//文件名:CHAPTER7-19.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 );
   c1.push_back( 30 );
   cout << "The size of the deque is initially " << c1.size( ) << endl;
   c1.clear( );
   cout << "The size of the deque after clearing is " << c1.size( ) << endl;
   return 0;
}