I have also seen this with GCC 4 when a virtual destructor is missing a body
eg:
virtual ~MyClass(void);
should be:
virtual ~MyClass(void){};

Also if you declare a virtual constructor but forget the '~' in its definition, e.g.:
virtual ~A(); // declaration in .h file
A::A() {} // .cpp implementation missing ~ in function name

I'm self studying from the book, C++ Primer Plus Fifth Edition, by Stephen Prata. The following relates to Chapter 13, Page 699, Programming Exercise #4. One task is to write the derived class method definitions based upon the given prototypes. The following are the said prototypes.

cpp Syntax (Toggle Plain Text)

class Port
{
    private:
        char *brand;
        char style[20];     // i.e. tawny, ruby, vintage
        int bottles;
    public:
        Port(const char *br = "none", const char *st = "none", int b = 0);
        Port(const Port &p);            // copy constructor
        virtual ~Port() { delete [] brand;}
        Port & operator=(const Port &p);
        Port & operator+=(int b);
        Port & operator-=(int b);
        int BottleCount() const {return bottles;}
        virtual void Show() const;
        friend ostream &operator<<(ostream &os, const Port &p);
};
 
class VintagePort : public Port
{
    private:
        char * nickname;            // i.e. The Noble, or Old Velvet, etc.
        int year;                   // vintage year
    public:
        VintagePort();
        VintagePort(const char *br, int b, const char *nn, int y);
        VintagePort(const VintagePort &vp);
        ~VintagePort() {delete [] nickname;}
        void Show() const;
        friend ostream & operator<<(ostream &os, const VintagePort & vp);
};

class Port { private: char *brand; char style[20]; // i.e. tawny, ruby, vintage int bottles; public: Port(const char *br = "none", const char *st = "none", int b = 0); Port(const Port &p); // copy constructor virtual ~Port() { delete [] brand;} Port & operator=(const Port &p); Port & operator+=(int b); Port & operator-=(int b); int BottleCount() const {return bottles;} virtual void Show() const; friend ostream &operator<<(ostream &os, const Port &p); }; class VintagePort : public Port { private: char * nickname; // i.e. The Noble, or Old Velvet, etc. int year; // vintage year public: VintagePort(); VintagePort(const char *br, int b, const char *nn, int y); VintagePort(const VintagePort &vp); ~VintagePort() {delete [] nickname;} void Show() const; friend ostream & operator<<(ostream &os, const VintagePort & vp); };

You will note that the base class destructor is virtual. That the derived class destructor is implemented inline.

I was creating the derived class method definitions in a cpp file and couldn't get the project to progressively compile correctly. At my first method definition, a default constructor, the compiler kept spitting out this error message:

The line number was pointing to my derived class constructor definition. I did some googling around and came across this workaround. I removed the inline effect of the derived class destructor, made that into a method definition in the cpp file and presto, compilation succeeded.

Am I to assume that the example in the book, as regards the inline feature of a derived class destructor, is in error. Are there any other explanations.