Automatic comparisons for custom types stored in QVariant

Hi all

I need to compare objects stored in QVariant automatically without knowing the type.
The following code explain what problem need to be solved.

Code:

class A // registered as custom type
{
    A(const QVariant& variant);
    A& operator=(const QVariant& variant);
    operator QVariant() const;
};
 
class B // registered as custom type
{
    B(const QVariant& variant);
    B& operator=(const QVariant& variant);
    operator QVariant() const;
};
 
class AnotherClass
{
public:
    bool operator==(const AnotherClass& other) const
    {
        // COMPARE THE VALUE
        return var == other.var; // <-- compare the address, not the value
    }
 
private:
    QVariant var; // var may contain A or B
};

Thanks...