text: #pragma once
  class cal_number
  {
  public:
  	enum OPER_Type { ADD = '+', SUB = '-', DIV = '/', MUL = '*', END = ')', NUL = ' ' };
  	virtual	double getValue() { return _data; };
  	OPER_Type getType() { return _op; };
  	virtual	void setValue(double data) { _data = data; };
  	cal_number(double data, OPER_Type op) :_data(data), _op(op) {};
  protected:
  	double _data;
  	OPER_Type _op;
  };
  