Method for_each

src/mpsc_linked_queue.hpp:140–161

  // the `std::for_each()`.
  template <typename F>
  void for_each(F&& f)
  {
    auto end = head.load();
    auto node = tail;

    for (;;) {
      node = node->next.load();

      // We are following the linked structure until we reach the end
      // node. There is a race with new nodes being added, so we limit
      // the traversal to the last node at the time we started.
      if (node == nullptr) {
        return;
      }

      f(node->element);

      if (node == end) {
        return;
      }
    }
  }

  // Single consumer only.
  bool empty()