make with boost 1.66.0 results in errors

chenso commented 6 years ago

cppwamp/examples/timeclient/../../cppwamp/include/cppwamp/internal/corosession.ipp:273:40: error: no matching constructor for initialization of 'boost::asio::async_result' (aka 'async_result<coro_handler<boost::asio::executor_binder<void (*)(), boost::asio::executor>, wamp::AsyncResult > >') in 4 different locations.

ecorm commented 6 years ago

There were major changes in Boost.Asio in version 1.66.0.

From the release notes:

Implemented interface changes to reflect the Networking TS (N4656).

Sorry, but I don't know when I'll have time to investigate. It's possible that I might have to overhaul CppWAMP to be more in tune with the way Asio treats async handlers.

I don't like that CppWAMP has two sets of APIs (callback-based and coroutines) and would like to unify them the same way as is done within the Asio library. CppWAMP needs to treat yield as a special type of async handler.

katreniak commented 3 years ago

I don't like that CppWAMP has two sets of APIs (callback-based and coroutines) ...

As a workaround, we managed to use wrap the existing callback based api to work with c++20 coroutines and asio::awaitable with this wrapper:

template <class T, typename F, class CompletitionToken>
auto wampAsyncInvoke(F &&f, CompletitionToken &&token) {
  return asio::async_initiate<CompletitionToken, void(std::exception_ptr, T)>(
      [f = AIZO_FWD(f)](auto &&handler_) {
        // convert move only handler to copyable handler
        auto sharedHandler = std::make_shared<std::decay_t<decltype(handler_)>>(std::move(handler_));
        try {
          f([sharedHandler](wamp::AsyncResult<T> result) mutable {
            if (result.errorCode()) {
              (*sharedHandler)(std::make_exception_ptr(std::system_error(result.errorCode(), result.errorInfo())), T{});
            } else {
              (*sharedHandler)({}, std::move(result.get()));
            }
          });
        } catch (const std::exception &e) {
          (*sharedHandler)(std::current_exception(), T{});
        }
      },
      token);
}

Example usage:

  co_await wampAsyncInvoke<size_t>(
      [&](auto &&handler) { m_session->connect(std::forward<decltype(handler)>(handler)); },
      asio::use_awaitable);

ecorm commented 3 years ago

Thank you for your contribution, @katreniak ! I haven't yet had the chance to wrap my head around c++20 coroutines. I'm glad to see there's still interest in this library, so I'm going to try to put the effort into resolving this issue in the next few months.

I'm working on a revamped "cppwamp2" which will come with it's own serialization sub-library that supports JSON & CBOR and will be much more efficient when converting to C++ types (it will bypass the wamp::variant "DOM type" entirely). Seeing contributions like this from the community will help me to convince my employer to make cppwamp2 open-source. The benefits like bug fixes has to ~~outweigh~~ balance the cost in supporting users for me to make the case.

katreniak commented 3 years ago

For me, our workaround works fine. I just wanted to share back, it may be useful for others. Although I did not see a simple way how to integrate this into cppwamp code. So I just posted it here.

When it comes to json DOM and cppwamp2 ... did you consider to use boost::json? It is designed as a vocabulary json type.

ecorm commented 3 years ago

When it comes to json DOM and cppwamp2 ... did you consider to use boost::json? It is designed as a vocabulary json type.

I looked at it briefly, but I prefer the API of what I'm currently working on. When I have the chance, I'll look at it more closely to borrow some ideas concerning custom memory allocation.