assert_default_params.c

void assert_func(int cond, const char *msg) {
    if (!cond) {
        fprintf(stderr, "assert failed: %s\n", msg);
        abort();
    }
}

#define assert_helper(x, y, ...) assert_func(x, y)
#define assert(x, ...) assert_helper((x), ## __VA_ARGS__, #x)

int main(int argc, char **argv) {
    assert(argc > 0);
    assert(argv[0] != 0, "argv[0] cannot be null");
}