[C++-sig] passing NoneType as argument to constructor

[Liam Herron]

For the following code:
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------
#include <boost/python.hpp>
using namespace boost::python;

namespace // unnamed
{

class NullableDouble
{
public:
   NullableDouble()
      : isNull_(true)
      , value_(0.0)
   {
   }

   NullableDouble(double x)
      : isNull_(false)
      , value_(x)
   {
   }

   double value() const
   {
      return value_;  // null check not relevant to this example
   }

   bool isNull() const
   {
      return isNull_;
   }

   // ... more functions but not needed for this example

private:
   bool isNull_;
   double value_;
};

} // end namespace unnamed

void init_pnic()
{
   class_<NullableDouble>
   ("NullableDouble", "NullableDouble", init<>())
      .def(init<double>())
      .def("value", &NullableDouble::value)
      .def("isNull", &NullableDouble::isNull)
   ;
}

BOOST_PYTHON_MODULE(_testPNIC)
{
   init_pnic();
}
-----------------------------------------------------------------------------------------------------------------------------------------------------------------------

I would like to have another constructor method in python that takes a 'None' and returns the same as the no arg constructor 'NullableDouble()'

What is the best way to do this?

Thanks,
--Liam




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