Method execute

example/cpp11/executors/fork_join.cpp:172–176

  template <class Func>
  void execute(Func f) const
  {
    auto p(std::make_shared<function<Func>>(std::move(f), work_count_));
    context_.do_execute(p, work_count_);
  }

  friend bool operator==(const fork_executor& a,
      const fork_executor& b) noexcept