ConstIterators

• Same behavior as Iterator, except container may not be mutated
• May be used when container is "const"

template < typename T >
  bool IsIn (const List<T>& list, T searchVal)
  {
    // List<T>::Iterator i;   // ERROR: const environment
    List<T>::ConstIterator i; // OK: using ConstIterator
    for (i = list.Begin(); i != list.End(); ++i) // calls "const" versions of Begin, End
    if (searchVal == *i)
      return true;
    return false;
  }

• Note distinction between ConstIterator and const Iterator