%union problem in 2.4 version

[Cleto Martin Angelina]

Hi!

Recently, i'm having troubles compiling my parser, which worked in bison
2.3. The output message is:

Parser.y:42: error: ISO C++ forbids declaration of ‘Invocation’ with no type
Parser.y:42: error: expected ‘;’ before ‘*’ token
Parser.y:43: error: ISO C++ forbids declaration of ‘Parameter’ with no type
Parser.y:43: error: expected ‘;’ before ‘*’ token
Parser.y:44: error: ISO C++ forbids declaration of ‘vector’ with no type
Parser.y:44: error: invalid use of ‘::’
Parser.y:44: error: expected ‘;’ before ‘<’ token

And header's .y file is:

%{
#include <stdio.h>
#include <stdlib.h>
#include "Driver.h"
%}

%skeleton "lalr1.cc"
%require "2.4"
%debug

%defines
%define "parser_class_name" "Parser"
%define "namespace" "ipk"

// The parsing context.
%parse-param { class Driver& driver }

%locations
%initial-action
{
  // Initialize the initial location.
  @$.begin.filename = @$.end.filename = &driver.file;
};

%debug
%error-verbose
%name-prefix="ipk"

// Symbols.
%union
{
  int          ival;
  std::string *sval;
  bool         bval;
  Invocation* inv;
  Parameter* par;
  std::vector<Parameter>* vpar;
};

"Invocation", "Parameter", etc. are types declared at Driver.h file and
defined in Driver.cc.

I've read about that in this mailing list, but i'm really lost. I don't know
which features have changed in 2.4 version that are affecting my project.
Can anyone guide me?.

Thanks in advance,
Cleto

---------------------------
Cleto Martín Angelina
address@hidden