I've tried what you have suggested but it does not work, here is the error

.../boost_1_33_1/boost/python/object/value_holder.hpp:135: error: no matching function for call to `boost::const_multi_array_ref<double, 2, const double*>::const_multi_array_ref()' .../boost_1_33_1/boost/multi_array/multi_array_ref.hpp:45: error: candidates are: boost::const_multi_array_ref<double, 2, const double*>::const_multi_array_ref(const boost::const_multi_array_ref<double, 2, const double*>&) .../boost_1_33_1/boost/multi_array/multi_array_ref.hpp:325: error: boost::const_multi_array_ref<T, NumDims, TPtr>::const_multi_array_ref(TPtr, const boost::general_storage_order<NumDims>&, typename boost::detail::multi_array::multi_array_impl_base<T, NumDims>::index*, typename boost::detail::multi_array::multi_array_impl_base<T, NumDims>::size_type*) [with T = double, unsigned int NumDims = 2, TPtr = const double*] .../boost_1_33_1/boost/multi_array/multi_array_ref.hpp:120: error: boost::const_multi_array_ref<T, NumDims, TPtr>::const_multi_array_ref(TPtr, const boost::detail::multi_array::extent_gen<NumDims>&, const boost::general_storage_order<NumDims>&) [with T = double, unsigned int NumDims = 2, TPtr = const double*] .../boost_1_33_1/boost/multi_array/multi_array_ref.hpp:111: error: boost::const_multi_array_ref<T, NumDims, TPtr>::const_multi_array_ref(TPtr, const boost::detail::multi_array::extent_gen<NumDims>&) [with T = double, unsigned int NumDims = 2, TPtr = const double*]

my interface file is

// Boost Includes ============================================================== #include "boost/multi_array.hpp" #include "boost/python/class.hpp" #include "boost/python/implicit.hpp" #include "boost/python/module.hpp" #include "boost/python.hpp" #include "boost/cstdint.hpp" // Includes ==================================================================== #include "Fstd.h" #include "MatrixAlgorithm2D.h" // Using ======================================================================= using namespace boost::python; // Module ====================================================================== BOOST_PYTHON_MODULE(matrix) { class_< Fstd >("Fstd", init< const Fstd& >()) .def(init< std::string >()) .def("getTT", &Fstd::getTT) .def("getUV", &Fstd::getUV) ; class_< MatrixAlgorithm2D >("MatrixAlgorithm2D", init< >()) .def(init< const MatrixAlgorithm2D& >()) .def("windChill", &MatrixAlgorithm2D::windChill) .def("display_d", &MatrixAlgorithm2D::display_d) .staticmethod("windChill") .staticmethod("display_d") ; class_<boost::multi_array<double, 2> >("multi_array_2d"); class_<boost::const_multi_array_ref<double, 2> >("const_multi_array_ref_2d"); implicitly_convertible<boost::multi_array<double, 2>, boost::multi_array_ref<double, 2> >(); implicitly_convertible<boost::multi_array<double, 2>, boost::const_multi_array_ref<double, 2> >(); }
Daniel Wallin wrote:

Sebastien Fortier wrote:

Thank you very much Daniel!

I had another question, is it possible to use multi_array and 
const_multi_array_ref together in python.
What I mean is, if I create a multi_array from python through my c++ 
functions and I want to pass this array to another c++ function that 
uses a const_multi_array_ref how do I manage this in the interface file? 
is this possible?

I added class_<const_multi_array_ref<double, 2> 
 >("const_multi_array_2d_ref"); to my interface file but the types seem 
to be incompatible.


You need to let Boost.Python know that the types are convertible:

  implicitly_convertible<
      multi_array<double, 2>
    , multi_array_ref<double, 2>
  >();

  implicitly_convertible<
      multi_array<double, 2>
    , const_multi_array_ref<double, 2>
  >();

Should do it. See http://www.boost.org/libs/python/doc/v2/implicit.html.

I would prefer to use the const_multi_array_ref with the multi_arrays to 
avoid copies...


If you already have multi_array's, why don't you just pass them by
reference?

Sébastien Fortier