April 2009 - Boost-users - lists.preview.boost.org

Re: [Boost-users] [serialization] Export question
by Tom Aylesworth 08 Apr '09

08 Apr '09

I think I just answered my own question regarding whether I can use the EXPORT macro in the header that declares the class being exported. Since the EXPORT macro instantiates a static guid_initializer for the class, including it in multiple source files creates multiple static objects and results in link errors. So at this point, I wonder, why bother with the EXPORT macro at all? Given that the class has to be registered with the archive, why not just use register_type when the archive is created? When I thought the EXPORT macro allowed me to register the class in the same header where the class is created, it seemed very useful. Now I guess I don't see any advantage of using EXPORT. Am I missing something? Thomas Aylesworth Senior Software Engineer Reality Mobile

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[mpl] newbie question about if_c et al
by Jonathan Leonard 08 Apr '09

08 Apr '09

Hi, I'm trying to make a class which is conditionally synchronized. What I have is like the following: template<bool SYNCH=true> class c { public: void f() { typename boost::mpl::if_c<SYNCH, ScopedCriticalSection<>, void*>::type scs(cs); // SCS == RAII wrapper around CS // do other stuff } private: typename boost::mpl::if_c<SYNCH, CriticalSection<>, void*>::type cs; }; This is not entirely optimal though as it requires 3 MOV instructions to create the scs void* copy when SYNCH is false (and I'd rather not lean on compiler optimizations even if they will help in this case). [Something like NullType, VoidType, or OptionType (a la F#) would be ideal but I can't seem to locate one (and I'm not sure the type system would allow such a thing-it doesn't seem to like a simple 'void']. Any better idiom or alternative approach anyone can offer for this purpose would be greatly appreciated. Many thanks, Jonathan

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Re: [Boost-users] Linking with dynamic boost thread library
by Steven Watanabe 08 Apr '09

08 Apr '09

AMDG Green, Jason M NSWCDL, W33 wrote: > I'm having a similar problem with my project. I'd like to use the dlls but > no matter what, the compile warns me that it "cannot open file > 'boost_regex-vc80-mt-gd-1_38.lib'" > You /are/ linking to the dll then. > I'm trying to find where I can set the project (in vis studio 2005) to use > the dynamic link libraries as opposed to the static. Based on previous > entries in this thread, I assume that is the first step that I need to take. > Have you added the location of the libraries to the library paths? (Tools->Options->Projects and Solutions->VC++ Directories, I think) > Can someone tell me where to set this? > In Christ, Steven Watanabe

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Re: [Boost-users] Linking with dynamic boost thread library
by Ovanes Markarian 08 Apr '09

08 Apr '09

Project Properties -> C/C++ -> Code Generation: Runtime Library: Multi-Threaded Debug DLL (/MDd) or Multi-Threaded DLL (/MD) for release version Good Luck, Ovanes On Wed, Apr 8, 2009 at 6:40 PM, Green, Jason M NSWCDL, W33 < jason.m.green3(a)navy.mil> wrote: > I’m having a similar problem with my project. I’d like to use the dlls > but no matter what, the compile warns me that it “cannot open file > ‘boost_regex-vc80-mt-gd-1_38.lib’” > > > > I’m trying to find where I can set the project (in vis studio 2005) to use > the dynamic link libraries as opposed to the static. Based on previous > entries in this thread, I assume that is the first step that I need to take. > > > > Can someone tell me where to set this? > > Jason > > > > *From:* boost-users-bounces(a)lists.boost.org [mailto: > boost-users-bounces(a)lists.boost.org] *On Behalf Of *Ovanes Markarian > *Sent:* Wednesday, April 08, 2009 11:01 AM > *To:* boost-users(a)lists.boost.org > *Subject:* Re: [Boost-users] Linking with dynamic boost thread library > > > > What I mean is the reversed order. You can not link the static runtime and > dynamic boost_thread or any other lib. > > On Wed, Apr 8, 2009 at 4:50 PM, Steven Watanabe <watanabesj(a)gmail.com> > wrote: > > AMDG > > > > Igor MI wrote: > > But now I wonder about what Ovanes said. Why did I linked successfully with > static thread library when my project is set to multi threaded debug dll? > > > > > You can link using the dll runtime and the static boost_thread. > > > > In Christ, > Steven Watanabe > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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[ASIO] Synchronous write on serial_port
by Daniele Barzotti 08 Apr '09

08 Apr '09

Hi, I'm developing a library that use ASIO Serial Port and I need to implement a synchronous write. The structure is: EuroATLib.cpp : library main file Serial.cpp : serial port class that wrap asio::serial_port ATDispatcher.cpp : a dispatcher object ATModem.cpp : the consumer object The problem is that my code writes characters on serial port very slowly (1 char every 10 seconds) and I can't understand why. Also, when the program ends, the io_service thread seems to be already alive: it continues to write to serial port for a while! The implementation is like this...can someone give me some feedback? PS: In the following code TBUFFER is std:string. In EuroATLib.cpp : ---------------------------------------------------------- // Main io_service static boost::asio::io_service io_service; static boost::scoped_ptr<boost::thread> io_service_thread; /*! \brief Factory function for ATModem objects creation */ EXTERN_C EUROATLIB_API ATModem* CALL CreateATModemObj() { static bool thread_started; if (!thread_started) { try { // run the IO service as a separate thread io_service_thread.reset(new boost::thread( boost::bind(&boost::asio::io_service::run, &io_service) )); thread_started = !thread_started; } catch (boost::thread_resource_error e) { // Failed to create the new thread return 0; } } // create the new object return new ATModem(io_service); }; ---------------------------------------------------------- In Serial.hpp : ---------------------------------------------------------- // the main IO service that runs this connection boost::asio::io_service& _io_service; // the serial port this instance is connected to boost::asio::serial_port _serialPort; ---------------------------------------------------------- In Serial.cpp : ---------------------------------------------------------- SerialPort::SerialPort(boost::asio::io_service &_io) : m_buffer_size(100), _io_service(_io), _serialPort(_io_service), _rx_timer(_io_service), ReadTimeOut(READ_TIMEOUT) { //init_dcs(); EosString = '\n'; _buf = 0; }; BOOL SerialPort::Write(TBUFFER &buffer) { _io_service.post(boost::bind(&SerialPort::do_write, this, buffer)); return true; }; void SerialPort::do_write(TBUFFER &buffer) { // size_t byte_written = boost::asio::write(_serialPort, boost::asio::buffer(buffer.c_str(), buffer.size())); size_t byte_written = _serialPort.write_some(boost::asio::buffer(buffer.c_str(), buffer.size())); }; ---------------------------------------------------------- In ATDispatcher.cpp simply have a SerialPort member and a function SendCommand that start a timer and call Serial.Write(cmd) In ATModem.cpp I have an ATDispatcher Object on which it calls disp_obj.SendCommand("AT+CMGS"): ---------------------------------------------------------- RET_VAL ATModem::Connect(std::string DevName) { if (DevName.length() > 0) SetComPort(DevName); if (!_serial_port.Open()) return -1; //Connect the OnDataReceived event to the ATDispatcher object _dispatcher->OnData(boost::bind(&EuroATLib::ATModem::OnDataReceived, this)); //Register Voice Service if ( _dispatcher->SendCommand("AT+CTSP=2,0,0") != ATDispatcher::RET_OK ) return DEV_AT_CMD_ERROR; //Register STATUS Service if ( _dispatcher->SendCommand("AT+CTSP=2,2,20") != ATDispatcher::RET_OK ) return DEV_AT_CMD_ERROR; this->SetStatus(STATE_READY); }; ---------------------------------------------------------- Finally in the main client program: // Create a ATModem object boost::scoped_ptr<ATModem> _devATModem( CreateATModemObj() ); _devATModem->Connect("\\\\.\\COM1");

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Linking with dynamic boost thread library
by Igor 08 Apr '09

08 Apr '09

I build the thread library with the following cmd command: bjam.exe toolset=msvc --with-thread --prefix=C:\boost\ variant=debug,release link=shared install after which I get the following libs: boost_thread-vc80-mt.lib boost_thread-vc80-mt-1_38.dll boost_thread-vc80-mt-1_38.lib boost_thread-vc80-mt-gd.lib boost_thread-vc80-mt-gd-1_38.dll boost_thread-vc80-mt-gd-1_38.lib In my application, I placed #define BOOST_THREAD_DYN_LINK in all the cpp files where thread library is included. I get the following error: LINK : fatal error LNK1104: cannot open file 'libboost_thread-vc80-mt-gd-1_38.lib' How many mistakes have I done?

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Re: [Boost-users] difference b/w regex lib files
by John Maddock 08 Apr '09

08 Apr '09

>I have a number of boost libs that I built (not being sure which one I > really needed). I understand the difference b/w them, with the exception > of > two. libboost*.lib are static link libraries, and boost*.lib are import libraries for the dll's. HTH, John.

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Re: [Boost-users] boost build interface
by Vladimir Prus 08 Apr '09

08 Apr '09

Green, Jason M NSWCDL, W33 wrote: > Not that I am volunteering, but it isn't that hard to come up with a simple > dialog based mfc project that would set up the commands to properly run the > boost build. I did not claim that coming up with an MFC project is hard per se. However: 1. It will require *me* quite some time, for I was not doing any real windows development in years. 2. It might be best to use some more lightweight solution, but I don't know what are scripting options on modern Windows. - Volodya

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[date_time] local time & date arithmetics
by Filip Konvička 08 Apr '09

08 Apr '09

Hi all, first, thanks for the date_time library. Although I see some issues with it, I still think it is highly needed and does a lot of good stuff for me. Recently I stumbled upon a problem with date arithmetic that involves local_date_time. The following code fragment local_date_time t( ptime(boost::gregorian::date(2008, 4, 7), time_duration(22, 0, 0)), boost::shared_ptr<posix_time_zone>(new posix_time_zone("CET+1CEST,M4.1.0,M10.1.0"))); cout << t.utc_time() << " UTC = " << t << endl; t -= boost::gregorian::days(6); cout << t.utc_time() << " UTC = " << t << endl; yields the following output 2008-Apr-07 22:00:00 UTC = 2008-Apr-08 00:00:00 CEST 2008-Apr-01 22:00:00 UTC = 2008-Apr-01 23:00:00 CET This indicates that the date operation just subtracted 6*24 hours from the internal representation of the local time. It missed the DST change within the time interval. I would rather expect the operation to do the following: 2008-Apr-07 22:00:00 UTC = 2008-Apr-08 00:00:00 CEST 2008-Apr-01 23:00:00 UTC = 2008-Apr-02 00:00:00 CET If the current behavior is intentional, it is not clear to me why have such operations as "+= days(...)" available in local_date_time at all, as they don't seem to obey the general local time semantics (at least as I understand it) - we could just use an UTC ptime for that, right? Another thing related to this is that many functions in local_date_time are inherited from the base class, which has a different semantics. From the user point of view, this seems to be quite dangerous - one has always to verify whether the function being called is overloaded in local_date_time (and so should have local time semantics) or whether it is defined in ptime and so works with the internal UTC representation. Why is the base class not protected? Thanks for any comments, Filip

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Re: [Boost-users] difference b/w regex lib files
by Steven Watanabe 08 Apr '09

08 Apr '09

AMDG Green, Jason M NSWCDL, W33 wrote: > I have a number of boost libs that I built (not being sure which one I > really needed). I understand the difference b/w them, with the exception of > two. > > > > All of the libs are libboost_regex..lib except 2 which are just > boost_regex...lib > > What is the difference between the 2? > The boost_regex*.lib files are import libraries for boost_regex*.dll In Christ, Steven Watanabe

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