python linking problem

From: Drew.Whitehouse_at_[hidden]
Date: 2001-10-18 00:49:58

Under VC6 I have a strange linking problem - if the specified line is 
uncommented things work, otherwise I see the error -

  Creating library Debug/_alchemy_d.lib and object 
Debug/_alchemy_d.exp
_alchemy.obj : error LNK2001: unresolved external symbol "class 
`anonymous namespace'::hello & __cdecl from_python(struct _object 
*,struct boost::python::type<class `anonymous namespace'::hello &>)" 
(?from_python@@YAAAVhello@?%D:\home\drw900\Project
s\pyAlchemy\SRC\boostAlchemy\_alchemy.cpp204027573@@PAU_object@@U?
$type_at_AAVhello@?%D:\home\drw900
\Projects\pyAlchemy\SRC\boostAlchemy\_alchemy.cpp204027573@@@python_at_bo
ost@@@Z)
_alchemy_d.pyd : fatal error LNK1120: 1 unresolved externals
Error executing link.exe.

_alchemy_d.pyd - 2 error(s), 0 warning(s)

The code is -

#include <iostream>
#include <string>
namespace 
{
  class hello
  {
  public:
    hello() { this->country = "none"; }
    void foo() const { std::cerr << "Hello from " + country; }
    std::string greet() const { return "Hello from " + country; }
  private:
    std::string country;
  };
}

#include <boost/python/class_builder.hpp>
namespace python = boost::python;
BOOST_PYTHON_MODULE_INIT(_alchemy)
{
  try
  {
    python::module_builder this_module("_alchemy");
    python::class_builder<hello> hello_class(this_module, "hello");
    hello_class.def(python::constructor<>());
    hello_class.def(&hello::foo, "foo");
    // module links if the next line uncommented.....
    //hello_class.def(&hello::greet, "greet");
  }
  catch(...)
  {
    python::handle_exception(); // Deal with the exception for Python
  }
}