Method for solving error: “cannot instantiate abstract class”

Question

I find one of the most time-consuming compiler errors for me is \"cannot instantiate abstract class,\" since the problem is always that I didn\'t intend for the class to be

Answer 1

C++Builder tells you which method is abstract:

class foo {
    virtual void x() const = 0;
};

class bar : public foo {
    virtual void x() { }
};

new bar;

[BCC32 Error] File55.cpp(20): E2352 Cannot create instance of abstract class 'bar'
[BCC32 Error] File55.cpp(20): E2353 Class 'bar' is abstract because of 'foo::x() const = 0'