C ++没有适当的默认构造函数

Question

I know this has been asked before, but I can't find the problem on my code. It's a fairly simple code, I have checked and the class Point works perfectly ( it has a default value of (0,0) ), though the Circle one isn't

 class Circle{
public:
    Circle(Point, double);
    Circle(const Circle& c);
    ~Circle();
    void setCenter(Point scenter);
    void setRadius(double sradius);
    double getSurface();
    Point getCenter() const;
    double getRadius() const;
    void print() const;

private:
    Point center;
    double radius;
};

Circle::Circle(Point c, double r)
{
    r = 1.0;
    setCenter(c);
    setRadius(r);
}

What am I doing wrong?

Answer 1

A default constructor is only generated for you if you have no other constructors. If you want to have a default constructor (ie, no arguments) in addition to constructors with arguments, you need to define it