[C++-sig] wchar_t* type conversion

[Nicolas Lara]

Hello,
I'm new to Boost::Python and am encountering a problem that seem to be
quite common: I need to expose a class to C++ whose constructor takes
a wchar_t* as a parameter.
The problem is that there is no default type converter from wchar_t to
python and vice-versa.

I wanted to know if there was a standard way of doing this. Or if
anyone could point me to an implementation of this type conversion.

So far I'm doing this (based on the faq):

struct wchar_t_to_python_str
{
 static PyObject* convert(wchar_t* const& w)
 {
   string s = "";
   wchar_t* w2 = w;
   while(*w2++ != 0){
     s += *w2;
   }
   return boost::python::incref(boost::python::object(s).ptr());
 }
};

struct wchar_t_from_python_str
{
 wchar_t_from_python_str()
 {
   boost::python::converter::registry::push_back(
                          &convertible,
                          &construct,
                          boost::python::type_id<wchar_t>());
 }

 static void* convertible(PyObject* obj_ptr)
 {
   if (!PyString_Check(obj_ptr)) return 0;
   return obj_ptr;
 }

 static void construct(
                       PyObject* obj_ptr,

boost::python::converter::rvalue_from_python_stage1_data* data)
 {
   const char* value = PyString_AsString(obj_ptr);
   Py_ssize_t l = PyString_Size(obj_ptr);
   if (value == 0) boost::python::throw_error_already_set();
   void* storage = (

(boost::python::converter::rvalue_from_python_storage<wchar_t*>*)
                    data)->storage.bytes;

   wchar_t* w = new wchar_t[l];
   for(int i=0;i<l;i++){
     w[i] = value[i];
   }
   data->convertible = w;
 }
};
 void init_module()
 {
   to_python_converter<wchar_t*,wchar_t_to_python_str>();
   wchar_t_from_python_str();
  }

BOOST_PYTHON_MODULE(queryparser){
 init_module();
}

But it doesn't seem to be working. It compiles, but python doesn't
understand the conversion.
Any thoughts?


Thanks in advance!

--
Nicolas Lara
Linux user #380134
http://nicolas-lara.blogspot.com/
Public key id: 0x152e7713 at http://subkeys.pgp.net/