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//
// deferred_3.cpp
// ~~~~~~~~~~~~~~
//
// Copyright (c) 2003-2023 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 <boost/asio.hpp>
#include <iostream>
using boost::asio::deferred;
template <typename CompletionToken>
auto async_wait_twice(boost::asio::steady_timer& timer, CompletionToken&& token)
{
return timer.async_wait(
deferred(
[&](boost::system::error_code ec)
{
std::cout << "first timer wait finished: " << ec.message() << "\n";
timer.expires_after(std::chrono::seconds(1));
return timer.async_wait(deferred);
}
)
)(
std::forward<CompletionToken>(token)
);
}
int main()
{
boost::asio::io_context ctx;
boost::asio::steady_timer timer(ctx);
timer.expires_after(std::chrono::seconds(1));
async_wait_twice(
timer,
[](boost::system::error_code ec)
{
std::cout << "second timer wait finished: " << ec.message() << "\n";
}
);
ctx.run();
return 0;
}
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