text: #ifndef RESOLVER_TRUNCATER_HPP
  #define RESOLVER_TRUNCATER_HPP
  
  #include <boost/optional.hpp>
  #include "data_type.hpp"
  #include "slide_algorithm/algorithm.hpp"
  
  class truncater
  {
  public:
      typedef answer_type return_type;
  
      truncater();
      virtual ~truncater();
  
      auto get() -> boost::optional<return_type>;
      void reset(question_data const& data);
  
  private:
      class impl;
      impl *pimpl_;
  };
  
  #endif
  