static Map<Class, Constructor> nuObjectWithoutArguments_cache = newDangerousWeakHashMap();

static O nuObjectWithoutArguments(S className) ctex {
  ret nuObjectWithoutArguments(classForName(className));
}

static <A> A nuObjectWithoutArguments(Class<A> c) ctex {
  if (nuObjectWithoutArguments_cache == null)
    // in class init
    ret (A) nuObjectWithoutArguments_findConstructor(c).newInstance();
    
  Constructor m = nuObjectWithoutArguments_cache.get(c);
  if (m == null)
    nuObjectWithoutArguments_cache.put(c, m = nuObjectWithoutArguments_findConstructor(c));
  return (A) m.newInstance();
}

static Constructor nuObjectWithoutArguments_findConstructor(Class c) {
  for (Constructor m : getDeclaredConstructors_cached(c))
    if (empty(m.getParameterTypes())) {
      makeAccessible(m);
      ret m;
    }
  fail("No default constructor found in " + c.getName());
}

Began life as a copy of #1001136