static O time(O f) {
  long time = sysNow();
  O o = callF(f);
  done2_always(str(f), time);
  ret o;
}

static <A> A time(F0<A> f) {
  ret (A) time((O) f);
}

static <A> A time(IF0<A> f) {
  ret (A) time((O) f);
}

static <A> A time(S msg, IF0<A> f) {
  long time = sysNow();
  A o = f.get();
  done2_always(msg, time);
  ret o;
}

svoid time(S msg default str(f), Runnable f) {
  time(msg, runnableToIF0(f));
}