#include "pile.h"

pile_t push(void* x, pile_t s)
{
  pile_t element = malloc(sizeof(struct s_stack));;

  element->next = s;
  element->data = x;
  return element;
}

void* pop(pile_t *pile)
{
  void* data;
  pile_t element;

  if (!stack_is_empty(*pile))
    {
      data = (*pile)->data;
      element = (*pile)->next;
      free(*pile);
      pile = &element;
      return data;
    }
  else
    return NULL;
}