I’m having a bit of a problem understanding the compile errors I’m getting when trying to create a boost::asio::deadline_timer. I get the errors below with the following code example on MSVC10. It was built with Boost 1.48
The first error looks like it is complaining about a member function set as a handler to async_wait being a reference. However, when I change the argument it gives a similar error.
I’ve been looking at Boost::Bind and Boost::Asio to try and figure out what I’m doing wrong. My code is similar to this example with the way I use bind and deadline_timer.
Sorry about how messy the compile errors look. I’m still trying to get a handle on Markdown.
Code Example
include
#include <boost/thread.hpp>
#include <boost/bind.hpp>
#include <boost/asio.hpp>
#include <boost/system/error_code.hpp>
#include <boost/date_time/posix_time/posix_time.hpp>
class TimerThing
{
protected:
boost::asio::deadline_timer* statusTimer_;
boost::thread_group worker_threads_;
boost::asio::io_service io_service_;
boost::shared_ptr<boost::asio::io_service::work> work_;
public:
TimerThing() {}
virtual ~TimerThing(){}
void updateStatus(boost::system::error_code& ec)
{
if (ec == boost::asio::error::operation_aborted)
return;
std::cout<<"Status Update"<<std::endl;
statusTimer_->expires_at(statusTimer_->expires_at() + boost::posix_time::seconds(1));
statusTimer_->async_wait(boost::bind(&TimerThing::updateStatus, this, , boost::asio::placeholders::error));
}
void start()
{
statusTimer_=new boost::asio::deadline_timer(io_service_);
boost::shared_ptr<boost::asio::io_service::work> myWork(new boost::asio::io_service::work(io_service_));
work_=myWork;
worker_threads_.create_thread( boost::bind( &TimerThing::threadAction, this ) );
statusTimer_->expires_at(statusTimer_->expires_at() + boost::posix_time::seconds(1));
statusTimer_->async_wait(boost::bind(&TimerThing::updateStatus, this, boost::asio::placeholders::error));
}
void threadAction()
{
io_service_.run();
}
void stop()
{
work_.reset();
io_service_.stop();
worker_threads_.join_all();
delete statusTimer_;
}
};
#include "TimerThing.h"
int main(int argc, const char* argv[] )
{
TimerThing t;
std::string input;
std::cout<<"Press f to stop"<<std::endl;
t.start();
std::cin>>input;
t.stop();
return 0;
}
Compiler errors
c:\Underware\version\include\boost/bind/bind.hpp(313): error C2664: ‘R boost::_mfi::mf1::operator ()(const U &,A1) const’ : cannot convert parameter 2 from ‘const boost::system::error_code’ to ‘boost::system::error_code &’
with [ R=void, T=TimerThing, A1=boost::system::error_code &, U=TimerThing * ] Conversion loses qualifiers c:\Underware\version\include\boost/bind/bind_template.hpp(47) : see reference to function template instantiation 'void boost::_bi::list2<A1,A2>::operator ()<F,boost::_bi::list1<const boost::system::error_code &>>(boost::_bi::type<T>,F &,A &,int)' being compiled with [ A1=boost::_bi::value<TimerThing *>, A2=boost::arg<1>, F=boost::_mfi::mf1<void,TimerThing,boost::system::error_code &>, T=void, A=boost::_bi::list1<const boost::system::error_code &> ] c:\Underware\version\include\boost/asio/detail/bind_handler.hpp(46) : see reference to function template instantiation 'void boost::_bi::bind_t<R,F,L>::operator ()<const Arg1>(const A1 &)' being compiled with [ R=void, F=boost::_mfi::mf1<void,TimerThing,boost::system::error_code &>, L=boost::_bi::list2<boost::_bi::value<TimerThing *>,boost::arg<1>>, Arg1=const boost::system::error_code, A1=const boost::system::error_code ] c:\Underware\version\include\boost/asio/detail/bind_handler.hpp(45) : while compiling class template member function 'void boost::asio::detail::binder1<Handler,Arg1>::operator ()(void)' with [ Handler=boost::_bi::bind_t<void,boost::_mfi::mf1<void,TimerThing,boost::system::error_code &>,boost::_bi::list2<boost::_bi::value<TimerThing *>,boost::arg<1>>>, Arg1=boost::system::error_code ] c:\Underware\version\include\boost/asio/detail/wait_handler.hpp(59) : see reference to class template instantiation 'boost::asio::detail::binder1<Handler,Arg1>' being compiled with [ Handler=boost::_bi::bind_t<void,boost::_mfi::mf1<void,TimerThing,boost::system::error_code &>,boost::_bi::list2<boost::_bi::value<TimerThing *>,boost::arg<1>>>, Arg1=boost::system::error_code ] c:\Underware\version\include\boost/asio/detail/wait_handler.hpp(45) : while compiling class template member function 'void boost::asio::detail::wait_handler<Handler>::do_complete(boost::asio::detail::io_service_impl *,boost::asio::detail::operation *,const boost::system::error_code &,size_t)' with [ Handler=boost::_bi::bind_t<void,boost::_mfi::mf1<void,TimerThing,boost::system::error_code &>,boost::_bi::list2<boost::_bi::value<TimerThing *>,boost::arg<1>>> ] c:\Underware\version\include\boost/asio/detail/deadline_timer_service.hpp(185) : see reference to class template instantiation 'boost::asio::detail::wait_handler<Handler>' being compiled with [ Handler=boost::_bi::bind_t<void,boost::_mfi::mf1<void,TimerThing,boost::system::error_code &>,boost::_bi::list2<boost::_bi::value<TimerThing *>,boost::arg<1>>> ] c:\Underware\version\include\boost/asio/deadline_timer_service.hpp(137) : see reference to function template instantiation 'void boost::asio::detail::deadline_timer_service<Time_Traits>::async_wait<WaitHandler>(boost::asio::detail::deadline_timer_service<Time_Traits>::implementation_type &,Handler)' being compiled with [ Time_Traits=boost::asio::time_traits<boost::posix_time::ptime>, WaitHandler=boost::_bi::bind_t<void,boost::_mfi::mf1<void,TimerThing,boost::system::error_code &>,boost::_bi::list2<boost::_bi::value<TimerThing *>,boost::arg<1>>>, Handler=boost::_bi::bind_t<void,boost::_mfi::mf1<void,TimerThing,boost::system::error_code &>,boost::_bi::list2<boost::_bi::value<TimerThing *>,boost::arg<1>>> ] c:\Underware\version\include\boost/asio/basic_deadline_timer.hpp(502) : see reference to function template instantiation 'void boost::asio::deadline_timer_service<TimeType,TimeTraits>::async_wait<WaitHandler>(boost::asio::detail::deadline_timer_service<Time_Traits>::implementation_type &,const WaitHandler &)' being compiled with [ TimeType=boost::posix_time::ptime, TimeTraits=boost::asio::time_traits<boost::posix_time::ptime>, WaitHandler=boost::_bi::bind_t<void,boost::_mfi::mf1<void,TimerThing,boost::system::error_code &>,boost::_bi::list2<boost::_bi::value<TimerThing *>,boost::arg<1>>>, Time_Traits=boost::asio::time_traits<boost::posix_time::ptime> ]
c:\users\tharper\documents\visual studio 2010\projects\asiotimer\asiotimer\TimerThing.h(48) : see reference to function template instantiation ‘void boost::asio::basic_deadline_timer::async_wait>(const WaitHandler &)’ being compiled
with [ Time=boost::posix_time::ptime, R=void, F=boost::_mfi::mf1<void,TimerThing,boost::system::error_code &>, L=boost::_bi::list2<boost::_bi::value<TimerThing *>,boost::arg<1>>,WaitHandler=boost::_bi::bind_t,boost::_bi::list2,boost::arg<1>>>
]
TimerThing.cpp
c:\Underware\version\include\boost/bind/bind.hpp(313): error C2664: ‘R boost::_mfi::mf1::operator ()(const U &,A1) const’ : cannot convert parameter 2 from ‘const boost::system::error_code’ to ‘boost::system::error_code &’
with [ R=void, T=TimerThing, A1=boost::system::error_code &, U=TimerThing * ] Conversion loses qualifiers
c:\Underware\version\include\boost/bind/bind_template.hpp(47) : see reference to function template instantiation ‘void boost::_bi::list2::operator ()>(boost::_bi::type,F &,A &,int)’ being compiled
with [ A1=boost::_bi::value<TimerThing *>, A2=boost::arg<1>, F=boost::_mfi::mf1<void,TimerThing,boost::system::error_code &>, T=void, A=boost::_bi::list1<const boost::system::error_code &> ] c:\Underware\version\include\boost/asio/detail/bind_handler.hpp(46) : see reference to function template instantiation 'void boost::_bi::bind_t<R,F,L>::operator ()<const Arg1>(const A1 &)' being compiled with [ R=void, F=boost::_mfi::mf1<void,TimerThing,boost::system::error_code &>, L=boost::_bi::list2<boost::_bi::value<TimerThing *>,boost::arg<>>, Arg1=const boost::system::error_code, A1=const boost::system::error_code ] c:\Underware\version\include\boost/asio/detail/bind_handler.hpp(45) : while compiling class template member function 'void boost::asio::detail::binder1<Handler,Arg1>::operator ()(void)' with [ Handler=boost::_bi::bind_t<void,boost::_mfi::mf1<void,TimerThing,boost::system::error_code &>,boost::_bi::list2<boost::_bi::value<TimerThing *>,boost::arg<1>>>, Arg1=boost::system::error_code ] c:\Underware\version\include\boost/asio/detail/wait_handler.hpp(59) : see reference to class template instantiation 'boost::asio::detail::binder1<Handler,Arg1>' being compiled with [ Handler=boost::_bi::bind_t<void,boost::_mfi::mf1<void,TimerThing,boost::system::error_code &>,boost::_bi::list2<boost::_bi::value<TimerThing *>,boost::arg<1>>>, Arg1=boost::system::error_code ] c:\Underware\version\include\boost/asio/detail/wait_handler.hpp(45) : while compiling class template member function 'void boost::asio::detail::wait_handler<Handler>::do_complete(boost::asio::detail::io_service_impl *,boost::asio::detail::operation *,const boost::system::error_code &,size_t)' with [ Handler=boost::_bi::bind_t<void,boost::_mfi::mf1<void,TimerThing,boost::system::error_code &>,boost::_bi::list2<boost::_bi::value<TimerThing *>,boost::arg<1>>> ] c:\Underware\version\include\boost/asio/detail/deadline_timer_service.hpp(185) : see reference to class template instantiation 'boost::asio::detail::wait_handler<Handler>' being compiled with [ Handler=boost::_bi::bind_t<void,boost::_mfi::mf1<void,TimerThing,boost::system::error_code &>,boost::_bi::list2<boost::_bi::value<TimerThing *>,boost::arg<1>>> ] c:\Underware\version\include\boost/asio/deadline_timer_service.hpp(137) : see reference to function template instantiation 'void boost::asio::detail::deadline_timer_service<Time_Traits>::async_wait<WaitHandler>(boost::asio::detail::deadline_timer_service<Time_Traits>::implementation_type &,Handler)' being compiled with [ Time_Traits=boost::asio::time_traits<boost::posix_time::ptime>, WaitHandler=boost::_bi::bind_t<void,boost::_mfi::mf1<void,TimerThing,boost::system::error_code &>,boost::_bi::list2<boost::_bi::value<TimerThing *>,boost::arg<1>>>, Handler=boost::_bi::bind_t<void,boost::_mfi::mf1<void,TimerThing,boost::system::error_code &>,boost::_bi::list2<boost::_bi::value<TimerThing *>,boost::arg<1>>> ] c:\Underware\version\include\boost/asio/basic_deadline_timer.hpp(502) : see reference to function template instantiation 'void boost::asio::deadline_timer_service<TimeType,TimeTraits>::async_wait<WaitHandler>(boost::asio::detail::deadline_timer_service<Time_Traits>::implementation_type &,const WaitHandler &)' being compiled with [ TimeType=boost::posix_time::ptime, TimeTraits=boost::asio::time_traits<boost::posix_time::ptime>, WaitHandler=boost::_bi::bind_t<void,boost::_mfi::mf1<void,TimerThing,boost::system::error_code &>,boost::_bi::list2<boost::_bi::value<TimerThing *>,boost::arg<1>>>, Time_Traits=boost::asio::time_traits<boost::posix_time::ptime> ] c:\users\tharper\documents\visual studio 2010\projects\asiotimer\asiotimer\TimerThing.h(48) : see reference to function template instantiation 'void boost::asio::basic_deadline_timer<Time>::async_wait<boost::_bi::bind_t<R,F,L>>(const WaitHandler &)' being compiled with [ Time=boost::posix_time::ptime, R=void, F=boost::_mfi::mf1<void,TimerThing,boost::system::error_code &>, L=boost::_bi::list2<boost::_bi::value<TimerThing *>,boost::arg<1>>, WaitHandler=boost::_bi::bind_t<void,boost::_mfi::mf1<void,TimerThing,boost::system::error_code &>,boost::_bi::list2<boost::_bi::value<TimerThing *>,boost::arg<1>>> ]
void updateStatus(boost::system::error_code& ec)should bevoid updateStatus(const boost::system::error_code& ec).And you have extra comma in
boost::bind(&TimerThing::updateStatus, this, , boost::asio::placeholders::error));