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Boost.PythonHeader <boost/python/return_opaque_pointer.hpp> |
return_opaque_pointerreturn_opaque_pointer synopsisreturn_opaque_pointer metafunctionsreturn_opaque_pointerreturn_opaque_pointer is a model of
ResultConverterGenerator
which can be used to wrap C++ functions returning pointers to
undefined types such that the return value is copied into a
new Python object.
In addition to specifying the return_opaque_pointer
policy the
BOOST_PYTHON_OPAQUE_SPECIALIZED_TYPE_ID macro must be
used to define specializations for the
type_id function
on the type pointed to by returned pointer.
return_opaque_pointer synopsis
namespace boost { namespace python
{
struct return_opaque_pointer
{
template <class R> struct apply;
};
}}
return_opaque_pointer metafunctionstemplate <class R> struct apply
# include <boost/python/return_opaque_pointer.hpp>
# include <boost/python/def.hpp>
# include <boost/python/module.hpp>
# include <boost/python/return_value_policy.hpp>
typedef struct opaque_ *opaque;
opaque the_op = ((opaque) 0x47110815);
opaque get () { return the_op; }
void use (opaque op) {
if (op != the_op)
throw std::runtime_error (std::string ("failed"));
}
void failuse (opaque op) {
if (op == the_op)
throw std::runtime_error (std::string ("success"));
}
BOOST_PYTHON_OPAQUE_SPECIALIZED_TYPE_ID(opaque_)
namespace bpl = boost::python;
BOOST_PYTHON_MODULE(opaque_ext)
{
bpl::def (
"get", &::get, bpl::return_value_policy<bpl::return_opaque_pointer>());
bpl::def ("use", &::use);
bpl::def ("failuse", &::failuse);
}
"""
>>> from opaque_ext import *
>>> #
>>> # Check for correct conversion
>>> use(get())
>>> failuse(get())
Traceback (most recent call last):
...
RuntimeError: success
>>> #
>>> # Check that there is no conversion from integers ...
>>> use(0)
Traceback (most recent call last):
...
TypeError: bad argument type for built-in operation
>>> #
>>> # ... and from strings to opaque objects
>>> use("")
Traceback (most recent call last):
...
TypeError: bad argument type for built-in operation
"""
def run(args = None):
import sys
import doctest
if args is not None:
sys.argv = args
return doctest.testmod(sys.modules.get(__name__))
if __name__ == '__main__':
print "running..."
import sys
sys.exit(run()[0])
Revised 28 January, 2003
© Copyright 2003 Haufe Mediengruppe. All Rights Reserved.