c08p406a.txt

来自「Data Abstraction & Problem Solving with 」· 文本 代码 · 共 10 行

class Sphere
{
public:
// constructors and operations as before
   friend void readSphereData(Sphere& s); 
   friend void writeSphereData(Sphere& s); 
private:
   double theRadius;  // the sphere's radius
};  // end class