Using bison++ with MSVC

[Dempe Dempe]

Hi,

I MUST use bison to generate C++ classes and compile it in MSVC.
I started compiling the basic example of  the "Calc++ -- C++ Calculator".
It works perfectly using gcc, but using MSVC in the declaration

class position
  {
  public:
    static const unsigned int initial_column =0;
…

I get the following error:

"error C2252: 'initial_column' : pure specifier can only be specified
for functions"

It means that the compiler "guess" that this is a function, not a variable.

Please, someone can help me with this problem?
Thanks