Pourquoi NELEMS( rules ) == 0 alors que NELEMS( HTML_ENTITIES) == 2 ?

struct_substitution_test.c

/*
 * main.c
 * 
 * Copyright 2012 Samir Chaouki <moebius.eye@gmail.com>
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
 * MA 02110-1301, USA.
 */


#include <stdio.h>

struct substitution {
  	char *to;
		char *from;
};

static struct substitution HTML_ENTITIES[] = {
		{ "&AElig;", "Æ" },
		{ "&Aacute;", "Á" },
		/* J'épargne le reste */
};

#define NELEMS(x)  (sizeof(x) / sizeof(x[0]))

void somefunction ( struct substitution *rules ) {
	printf("%d", NELEMS( rules ) );
}

int main(int argc, char **argv)
{
	somefunction( HTML_ENTITIES );
	return 0;
}