dynamic array thing

dynamic-array.c

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

// I have no idea if this is a good idea, or a bad idea?

typedef enum {
  K_STRING,
  K_INT,
  K_COMPLEX
} kind;

typedef struct complex_type {
  int number;
  char *message;
} complex_type;

typedef struct element {
  kind type;
  size_t width;
  void *data;
} element;

typedef struct d_array {
  int max_size;
  int end;
  element **elements;
} d_array;

void die(char *message)
{
  printf("Error: %s", message);
  exit(1);
}

d_array *create_d_array(int initial_size)
{
  d_array *array;
  if((array = malloc(sizeof(d_array))) == NULL) die("Couldn't allocate d_array");
  
  array->max_size = initial_size;
  array->end = 0;
  array->elements = calloc(initial_size, sizeof(element *));
  return array;
}

int array_push(d_array *array, kind type, size_t width, void *thing)
{
  // add some logic to expand the size of the array, but for now, die if adding this element will be too big
  if (array->end == (array->max_size - 1)) return 0;
  
  element *el;
  if((el = malloc(sizeof(element))) == NULL) die("Couldn't allocate el");
  el->type  = type;
  el->width = width;
  el->data = malloc(el->width);
  memcpy(el->data, thing, el->width);

  array->elements[array->end] = el;
  array->end++;

  return 1;
}

void element_pp(element *el)
{
  complex_type *complex;
  switch (el->type)
  {
  case K_INT:
    printf("The value is: %d\r\n", *(int *)el->data);
    break;
  case K_STRING:
    printf("The value is: %s\r\n", (char *)el->data);
    break;
  case K_COMPLEX:
    complex = (complex_type *)el->data;
    printf("The number is %d and the message is %s\r\n", complex->number, complex->message);
    break;
  default:
    printf("I don't know what this is\r\n");
    break;
  }
}

int main(void) {
  d_array *array;
  printf("sizeof(size_t) = %lu\r\n", sizeof(size_t));
  
  array = create_d_array(10);

  int fortytwo = 42;
  char *message = "42 is the answer...";
  complex_type *fun;

  fun = malloc(sizeof(complex_type));
  fun->message = "This is fun";
  fun->number  = 10;

  array_push(array, K_INT, sizeof(int), &fortytwo);
  array_push(array, K_STRING, strlen(message), message);
  array_push(array, K_COMPLEX, sizeof(complex_type), fun);

  element_pp(array->elements[0]);
  element_pp(array->elements[1]);
  element_pp(array->elements[2]);

  return 0;
}