updatingiterator.cpp

#include <vector>
#include <iostream>
using namespace std;

int main() {

  std::vector<int> foo;
  
  // Add an item and then obtain an iterator to it
  foo.push_back(3);
  vector<int>::iterator current = foo.begin();
  
  // Check the addresses of our iterator and the first item
  std::cerr 
     << "Address of the current iterator: " << &current << std::endl;
  std::cerr 
     << "Address of our first object: " << &foo.at(0) << std::endl;
  
  // Add a new item to the end and update our iterator
  current = foo.insert(foo.end(),4);
  std::cerr 
      << "Address of the current iterator (same as before): " 
      << &current << std::endl;
  
  // Check the address of the first item
  std::cerr 
      << "Address of our first object different from before): " 
      << &foo.at(0) << std::endl;
  
  // See if our iterator is valid
  std::cerr << "current (4): " << *current << std::endl;
  
  return 0;

}

// output
//
// Address of the current iterator: 
//   0xbf809f40
// Address of our first object: 
//   0x8ba1008
// Address of the current iterator after adding a new item:
//   0xbf809f40
// Address of our first object (different from before): 
//   0x8ba1018
// current (4): 4