Test struct existance against sizeof() operator Instead of declaring an "unused-variable" or "unused-but-set-variable" structure. This avoid unexpected broken configurations when using something like: $ ./configure CFLAGS="-Wall -Wextra -Werror" It causes AC_COMPILE_IFELSE to fail and thus leading to a mismatch configuration (because the CFLAGS are passed to the macro).

/* small demo app that just includes a cipher/hash/prng */
#include <tomcrypt.h>

int main(void)
{
   register_cipher(&rijndael_enc_desc);
   register_prng(&yarrow_desc);
   register_hash(&sha256_desc);
   return 0;
}

/* $Source: /cvs/libtom/libtomcrypt/demos/small.c,v $ */
/* $Revision: 1.3 $ */
/* $Date: 2006/06/07 22:25:09 $ */