ceph/src/boost/libs/python/include/boost/python/converter/shared_ptr_from_python.hpp

   1 // Copyright David Abrahams 2002.
   2 // Copyright Stefan Seefeld 2016.
   3 // Distributed under the Boost Software License, Version 1.0. (See
   4 // accompanying file LICENSE_1_0.txt or copy at
   5 // http://www.boost.org/LICENSE_1_0.txt)
   6
   7 #ifndef boost_python_converter_shared_ptr_from_python_hpp_
   8 #define boost_python_converter_shared_ptr_from_python_hpp_
   9
  10 #include <boost/python/handle.hpp>
  11 #include <boost/python/converter/shared_ptr_deleter.hpp>
  12 #include <boost/python/converter/from_python.hpp>
  13 #include <boost/python/converter/rvalue_from_python_data.hpp>
  14 #include <boost/python/converter/registered.hpp>
  15 #ifndef BOOST_PYTHON_NO_PY_SIGNATURES
  16 # include <boost/python/converter/pytype_function.hpp>
  17 #endif
  18 #include <boost/shared_ptr.hpp>
  19 #include <memory>
  20
  21 namespace boost { namespace python { namespace converter {
  22
  23 template <class T, template <typename> class SP>
  24 struct shared_ptr_from_python
  25 {
  26   shared_ptr_from_python()
  27   {
  28     converter::registry::insert(&convertible, &construct, type_id<SP<T> >()
  29 #ifndef BOOST_PYTHON_NO_PY_SIGNATURES
  30                                 , &converter::expected_from_python_type_direct<T>::get_pytype
  31 #endif
  32                                 );
  33   }
  34
  35  private:
  36   static void* convertible(PyObject* p)
  37   {
  38     if (p == Py_None)
  39       return p;
  40
  41     return converter::get_lvalue_from_python(p, registered<T>::converters);
  42   }
  43
  44   static void construct(PyObject* source, rvalue_from_python_stage1_data* data)
  45   {
  46     void* const storage = ((converter::rvalue_from_python_storage<SP<T> >*)data)->storage.bytes;
  47     // Deal with the "None" case.
  48     if (data->convertible == source)
  49       new (storage) SP<T>();
  50     else
  51     {
  52       SP<void> hold_convertible_ref_count(
  53          (void*)0, shared_ptr_deleter(handle<>(borrowed(source))) );
  54       // use aliasing constructor
  55       new (storage) SP<T>(hold_convertible_ref_count,
  56                           static_cast<T*>(data->convertible));
  57     }
  58
  59     data->convertible = storage;
  60   }
  61 };
  62
  63 }}} // namespace boost::python::converter
  64
  65 #endif