#ifndef ARRAY_H
#define ARRAY_H
#include <stddef.h>

#define ARRAY_INITIAL_CAPACITY 4

#define array(T) (T *)array_new(sizeof(T))

#define array_append(arr, item) do {               \
        array_header_t *h = array_get_header(arr); \
        if (h->capacity < h->length + 1) {         \
            arr = array_grow(arr);                 \
		}                                          \
        arr[h->length++] = item;                   \
    } while (0)

typedef struct array_header {
    size_t capacity;
    size_t item_size;
    size_t length;
} array_header_t;

void *
array_new(size_t item_size);

array_header_t *
array_get_header(void *arr);

void *
array_grow(void *arr);

size_t
array_length(void *arr);

#endif /* ARRAY_H */