:   {
sl@0:       return expect_non_null(p);
sl@0:   }
sl@0: }
sl@0: 
sl@0: template <class T>
sl@0: class handle
sl@0: {
sl@0:     typedef T* (handle::* bool_type )() const;
sl@0: 
sl@0:  public: // types
sl@0:     typedef T element_type;
sl@0:     
sl@0:  public: // member functions
sl@0:     handle();
sl@0:     ~handle();
sl@0: 
sl@0:     template <class Y>
sl@0:     explicit handle(Y* p)
sl@0:         : m_p(
sl@0:             python::upcast<T>(
sl@0:                 detail::manage_ptr(p, 0)
sl@0:                 )
sl@0:             )
sl@0:     {
sl@0:     }
sl@0: 
sl@0:     handle& operator=(handle const& r)
sl@0:     {
sl@0:         python::xdecref(m_p);
sl@0:         m_p = python::xincref(r.m_p);
sl@0:         return *this;
sl@0:     }
sl@0: 
sl@0: #if !defined(BOOST_MSVC) || (BOOST_MSVC >= 1300)
sl@0: 
sl@0:     template<typename Y>
sl@0:     handle& operator=(handle<Y> const & r) // never throws
sl@0:     {
sl@0:         python::xdecref(m_p);
sl@0:         m_p = python::xincref(python::upcast<T>(r.get()));
sl@0:         return *this;
sl@0:     }
sl@0: 
sl@0: #endif
sl@0: 
sl@0:     template <typename Y>
sl@0:     handle(handle<Y> const& r)
sl@0:         : m_p(python::xincref(python::upcast<T>(r.get())))
sl@0:     {
sl@0:     }
sl@0:     
sl@0:     handle(handle const& r)
sl@0:         : m_p(python::xincref(r.m_p))
sl@0:     {
sl@0:     }
sl@0:     
sl@0:     T* operator-> () const;
sl@0:     T& operator* () const;
sl@0:     T* get() const;
sl@0:     T* release();
sl@0:     void reset();
sl@0:     
sl@0:     operator bool_type() const // never throws
sl@0:     {
sl@0:         return m_p ? &handle<T>::get : 0;
sl@0:     }
sl@0:     bool operator! () const; // never throws
sl@0: 
sl@0:  public: // implementation details -- do not touch
sl@0:     // Defining this in the class body suppresses a VC7 link failure
sl@0:     inline handle(detail::borrowed_reference x)
sl@0:         : m_p(
sl@0:             python::incref(
sl@0:                 downcast<T>((PyObject*)x)
sl@0:                 ))
sl@0:     {
sl@0:     }
sl@0:     
sl@0:  private: // data members
sl@0:     T* m_p;
sl@0: };
sl@0: 
sl@0: #ifdef BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP
sl@0: } // namespace python
sl@0: #endif
sl@0: 
sl@0: template<class T> inline T * get_pointer(python::handle<T> const & p)
sl@0: {
sl@0:     return p.get();
sl@0: }
sl@0: 
sl@0: #ifdef BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP
sl@0: namespace python {
sl@0: #else
sl@0: 
sl@0: // We don't want get_pointer above to hide the others
sl@0: using boost::get_pointer;
sl@0: 
sl@0: #endif
sl@0: 
sl@0: typedef handle<PyTypeObject> type_handle;
sl@0: 
sl@0: //
sl@0: // Compile-time introspection
sl@0: //
sl@0: # ifndef BOOST_NO_TEMPLATE_PARTIAL_SPECIALIZATION
sl@0: template<typename T>
sl@0: class is_handle
sl@0: {
sl@0:  public:
sl@0:     BOOST_STATIC_CONSTANT(bool, value = false); 
sl@0: };
sl@0: 
sl@0: template<typename T>
sl@0: class is_handle<handle<T> >
sl@0: {
sl@0:  public:
sl@0:     BOOST_STATIC_CONSTANT(bool, value = true);
sl@0: };
sl@0: # else
sl@0: namespace detail
sl@0: {
sl@0:   typedef char (&yes_handle_t)[1];
sl@0:   typedef char (&no_handle_t)[2];
sl@0:       
sl@0:   no_handle_t is_handle_test(...);
sl@0: 
sl@0:   template<typename T>
sl@0:   yes_handle_t is_handle_test(boost::type< handle<T> >);
sl@0: }
sl@0: 
sl@0: template<typename T>
sl@0: class is_handle
sl@0: {
sl@0:  public:
sl@0:     BOOST_STATIC_CONSTANT(
sl@0:         bool, value = (
sl@0:             sizeof(detail::is_handle_test(boost::type<T>()))
sl@0:             == sizeof(detail::yes_handle_t)));
sl@0: };
sl@0: # endif
sl@0: 
sl@0: //
sl@0: // implementations
sl@0: //
sl@0: template <class T>
sl@0: inline handle<T>::handle()
sl@0:     : m_p(0)
sl@0: {
sl@0: }
sl@0: 
sl@0: template <class T>
sl@0: inline handle<T>::~handle()
sl@0: {
sl@0:     python::xdecref(m_p);
sl@0: }
sl@0: 
sl@0: template <class T>
sl@0: inline T* handle<T>::operator->() const
sl@0: {
sl@0:     return m_p;
sl@0: }
sl@0: 
sl@0: template <class T>
sl@0: inline T& handle<T>::operator*() const
sl@0: {
sl@0:     return *m_p;
sl@0: }
sl@0: 
sl@0: template <class T>
sl@0: inline T* handle<T>::get() const
sl@0: {
sl@0:     return m_p;
sl@0: }
sl@0:     
sl@0: template <class T>
sl@0: inline bool handle<T>::operator!() const
sl@0: {
sl@0:     return m_p == 0;
sl@0: }
sl@0: 
sl@0: template <class T>
sl@0: inline T* handle<T>::release()
sl@0: {
sl@0:     T* result = m_p;
sl@0:     m_p = 0;
sl@0:     return result;
sl@0: }
sl@0: 
sl@0: template <class T>
sl@0: inline void handle<T>::reset()
sl@0: {
sl@0:     python::xdecref(m_p);
sl@0:     m_p = 0;
sl@0: }
sl@0: 
sl@0: // Because get_managed_object must return a non-null PyObject*, we
sl@0: // return Py_None if the handle is null.
sl@0: template <class T>
sl@0: inline PyObject* get_managed_object(handle<T> const& h, tag_t)
sl@0: {
sl@0:     return h.get() ? python::upcast<PyObject>(h.get()) : Py_None;
sl@0: }
sl@0: 
sl@0: }} // namespace boost::python
sl@0: 
sl@0: 
sl@0: #endif // HANDLE_DWA200269_HPP