A trick for partial specialization of function template

printinfo.hpp

/**
 partial specialization of function template is under consideration of C++ Standards Committee
 
 But before that, we need some tricks
 */
 
 
 #include "boost/format.hpp"

namespace bamutils{

template <typename prompt_type, typename content_type>
struct myinfo_imp
{
  void operator()(const prompt_type& prompt, const content_type& content){
    std::cout<<prompt<<" : "<< content<<std::endl;
  }
};

template <typename prompt_type>
struct myinfo_imp<prompt_type, boost::format>
{
  void operator ()(const prompt_type& prompt, const boost::format& content){
    std::cout<<prompt<<" : "<< content.str()<<std::endl;
  }
};

template <typename content_type>
struct myinfo_imp<boost::format, content_type>
{
  void operator() (const boost::format& prompt, const content_type& content){
    std::cout<<prompt.str()<<" : "<< content<<std::endl;
  }
};

template <>
struct myinfo_imp<boost::format, boost::format>
{
  void operator() (const boost::format& prompt, const boost::format& content){
    std::cout<<prompt.str()<<" : "<< content.str()<<std::endl;
  }
};

template <typename prompt_type, typename content_type>
void myinfo(const prompt_type& prompt, const content_type& content){
  myinfo_imp<prompt_type, content_type> imp;
  imp(prompt, content);
}

template <typename string_type>
void myinfo(const string_type& info){
  std::cout<<info<<std::endl;
}

template<>
void myinfo(const boost::format& info){
  std::cout<<info.str()<<std::endl;
}
}