[Discuss-gnuradio] Instantiating a C++ object derived from `boost::enable_shared_from_this' from Python

[Frank Restuccia]

Hi all,
I am trying to instantiate a C++ object from Python as follows.

This is my .H file:

/***********************/

#ifndef INCLUDED_COMMON_MODULES_COVERT_CONSTELLATION_H
#define INCLUDED_COMMON_MODULES_COVERT_CONSTELLATION_H

#include <common_modules/api.h>
#include <gnuradio/gr_complex.h>
#include <vector>
#include <boost/enable_shared_from_this.hpp>
#include <gnuradio/math.h>

namespace gr {
    namespace common_modules {

        /*!
        * \brief Covert constellation
        *
        */
        class covert_constellation;
        typedef boost::shared_ptr<covert_constellation> constellation_sptr;

        class COMMON_MODULES_API covert_constellation : public 
boost::enable_shared_from_this<covert_constellation> {

        protected:
            std::vector<gr_complex> d_points;

        public:

            covert_constellation(
                std::vector<gr_complex> points
            );
            covert_constellation();

            virtual ~covert_constellation();

            gr_complex get_point_from_value(unsigned int value);
            virtual unsigned int decision_maker(const gr_complex 
*sample) = 0;
            constellation_sptr base() { return shared_from_this(); }

        };



        class COMMON_MODULES_API constellation_cbpsk : public 
covert_constellation {

        public:

            typedef boost::shared_ptr<constellation_cbpsk> sptr;

            // public constructor
            static sptr make();

            ~constellation_cbpsk();

            unsigned int decision_maker(const gr_complex *sample);

        protected:

            constellation_cbpsk();
    };


        class COMMON_MODULES_API constellation_cqpsk : public 
covert_constellation {

        public:
            typedef boost::shared_ptr<constellation_cqpsk> sptr;

            // public constructor
            static sptr make();

            ~constellation_cqpsk();

            unsigned int decision_maker(const gr_complex *sample);

        protected:

            constellation_cqpsk();
        };

  } // namespace common_modules
} // namespace gr

#endif /* INCLUDED_COMMON_MODULES_COVERT_CONSTELLATION_H */

/*****************************/

And this is my .CC file:

/****************/

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <gnuradio/io_signature.h>
#include <common_modules/covert_constellation.h>

#define SQRT_TWO 0.707107


namespace gr {
    namespace common_modules {

        covert_constellation::
        covert_constellation() { }

        covert_constellation::
        ~covert_constellation() { }

        gr_complex
        covert_constellation::
        get_point_from_value(
            unsigned int value)
        {
           return d_points[value];
        }



    constellation_cbpsk::sptr
    constellation_cbpsk::make()
    {
      return constellation_cbpsk::sptr(new constellation_cbpsk());
    }

    constellation_cbpsk::constellation_cbpsk()
    {
        d_points.resize(2);
        d_points[0] = gr_complex(-1, 0);
        d_points[1] = gr_complex(1, 0);
    }

    constellation_cbpsk::~constellation_cbpsk()
    {
    }

    unsigned int
    constellation_cbpsk::decision_maker(const gr_complex *sample)
    {
      return (real(*sample) > 0);
    }


/********************************************************************/


    constellation_cqpsk::sptr
    constellation_cqpsk::make()
    {
      return constellation_cqpsk::sptr(new constellation_cqpsk());
    }

    constellation_cqpsk::constellation_cqpsk()
    {
      // Gray-coded
      d_points.resize(4);
      d_points[0] = gr_complex(-SQRT_TWO, -SQRT_TWO);
      d_points[1] = gr_complex(SQRT_TWO, -SQRT_TWO);
      d_points[2] = gr_complex(-SQRT_TWO, SQRT_TWO);
      d_points[3] = gr_complex(SQRT_TWO, SQRT_TWO);

    }

    constellation_cqpsk::~constellation_cqpsk()
    {
    }

    unsigned int
    constellation_cqpsk::decision_maker(const gr_complex *sample)
    {
      // Real component determines small bit.
      // Imag component determines big bit.
      return 2*(imag(*sample)>0) + (real(*sample)>0);
    }



  } /* namespace common_modules */
} /* namespace gr */

/************************/

I am instantiating the module in the Python file as follows:

        a = common_modules.constellation_cqpsk()

This is what I am getting:

  File "./custom_ofdm_system_covert.py", line 12, in <module>
    from custom_ofdm_txer_covert import custom_ofdm_txer_covert
  File 
"/home/frank/Documents/reconfigurable_ofdm/gr-custom_tx_ofdm/python/custom_ofdm_txer_covert.py", 
line 14, in <module>
    import common_modules_swig as common_modules
  File 
"/home/frank/Documents/reconfigurable_ofdm/gr-common_modules/build/swig/common_modules_swig.py", 
line 238, in <module>
    constellation_cbpsk = constellation_cbpsk.make;
NameError: name 'constellation_cbpsk' is not defined


However, I am able to use constellation_cbpsk perfectly from C++. So I 
am guessing it's a SWIG problem.
Any ideas?

Thanks,
Frank