static <A> A assertEqualsVerbose_struct(O x, A y) {
  assertEqualsVerbose_struct((S) null, x, y);
  ret y;
}

static <A> A assertEqualsVerbose_struct(S msg, O x, A y) {
  if (!eq(x, y)) {
    fail((msg != null ? msg + ": " : "") + "expected " + sfu(y) + ", got " + sfu(x));
  } else
    print("OK: " + sfu(x));
  ret y;
}


ifclass Scorer
static void assertEqualsVerbose_struct(Scorer scorer, O x, O y) {
  if (!eq(x, y)) {
    print(sfu(y) + " != " + sfu(x));
    scorer.add(false);
  } else {
    print("OK: " + sfu(x));
    scorer.add(true);
  }
}
endif

Began life as a copy of #1002936