//Purpose:
//  demonstrate if_recur.
//
#include <boost/iostreams/utility/indent_scoped_ostreambuf.hpp>
#include <iostream>

      struct indent_undent_cout
      {
          indent_undent_cout(void)
          {
              std::cout<<indent_buf_in;
          }
          ~indent_undent_cout(void)
          {
              std::cout<<indent_buf_out;
          }
      };
      
#include <boost/fusion/algorithm/if_recur.hpp>

namespace boost
{
namespace fusion
{
namespace example
{

  void show_default(void)
  {
      typedef if_recur<int> ir_t;
      std::cout<<"show_default="<<ir_t::call( 9)<<"\n";
  }
  
  
        template
        < int Max
        >
      struct less
      {
          typedef bool result_type;
          static result_type call(int const& state)
          {
              return state<Max;
          }
      };

      struct increment
      {
          typedef int result_type;
          static result_type call(int const& state)
          {
              std::cout<<"increment:state="<<state<<"\n";
              return state+1;
          }
      };
      
      struct print_pair
      {
          typedef int result_type;
          static result_type call(int const& state_now, int const& state_up)
          {
              std::cout
              <<"print_pair"
              <<":state_now="<<state_now
              <<":state_up="<<state_up
              <<"\n";
              return state_up;
          }
      };
  
      struct print_btm
      {
          typedef int result_type;
          static result_type call(int const& state_btm)
          {
              std::cout
              <<"print_btm"
              <<":state_btm="<<state_btm
              <<"\n";
              return state_btm;
          }
      };
  
  void show_less_increment(void)
  {
      typedef less<4> recur_t;
      typedef increment then_down_t;
      typedef aux::if_recur::identity<int> now_now_t;
      typedef print_pair now_up_t;
      typedef print_btm else_btm_t;
          typedef
        if_recur
        < int
        , recur_t
        , then_down_t
        , now_now_t
        , now_up_t
        , else_btm_t
        > 
      ir_t;
      std::cout<<"show_less_increment="<<ir_t::call( 0)<<"\n";
  }
  
}//exit example namespace
}//exit fusion namespace
}//exit boost namespace

int main(void)
{
    boost::iostreams::indent_scoped_ostreambuf<char> iob(std::cout);
    boost::fusion::example::show_default();
    boost::fusion::example::show_less_increment();
    return 0;
}