executing a for loop or once depending on a test

Hi,

I am trying to avoid redundancy in my code and would like to know if
there is an elegant solution for this.

Let's say I have 2 vectors (va and vb) that may contain Int and String
elements respectively, or be empty. I'd like to generate all
combinations of Int/String so I could use a nested loop :

for (vector<int>::iterator vai = va.begin(); vai != va.end(); ++vai)
  {
    for (vector<string>::iterator vbi = vb.begin(); vbi != vb.end(); +
+vbi)
      {
        // create the object
        Object* oneobject = new Object();
        // store vai and vbi combination
        oneobject->addInt(*vai);
        oneobject->addString(*vbi);
        // store the object pointer somewhere;
        vector_objects.push_back(oneobject);
      }
  }

The problem here is that if one of my vectors is empty, no object at
all will be created.

So I solved it using some tests:

if (!va.empty() && vb.empty()) //only ints
  {
    for (vector<int>::iterator vai = va.begin(); vai != va.end(); +
+vai)
      {
        // create object
        oneobject->addInt(*vai);
        // store
      }
  }
else if (va.empty() && !vb.empty()) //only strings
  for (vector<int>::iterator vbi = vb.begin(); vbi != vb.end(); ++vbi)
      {
        // etc...
      }
else if (!va.empty() && !vb.empty()) //int and strings
  {
    for (vector<int>::iterator vbi = vb.begin(); vbi != vb.end(); +
+vbi)
      {
        for (vector<int>::iterator vbi = vb.begin(); vbi != vb.end(); +
+vbi)
          {
            // etc...
          }
      }
  }
else if (!va.empty() && !vb.empty()) //no int no strings
  {
      // etc...
  }

The problem is that there is a lot of code redundency (common parts in
the loops), and if there are more than two vectors, the number of if
statements would be impossible to manage.

Actually, instead of Int and String, if I have pointers to objects, I
know I could use inheritance/polymorphism in order to store them in
the same container. However, the objects can be heterogenous and
inheritence is not suitable.

Is there an elegant way to avoid all the if statements ?