C# 5.0 Unleashed

How Base Calls Work

Now that you know how virtual calls are made, one remaining question is how a base call avoids getting trapped in some kind of endless recursion. Consider the following code we wrote for Student:

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class Student : Person{    public override string ToString()    {        return base.ToString() + " and attends " + College;    }}

Assume the base call for ToString would be handled in a virtual manner using a callvirt instruction for System.Object::ToString. The innards of virtual dispatch would inspect the vtable of the runtime type of the object (that is, a Student). In the slot for ToString, a reference would be found to the Student’s ToString code, as shown in the preceding code. So, we end up where ...