1   // Fig. 20.11: fig20_11.cpp
 2   // Using the bitwise shift operators.
 3   #include <iostream>
 4   #include <iomanip>
 5   using namespace std;
 6
 7   void displayBits( unsigned ); // prototype
 8
 9   int main()
10   {
11      unsigned number1 = 960;
12
13      // demonstrate bitwise left shift
14      cout << "The result of left shifting ";
15      displayBits( number1 );
16      cout << "8 bit positions using the left-shift operator is ";
17      displayBits( number1 << 8 );
18
19      // demonstrate bitwise right shift
20      cout << " The result of right shifting ";
21      displayBits( number1 );
22      cout << "8 bit positions using the right-shift operator is ";
23      displayBits( number1 >> 8 );
24   } // end main
25
26   // display bits of an unsigned integer value
27   void displayBits( unsigned value )
28   {
29      const int SHIFT = 8 * sizeof( unsigned ) - 1;
30      const unsigned MASK = 1 << SHIFT;
31
32      cout << setw( 10 ) << value << " = ";
33
34      // display bits
35      for ( unsigned i = 1; i <= SHIFT + 1; ++i )
36      {
37         cout << ( value & MASK ? '1' : '0' );
38         value <<= 1; // shift value left by 1
39
40         if ( i % 8 == 0 ) // output a space after 8 bits
41            cout << ' ';
42      } // end for
43
44      cout << endl;
45   } // end function displayBits