Static polymorphism

Hello,

for my data parser I want to use different generic checking policies 
using static polymorphism. But the way I've used won't compile (concrete 
the grammar class). The check policy p***** the data the parse actions 
which fills (and knows about) the data container.

What is the correct syntax for this? Note, that boost::spirit::grammar 
self uses static polymorphism.

Thanks,
Olaf

---8<---
struct parse_actions { ... };

struct parse_error_handler { ... };

template<typename DerivedT, typename ActionsT>
struct check_policy
{
     explicit check_policy( const ActionsT& actions )
     ...
};

template <typename ActionsT      = parse_actions,
           typename CheckPolicyT  = check_policy,
           typename ErrorHandlerT = parse_error_handler>
struct grammar :
     CheckPolicyT< grammar<CheckPolicyT, ActionsT, ErrorHandlerT> >,
     boost::spirit::grammar<
        grammar<CheckPolicyT, ActionsT, ErrorHandlerT>
     >
{
     explicit grammar(const ActionsT& actions      = ActionsT(),
                      const ErrorHandlerT& handler = ErrorHandlerT())
         : CheckPolicyT( actions ),
           actions(actions),
           error_handler(handler)
     { }

--->8---