Question

If I have the following code (simplified version of the problem):

class TestA
{
    public:
    int A,B,C;

    TestA(){A = 1; B = 5; C = 10;}
};

//This is a referencing class to allow for universal and consistent operations
class TestB
{
   public:
   int &A, &B, &C; //Note references

   TestB(TestA &A) : A(A.A), B(A.B), C(A.C){}; //This is fine
   TestB(TestC &C) : A(C.A), B(C.B), C(C.C){}; //This needs to be prototyped
};

//Similar class to TestA but in the main program would have...
//...many different and conflicting variables and has to be treated as stand alone
class TestC
{
    public:
    int A, B, C;
    int Size;

    void Function()
    {
        TestB B(*this); //This uses TestB. TestB cannot be prototyped. 
        //etc etc
    }
};

I want to know, is it possible to prototype initialiser list based constructors?

If not, what is the alternative? Bear in mind references have to be immediately initialised.

Answer 1

If by “prototyping” you mean separation of function declaration and definition, this should work:

class TestB {
   // ...
   TestB(TestC &C);
};

TestB::TestB(TestC &C) : A(C.A), B(C.B), C(C.C) {
};