Question

I have a method that I want to run iteratively on one of two data members, alternating between them. I thought of doing the following

void myClass::alternating_method(){
    Graph G;
    &G = iteration_number%2 ? &A : &B;
    helper_method_which_modifies(G);
    iteration_number++;
    return;
}

where A and B and iteration_number are all myClass members but I’m not sure it will work. It seems right to me but the style rubs me wrong. The desired result is to call object.alternating_method() in a loop and have it modify object.A and object.B .

Will this work? Is there a better way? Will it have unexpected consequences? Do I need to worry about a destructor being called for G when it goes out of scope?

EDIT: To clarify, I meant helper_method_which_modifies as shorthand for 100 lines containing several methods. The ones that modify G are mostly boost graph methods. Now that I see the answers, it seems the best thing is to have an alternator which does nothing but choose between A and B and then pass the correct variable off to another method.

Answer 1

As already stated by Luchian Grigore, it won’t work because you need a L-value.

The idea is working though with little changes.

void myClass::alternating_method(){
    Graph& G = iteration_number%2 ? A : B;
    helper_method_which_modifies(G);
    iteration_number++;
    return;
}

Or with a bit more changes:

void myClass::alternating_method(){
    helper_method_which_modifies((++iteration_number%2) ? A : B);
}