Christopher Kohlhoff e618857ff3 Add associator trait. ...

The associator trait is used to generically forward associators, such as
associated_executor<> and associated_allocator<>, through intermediate
completion handlers. For example:

    template <typename Handler>
    struct intermediate_handler
    {
      Handler handler_;

      template <typename... Args>
      void operator()(Args&... args)
      {
        // ...
      }
    };

    namespace boost {
    namespace asio {

      template <
          template <typename, typename> class Associator,
          typename Handler,
          typename DefaultCandidate>
      struct associator<
          Associator,
          intermediate_handler<Handler>,
          DefaultCandidate>
      {
        using type =
          typename Associator<Handler, DefaultCandidate>::type;

        static type get(
            const intermediate_handler<Handler>& h,
            const DefaultCandidate& c = DefaultCandidate()) noexcept
        {
          return Associator<Handler, DefaultCandidate>::get(
              h.handler_, c);
        }
      };

    } // namespace asio
    } // namespace boost

2021-06-05 17:43:30 +10:00

..

boost

Add associator trait.

2021-06-05 17:43:30 +10:00