svoid test_negateRegexp() {
  embedded bool testIt(S regexp, S s) {
    ret !regexpFind(negateRegexp(regexp), s);
  }
  
  testFunctionValues_twoArgs_flat((IF2<S, S, Bool>) (re, s) -> testIt(re, s),
    "bc", "abcd", true,
    "bc", "xyz", false,
  );
}