5. Simple State Check

• 
  #include <iostream>
  using std::cin;
  int main()
  {
      int value = 0;
      if ( !( cin >> value ) ) {
          // cin is not good, more checks required...
          if ( cin.bad() ) {
              // stream is corrupted...
          }
          if ( cin.eof() ) {
              // no data is available...
          }
          if ( cin.fail() ) {
              cin.clear(); // go back to good state...
              // do something to recover...
          }
      }
      // use value, everything is ok
      return 0;
  }