boost-asio

This question already has an answer here : How to use boost bind with a member function (1 answer) Closed 4 years ago . In this example of using a boost asynchronous timer inside a class, the author added "this" pointer to the bind function inside m_timer.async_wait method. That's strange because the handler is a public method (message(void)) that takes no argument, so why the hell using boost::bind and especially the pointer "this" ? class handler { public: handler(boost::asio::io_service& io) : m_timer(io, boost::posix_time::seconds(1)), m_count(0) { m_timer.async_wait(boost::bind(&handler:

I can't figure out why I get this error : /usr/local/include/boost/asio/impl/read.hpp: In member function ‘void boost::asio::detail::read_op<AsyncReadStream, boost::asio::mutable_buffers_1, CompletionCondition, ReadHandler>::operator()(const boost::system::error_code&, size_t, int) [with AsyncReadStream = boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> >, CompletionCondition = boost::asio::detail::transfer_at_least_t, ReadHandler = boost::function<void ()(long unsigned int)>]’: /usr/local/include/boost/asio/impl/read.hpp:263:

I would like to know what is lifetime of objects passed to mentioned methods. async_resolve ip::basic_resolver::async_resolve(const query & q, ResolveHandler handler); (1) Do I need to keep resolver alive until handler is called? (yes) (2) Does async_resolve copy query object? (I am passing one created on the stack - yes) { boost::asio::ip::tcp::resolver::query query(host_, port_); resolver_.async_resolve(query, ); } (3) Is boost::asio::ip::tcp::resolver::iterator returned in handler by value? (yes) async_connect template<..> void async_connect(basic_socket<Protocol, SocketService> & s,

I have a boost::process::child. There are many examples on how to get all its stdout or stderr in a single vector, but in this method you capture all data at once. But how to retrieve lines/characters as soon as they are printed in child process? The docs are here: Synchronous IO Asynchronous IO Using ipstream The simplest way: Live On Coliru #include <boost/process.hpp> #include <iostream> namespace bp = boost::process; int main() { std::vector<std::string> args { "-c", R"--(for a in one two three four; do sleep "$(($RANDOM%2)).$(($RANDOM%10))"; echo "line $a"; done)--" }; bp::ipstream output

What is the performance difference between strand::post() and strand::wrap() ? And what's the story about race condition when use strand::wrap( )? Just for clarification, strand::wrap only creates a handler, neither the provided handler nor returned handler are dispatched or posted to the io_service . If the result from strand::wrap is executed, then performance differences from overhead is negligible. However, a perceived performance difference could occur as the result of the wrapped handler using dispatch() , where under certain conditions the user's handler will be executed immediately,