[C++-sig] Wrapping boost::multi_array

[Thomas Kolb]

Hi all,

I have lots of classes in my library that deal heavily with 
boost::multi_array, so I'm trying to wrap this class for some special 
dimensions and data types.

My source code is:

namespace  {

	typedef boost::multi_array<double, 1> DoubleVector;	

	DoubleVector* cTorWrapper(unsigned int size)
	{
		return new DoubleVector(boost::extents[size]);
	}
	
	double& operatorWrapper(DoubleVector& vec, DoubleVector::size_type id)
	{
		return vec[0];
	}

}// namespace


// Module 
======================================================================
void Export_Multi_Array()
{
     class_< DoubleVector, std::auto_ptr<DoubleVector> >("DoubleVector")
     	.def("__init__", make_constructor(cTorWrapper))
	.def("get",&operatorWrapper, return_internal_reference< 1 >())
     ;
}

this leads to the following compiler error:

/usr/local/include/boost-1_31/boost/python/object/make_instance.hpp: 
In static
    member function `static PyObject*
    boost::python::objects::make_instance_impl<T, Holder,
    Derived>::execute(Arg&) [with Arg = double*, T = double, Holder =
    boost::python::objects::pointer_holder<double*, double>, Derived =
    boost::python::objects::make_ptr_instance<double,
    boost::python::objects::pointer_holder<double*, double> >]':
/usr/local/include/boost-1_31/boost/python/to_python_indirect.hpp:64: 
   instantiated from `static PyObject* 
boost::python::detail::make_reference_holder::execute(T*) [with T = 
double]'
/usr/local/include/boost-1_31/boost/python/detail/unwind_type.hpp:19: 
   instantiated from `typename Generator::result_type 
boost::python::detail::unwind_type_cv(U*, 
boost::python::detail::cv_tag<false, false>, Generator*) [with 
Generator = boost::python::detail::make_reference_holder, U = double]'
/usr/local/include/boost-1_31/boost/python/detail/unwind_type.hpp:48: 
   instantiated from `typename Generator::result_type 
boost::python::detail::unwind_ptr_type(U*, Generator*) [with Generator 
= boost::python::detail::make_reference_holder, U = double]'
/usr/local/include/boost-1_31/boost/python/detail/unwind_type.hpp:58: 
   instantiated from `static typename Generator::result_type 
boost::python::detail::unwind_helper<is_ptr>::execute(U, Generator*) 
[with Generator = boost::python::detail::make_reference_holder, U = 
double*, bool is_ptr = true]'
/usr/local/include/boost-1_31/boost/python/detail/unwind_type.hpp:77: 
   instantiated from `typename Generator::result_type 
boost::python::detail::unwind_type(const U&, Generator*) [with 
Generator = boost::python::detail::make_reference_holder, U = double*]'
/usr/local/include/boost-1_31/boost/python/detail/unwind_type.hpp:26: 
   instantiated from `typename Generator::result_type 
boost::python::detail::unwind_type_cv(const U*, 
boost::python::detail::cv_tag<true, false>, Generator*) [with 
Generator = boost::python::detail::make_reference_holder, U = double]'
/usr/local/include/boost-1_31/boost/python/detail/unwind_type.hpp:48: 
   instantiated from `typename Generator::result_type 
boost::python::detail::unwind_ptr_type(U*, Generator*) [with Generator 
= boost::python::detail::make_reference_holder, U = const double]'
/usr/local/include/boost-1_31/boost/python/detail/unwind_type.hpp:69: 
   instantiated from `static typename Generator::result_type 
boost::python::detail::unwind_helper<false>::execute(U&, Generator*) 
[with Generator = boost::python::detail::make_reference_holder, U = 
const double]'
/usr/local/include/boost-1_31/boost/python/detail/unwind_type.hpp:77: 
   instantiated from `typename Generator::result_type 
boost::python::detail::unwind_type(const U&, Generator*) [with 
Generator = boost::python::detail::make_reference_holder, U = double]'
/usr/local/include/boost-1_31/boost/python/to_python_indirect.hpp:105: 
   instantiated from `PyObject* boost::python::to_python_indirect<T, 
MakeHolder>::operator()(T) const [with T = double&, MakeHolder = 
boost::python::detail::make_reference_holder]'
/usr/local/include/boost-1_31/boost/python/detail/invoke.hpp:76: 
instantiated from `PyObject* 
boost::python::detail::invoke(boost::python::detail::invoke_tag_<false, 
false>, const RC&, F&, AC0&, AC1&) [with RC = 
boost::python::to_python_indirect<double&, 
boost::python::detail::make_reference_holder>, F = 
double&(*)(<unnamed>::DoubleVector*, long unsigned int), AC0 = 
boost::python::arg_from_python<<unnamed>::DoubleVector*>, AC1 = 
boost::python::arg_from_python<long unsigned int>]'
/usr/local/include/boost-1_31/boost/python/detail/caller.hpp:199: 
instantiated from `PyObject* 
boost::python::detail::caller_arity<2>::impl<F, Policies, 
Sig>::operator()(PyObject*, PyObject*) [with F = 
double&(*)(<unnamed>::DoubleVector*, long unsigned int), Policies = 
boost::python::return_internal_reference<1, 
boost::python::default_call_policies>, Sig = 
boost::mpl::vector3<double&, <unnamed>::DoubleVector*, long unsigned 
int>]'
/usr/local/include/boost-1_31/boost/python/object/py_function.hpp:39: 
   instantiated from `PyObject* 
boost::python::objects::caller_py_function_impl<Caller>::operator()(PyObject*, 
PyObject*) [with Caller = 
boost::python::detail::caller<double&(*)(<unnamed>::DoubleVector*, 
long unsigned int), boost::python::return_internal_reference<1, 
boost::python::default_call_policies>, boost::mpl::vector3<double&, 
<unnamed>::DoubleVector*, long unsigned int> >]'
/usr/local/include/boost-1_31/boost/python/make_constructor.hpp:40: 
instantiated from here
/usr/local/include/boost-1_31/boost/python/object/make_instance.hpp:25: 
error: invalid
    application of `sizeof' to an incomplete type

returning the result of operator[] by values compiles great, but 
that's not what I want.

Anybody has an idea what's wrong?

Best Regards