static T3 tripleMap(O f, T3 t) {
  ret t == null ? null : triple(callF(f, t.a), callF(f, t.b), callF(f, t.c));
}

static <A> T3<A> tripleMap(T3<A> t, IF1<A> f) {
  ret tripleMap(f, t);
}

static <A> T3<A> tripleMap(IF1<A> f, T3<A> t) {
  ret t == null ? null : triple(callF(f, t.a), callF(f, t.b), callF(f, t.c));
}

static T3 tripleMap(T3 t, O f) {
  ret tripleMap(f, t);
}