C++ Calling a function before base-class initialization in the initialization list

Question

The Scenario:

In a project, I have class B which is derived from class A, where class A has an inaccessible default constructor.

Class B is set up as follows:

class B : public A
{
private:
    void SetupFunction() { /*Crucial code*/ }
public:
    B() : A(Value) {}
}

Supposing it is crucial for SetupFunction() to be called during initialization before the A(Value) constructor, how would I go about achieving this? Is it possible?

I'm using Code::Blocks 13.12 on Windows 7

Answer 1

You could make SetupFunction() return the value that's then passed to initialise A, e.g:

class B : public A
{
private:
    int SetupFunction() { /*Crucial code*/ return Value; }
public:
    B() : A(SetupFunction()) {}
}

Or use the comma operator if you don't want to change SetupFunction():

class B : public A
{
private:
    void SetupFunction() { /*Crucial code*/ }
public:
    B() : A((SetupFunction(), Value)) {}
}