#ifndef MAP_VALUE_H

 #define MAP_VALUE_H

 #include <exception>

 #include <functional>

 #include <iosfwd>

 class MapValue

 {

   public:

     friend std::ostream& operator<<(std::ostream &os, const MapValue& v);

     class IllegalOperation : public std::exception

     {

       virtual const char* what() const throw()

       {

         return "Illegal operation.";

       }

     };

     typedef enum

     {

       NUMERIC = 1 << 0,

       STRING  = 1 << 1

     } Type;

   private:

     bool has_value;

     void* p_value;

     MapValue::Type type;

     void clear();

   public:

     MapValue();

     MapValue(double);

     MapValue(std::string);

     MapValue(const char* str);

     MapValue(const MapValue& v);

     MapValue& operator=(const MapValue& v);

     ~MapValue();

     operator std::string() const;

     operator double() const;

     Type getType() const;

     bool hasValue() const;

 };

 #endif