cobalt/detail/leaf.hpp

0001 // Copyright (c) 2023 Klemens D. Morgenstern
0002 //
0003 // Distributed under the Boost Software License, Version 1.0. (See accompanying
0004 // file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0005 #ifndef BOOST_COBALT_DETAIL_LEAF_HPP
0006 #define BOOST_COBALT_DETAIL_LEAF_HPP
0007
0008 #include <boost/cobalt/detail/await_result_helper.hpp>
0009 #include <boost/leaf/config.hpp>
0010 #include <boost/leaf/capture.hpp>
0011 #include <boost/leaf/handle_errors.hpp>
0012
0013 namespace boost::cobalt::detail
0014 {
0015
0016 template<typename Awaitable, typename ... H>
0017 struct [[nodiscard]] try_catch_awaitable
0018 {
0019   Awaitable aw;
0020   std::tuple<H...> handler;
0021
0022   bool await_ready() {return aw.await_ready(); }
0023   template<typename Promise>
0024   auto await_suspend(std::coroutine_handle<Promise> h) {return aw.await_suspend(h);}
0025
0026   auto await_resume()
0027   {
0028     return std::apply(
0029         [this](auto && ... h)
0030         {
0031           return leaf::try_catch(
0032               [this]{return std::move(aw).await_resume();},
0033               std::move(h)...);
0034         }, std::move(handler));
0035   }
0036 };
0037
0038 template<typename Awaitable, typename ... H>
0039 struct [[nodiscard]] try_handle_all_awaitable
0040 {
0041   Awaitable aw;
0042   std::tuple<H...> handler;
0043
0044   bool await_ready() {return aw.await_ready(); }
0045   template<typename Promise>
0046   auto await_suspend(std::coroutine_handle<Promise> h) {return aw.await_suspend(h);}
0047
0048   auto await_resume()
0049   {
0050     return std::apply(
0051         [this](auto && ... h)
0052         {
0053           return leaf::try_handle_all(
0054               [this]{return std::move(aw).await_resume();},
0055               std::move(h)...);
0056         }, std::move(handler));
0057   }
0058 };
0059
0060
0061
0062 template<typename Awaitable, typename ... H>
0063 struct [[nodiscard]] try_handle_some_awaitable
0064 {
0065   Awaitable aw;
0066   std::tuple<H...> handler;
0067
0068   bool await_ready() {return aw.await_ready(); }
0069   template<typename Promise>
0070   auto await_suspend(std::coroutine_handle<Promise> h) {return aw.await_suspend(h);}
0071
0072   auto await_resume()
0073   {
0074     return std::apply(
0075         [this](auto && ... h)
0076         {
0077           return leaf::try_handle_some(
0078               [this]{return std::move(aw).await_resume();},
0079               std::move(h)...);
0080         }, std::move(handler));
0081   }
0082 };
0083
0084 }
0085
0086 #endif //BOOST_COBALT_DETAIL_LEAF_HPP