#include "named_param.hh"
#include "typelist.hh"
#include <typeinfo>
#include <iostream>

struct print_policy_tag {};
struct dec_print_policy {};
struct hex_print_policy {};

struct promote_policy_tag {};
struct precise_promote_policy {};
struct stdc_promote_policy {};

template<typename Policies = mpl::make_typelist_1<mpl::nil>::type>
class ntp_test {
private:
  // The user-provided parameter tag/type map.
  typedef Policies policy_typelist;

  // Find the pair corresponding to the print policy and extract
  // the given type, or the default (dec_print_policy) if it is not there.
  typedef typename mpl::extract_named_param_or_default::
  template apply<policy_typelist, 
		 print_policy_tag,  // We're looking for this
		 // This is the default
		 dec_print_policy>::result print_policy;

  // Ditto for the promotion policy.
  typedef typename mpl::extract_named_param_or_default::
  template apply<policy_typelist, 
		 promote_policy_tag,
		 precise_promote_policy>::result promote_policy;

public:
  ntp_test(void) {
    std::cout << typeid(*this).name() << std::endl;
    std::cout << "Print policy: " << typeid(print_policy).name() << std::endl;
    std::cout << "Promote policy: " << typeid(promote_policy).name() 
	      << std::endl;
  };
};

int main(void)
{
  // Default print and promote policies
  ntp_test<> defaults;

  // Default promote policy
  ntp_test<mpl::make_typelist_1<mpl::map_param::
    template apply<print_policy_tag, 
                   hex_print_policy>::result>::type> 
    default_promote;

  // Alternateively:
  // ntp_test<mpl::make_typelist_1<map_param<print_policy_tag, 
  //                                         hex_print_policy> >::type> 
  //   default_promote;

  // Default print policy
  ntp_test<mpl::make_typelist_1<mpl::map_param::
    template apply<promote_policy_tag, 
                   stdc_promote_policy>::result>::type> 
    default_print;

  // Alternateively:
  // ntp_test<mpl::make_typelist_1<map_param<promote_policy_tag, 
  //                                         std_promote_policy> >::type> 
  //   default_print;

  return(0);
}