static void test_consume_char(void) {
        const char *string = "a";
        char buf[strlen(string)];
        char *out = buf;
        size_t n_out = sizeof(buf);
        const char *in = string;
        size_t n_in = strlen(string);
        int r;

        r = c_shquote_consume_char(&out, &n_out, &in, &n_in);
        c_assert(!r);
        c_assert(*buf == *string);
        c_assert(out == buf + 1);
        c_assert(n_out == sizeof(buf) - 1);
        c_assert(in == string + 1);
        c_assert(n_in == strlen(string) - 1);
}
static void test_consume_char(void) {
        const char *string = "a";
        char buf[strlen(string)];
        char *out = buf;
        size_t n_out = sizeof(buf);
        const char *in = string;
        size_t n_in = strlen(string);
        int r;

        r = c_shquote_consume_char(&out, &n_out, &in, &n_in);
        c_assert(!r);
        c_assert(*buf == *string);
        c_assert(out == buf + 1);
        c_assert(n_out == sizeof(buf) - 1);
        c_assert(in == string + 1);
        c_assert(n_in == strlen(string) - 1);
}