ceph/src/boost/boost/python/object/value_holder.hpp

   1 #if !defined(BOOST_PP_IS_ITERATING)
   2
   3 // Copyright David Abrahams 2001.
   4 // Distributed under the Boost Software License, Version 1.0. (See
   5 // accompanying file LICENSE_1_0.txt or copy at
   6 // http://www.boost.org/LICENSE_1_0.txt)
   7
   8 # ifndef VALUE_HOLDER_DWA20011215_HPP
   9 #  define VALUE_HOLDER_DWA20011215_HPP
  10
  11 #  include <boost/python/object/value_holder_fwd.hpp>
  12
  13 #  include <boost/python/instance_holder.hpp>
  14 #  include <boost/python/type_id.hpp>
  15 #  include <boost/python/wrapper.hpp>
  16
  17 #  include <boost/python/object/inheritance_query.hpp>
  18 #  include <boost/python/object/forward.hpp>
  19
  20 #  include <boost/python/detail/force_instantiate.hpp>
  21 #  include <boost/python/detail/preprocessor.hpp>
  22
  23 #  include <boost/preprocessor/comma_if.hpp>
  24 #  include <boost/preprocessor/enum_params.hpp>
  25 #  include <boost/preprocessor/iterate.hpp>
  26 #  include <boost/preprocessor/repeat.hpp>
  27 #  include <boost/preprocessor/debug/line.hpp>
  28
  29 #  include <boost/preprocessor/repetition/enum_params.hpp>
  30 #  include <boost/preprocessor/repetition/enum_binary_params.hpp>
  31
  32 #  include <boost/utility/addressof.hpp>
  33
  34 namespace boost { namespace python { namespace objects {
  35
  36 #define BOOST_PYTHON_UNFORWARD_LOCAL(z, n, _) BOOST_PP_COMMA_IF(n) objects::do_unforward(a##n,0)
  37
  38 template <class Value>
  39 struct value_holder : instance_holder
  40 {
  41     typedef Value held_type;
  42     typedef Value value_type;
  43
  44     // Forward construction to the held object
  45 #  define BOOST_PP_ITERATION_PARAMS_1 (4, (0, BOOST_PYTHON_MAX_ARITY, <boost/python/object/value_holder.hpp>, 1))
  46 #  include BOOST_PP_ITERATE()
  47
  48  private: // required holder implementation
  49     void* holds(type_info, bool null_ptr_only);
  50
  51     template <class T>
  52     inline void* holds_wrapped(type_info dst_t, wrapper<T>*,T* p)
  53     {
  54         return python::type_id<T>() == dst_t ? p : 0;
  55     }
  56
  57     inline void* holds_wrapped(type_info, ...)
  58     {
  59         return 0;
  60     }
  61  private: // data members
  62     Value m_held;
  63 };
  64
  65 template <class Value, class Held>
  66 struct value_holder_back_reference : instance_holder
  67 {
  68     typedef Held held_type;
  69     typedef Value value_type;
  70
  71     // Forward construction to the held object
  72 #  define BOOST_PP_ITERATION_PARAMS_1 (4, (0, BOOST_PYTHON_MAX_ARITY, <boost/python/object/value_holder.hpp>, 2))
  73 #  include BOOST_PP_ITERATE()
  74
  75 private: // required holder implementation
  76     void* holds(type_info, bool null_ptr_only);
  77
  78  private: // data members
  79     Held m_held;
  80 };
  81
  82 #  undef BOOST_PYTHON_UNFORWARD_LOCAL
  83
  84 template <class Value>
  85 void* value_holder<Value>::holds(type_info dst_t, bool /*null_ptr_only*/)
  86 {
  87     if (void* wrapped = holds_wrapped(dst_t, boost::addressof(m_held), boost::addressof(m_held)))
  88         return wrapped;
  89
  90     type_info src_t = python::type_id<Value>();
  91     return src_t == dst_t ? boost::addressof(m_held)
  92         : find_static_type(boost::addressof(m_held), src_t, dst_t);
  93 }
  94
  95 template <class Value, class Held>
  96 void* value_holder_back_reference<Value,Held>::holds(
  97     type_info dst_t, bool /*null_ptr_only*/)
  98 {
  99     type_info src_t = python::type_id<Value>();
 100     Value* x = &m_held;
 101
 102     if (dst_t == src_t)
 103         return x;
 104     else if (dst_t == python::type_id<Held>())
 105         return &m_held;
 106     else
 107         return find_static_type(x, src_t, dst_t);
 108 }
 109
 110 }}} // namespace boost::python::objects
 111
 112 # endif // VALUE_HOLDER_DWA20011215_HPP
 113
 114 // --------------- value_holder ---------------
 115
 116 // For gcc 4.4 compatability, we must include the
 117 // BOOST_PP_ITERATION_DEPTH test inside an #else clause.
 118 #else // BOOST_PP_IS_ITERATING
 119 #if BOOST_PP_ITERATION_DEPTH() == 1 && BOOST_PP_ITERATION_FLAGS() == 1
 120 # if !(BOOST_WORKAROUND(__MWERKS__, > 0x3100)                      \
 121         && BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3201)))
 122 #  line BOOST_PP_LINE(__LINE__, value_holder.hpp(value_holder))
 123 # endif
 124
 125 # define N BOOST_PP_ITERATION()
 126
 127 # if (N != 0)
 128     template <BOOST_PP_ENUM_PARAMS_Z(1, N, class A)>
 129 # endif
 130     value_holder(
 131       PyObject* self BOOST_PP_COMMA_IF(N) BOOST_PP_ENUM_BINARY_PARAMS_Z(1, N, A, a))
 132         : m_held(
 133             BOOST_PP_REPEAT_1ST(N, BOOST_PYTHON_UNFORWARD_LOCAL, nil)
 134             )
 135     {
 136         python::detail::initialize_wrapper(self, boost::addressof(this->m_held));
 137     }
 138
 139 # undef N
 140
 141 // --------------- value_holder_back_reference ---------------
 142
 143 #elif BOOST_PP_ITERATION_DEPTH() == 1 && BOOST_PP_ITERATION_FLAGS() == 2
 144 # if !(BOOST_WORKAROUND(__MWERKS__, > 0x3100)                      \
 145         && BOOST_WORKAROUND(__MWERKS__, BOOST_TESTED_AT(0x3201)))
 146 #  line BOOST_PP_LINE(__LINE__, value_holder.hpp(value_holder_back_reference))
 147 # endif
 148
 149 # define N BOOST_PP_ITERATION()
 150
 151 # if (N != 0)
 152     template <BOOST_PP_ENUM_PARAMS_Z(1, N, class A)>
 153 # endif
 154     value_holder_back_reference(
 155         PyObject* p BOOST_PP_COMMA_IF(N) BOOST_PP_ENUM_BINARY_PARAMS_Z(1, N, A, a))
 156         : m_held(
 157             p BOOST_PP_COMMA_IF(N)
 158             BOOST_PP_REPEAT_1ST(N, BOOST_PYTHON_UNFORWARD_LOCAL, nil)
 159             )
 160     {
 161     }
 162
 163 # undef N
 164
 165 #endif // BOOST_PP_ITERATION_DEPTH()
 166 #endif