boost/python/scope.hpp

   1 // Copyright David Abrahams 2002.
   2 // Distributed under the Boost Software License, Version 1.0. (See
   3 // accompanying file LICENSE_1_0.txt or copy at
   4 // http://www.boost.org/LICENSE_1_0.txt)
   5 #ifndef SCOPE_DWA2002724_HPP
   6 # define SCOPE_DWA2002724_HPP
   7
   8 # include <boost/python/detail/prefix.hpp>
   9 # include <boost/python/object.hpp>
  10 # include <boost/python/refcount.hpp>
  11 # include <boost/utility.hpp>
  12
  13 namespace boost { namespace python {
  14
  15 namespace detail
  16 {
  17   // Making this a namespace-scope variable to avoid Cygwin issues.
  18   // Use a PyObject* to avoid problems with static destruction after Py_Finalize
  19   extern BOOST_PYTHON_DECL PyObject* current_scope;
  20 }
  21
  22 class scope
  23   : public object
  24 {
  25  public:
  26     inline scope(scope const&);
  27     inline scope(object const&);
  28     inline scope();
  29     inline ~scope();
  30
  31  private: // data members
  32     PyObject* m_previous_scope;
  33
  34  private: // unimplemented functions
  35     void operator=(scope const&);
  36 };
  37
  38 inline scope::scope(object const& new_scope)
  39     : object(new_scope)
  40     , m_previous_scope(detail::current_scope)
  41 {
  42     detail::current_scope = python::incref(new_scope.ptr());
  43 }
  44
  45 inline scope::scope()
  46     : object(detail::borrowed_reference(
  47                  detail::current_scope ? detail::current_scope : Py_None
  48                  ))
  49     , m_previous_scope(python::xincref(detail::current_scope))
  50 {
  51 }
  52
  53 inline scope::~scope()
  54 {
  55     python::xdecref(detail::current_scope);
  56     detail::current_scope = m_previous_scope;
  57 }
  58
  59 namespace converter
  60 {
  61   template <>
  62   struct object_manager_traits<scope>
  63       : object_manager_traits<object>
  64   {
  65   };
  66 }
  67
  68 // Placing this after the specialization above suppresses a CWPro8.3 bug
  69 inline scope::scope(scope const& new_scope)
  70     : object(new_scope)
  71     , m_previous_scope(detail::current_scope)
  72 {
  73     detail::current_scope = python::incref(new_scope.ptr());
  74 }
  75
  76 }} // namespace boost::python
  77
  78 #endif // SCOPE_DWA2002724_HPP