This question was mentioned here.

My doubt is: If a pointer variable has the same address as its value, is it really pointing to itself?

For example - in the following piece of code, is a a pointer to itself?

#include<stdio.h>

int main(){
   int* a;
   int b = (int)&a;
   a = b;
   printf("address of a = %d\n", &a);
   printf("  value of a = %d\n", a);
}

If a is not a pointer to itself, then the same question poses again: Can a pointer point to itself?
Also, how is a self pointing pointer useful?