// Copyright David Abrahams 2002. | |
// Distributed under the Boost Software License, Version 1.0. (See | |
// accompanying file LICENSE_1_0.txt or copy at | |
// http://www.boost.org/LICENSE_1_0.txt) | |
#ifndef WITH_CUSTODIAN_AND_WARD_DWA2002131_HPP | |
# define WITH_CUSTODIAN_AND_WARD_DWA2002131_HPP | |
# include <boost/python/detail/prefix.hpp> | |
# include <boost/python/default_call_policies.hpp> | |
# include <boost/python/object/life_support.hpp> | |
# include <algorithm> | |
namespace boost { namespace python { | |
namespace detail | |
{ | |
template <std::size_t N> | |
struct get_prev | |
{ | |
template <class ArgumentPackage> | |
static PyObject* execute(ArgumentPackage const& args, PyObject* = 0) | |
{ | |
int const pre_n = static_cast<int>(N) - 1; // separate line is gcc-2.96 workaround | |
return detail::get(mpl::int_<pre_n>(), args); | |
} | |
}; | |
template <> | |
struct get_prev<0> | |
{ | |
template <class ArgumentPackage> | |
static PyObject* execute(ArgumentPackage const&, PyObject* zeroth) | |
{ | |
return zeroth; | |
} | |
}; | |
} | |
template < | |
std::size_t custodian | |
, std::size_t ward | |
, class BasePolicy_ = default_call_policies | |
> | |
struct with_custodian_and_ward : BasePolicy_ | |
{ | |
BOOST_STATIC_ASSERT(custodian != ward); | |
BOOST_STATIC_ASSERT(custodian > 0); | |
BOOST_STATIC_ASSERT(ward > 0); | |
template <class ArgumentPackage> | |
static bool precall(ArgumentPackage const& args_) | |
{ | |
unsigned arity_ = detail::arity(args_); | |
if (custodian > arity_ || ward > arity_) | |
{ | |
PyErr_SetString( | |
PyExc_IndexError | |
, "boost::python::with_custodian_and_ward: argument index out of range" | |
); | |
return false; | |
} | |
PyObject* patient = detail::get_prev<ward>::execute(args_); | |
PyObject* nurse = detail::get_prev<custodian>::execute(args_); | |
PyObject* life_support = python::objects::make_nurse_and_patient(nurse, patient); | |
if (life_support == 0) | |
return false; | |
bool result = BasePolicy_::precall(args_); | |
if (!result) { | |
Py_DECREF(life_support); | |
} | |
return result; | |
} | |
}; | |
template <std::size_t custodian, std::size_t ward, class BasePolicy_ = default_call_policies> | |
struct with_custodian_and_ward_postcall : BasePolicy_ | |
{ | |
BOOST_STATIC_ASSERT(custodian != ward); | |
template <class ArgumentPackage> | |
static PyObject* postcall(ArgumentPackage const& args_, PyObject* result) | |
{ | |
std::size_t arity_ = detail::arity(args_); | |
#if BOOST_WORKAROUND(BOOST_MSVC, < 1300) | |
if ( custodian > arity_ || ward > arity_ ) | |
#else | |
// check if either custodian or ward exceeds the arity | |
// (this weird formulation avoids "always false" warnings | |
// for arity_ = 0) | |
if ( (std::max)(custodian, ward) > arity_ ) | |
#endif | |
{ | |
PyErr_SetString( | |
PyExc_IndexError | |
, "boost::python::with_custodian_and_ward_postcall: argument index out of range" | |
); | |
return 0; | |
} | |
PyObject* patient = detail::get_prev<ward>::execute(args_, result); | |
PyObject* nurse = detail::get_prev<custodian>::execute(args_, result); | |
if (nurse == 0) return 0; | |
result = BasePolicy_::postcall(args_, result); | |
if (result == 0) | |
return 0; | |
if (python::objects::make_nurse_and_patient(nurse, patient) == 0) | |
{ | |
Py_XDECREF(result); | |
return 0; | |
} | |
return result; | |
} | |
}; | |
}} // namespace boost::python | |
#endif // WITH_CUSTODIAN_AND_WARD_DWA2002131_HPP |