Demonstrate how we can store local vars to heap using `calloc`, `malloc` so that we can return the references to the caller.

storing_locals_to_heap.c

#include <stdio.h>
#include <stdlib.h>
#include <assert.h>

int* getSum(int a, int b){
  /* Local var stored in `heap` instead of `stack` */
  int* sum = malloc(sizeof(int));

  *sum = a + b;

  return sum;
}

void main(){
  /* Writing assertions to test the result */
  assert(*getSum(12, 12) == 24);
  assert(*getSum( 0, 12) == 12);
  assert(*getSum(-1, 12) == 11);
  assert(*getSum(-3, 12) ==  9);
}