Home Is there a way to emit a warning if an overriding method don't call the overridden implementation in C++?

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Is there a way to emit a warning if an overriding method don't call the overridden implementation in C++?

March 1, 2023

Is there a function attribute (standard or compiler extension) that emits a warning if an overriding method doesn’t call the overridden method?

Like this:

class A
{
protected:
    [[please_call]]
    virtual void foo() { /* ... */ };
};

class B : public A
{
protected:
    void foo() override {}
    // WARNING: B::foo() does not call A::foo()
};

>Solution :

One way to do this is to use another function in the base class and the call the virtual function in that function. That would look like

class Base
{
public:
    void doFoo() { Base::doFooImpl(); doFooImpl(); }
private:
    virtual void doFooImpl() { std::cout << "Base\n"; }
};

class Derived : public Base
{
private:
    void doFooImpl() override { std::cout << "Dervied\n"; }
};

int main()
{
    Derived d;
    d.doFoo();
}

output: