c++ bitmask example

Example: bitmask c++

- Set ith bit:    x|(1<<i)
   1100 1100
|  0001 0000    (1<<i)
  -----------
   1101 1100  
  
- Get ith bit:    (x&(1<<i) != 0)
    0010 1100
&   0010 0000   (1<<i)
  ------------
    0010 0000   (is not zero)

- Clear ith bit:   x&(~(1<<i))
                      ~ : inverts
   0011 0110
&  1101 1111   ~(1<<i)
  -----------
   0001 0110