Virtual function defined, how to define a destructor?

[northfly]

I wrote the following program, it can be compiled and run, but there is warning saying that if virtual function is defined, there should be a destructor. How to do that I tried many different ways I can thought of, but none of them works. Please help me complete this programming, make it no warnings......

#include <iostream>
using namespace std;

class cell_c {
public:
	double p;
	cell_c() {p=1;}

	virtual void print() {cout<<p<<endl;}
//	virtual ~cell_c();
//	virtual void ~print()=default;
};

class uvcell_c:public cell_c {
public:
	double q;
	uvcell_c() {q=0;}

	inline void print() {cout<<p<<q<<endl;}
//	virtual ~uvcell_c();
};
int main() {
	cell_c c;
	uvcell_c uv;
	c.print();
	uv.print();
	cell_c & cuv=uv;
	cuv.print();
	return 0;
}

Thanks!

[JLBorges]

#include <iostream>

class cell_c {
    public:
        double p;
        cell_c() {p = 1;}

        virtual ~cell_c() = default ; // virtual ~cell_c() {}
        virtual void print() const  { std::cout << p << '\n' ; }
};

class uvcell_c: public cell_c {
    public:
        double q;
        uvcell_c() { q = 0; }

        inline virtual void print() const override
        { std::cout << p << ' ' << q << '\n' ;}
};

int main() {
    cell_c c;
    uvcell_c uv;
    c.print();
    uv.print();
    cell_c & cuv = uv;
    cuv.print();
}