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

#include "util.h"

typedef int T;

struct ring_buffer {
	size_t head, tail;
	T      array[8]; /* fit for your needs... */
};

void
ring_init(struct ring_buffer *rb)
{
	rb->head = rb->tail = 0;
}

bool
ring_put(struct ring_buffer *rb, T data)
{
	const size_t next = (rb->head + 1) % NELEM(rb->array);

	if ( next == rb->tail )
		return false;

	rb->array[rb->head] = data;
	rb->head            = next;

	return true;
}

bool
ring_get(struct ring_buffer *rb, T *data)
{
	if ( rb->head == rb->tail )
		return false;

	const size_t next = (rb->tail + 1) % NELEM(rb->array);

	*data    = rb->array[rb->tail];
	rb->tail = next;

	return true;
}

void
f()
{
	ERROR("");
}

int
main(void)
{
#if 0
	struct ring_buffer rb;
	ring_init(&rb);
#else
	struct ring_buffer rb = { .head = 0, .tail = 0 };
#endif

	for ( int i = 0; i != 30; ++i ) {
		if ( !ring_put(&rb, i) )
			break;
	}

	int j;
	while ( ring_get(&rb, &j) ) {
		printf("%d\n", j);
	}

	return EXIT_SUCCESS;
}