Migrate UDXs from API version 1 to API version 2

If you have UDXs that use UDX version 1 and the nz::udx namespace, those UDXs will continue to run following an upgrade to release 6.0 or later. If you want to migrate your UDXs to version 2 to take advantage of features such as the new version 2 API methods, environment access, or others, there are a few small changes that must be made to the C++ source code files:

• Change the namespace from nz::udx to nz::udx_ver2.
• The constructor and instantiator for a UDX must be revised to take a UdxInit object.
  For example, in API version 1, an UDX can have the following form:

     using namespace nz::udx;
  class CCustomerName: public Udf
  {
  public:
       static Udf* instantiate();
  };
  Udf* CCustomerName::instantiate()
  {
       return new CCustomerName;
  }

  In API version 2, the instantiator and constructor take a UdxInit argument. As a result, you must declare the constructor, even if it does not take any arguments, as in this example:

     using namespace nz::udx_ver2;
  class CCustomerName: public nz::udx_ver2::Udf
  {
  public:
       CCustomerName(UdxInit *pInit) : Udf(pInit){}
       static nz::udx_ver2::Udf* instantiate(UdxInit *pInit);
  };
  
  nz::udx_ver2::Udf* CCustomerName::instantiate(UdxInit *pInit)
  {
       return new CCustomerName(pInit);
  }