c++ - Bitwise operator to get byte from 32 bits -

I'm interested in writing a function getMyByteChunkFunction which accepts two parameters - a 32 For example, this integer is given: -

  - For example, the bit integer and a byte offset (0, 1, 2, or 3), then removes bytes related to 32-bit integers. (3) (2) (1) (0) --- byte numbers int word = 10101010 00001001 11001010 00000101   
 function call  getMeByteChunkFunction (word, 2)  Returns  00001001 .  
 However, I can use bitwise operators limited in it. Only me  & gt; & Gt; ,  & lt; I am allowed to use a , and  exactly one  subtraction I know how to do this and using XOR, but I do not know how I use a subtraction here Any thoughts?  
 
 One idea is as follows: Suppose that you have a four-byte value:  
  aaaaaaaa bbbbbbbb cccccccc dddddddd   
 Suppose you want to get a byte  BBBBBBBB  out of this if you move right by two bytes If you do, you can  
  ???????? Reciprocity Aaaaaaaa bbbbbbbb   
 This value is equal to what you want, except the  ???????? Reciprocity Aaaaaaa  (because we are not sure if the change is signal-protected or not, because I do not know if your value is unsigned). No worries; We can get rid of these unknown values ​​and  a  bytes. To get rid of the top, let's make a change to another byte,  
  ???????? Reciprocity Reciprocity Aaaaaaa   
 Now, get a byte to get it  
  ???????? Reciprocity Aaaaaaaa 00000000   
 If you subtract this again, then you  
  ???????? Reciprocity Aahaya bbbbbbbb - ???????? Reciprocity Aaaaaaa 00000000 --------------------------------------- 00000000 00000000 00000000 Bbbbbbbb  < / Ex> 
 and voice ... you've got the value you want!  
 I will leave the actual code as a practice for the reader. do not worry; This is not particularly difficult: -)