Sruct size

Hi ,
Could you please explane why the size of the struct is 4 byte?

Code:

struct bitfield
{
  int a:5;
  int c:5;
  int b:6;
 
};

 

Your machine likely uses 32 bits for ints - to verify, you can multiply the macro CHAR_BIT by sizeof(int). Since the bitfield you've posted is comprised of 16 bits, it needs the space of 1 int or 4 bytes on your machine. You can test it by adding more

Code:

struct bitfield
{
    int a:5;
    int c:5;
    int b:6;
    int d:16;
    int e:32;
    int f:4;
};

a-d utilizes 32 bits, e utilizes 32 bits, and f utilizes 4 bits; the sizeof(bitfield) *should* require 12 bytes as space of 3 ints are needed.