11. Iterator Pitfalls

• 
      // Using iterator after content of the container changes:
      vect.insert( data );
      ++iter; // Can be DANGEROUS! Iterator may be invalid!
  
      // Navigating and dereferencing the iterator to access the data:
      ++iter;
      *iter = data;
      cout << *iter;
      iter = data;   // incorrect
      cout << iter;  // incorrect