Method execute

include/exec/asio/completion_token.hpp:520–523

      template <typename T>
      void execute(T&& t) const noexcept
      {
        self_.run_([&]() { ex_.execute(wrap_(static_cast<T&&>(t))); });
      }

      constexpr void on_work_started() const noexcept
        requires requires { std::declval<Executor const &>().on_work_started(); }