指向成员函数的指针

Question

I have the following class:

class Point2D
{
    protected:

            double x;
            double y;
    public:
            double getX() const {return this->x;}
            double getY() const {return this->y;}
   ...

};

有时我需要返回x坐标,有时是y坐标,所以我使用指向成员函数getX(),getY()的指针.但我无法返回坐标,请参阅下文.

double ( Point2D :: *getCoord) () const;

class Process
{
   ......
   public processPoint(const Point2D *point)
   {

      //Initialize pointer
      if (condition)
      {
         getCoord = &Point2D::getX;
      }
      else
      {
         getCoord = &Point2D::getY;
      }

      //Get coordinate
      double coord = point->( *getCoordinate ) (); //Compiler error

   }

}

谢谢你的帮助.

Answer 1

您需要使用->*运算符通过指针调用成员函数:

(point->*getCoordinate)();