Question

Here is my issue. I want to have something like this:

class A {
protected:
int someInt;
virtual void someFunc() = 0;

};

class B : public A {
protected:
virtual void someFunc() { // uses someInt}
public:
B() {//tell the A inside of B to set someInt to whatever it wants}
};

so basically, someInt can be changed, it’s not constant, but I want all the classes that implement A to use a value provided by A for someInt.

Thanks

Answer 1

You can use initializer lists in the constructor to call parent constructors:

class A {
protected:
    int someInt;
    virtual void someFunc() = 0;
    A(int x) : someInt(x) {}  // Base-class constructor (initialises someInt)
};

class B : public A {
protected:
    virtual void someFunc() {}
public:
    B() : A(10) {}  // Initialises base class via constructor
};