Function foreachvalue

src/slave/containerizer/fetcher.cpp:481–486

  vector<Future<shared_ptr<Cache::Entry>>> futures;

  foreachvalue (const Option<Future<shared_ptr<Cache::Entry>>>& entry,
                entries) {
    if (entry.isSome()) {
      futures.push_back(entry.get());
    }
  }

  return await(futures)
    .then(defer(self(), [=]() {