ceph/src/boost/boost/python/detail/caller.hpp

   1 #if !defined(BOOST_PP_IS_ITERATING)
   2
   3 // Copyright David Abrahams 2002.
   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 CALLER_DWA20021121_HPP
   9 #  define CALLER_DWA20021121_HPP
  10
  11 #  include <boost/python/type_id.hpp>
  12 #  include <boost/python/handle.hpp>
  13
  14 #  include <boost/detail/indirect_traits.hpp>
  15
  16 #  include <boost/python/detail/invoke.hpp>
  17 #  include <boost/python/detail/signature.hpp>
  18 #  include <boost/python/detail/preprocessor.hpp>
  19 #  include <boost/python/detail/type_traits.hpp>
  20
  21 #  include <boost/python/arg_from_python.hpp>
  22 #  include <boost/python/converter/context_result_converter.hpp>
  23 #  include <boost/python/converter/builtin_converters.hpp>
  24
  25 #  include <boost/preprocessor/iterate.hpp>
  26 #  include <boost/preprocessor/cat.hpp>
  27 #  include <boost/preprocessor/dec.hpp>
  28 #  include <boost/preprocessor/if.hpp>
  29 #  include <boost/preprocessor/iteration/local.hpp>
  30 #  include <boost/preprocessor/repetition/enum_trailing_params.hpp>
  31 #  include <boost/preprocessor/repetition/repeat.hpp>
  32
  33 #  include <boost/compressed_pair.hpp>
  34
  35 #  include <boost/mpl/apply.hpp>
  36 #  include <boost/mpl/eval_if.hpp>
  37 #  include <boost/mpl/identity.hpp>
  38 #  include <boost/mpl/size.hpp>
  39 #  include <boost/mpl/at.hpp>
  40 #  include <boost/mpl/int.hpp>
  41 #  include <boost/mpl/next.hpp>
  42
  43 namespace boost { namespace python { namespace detail {
  44
  45 template <int N>
  46 inline PyObject* get(mpl::int_<N>, PyObject* const& args_)
  47 {
  48     return PyTuple_GET_ITEM(args_,N);
  49 }
  50
  51 inline Py_ssize_t arity(PyObject* const& args_)
  52 {
  53     return PyTuple_GET_SIZE(args_);
  54 }
  55
  56 // This "result converter" is really just used as
  57 // a dispatch tag to invoke(...), selecting the appropriate
  58 // implementation
  59 typedef int void_result_to_python;
  60
  61 // Given a model of CallPolicies and a C++ result type, this
  62 // metafunction selects the appropriate converter to use for
  63 // converting the result to python.
  64 template <class Policies, class Result>
  65 struct select_result_converter
  66   : mpl::eval_if<
  67         is_same<Result,void>
  68       , mpl::identity<void_result_to_python>
  69       , mpl::apply1<typename Policies::result_converter,Result>
  70     >
  71 {
  72 };
  73
  74 template <class ArgPackage, class ResultConverter>
  75 inline ResultConverter create_result_converter(
  76     ArgPackage const& args_
  77   , ResultConverter*
  78   , converter::context_result_converter*
  79 )
  80 {
  81     return ResultConverter(args_);
  82 }
  83
  84 template <class ArgPackage, class ResultConverter>
  85 inline ResultConverter create_result_converter(
  86     ArgPackage const&
  87   , ResultConverter*
  88   , ...
  89 )
  90 {
  91     return ResultConverter();
  92 }
  93
  94 #ifndef BOOST_PYTHON_NO_PY_SIGNATURES
  95 template <class ResultConverter>
  96 struct converter_target_type
  97 {
  98     static PyTypeObject const *get_pytype()
  99     {
 100         return create_result_converter((PyObject*)0, (ResultConverter *)0, (ResultConverter *)0).get_pytype();
 101     }
 102 };
 103
 104 template < >
 105 struct converter_target_type <void_result_to_python >
 106 {
 107     static PyTypeObject const *get_pytype()
 108     {
 109         return 0;
 110     }
 111 };
 112 #endif
 113
 114
 115 template <unsigned> struct caller_arity;
 116
 117 template <class F, class CallPolicies, class Sig>
 118 struct caller;
 119
 120 #  define BOOST_PYTHON_NEXT(init,name,n)                                                        \
 121     typedef BOOST_PP_IF(n,typename mpl::next< BOOST_PP_CAT(name,BOOST_PP_DEC(n)) >::type, init) name##n;
 122
 123 #  define BOOST_PYTHON_ARG_CONVERTER(n)                                         \
 124      BOOST_PYTHON_NEXT(typename mpl::next<first>::type, arg_iter,n)             \
 125      typedef arg_from_python<BOOST_DEDUCED_TYPENAME arg_iter##n::type> c_t##n;  \
 126      c_t##n c##n(get(mpl::int_<n>(), inner_args));                              \
 127      if (!c##n.convertible())                                                   \
 128           return 0;
 129
 130 #  define BOOST_PP_ITERATION_PARAMS_1                                            \
 131         (3, (0, BOOST_PYTHON_MAX_ARITY + 1, <boost/python/detail/caller.hpp>))
 132 #  include BOOST_PP_ITERATE()
 133
 134 #  undef BOOST_PYTHON_ARG_CONVERTER
 135 #  undef BOOST_PYTHON_NEXT
 136
 137 // A metafunction returning the base class used for caller<class F,
 138 // class ConverterGenerators, class CallPolicies, class Sig>.
 139 template <class F, class CallPolicies, class Sig>
 140 struct caller_base_select
 141 {
 142     enum { arity = mpl::size<Sig>::value - 1 };
 143     typedef typename caller_arity<arity>::template impl<F,CallPolicies,Sig> type;
 144 };
 145
 146 // A function object type which wraps C++ objects as Python callable
 147 // objects.
 148 //
 149 // Template Arguments:
 150 //
 151 //   F -
 152 //      the C++ `function object' that will be called. Might
 153 //      actually be any data for which an appropriate invoke_tag() can
 154 //      be generated. invoke(...) takes care of the actual invocation syntax.
 155 //
 156 //   CallPolicies -
 157 //      The precall, postcall, and what kind of resultconverter to
 158 //      generate for mpl::front<Sig>::type
 159 //
 160 //   Sig -
 161 //      The `intended signature' of the function. An MPL sequence
 162 //      beginning with a result type and continuing with a list of
 163 //      argument types.
 164 template <class F, class CallPolicies, class Sig>
 165 struct caller
 166     : caller_base_select<F,CallPolicies,Sig>::type
 167 {
 168     typedef typename caller_base_select<
 169         F,CallPolicies,Sig
 170         >::type base;
 171
 172     typedef PyObject* result_type;
 173
 174     caller(F f, CallPolicies p) : base(f,p) {}
 175
 176 };
 177
 178 }}} // namespace boost::python::detail
 179
 180 # endif // CALLER_DWA20021121_HPP
 181
 182 #else
 183
 184 # define N BOOST_PP_ITERATION()
 185
 186 template <>
 187 struct caller_arity<N>
 188 {
 189     template <class F, class Policies, class Sig>
 190     struct impl
 191     {
 192         impl(F f, Policies p) : m_data(f,p) {}
 193
 194         PyObject* operator()(PyObject* args_, PyObject*) // eliminate
 195                                                          // this
 196                                                          // trailing
 197                                                          // keyword dict
 198         {
 199             typedef typename mpl::begin<Sig>::type first;
 200             typedef typename first::type result_t;
 201             typedef typename select_result_converter<Policies, result_t>::type result_converter;
 202             typedef typename Policies::argument_package argument_package;
 203
 204             argument_package inner_args(args_);
 205
 206 # if N
 207 #  define BOOST_PP_LOCAL_MACRO(i) BOOST_PYTHON_ARG_CONVERTER(i)
 208 #  define BOOST_PP_LOCAL_LIMITS (0, N-1)
 209 #  include BOOST_PP_LOCAL_ITERATE()
 210 # endif
 211             // all converters have been checked. Now we can do the
 212             // precall part of the policy
 213             if (!m_data.second().precall(inner_args))
 214                 return 0;
 215
 216             PyObject* result = detail::invoke(
 217                 detail::invoke_tag<result_t,F>()
 218               , create_result_converter(args_, (result_converter*)0, (result_converter*)0)
 219               , m_data.first()
 220                 BOOST_PP_ENUM_TRAILING_PARAMS(N, c)
 221             );
 222
 223             return m_data.second().postcall(inner_args, result);
 224         }
 225
 226         static unsigned min_arity() { return N; }
 227
 228         static py_func_sig_info  signature()
 229         {
 230             const signature_element * sig = detail::signature<Sig>::elements();
 231 #ifndef BOOST_PYTHON_NO_PY_SIGNATURES
 232
 233             typedef BOOST_DEDUCED_TYPENAME Policies::template extract_return_type<Sig>::type rtype;
 234             typedef typename select_result_converter<Policies, rtype>::type result_converter;
 235
 236             static const signature_element ret = {
 237                 (is_void<rtype>::value ? "void" : type_id<rtype>().name())
 238                 , &detail::converter_target_type<result_converter>::get_pytype
 239                 , boost::detail::indirect_traits::is_reference_to_non_const<rtype>::value
 240             };
 241             py_func_sig_info res = {sig, &ret };
 242 #else
 243             py_func_sig_info res = {sig, sig };
 244 #endif
 245
 246             return  res;
 247         }
 248      private:
 249         compressed_pair<F,Policies> m_data;
 250     };
 251 };
 252
 253
 254
 255 #endif // BOOST_PP_IS_ITERATING
 256
 257