//文件名:CHAPTER7-20.cpp
#include <deque>
#include <iostream>
#if _MSC_VER > 1020   // if VC++ version is > 4.2
   using namespace std;  // std c++ libs implemented in std
#endif
int main( ) 
{  using namespace std;
   deque <int> c1;
   c1.push_back( 10 );
   c1.push_back( 20 );
   cout << "The first integer of c1 is " << c1[0] << endl;
   int& i = c1[1];
   cout << "The second integer of c1 is " << i << endl;
}