diff options
Diffstat (limited to '3rdparty/asio/src/examples/cpp14/deferred/deferred_6.cpp')
-rw-r--r-- | 3rdparty/asio/src/examples/cpp14/deferred/deferred_6.cpp | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/3rdparty/asio/src/examples/cpp14/deferred/deferred_6.cpp b/3rdparty/asio/src/examples/cpp14/deferred/deferred_6.cpp new file mode 100644 index 00000000000..502d43bc67c --- /dev/null +++ b/3rdparty/asio/src/examples/cpp14/deferred/deferred_6.cpp @@ -0,0 +1,77 @@ +// +// deferred_6.cpp +// ~~~~~~~~~~~~~~ +// +// Copyright (c) 2003-2021 Christopher M. Kohlhoff (chris at kohlhoff dot com) +// +// Distributed under the Boost Software License, Version 1.0. (See accompanying +// file LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt) +// + +#include <asio.hpp> +#include <asio/experimental/append.hpp> +#include <asio/experimental/deferred.hpp> +#include <iostream> + +using asio::experimental::append; +using asio::experimental::deferred; + +template <typename CompletionToken> +auto async_wait_twice(asio::steady_timer& timer, CompletionToken&& token) +{ + return deferred.values(&timer)( + deferred( + [](asio::steady_timer* timer) + { + timer->expires_after(std::chrono::seconds(1)); + return timer->async_wait(append(deferred, timer)); + } + ) + )( + deferred( + [](std::error_code ec, asio::steady_timer* timer) + { + std::cout << "first timer wait finished: " << ec.message() << "\n"; + timer->expires_after(std::chrono::seconds(1)); + return deferred.when(!ec) + .then(timer->async_wait(deferred)) + .otherwise(deferred.values(ec)); + } + ) + )( + deferred( + [](std::error_code ec) + { + std::cout << "second timer wait finished: " << ec.message() << "\n"; + return deferred.when(!ec) + .then(deferred.values(42)) + .otherwise(deferred.values(0)); + } + ) + )( + std::forward<CompletionToken>(token) + ); +} + +int main() +{ + asio::io_context ctx; + + asio::steady_timer timer(ctx); + timer.expires_after(std::chrono::seconds(1)); + + async_wait_twice( + timer, + [](int result) + { + std::cout << "result is " << result << "\n"; + } + ); + + // Uncomment the following line to trigger an error in async_wait_twice. + //timer.cancel(); + + ctx.run(); + + return 0; +} |