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[Boost.Serialization] Unnecessary use of <iostream> in boost/serialization/export.hpp
by dariomt＠gmail.com 18 Oct '18

18 Oct '18

Hi, I see #include <iostream> in header boost/serialization/export.hpp, but that header uses nothing from namespace std. To me it looks like that #include is unnecessary, as all my code compiles fine if I remove that #include, but maybe I'm wrong. Was it included by mistake? PS: I'm using Boost 1.64, but I see the same #include in Boost 1.68

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Questions about Boost multiprecision library.
by A Z 11 Oct '18

11 Oct '18

I have some basic startup for use questions pertaining to the Boost multiprecision library. I have downloaded the set of 64 bit .dll files successfully online, and would like some help points to help me get going. *I have heard that there are some strange results that can happen if you are quizzing multiprecision for trigonometry and try to keep using the double type. Is this true, so that I can just kee relying on the std library instead? -What is the name of the 64 bit windows .dll, or .dll files, that are the ones for the multiprecision library? -If I wish to go into arbitrary precision and scale numbers, what is the type I should use for an integer? What is the #include statement I should use, and how do I specify the number of whole number points and decimal points, before starting my operations? -If I wish to go into arbitrary precision and scale numbers, what is the type I should use for a rational number? What is the #include statement I should use, and how do I specify the number of whole number points and decimal points, before starting my operations? -For these two types, I wish to do sine, cosine, tangent, arcsine, arccosine, arctangent, base 10 logarithm, base e logarithm, power, nth root. I also want to obtain pi, but also Euler's constant, to any number of significang figure or decimal places that I would like. -If the files are separate for the function support or not, what are the 64 bit .dll files for this? What #include statements should I use?

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signals2
by tim＠raisedbar.net 04 Oct '18

04 Oct '18

Hi, A friend pointed me at this library, as it may solve a problem for me. Am I correct in thinking that a signal can be activated once all of its slots are filled and not before? Best wishes. Tim Burgess Raised Bar Ltd. E: <mailto:tim@raisedbar.net> tim(a)raisedbar.net M: +44 (0)7989 486976

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Twenty years and time to retire
by Beman Dawes 04 Oct '18

04 Oct '18

The idea behind Boost was hatched in March, 1998, and the proposal document <https://www.boost.org/users/proposal.pdf> was released May 6, 1998. That makes Boost twenty years old, and makes me twenty years older. It is high time I retire from Boost; I haven't been able to contribute for some time now. Thanks to all of you who made Boost such an overwhelming success in the past and will drive Boost forward into a bright future! --Beman

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Making interprocess::message_queue use Windows_shared_memory instead of shared_memory_object
by Gaurav Sehgal 04 Oct '18

04 Oct '18

Hi, I am trying to make boost::interprocess::message_queue to use windows_shared_memory, instead of shared_memory_object. I have made the below changes to boost version 1.65.1 1) In ipc\message_queue.hpp, included windows_shared_memory.hpp instead of shared_memory_object.hpp 2) Changed typedef ipcdetail::managed_open_or_create_impl<shared_memory_object, 0, true, false> open_create_impl_t; to typedef ipcdetail::managed_open_or_create_impl<windows_shared_memory, 0, false, false> open_create_impl_t; 3) Changed the below in mq_hdr_t:: typedef ipcdetail::managed_open_or_create_impl<shared_memory_object, 0, true, false> open_create_impl_t; to typedef ipcdetail::managed_open_or_create_impl<windows_shared_memory, 0, false, false> open_create_impl_t; 4) Changed inline bool message_queue_t<VoidPointer>::remove(const char *name) { return shared_memory_object::remove(name); } to inline bool message_queue_t<VoidPointer>::remove(const char *name) { return true; } 5)Changed the below in detail\managed_open_or_create_impl.hpp template<bool dummy> static void truncate_device(DeviceAbstraction &dev, offset_t size, true_) { dev.truncate(size); } to template<bool dummy> static void truncate_device(DeviceAbstraction &dev, offset_t size, true_) { } After the above changes, no file is getting created and everything seems to work. Is there something else i should care about? Regards, Gaurav.

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undefined reference to `boost::log::v2_mt_posix::...
by Antonis Polykratis 01 Oct '18

01 Oct '18

Hello I face this error and I cannot figure out a fix. I use bjam to build the application code, and inside site-config file, I have also the following a section where I define BOOST_ALL_DYN_LINK: ''' using gcc : : : where I have defined <define> BOOST_ALL_DYN_LINK ''' I have build boost libraries with the following command: sudo bjam toolset=gcc --with-system --with-thread --with-timer --with-chrono --with-filesystem --with-program_options --with-timer *--with-log* --with-program_options --with-date_time --with-math --with-serialization --with-regex --with-chrono --with-atomic runtime-link=shared define=*BOOST_ALL_DYN_LINK* --prefix=/opt/boost_shared install | tee output.txt I also changed some files (macro definitions and jam files) because I had an error that system and filesystem are configured to be compiled both as static and shared. I compiled them as shared. When I build the application code, I have plenty of `boost::log::v2_mt_posix::...` error messages. Could you give me some guide why this problem exist? Thanks, Antonis

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error: ‘class boost::mutex’ has no member named ‘try_lock_for’
by Antonis Polykratis 28 Sep '18

28 Sep '18

Hi, I face this error, in linux, does this indicates that I have not build the library correctly? the error is in that line: boost/thread/lock_types.hpp:162:45 #ifdef BOOST_THREAD_USES_CHRONO template <class Clock, class Duration> unique_lock(Mutex& mtx, const chrono::time_point<Clock, Duration>& t) : m(&mtx), is_locked(mtx.try_lock_until(t)) { } template <class Rep, class Period> unique_lock(Mutex& mtx, const chrono::duration<Rep, Period>& d) : m(&mtx), is_locked(mtx.try_lock_for(d)) <--- here is the error { } #endif Thanks, Antonis

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Boost.Units Example: Convert between nautical mile and imperial foot
by Carel Combrink 27 Sep '18

27 Sep '18

Hi, I am trying to use Boost.Units to convert between different units. I have implemented the example code for the "Radar Beam Height" [1] section but trying to convert between nautical mile and imperial foot result in a compiler error: I have: typedef boost::units::quantity<boost::units::si::length> Meters; typedef boost::units::quantity<imperial::length> Feet; typedef boost::units::quantity<nautical::length> NMiles; double func() { // Working const Meters si1(300.0*nautical::miles); const Meters si2(300.0*imperial::feet); const Feet feet1(300.0*imperial::feet); const Feet feet2(300.0*boost::units::si::meters); const NMiles mile1(300.0*nautical::miles); const NMiles mile2(300.0*boost::units::si::meters); // BROKEN const Feet feet3(300.0*nautical::miles); const NMiles mile3(300.0*imperial::feet); } The first few works, converting between meters and the new units, but converting between the two does not work. To see the issue see the code on Compiler Explorer here: https://gcc.godbolt.org/z/MpvuMy How can I get this working? [1] https://www.boost.org/doc/libs/1_68_0/doc/html/boost_units/Examples.html#bo… Regards,

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Serialization with BOOST _CLASS_EXPORT_KEY() is not the same as registert_type<>()
by Kosby, Ray B. (GSFC-428.0)[COLUMBUS TECHNOLOGIES AND SERVICES INC] 25 Sep '18

25 Sep '18

Hi, I’m trying to serialize a derived object with polymorphism into a file and deserialize to a base class pointer. This works when I use the register_type function but not the BOOST_CLASS_EXPORT_KEY() and BOOST_CLASS_IMPLEMENT() macros. I need to use the macros since I am using shared libraries. Here is a sample of code to demonstrate the problem. When run it gets a unregistered class exception. I’m using RHEL 7.4 with Boost 1.53. cat testera.h #ifndef testera_h #define testera_h #include <boost/serialization/serialization.hpp> #include <boost/archive/polymorphic_oarchive.hpp> #include <boost/archive/polymorphic_iarchive.hpp> #include <boost/serialization/export.hpp> #include <boost/serialization/string.hpp> class A { private: friend class boost::serialization::access; template< class Arch > void serialize( Arch &ar, const unsigned int ver ); public: A(); virtual ~A() {} void setStr( const std::string &s ); std::string getStr(); protected: std::string myStr; }; BOOST_CLASS_EXPORT_KEY(A) #endif boost_ptr> cat testera.C #include "testera.h" BOOST_CLASS_EXPORT_IMPLEMENT(A) template void A::serialize<boost::archive::polymorphic_oarchive>( boost::archive::polymorphic_oarchive &ar, const unsigned int ver ); template void A::serialize<boost::archive::polymorphic_iarchive>( boost::archive::polymorphic_iarchive &ar, const unsigned int ver ); A::A() : myStr( "a" ) { } void A::setStr( const std::string &s ) { myStr = s; } std::string A::getStr() { return myStr; } template<class Arch> void A::serialize( Arch &ar, const unsigned int ver ) { ar & myStr; } boost_ptr> cat testerb.h #ifndef testerb_h #define testerb_h #include "testera.h" class B : public A { private: friend class boost::serialization::access; template< class Arch > void serialize( Arch &ar, const unsigned int ver ); public: B(); virtual ~B() {} void set( const int i ); int get(); protected: int myI; }; BOOST_CLASS_EXPORT_KEY(B) #endif boost_ptr> cat testerb.C #include "testerb.h" BOOST_CLASS_EXPORT_IMPLEMENT(B) template void B::serialize<boost::archive::polymorphic_oarchive>( boost::archive::polymorphic_oarchive &ar, const unsigned int ver ); template void B::serialize<boost::archive::polymorphic_iarchive>( boost::archive::polymorphic_iarchive &ar, const unsigned int ver ); B::B(): myI( 1 ) { myStr = "b"; } void B::set( const int i ) { myI = i; } int B::get() { return myI; } template< class Arch > void B::serialize( Arch &ar, const unsigned int ver ) { // boost::serialization::void_cast_register< B, A >( static_cast< B *>( NULL ), static_cast< A * >( NULL ) ); ar & boost::serialization::base_object<A>( *this ); ar & myI; } int main( int argc, char *argv[] ) { int ret = 0; B obj; B obj2; obj.set( 2 ); A *ptr = NULL; B *bptr = NULL; bptr = &obj; ptr = &obj; if( argc > 1 ) { std::string fl = argv[ 1 ]; { std::ofstream ofl( fl.c_str() ); boost::archive::polymorphic_text_oarchive toar( ofl ); boost::archive::polymorphic_oarchive *oar = &toar; /* oar->register_type(static_cast<A *>(NULL)); oar->register_type(static_cast<B *>(NULL)); */ try { *oar & obj; // *oar & ptr; } catch( std::exception &e ) { std::cerr << "Error: archive from B to file " << fl << " - " << e.what() << std::endl; ret = 1; } } if( ! ret ) { ptr = NULL; bptr = NULL; { std::ifstream ifl( fl.c_str() ); boost::archive::polymorphic_text_iarchive tiar( ifl ); boost::archive::polymorphic_iarchive *iar = &tiar; /* iar->register_type(static_cast<A *>(NULL)); iar->register_type(static_cast<B *>(NULL)); */ try { *iar & ptr; // *iar & bptr; } catch( std::exception &e ) { std::cerr << "Error: archive from file " << fl << " to B * - " << e.what() << std::endl; ret = 1; } } if( ! ret ) { // std::cout << bptr->get() << std::endl; std::cout << static_cast<B*>( ptr )->get() << std::endl; } } } return ret; } testera and testerb are compiled into a shared library with this: boost_ptr> cat Makefile_lib CXXFLAGS = -c -ggdb3 -fPIC -funswitch-loops -fgcse-after-reload -std=c++11 LDFLAGS = -std=c++11 -lboost_serialization -lboost_thread -lboost_system -lboost_filesystem OBJLOC = obj OBJS = $(OBJLOC)/testera.o \ $(OBJLOC)/testerb.o LIBRARY_NAME = libtester.so libs:$(LIBRARY_NAME) $(LIBRARY_NAME): $(OBJS) ${CXX} -shared -o $@ $(OBJS) $(OBJLOC)/%.o: ./%.C $(CXX) $(CXXFLAGS) ./$*.C -o $(OBJLOC)/$*.o tester_mn is compiled into the executable with this: boost_ptr> cat Makefile_mn CXXFLAGS = -ggdb3 -funswitch-loops -fgcse-after-reload -std=c++11 LDFLAGS = -lboost_serialization -lboost_thread -lboost_system -lboost_filesystem -L. -ltester tester_mn: tester_mn.o ${CXX} $(CXXFLAGS) $(LDFLAGS) tester_mn.C -o $@ If I were to comment out the BOOST macros and uncomment the register_type() functions from tester_mn.C everything works. Is there a way to get the macros to work? -- Ray Kosby Software Engineer Columbus Technologies and Services, Inc www.columbususa.com<http://www.columbususa.com> Office - (301) 286-5095, fax - (301) 286-7475 NASA Goddard Space Flight Center, MS 452.1 Bldg 13 Rm 141 8800 Greenbelt Rd Greenbelt, MD 20771 USA

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Re: [Boost-users] [Boost.Beast] Libraries augmenting Boost.Beast
by Damian Jarek 24 Sep '18

24 Sep '18

Hi Sean, I've been recently working on a library that is supposed to abstract some of the platform-specific aspects of TLS peer verification (e.g. accessing the OS cert store) and obtaining the system proxy information. The project is in its early stages but is actively being worked on (https://github.com/djarek/ netutils). Another library you might be interested in, though still fairly experimental is Foxy (https://github.com/LeonineKing1199/f3) which abstracts away HTTP session management. Best Regards, Damian Jarek

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Formal Review of Proposed Boost.Histogram Library is HALFWAY through
by Mateusz Loskot 22 Sep '18

22 Sep '18

Dear Boost Community, We've reach half-way through the formal review of Hans Dembinski's Histogram library. The review lasts until the end of September 26th. If you are interested in applications for mathematics, statistics graphics, image analysis, and such, or in the Histogram library itself, please consider reviewing the Histogram library by the end of September 26th. Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

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[filesystem] Library maintainers needed
by Beman Dawes 22 Sep '18

22 Sep '18

I'm retiring, so Boost.Filesystem needs one or more maintainers. This is a high complexity library, further complicated by (1) requiring both Windows and non-Windows implementation code and (2) needing a major upgrade for compatibility with the new standard library version shipped in C++17. Furthermore, there are constant Pull Requests and Issues that arise, and these almost invariably take a lot of time for the maintainer to process. My personal opinion is that Boost should deprecate the Boost library in favor of the standard library implementations, and do only minimal maintenance for several years until most users have migrated to C++17 or later. But that's up to the new maintainers to decide. Thanks, --Beman

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[endian] Library maintainer needed
by Beman Dawes 22 Sep '18

22 Sep '18

I'm retiring, so Boost.Endian needs a maintainer. This is a low/medium complexity library that requires only minor effort to maintain. --Beman

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[timer] Library maintainer needed
by Beman Dawes 22 Sep '18

22 Sep '18

I'm retiring, so Boost.Timer needs a maintainer. This is a simple low complexity library, and requires little effort to effort to maintain. --Beman

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undefined reference to `boost::system::detail::generic_category_ncx()'
by Antonis Polykratis 20 Sep '18

20 Sep '18

Hello all, I am new to boost. I try to use some boost files in my program, but I have trouble with some of them. For example compiling the following program #include <boost/log/expressions/formatters/date_time.hpp> int main() { return 0; } with the command g++ -std=c++11 test.cpp -o main -I/home/user101/boost/ -L/home/user101/boost I have a message like the following /tmp/ccm6UOud.o: In function `boost::system::generic_category()': test.cpp:(.text._ZN5boost6system16generic_categoryEv[_ZN5boost6system16generic_c ategoryEv]+0x5): undefined reference to `boost::system::detail::generic_category _ncx()' I also tried to append -lboost_system in the command, but I take back the following message: /usr/bin/ld: cannot find -lboost_system collect2: error: ld returned 1 exit status Could you please guide me with that? I use boost_1_67 if that makes any difference (which I do not think so). Thanks, Antonis

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[Boost.Beast] Libraries augmenting Boost.Beast
by Sean Farrow 20 Sep '18

20 Sep '18

Hi all, Is there a list of open source libraries that augment Boost.Beast. I'm thinking things like OAuth/OpenID connect for example. Any help appreciated. Kind regards Sean.

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Fwd: Formal Review of Proposed Boost.Histogram Library
by Mateusz Loskot 19 Sep '18

19 Sep '18

FYI, We are reviewing Histogram library proposed to proposed . If you are interested in applications for mathematics, statistics, graphics, image analysis, and such, or in the Histogram library itself, please consider reviewing the Histogram library by the end of September 26th. Further details included below. You can post your review to the Boost development list to boost (at)lists.boost.org or directly to me to. Thank you! Mateusz Review Manager for the proposed Boost.Histogram ---------- Forwarded message --------- From: Mateusz Loskot <mateusz(a)loskot.net> Date: Mon, 17 Sep 2018 at 11:06 Subject: Formal Review of Proposed Boost.Histogram Library Starts TODAY To: <boost(a)lists.boost.org> Dear Boost Community, The formal review of Hans Dembinski's Histogram library starts TODAY, the September 17th, and lasts until September 26th, unless an extension occurs. =========== What is it? =========== Histogram is a header-only C++11 library, provides multi-dimensional histogram template class for counting, statistics and data exploration. The histogram class interface has been carefully designed to make the library * offer simple and convenient default behaviour * easy to learn and safe to use * convenient to use for one- as well as multi-dimensional analysis * compatible with STL algorithms * dependant only on C++11 standard library and optionally on Boost The author followed the "Don't pay for what you don't use" principle. The histogram class is customisable through policy classes, but the default policies were carefully crafted so that most users do not need to customize anything. The default policies guarantee the histogram to be safe to use as a black box, memory efficient, and very fast, where safety is related to overflow prevention and large values capping. This guarantees is one of unique features of the library in comparison to other implementations. The histogram class comes in two variants, which share a common interface: * static variant is optimised at compile-time to provide maximum performance, at the cost of reduced runtime flexibility and potentially larger executables; * dynamic variant is a bit slower, but configurable at run-time. Both variants of the histogram class provide optional serialization support implemented with Boost.Serialization. The library itself is header-only and the tests as well as examples can be built using both, Boost.Build and CMake. There are no dependencies required other than C++11 compiler. Optional dependencies include the GNU Scientific Library (GSL) and the ROOT framework from CERN which are needed the corresponding speed test programs used for performance comparison. A note on history: The library was first announced to the Boost community in May, 2016 [1] and the author received extensive feedback. Then, after a year of work posted second request for comments in April, 2017 [2]. =================== Getting the library =================== Checkout the `master` branch from the library git repository: https://github.com/HDembinski/histogram/ NOTE: The author follows the library submission process [3]: the master branch remains frozen for the period of the formal review, modifications in response to feedback should go to `develop` branch and big items may be worked and discussed via opening an issue on GitHub. Documentation: http://hdembinski.github.io/histogram/doc/html/ Website: http://hdembinski.github.io/histogram/ ================ Writing a review ================ Please, follow the official Boost formal review procedure [4]. If you feel this is an interesting library, then please submit your review to the Boost developer list (preferably), or the review manager to mateusz (at) loskot (dot) net. Here are some questions you might want to answer in your review: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? And finally, every review should answer this question: - Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion. If needed, refer to the Boost Library Requirements and Guidelines [5]. Please, give constructive criticism! [1] https://lists.boost.org/Archives/boost/2016/05/229389.php [2] https://lists.boost.org/Archives/boost/2017/04/234410.php [3] https://www.boost.org/development/submissions.html#Review [4] https://www.boost.org/community/reviews.html [5] https://www.boost.org/development/requirements.html Mateusz Review Manager for the proposed Boost.Histogram -- Mateusz Loskot, http://mateusz.loskot.net

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[asio] is the io_context queue FIFO?
by Frédéric 19 Sep '18

19 Sep '18

Is there a guarantee that the events posted using boost::asio::post() are called in the order of submission or can they be called in any order? Note that I have multiple threads running io_context.run(). Thanks, F

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[asio] How to prevent high load CPU by io_context::run ?
by Dmitrij V 18 Sep '18

18 Sep '18

Hi. After run io and after connection an one client, I have 25% CPU loading by server. What I doing wrong ? How can I minimize it ? PS: Client connected to TCP server without limits by time, - persistent connections... -- the best regards

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[asio] are defer/dispatch/post identical?
by Frédéric 18 Sep '18

18 Sep '18

Hi, Is there a difference between defer, dispatch and post free functions? They look very similar, there files look the same apart from the fact that they call defer, dispatch and post of the executor. The doc in executor seems to be the same. Thanks, F

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Cannot cast from std::string to seastar::sstring.
by José Guilherme Vanz 17 Sep '18

17 Sep '18

Hi guys, I'm investigating a [bug](https://github.com/scylladb/scylla/issues/2905) in the Seastar/lexical_cast and I got stuck. Let me introduce what's going on and the further investigation that I did. The Seastar framework uses the boost program options to parse the command line arguments. But when the user try to pass a command line argument of seastar::sstring (Seastar string type) with a white space, the lib tells us that is invalid value. Turns out the boost program options call lexical_cast to cast from std::string to seastar::sstring. This cast is failing. The lexical_cast uses a stream to extract the value from the source, but the operator>> stops in the white space. Making the second validation in the same [line](https://github.com/boostorg/lexical_cast/blob/boost-1.66.0/include/bo… false. Note, there is a [call](https://github.com/boostorg/lexical_cast/blob/boost-1.66.0/include/bo… to unsetf to ensure that the white space will be skipped: stream.unsetf(std::ios::skipws);. What's am I trying to do is figure out where the problems live? Is there a bug in boost or is a sstring implemantion problem? Am I missing something? Thanks!

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Re: [Boost-users] Looking for a mechanism (boost::asio
by Bjorn Reese 15 Sep '18

15 Sep '18

On 09/14/18 23:21, Tim Burgess via Boost-users wrote: > I need my main code to pause until I receive a response from the > hardware. I don’t want to use a timer, as this would be potentially Sounds like you need a promise/future.

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Re: [Boost-users] Looking for a mechanism (boost::asio
by tim＠raisedbar.net 15 Sep '18

15 Sep '18

OK, I’ve just read the preamble for the ASIO library (Chapter 32) and it seems that this library, whilst extremely useful, does exactly the opposite of what I’m trying to achieve, as it allows main code execution to continue whilst waiting for a response from an external device. I need my main code to pause until I receive a response from the hardware. I don’t want to use a timer, as this would be potentially unreliable - I can never know how long a pause would be required and there would be the danger of having the code hanging around wasting time if the timer value is too generous. Best wishes. Tim Burgess From: Boost-users <boost-users-bounces(a)lists.boost.org> On Behalf Of Tim Burgess via Boost-users Sent: 14 September 2018 20:49 To: boost-users(a)lists.boost.org Cc: tim(a)raisedbar.net Subject: Re: [Boost-users] Looking for a mechanism Thanks – I’ll go and do some reading. Just to add more information: the hardware is a MIDI device, with the sent messages being groups of 6 individual short MIDI messages, so a total of 18 7-bit bytes per transmitted query. The response messages are groups of 4 MIDI short messages. There is something like 200 parameters to be queried – the MIDI connection is either via traditional DIN cables with a transfer rate of 31kbps, or over USB. Over the USB connection the manufacturer estimates that I should be able to get a full set of responses back in around 100ms. I’m using the rtMIDI library to do the heavy lifting in terms of handling the MIDI I/O devices and handling themessage formatting. Best wishes. Tim Burgess From: Boost-users <boost-users-bounces(a)lists.boost.org <mailto:boost-users-bounces@lists.boost.org> > On Behalf Of Keith Bennett via Boost-users Sent: 14 September 2018 18:54 To: boost-users(a)lists.boost.org <mailto:boost-users@lists.boost.org> Cc: Keith Bennett <kanezor(a)gmail.com <mailto:kanezor@gmail.com> > Subject: Re: [Boost-users] Looking for a mechanism Without more information it'd be hard to say. Are you familiar with Boost ASIO? It's a common method of handling asynchronous communication, though how much it can be used in your situation may depend on the particular hardware interface. The typical situation for a single-threaded process is to set up an executor context, maybe set up signal handlers, then make an asynchronous call using ASIO's objects. When making the asynchronous calls, you provide a callback function object. Your callback function object may then make another request during its processing. ASIO handles the under-the-hood abstraction (and generally simplifies it for most situations). But it's up to you to ensure that your call sequence is safe: for example ASIO will not prevent you from making multiple simultaneous writes to the same file descriptor despite it being unsafe in many situations. My understanding is that your callback is placed onto a function queue rather than called directly (contrast to POSIX signals where the OS interrupts whatever function is running right now). That can hurt your response performance if you're doing long-running tasks so it's worth considering. On Fri, Sep 14, 2018 at 12:03 PM Tim Burgess via Boost-users <boost-users(a)lists.boost.org <mailto:boost-users@lists.boost.org> > wrote: Hi, I’m trying to find a method of solving the problem detailed below using Boost (or an alternative: 1 – I have to send a series of messages to a hardware device to query its internal parameter values at application load-time. This I can do; 2 – I have a callback that receives responses from the hardware, though I get some replies go missing due to saturation; 3 * The hardware manufacturer tells me that I should send 1 query then wait for the response before sending the next query. I could use Sleep, but this depends on a specific wait time and I’m not sure if it suspends all processing, including my callback, so this doesn’t look satisfactory. What I’m looking for is a “wait until response” kind of thing, but I haven’t found such a thing so far, though I have found several wait routines for handling multiple threads. I’d appreciate any guidance as to what to look for, as my searches are obviously not asking the right questions. Best wishes. Tim Burgess Raised Bar Ltd. E: tim(a)raisedbar.net <mailto:tim@raisedbar.net> M: +44 (0)7989 486976 _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org <mailto:Boost-users@lists.boost.org> https://lists.boost.org/mailman/listinfo.cgi/boost-users -- Keith Bennett

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Looking for a mechanism
by tim＠raisedbar.net 14 Sep '18

14 Sep '18

Hi, I'm trying to find a method of solving the problem detailed below using Boost (or an alternative: 1 - I have to send a series of messages to a hardware device to query its internal parameter values at application load-time. This I can do; 2 - I have a callback that receives responses from the hardware, though I get some replies go missing due to saturation; 3 * The hardware manufacturer tells me that I should send 1 query then wait for the response before sending the next query. I could use Sleep, but this depends on a specific wait time and I'm not sure if it suspends all processing, including my callback, so this doesn't look satisfactory. What I'm looking for is a "wait until response" kind of thing, but I haven't found such a thing so far, though I have found several wait routines for handling multiple threads. I'd appreciate any guidance as to what to look for, as my searches are obviously not asking the right questions. Best wishes. Tim Burgess Raised Bar Ltd. E: <mailto:tim@raisedbar.net> tim(a)raisedbar.net M: +44 (0)7989 486976

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[Beast] Downloading multiple urls in parallel
by Sean Farrow 13 Sep '18

13 Sep '18

Hi, Are there functions within beast to allow me to start downloading multiple url's in parallel and then handle each returned result with a different continuation function? Any help appreciated. Kind regards Sean.

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[ASIO] Reestablish TCP connection after EOF
by csizmadiatamas 12 Sep '18

12 Sep '18

I would like to make a c++ TCP client using boost::asio based on this article: https://www.gamedev.net/blogs/entry/2249317-a-guide-to-getting-started-with… I have an existing server which behaviour is similar to a router configuration. You can connect to it and as soon as you have a command promt you can send a command to the server. It executes it and sends back the result and a command promt. Then you can send the next command... There is no problem with this part. My code is able to establish the connection, send and recive data until my client gets EOF. It means the server broke the connection. I would like my client to be able to reestablish the connection and this part is not working. Very much would appreciate your help. *Here is my header:* #pragma once #include <boost/asio.hpp> #include <boost/thread.hpp> #include <boost/asio/io_context_strand.hpp> class Hive; class Connection; class Connection : public boost::enable_shared_from_this< Connection > { friend class Hive; private: static const int m_reconnect_interval = 15000; boost::shared_ptr< Hive > m_hive; boost::asio::ip::tcp::socket m_socket; boost::asio::io_service::strand m_io_strand; boost::asio::deadline_timer m_keepalive_timer; boost::asio::deadline_timer m_reconnect_timer; boost::posix_time::ptime m_last_time; std::vector< uint8_t > m_recv_buffer; std::list< int32_t > m_pending_recvs; std::list< std::vector< uint8_t > > m_pending_sends; int32_t m_receive_buffer_size; int32_t m_keepalive_timer_interval; protected: Connection( boost::shared_ptr< Hive > hive ); virtual ~Connection(); private: Connection( const Connection & rhs ); Connection & operator =( const Connection & rhs ); void StartSend(); void StartRecv( int32_t total_bytes ); void StartKeepAliveTimer(); void StartReconnectTimer(); void StartError(const boost::system::error_code &error, std::string caller); void DispatchSend( std::vector< uint8_t > buffer ); void DispatchRecv( int32_t total_bytes ); void DispatchTimer( const boost::system::error_code & error ); void ReconnectTimer( const boost::system::error_code & error ); void HandleConnect( const boost::system::error_code & error ); void HandleSend( const boost::system::error_code & error, std::list< std::vector< uint8_t > >::iterator itr ); void HandleRecv( const boost::system::error_code & error, int32_t actual_bytes ); void HandleKeepAliveTimer(const boost::system::error_code &error); void HandleReconnectTimer( const boost::system::error_code & error ); void Reconnect(); private: // Called when the connection has successfully connected to the local host. virtual void OnAccept( const std::string & host, uint16_t port ) = 0; // Called when the connection has successfully connected to the remote host. virtual void OnConnect( const std::string & host, uint16_t port ) = 0; // Called when data has been sent by the connection. virtual void OnSend( const std::vector< uint8_t > & buffer ) = 0; // Called when data has been received by the connection. virtual void OnRecv( std::vector< uint8_t > & buffer ) = 0; // Called on each timer event. virtual void OnTimer( const boost::posix_time::time_duration & delta ) = 0; // Called when an error is encountered. virtual void OnError(const std::string error) = 0; public: // Starts an a/synchronous connect. void Connect(const std::string &host, const std::string &port); // Posts data to be sent to the connection. void Send(std::string message); // Posts a recv for the connection to process. If total_bytes is 0, then // as many bytes as possible up to GetReceiveBufferSize() will be // waited for. If Recv is not 0, then the connection will wait for exactly // total_bytes before invoking OnRecv. void Recv( int32_t total_bytes = 0 ); // Posts an asynchronous disconnect event for the object to process. void Disconnect(); }; class Hive : public boost::enable_shared_from_this< Hive > { private: boost::asio::io_service m_io_service; boost::shared_ptr< boost::asio::io_service::work > m_work_ptr; private: Hive( const Hive & rhs ); Hive & operator =( const Hive & rhs ); public: Hive(); virtual ~Hive(); // Returns the io_service of this object. boost::asio::io_service & GetService(); // Polls the networking subsystem once from the current thread and returns. void Poll(); // Runs the networking system on the current thread. This function blocks // until the networking system is stopped, so do not call on a single // threaded application with no other means of being able to call Stop // unless you code in such logic. void Run(); // Stops the networking system. All work is finished and no more // networking interactions will be possible afterwards until Reset is called. void Stop(); // Restarts the networking system after Stop as been called. A new work // object is created ad the shutdown flag is cleared. void Reset(); }; *and here is my cpp:* #include "network.h" #include <boost/interprocess/detail/atomic.hpp> #include <boost/interprocess/detail/config_begin.hpp> #include <boost/interprocess/detail/workaround.hpp> #include <boost/cstdint.hpp> #include <iostream> Hive::Hive() : m_work_ptr( new boost::asio::io_service::work( m_io_service ) ) { } Hive::~Hive() { } boost::asio::io_service & Hive::GetService() { return m_io_service; } void Hive::Poll() { m_io_service.poll(); } void Hive::Run() { m_io_service.run(); } void Hive::Stop() { m_work_ptr.reset(); m_io_service.run(); m_io_service.stop(); } void Hive::Reset() { m_io_service.reset(); m_work_ptr.reset( new boost::asio::io_service::work( m_io_service ) ); } Connection::Connection( boost::shared_ptr< Hive > hive ) : m_hive( hive ), m_socket( hive->GetService() ), m_io_strand( hive->GetService() ), m_keepalive_timer( hive->GetService() ), m_reconnect_timer(hive->GetService()), m_receive_buffer_size( 4096 ), m_keepalive_timer_interval( 2000 ) { } Connection::~Connection() { } void Connection::StartSend() { if( !m_pending_sends.empty() ) boost::asio::async_write( m_socket, boost::asio::buffer( m_pending_sends.front() ), boost::asio::bind_executor(m_io_strand, boost::bind( &Connection::HandleSend, shared_from_this(), boost::asio::placeholders::error, m_pending_sends.begin() ) ) ); } void Connection::StartRecv( int32_t total_bytes ) { if( total_bytes > 0 ) { m_recv_buffer.resize( total_bytes ); boost::asio::async_read( m_socket, boost::asio::buffer( m_recv_buffer ), boost::asio::bind_executor(m_io_strand, boost::bind( &Connection::HandleRecv, shared_from_this(), _1, _2 ) ) ); } else { m_recv_buffer.resize( m_receive_buffer_size ); m_socket.async_read_some( boost::asio::buffer( m_recv_buffer ), boost::asio::bind_executor(m_io_strand, boost::bind( &Connection::HandleRecv, shared_from_this(), _1, _2 ) ) ); } } void Connection::StartKeepAliveTimer() { std::cout << "[" << __FUNCTION__ << "] " << std::endl; m_last_time = boost::posix_time::microsec_clock::local_time(); m_keepalive_timer.expires_from_now( boost::posix_time::milliseconds( m_keepalive_timer_interval ) ); m_keepalive_timer.async_wait( boost::asio::bind_executor(m_io_strand, boost::bind( &Connection::DispatchTimer, shared_from_this(), _1 ) ) ); } void Connection::StartReconnectTimer() { std::cout << "[" << __FUNCTION__ << "] " << std::endl; m_last_time = boost::posix_time::microsec_clock::local_time(); m_reconnect_timer.expires_from_now( boost::posix_time::milliseconds( m_reconnect_interval ) ); m_reconnect_timer.async_wait( boost::asio::bind_executor(m_io_strand, boost::bind( &Connection::ReconnectTimer, shared_from_this(), _1 ) ) ); } void Connection::StartError(const boost::system::error_code &error, std::string caller) { OnError(caller + " " + error.message() + "(" + error.category().name() + ":" + std::to_string(error.value()) + ")"); boost::system::error_code ec; m_socket.shutdown(boost::asio::ip::tcp::socket::shutdown_both, ec); m_socket.close(ec); m_keepalive_timer.cancel(ec); if (error == boost::asio::error::misc_errors::eof || error == boost::system::errc::timed_out) StartReconnectTimer(); } void Connection::HandleConnect( const boost::system::error_code & error ) { if( error ) StartError(error, __FUNCTION__); else { if( m_socket.is_open() ) { OnConnect( m_socket.remote_endpoint().address().to_string(), m_socket.remote_endpoint().port() ); m_reconnect_timer.cancel(); StartKeepAliveTimer(); } else StartError(error, __FUNCTION__); } } void Connection::HandleSend( const boost::system::error_code & error, std::list< std::vector< uint8_t > >::iterator itr ) { if( error ) StartError(error, __FUNCTION__); else { OnSend( *itr ); m_pending_sends.erase( itr ); StartSend(); } } void Connection::HandleRecv( const boost::system::error_code & error, int32_t actual_bytes ) { if( error ) StartError(error, __FUNCTION__); else { m_recv_buffer.resize( actual_bytes ); OnRecv( m_recv_buffer ); m_pending_recvs.pop_front(); if( !m_pending_recvs.empty() ) StartRecv( m_pending_recvs.front() ); } } void Connection::HandleKeepAliveTimer(const boost::system::error_code &error) { if( error ) StartError(error, __FUNCTION__); else { OnTimer( boost::posix_time::microsec_clock::local_time() - m_last_time ); StartKeepAliveTimer(); } } void Connection::HandleReconnectTimer( const boost::system::error_code & error ) { std::cout << "[" << __FUNCTION__ << "] Calling reconnect... " << std::endl; Reconnect(); } void Connection::DispatchSend( std::vector< uint8_t > buffer ) { bool should_start_send = m_pending_sends.empty(); m_pending_sends.push_back( buffer ); if( should_start_send ) StartSend(); } void Connection::DispatchRecv( int32_t total_bytes ) { bool should_start_receive = m_pending_recvs.empty(); m_pending_recvs.push_back( total_bytes ); if( should_start_receive ) StartRecv( total_bytes ); } void Connection::DispatchTimer( const boost::system::error_code & error ) { boost::asio::post(m_io_strand, boost::bind(&Connection::HandleKeepAliveTimer, shared_from_this(), error ) ); } void Connection::ReconnectTimer( const boost::system::error_code & error ) { boost::asio::post(m_io_strand, boost::bind( &Connection::HandleReconnectTimer, shared_from_this(), error ) ); } void Connection::Connect(const std::string &host, const std::string &port) { std::cout << "[" << __FUNCTION__ << "] connecting to "<< host << ":" << port << std::endl; boost::system::error_code ec; boost::asio::ip::tcp::resolver resolver( m_hive->GetService() ); boost::asio::ip::tcp::resolver::query query( host, port ); boost::asio::ip::tcp::resolver::iterator iterator = resolver.resolve( query ); m_socket.async_connect( *iterator, boost::asio::bind_executor(m_io_strand, boost::bind( &Connection::HandleConnect, shared_from_this(), _1 ) ) ); } void Connection::Reconnect() { m_hive->Reset(); Connect("10.40.60.72", "23"); } void Connection::Disconnect() { boost::asio::post(m_io_strand, boost::bind(&Connection::HandleKeepAliveTimer, shared_from_this(), boost::asio::error::connection_reset ) ); } void Connection::Recv( int32_t total_bytes ) { boost::asio::post(m_io_strand, boost::bind( &Connection::DispatchRecv, shared_from_this(), total_bytes ) ); } void Connection::Send(std::string message) { std::vector< uint8_t > request; std::copy( message.begin(), message.end(), std::back_inserter( request ) ); boost::asio::post(m_io_strand, boost::bind( &Connection::DispatchSend, shared_from_this(), request ) ); } -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Users-f2553780.html

1 0

Memory header not found
by Sudhanshu Dubey 11 Sep '18

11 Sep '18

Hey guys, I am new here and wanted some help from you guys. I was trying to upgrade and compile the FElt software, a software for finite element analysis. The source code is here : https://github.com/AkMecha/felt Now, the problem is that during compilation, one of the source file is including some header file from the boost library. The chain of including goes on and reaches the memory.hpp file which is present in /usr/include/boost/config/no_tr1/ directory. This memory.hpp is in turn including the memory header file from the standard C++ library, but it can't find that memory header file. And this is strange because I personally went and checked that the memory header is there in the standard location, as you can see below : sudhanshu@sudhanshu-Inspiron-15-3567:/usr/include/c++/7.3.0$ ls algorithm cerrno complex cstdio decimal initializer_list map queue stdlib.h typeindex any cfenv complex.h cstdlib deque iomanip math.h random streambuf typeinfo array cfloat condition_variable cstring exception ios memory ratio string type_traits atomic chrono csetjmp ctgmath experimental iosfwd mutex regex string_view unordered_map backward cinttypes csignal ctime ext iostream new scoped_allocator system_error unordered_set bits ciso646 cstdalign cuchar fenv.h istream numeric set tgmath.h utility bitset climits cstdarg cwchar forward_list iterator optional shared_mutex thread valarray cassert clocale cstdbool cwctype fstream limits ostream sstream tr1 variant ccomplex cmath cstddef cxxabi.h functional list parallel stack tr2 vector cctype codecvt cstdint debug future locale profile stdexcept tuple The error message shown during the compilation is : [ 51%] Building C object src/Burluap/CMakeFiles/burluap.dir/apply.c.o In file included from /usr/include/boost/smart_ptr/shared_ptr.hpp:23:0, from /usr/include/boost/shared_ptr.hpp:17, from /home/sudhanshu/Pictures/felt/include/matrix.h:23, from /home/sudhanshu/Pictures/felt/src/Burluap/descriptor.h:35, from /home/sudhanshu/Pictures/felt/src/Burluap/trap.h:31, from /home/sudhanshu/Pictures/felt/src/Burluap/apply.c:29: /usr/include/boost/config/no_tr1/memory.hpp:21:12: fatal error: memory: No such file or directory # include <memory> ^~~~~~~~ compilation terminated. src/Burluap/CMakeFiles/burluap.dir/build.make:62: recipe for target 'src/Burluap/CMakeFiles/burluap.dir/apply.c.o' failed make[2]: *** [src/Burluap/CMakeFiles/burluap.dir/apply.c.o] Error 1 CMakeFiles/Makefile2:504: recipe for target 'src/Burluap/CMakeFiles/burluap.dir/all' failed make[1]: *** [src/Burluap/CMakeFiles/burluap.dir/all] Error 2 Makefile:129: recipe for target 'all' failed make: *** [all] Error 2 So can I get some help as to what should I do to make the memory.hpp find the memory header file? -- Sudhanshu Dubey https://hacksd.wordpress.com https://github.com/Sudhanshu-Dubey14

1 0

ASIO?
by tim＠raisedbar.net 05 Sep '18

05 Sep '18

Hi, I'm looking for a mechanism allowing me to enumerate serial (Com) ports on Windows/Mac. I also need to be able to retrieve the name of a given serial device. I've had a quick look at boost::asio, but it isn't clear to me if it can do what I want. I'd be grateful for any advice, including alternatives if boost and/or ASIO aren't up to the job. Best wishes. Tim Burgess Raised Bar Ltd. E: <mailto:tim@raisedbar.net> tim(a)raisedbar.net M: +44 (0)7989 486976

3 2

mcgregor_common_subgraphs usage/complexity/performance/runtime
by Julian Wolf 01 Sep '18

01 Sep '18

Hello everyone, I'm new to Boost and today I tried to use the mcgregor_common_subgraphs functions but can't find an explanation why the function shows such bad performance when I use it. According to the documentation [1] the algorithm runs in O(V1 * V2) for the entire space with V being the number of vertices in the two graphs. So not great, but I'd expect that to run in reasonable time for graphs with less than 100 vertices. But in my case it doesn't, therefore any help appreciated whether I have some error or misconception on my side or whether this is expected performance. What I'm trying to achieve: I want to check whether two graphs have a common subgraph of size x. x depends on the size of smaller graph, I'm using a factor y for this with 0 < y < 1. With smaller values for x (e.g. x = 0.7 * V1) the example returns very fast, which makes sense since a smaller part of the search space needs to be explored. If I increase the factor to 0.8 * V1 or even run through the whole search space the program does not terminate within 10 minutes (where I canceled) I'll attach a working example as well as two graphs (44 and 46 vertices) showing the behaviour described. # gcc CommonSubgraph.cpp -o common_subgraph_example -lboost_graph -lstdc++ # time ./common_subgraph_example 0.7 graph1.dot graph2.dot Factor 0.7 Size: 30 real 0m0.043s # time ./common_subgraph_example 0.8 graph1.dot graph2.dot Factor 0.8 ^C real 10m39.741s My system runs openSUSE Tumbleweed with Boost 1.67 > rpm -q --whatprovides /usr/include/boost/graph/mcgregor_common_subgraphs.hpp libboost_headers1_67_0-devel-1.67.0-2.3.x86_64 Thank you! Julian [1] https://www.boost.org/doc/libs/1_68_0/libs/graph/doc/ mcgregor_common_subgraphs.html

2 2

Testing and faking ASIO I/O objects
by Cristian Morales Vega 31 Aug '18

31 Aug '18

How is people around here testing code which uses ASIO? I guess something like GIVEN("SOMETHING THAT STARTS BY DOING A NAME RESOLVER IS STARTED") fakeResolver.async_resolve("www.google.com", "80", HandlerCallingConnect); // This stores the completion handler (and an executor_work_guard) internally WHEN("THE RESOLVER RETURNS WITHOUT ERROR") fakeResolver.completeWithFakeResult("1.2.3.4", error_code()); // This post() the completion handler with the arguments you give it here io_context.poll(); THEN("A CONNECTION IS ATTEMPTED") EXPECT_CALL(fakeSocket, async_connect()); would be nice. But the "stores the completion handler" part doesn't look that simple. I have found some attempts online, but they seems to store the completion handlers into a vector of std::function and post them through std::bind, so possibly using the wrong executor, etc. There is any good set of ASIO I/O object fakes available?

2 2

linker errors with latest Visual Studio 15.8.2 update
by Damien 30 Aug '18

30 Aug '18

All, It looks like with 15.8.2 you might need to rebuild if you are linking to Boost compiled with earlier versions in the 15.6 or 15.7 series. Screens full of unresolved symbols..... Just a heads-up. Damien

1 0

[boost.test] parsing runtime arguments
by Olaf Peter 27 Aug '18

27 Aug '18

Hi, how get an 'user' API for the boost.test like this: testsuite_xyz -- --help or even testsuite_xyz -- --save-path=/foo to get the user aspects. I know I can get the args by int argc{ framework::master_test_suite().argc }; char** argv{ framework::master_test_suite().argv }; Further, at test/include/boost/test/utils/runtime/cla/parser.hpp are some utils used by boost.test self. Anyway, the problem rises to get the behaviour desribed above, simply using a global fixture with: fixture::fixture() { int argc{ utf::framework::master_test_suite().argc }; char** argv{ utf::framework::master_test_suite().argv }; for (int i = 0; i != argc; ++i) { std::cerr << "test_observer_fixture: " << argv[i] << "\n"; } } doesn't give the expected results - all the BOOST_AUTO_TEST_SUITE test cases are called even they depend on this arguments. Thanks, Olaf

2 3

Boost.Test BOOST_TEST/BOOST_REQUIRE_MESSAGE message arg problems
by Olaf Peter 27 Aug '18

27 Aug '18

Hello Boost Users, for my project I'm testing using BOOST_AUTO_TEST_SUITE and data driven test sets (BOOST_DATA_TEST_CASE). The goal is to check the proper working of a parser by checking success as such and compare the result with a "expected" data (string) vector. In case of parse error, I want to write the captured cout/cerr by boost.test into a file. In case of compare error the parsed result also shall be written to a file. The fragments show the concept/current state: namespace x3_test { // aka utils .... /* [Detect if boost test case failed]( * https://stackoverflow.com/questions/18466857/detect-if-boost-test-case-fail…) */ bool current_test_passing() { using namespace boost::unit_test; auto const id = framework::current_test_case().p_id; auto const test_results = results_collector.results(id); return test_results.passed(); } std::string report_diagnostic(fs::path const& test_case_name, std::string const& input, std::string const& result) { ... if(!x3_test::current_test_passing()) { // only write in case of failed test test_case_result_writer result_writer(test_case_name); result_writer.write(result); } return ss.str(); } } // x3_test ... BOOST_AUTO_TEST_SUITE(.... BOOST_DATA_TEST_CASE( declaration, dataset.input() ^ dataset.expect() ^ dataset.test_case_name(), code, expect_AST, test_case_name) { using attribute_type = ast::declaration; auto const parser = parser::declaration; x3_test::testing_parser<attribute_type> parse; auto [parse_ok, parsed_AST] = parse(code, parser); BOOST_TEST(parse_ok); BOOST_REQUIRE_MESSAGE(parse_ok, x3_test::report_diagnostic(test_case_name, code, parsed_AST) ); BOOST_TEST(parsed_AST == expect_AST, btt::per_element()); BOOST_REQUIRE_MESSAGE(x3_test::current_test_passing(), x3_test::report_diagnostic(test_case_name, code, parsed_AST) ); } BOOST_AUTO_TEST_SUITE_END() After some testing, the error count is twice the real (obviously here) but it's all above a work arround. It seems, that BOOST_REQUIRE_MESSAGE evaluates always the message predicate (shown by using --log_level=all) nevertheless the test case successed or failed. If failed it is streamed to the console. My first thoughs where that the message is called only in case of test failure which isn't true. The problem is now, that my report_diagnostic function write the test output (parsed_AST) to a special dir/file for later evaluating etc. The intuitive way would be: std::string report_diagnostic(fs::path const& test_case_name, std::string const& input, std::string const& result) { ... test_case_result_writer result_writer(test_case_name); result_writer.write(result); return ss.str(); } BOOST_REQUIRE_MESSAGE(parse_ok, // call diagnostic only in failure case and write then x3_test::report_diagnostic(test_case_name, code, parsed_AST) ); BOOST_REQUIRE_MESSAGE((parsed_AST == expect_AST, btt::per_element()), // call diagnostic only in failure case and write then x3_test::report_diagnostic(test_case_name, code, parsed_AST) ); Hence not depending on current_test_passing() any more. How to get this? Further, how can I get the captured std::cerr in case of '!parse_ok' inside report_diagnostic? Thanks, Olaf

2 10

[signals2] Warn unused result
by Deven 24 Aug '18

24 Aug '18

Hi, I am using boost::signals2 library for event callback mechanism. The event register callback function returns a boost::signals2::scope_connection object for optional disconnect by the function registering itself. I want to mandate using the returns result (scoped_connection) object by the user. So, I use the gcc attribute "__attribute__( ( warn_unused_result ) )" with the function. The problem is that the compiler does not warn for unused result. Any ideas, why would this happen? I am using Linux with g++ 4.8.4 and c++11 is enabled. Boost version: 1.67.0 I have attached a minimal working example. Thanks, -Deven

1 0

Setting cxxflags for intel compiler
by Michalke, Simon 23 Aug '18

23 Aug '18

Hi, in order to compile boost I need to tell the intel compiler which gcc version to use. I am trying to achive this with a user-config.jam using intel-linux : icpc : <cxxflags> -gcc-name=gcc-7 -gxx-name=g++-7 ; But none of the flags appear in the compile log. Which syntax am I supposed to use to get them working? Regards, Simon

3 2

[multi_index] Introducing C++17 terse key specification syntax
by Joaquin M López Muñoz 22 Aug '18

22 Aug '18

Following some ideas discussed about a year ago, I've added a new boost::multi_index::key construct allowing for a very terse specification of predefined key extractors in C++17 compliant environments. For instance, given struct phonebook_entry { std::string family_name; std::string given_name; std::string phone_number()const; }; int num_calls(const phonebook_entry&); a classical definition like typedef multi_index_container< phonebook_entry, indexed_by< ordered_unique< const_mem_fun<phonebook_entry,std::string,&phonebook_entry::phone_number> >, ordered_unique< global_fun<const phonebook_entry&,int,num_calls> >, ordered_non_unique< composite_key< phonebook_entry, member<phonebook_entry,std::string,&phonebook_entry::family_name>, member<phonebook_entry,std::string,&phonebook_entry::given_name> > > > > phonebook; can now be written as typedef multi_index_container< phonebook_entry, indexed_by< ordered_unique< key<&phonebook_entry::phone_number> >, ordered_unique< key<num_calls> >, ordered_non_unique< key<&phonebook_entry::family_name,&phonebook_entry::given_name> > > > phonebook; If you have a C++17 compiler, you can play with this new feature by simply copying https://github.com/boostorg/multi_index/blob/develop/include/boost/multi_in… into your local Boost installation. More info at https://www.boost.org/doc/libs/develop/libs/multi_index/doc/tutorial/key_ex… https://www.boost.org/doc/libs/develop/libs/multi_index/doc/reference/key_e… Comments and suggestions, specially before Boost 1.69 ships and this becomes more or less frozen, are most welcome. Best regards, Joaquín M López Muñoz

1 0

Where is the Wave Driver in Boost 1.86?
by Stirling Westrup 20 Aug '18

20 Aug '18

I recently tried to recompile an old version of the Wave Driver using the latest version of Boost::Wave and there were many cryptic warnings and errors. So, I figured I'd just upgrade to the latest copy of the source, only I cannot find it in the latest Boost::Wave, despite the documentation still referring to it. Nor does there appear to be an already-compiled tool supplied with the distro versions of Boost. (Something which has always been claimed by the docs, but has never been true in my experience -- which is why I was forced to originally compile it from source.) -- Stirling Westrup Programmer, Entrepreneur. https://www.linkedin.com/e/fpf/77228 http://www.linkedin.com/in/swestrup http://technaut.livejournal.com http://sourceforge.net/users/stirlingwestrup

1 0

Why I had to use-D_GLIBCXX_USE_CXX11_ABI=0 to get a Boost.Test unit test to build and run
by Arved Sandstrom 20 Aug '18

20 Aug '18

This is in the nature of a question, I am wondering *why* I had to use the -D_GLIBCXX_USE_CXX11_ABI=0 setting. This development is happening on Centos 7, where the system gcc/g++ is 4.8.5. So I recently built and installed gcc/g++ 8.2.0 from source, because I like Linux and prefer to try out C++17 stuff there rather than using a recent Visual Studio. That's just background. In any case I built the Boost Test module with ./b2 cxxflags="-stdlib=libc++ -std=c++14" linkflags="-stdlib=libc++ -std=c++14" going off suggestions I found. No evident problems there. After the install, among other things I end up with /usr/local/lib/libboost_unit_test_framework.so Now, I attempted to build a unit test with g++ -std=c++14 DocumentTest.cpp ../src/Document.cpp -I../include -L/usr/local/include -DBOOST_TEST_DYN_LINK -lboost_unit_test_framework The linker complained about an undefined reference for boost::unit_test::ut_detail::normalize_test_case_name[abi:cxx11](boost::unit_test::basic_cstring<char const>) Using nm -D on the shared library I see that the proper export symbol is there. abi:cxx11 seemed to offer some indication as to the problem, which is why after some experimentation I found that adding -D_GLIBCXX_USE_CXX11_ABI=0 to the unit test build command did the trick. The resulting a.out executes just fine (purely for debugging I made sure the unit test had a C++14 feature). I thought I sort of understood the ABI change business, gcc 5.1 before and after, but I guess I don't. What do I need to do, perhaps at the stage of building a Boost shared library, to not have to use that flag? Thanks for any wisdom. Arved Sandstrom

2 1

Specifying Compiler when invoking bootstrap.sh
by Michalke, Simon 20 Aug '18

20 Aug '18

Hello all, simple question: How do I specify the compiler that will be used to compile boost directly? I would like to provide the whole path. I have a big CMakeProject that depends on Boost. And boost should be preferably build with the same Compiler. Regards, Simon

3 5

[boost.locale] linguistic case discrimination in translation
by Olaf Peter 19 Aug '18

19 Aug '18

Hello Users, I like to join two translation into a single one using the word 'and' if the code path require it, e.g. translation 1 is: "{1} error" and translation 2 is: "{1} warning" if the relevant err/warn counter are both != 0 I want to combine this statement using the mentioned 'and'. I guess, an example teels more than this here: see https://wandbox.org/permlink/HbnCLQKhHAb3eqZr or even on bottom. Line 89 ... 94 looks too complicated to me even for the translator which need an own context of the intend. I've seen a lot of dating formating flags, but nothings useful for my use case. BTW; does boost.locate still using auto_ptr? I had to add the option '-Wno-deprecated' to rid the warnings... Thanks, Olaf -----------------------8<-------------------------- #include <iostream> #include <boost/locale.hpp> struct context { std::size_t error_count; std::size_t warning_count; context() : error_count{ 0 } , warning_count{ 0 } { } }; struct failure_status { context const& ctx; failure_status(context const& ctx_) : ctx{ ctx_ } { } std::ostream& operator()(std::ostream& os) const; }; static inline std::ostream& operator<<(std::ostream& os, failure_status const& status) { return status(os); } namespace detail { struct error_message { std::size_t const count; explicit error_message(std::size_t count_) : count{ count_ } { } std::ostream& operator()(std::ostream& os) const { using boost::locale::format; using boost::locale::translate; if(count) { os << format(translate( "{1} error", "{1} errors", count)) % count ; } return os; } }; std::ostream& operator<<(std::ostream& os, error_message const& err_msg) { return err_msg(os); } struct warning_message { std::size_t const count; explicit warning_message(std::size_t count_) : count{ count_ } { } std::ostream& operator()(std::ostream& os) const { using boost::locale::format; using boost::locale::translate; if(count) { os << format(translate( "{1} warning", "{1} warnings", count)) % count ; } return os; } }; std::ostream& operator<<(std::ostream& os, warning_message const& warn_msg) { return warn_msg(os); } } // namespace detail std::ostream& failure_status::operator()(std::ostream& os) const { using detail::warning_message; using detail::error_message; using boost::locale::translate; bool const any_failure = [&] { return ctx.error_count || ctx.warning_count; }(); if(any_failure) { os << error_message(ctx.error_count); if(ctx.warning_count) { os << translate(" and "); // poor translator ... } os << warning_message(ctx.warning_count); os << translate(" generated."); } return os; } int main() { context ctx; ctx.error_count = 1; ctx.warning_count = 42; std::cout << failure_status(ctx) << "\n"; } ----------------------->8--------------------------

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[release][build] Errors compiling 1.68.0 with VS2015 after VS2017
by Gavin Lambert 10 Aug '18

10 Aug '18

I first used the following to compile Boost 1.68.0 for VS2017: cd boost_1_68_0 bootstrap b2 -j8 --build-dir=build toolset=msvc-14.1 variant=debug,release link=shared threading=multi runtime-link=shared address-model=32,64 stage This appears to have built successfully, although I didn't review the logs. Afterwards, I tried to build it also for VS2015: b2 -j8 --build-dir=build15 toolset=msvc-14.0 variant=debug,release link=shared threading=multi runtime-link=shared address-model=32,64 stage This build output is full of these errors, however (not specific to Boost.Math, this is just one I happened to capture): Creating library build15\boost\bin.v2\libs\math\build\msvc-14.0\debug\threading-multi\boost_math_c99l-vc140-mt-gd-x32-1_68.lib and object build15\boost\bin.v2\libs\math\build\msvc-14.0\debug\threading-multi\boost_math_c99l-vc140-mt-gd-x32-1_68.exp msvc.manifest.dll build15\boost\bin.v2\libs\math\build\msvc-14.0\debug\threading-multi\boost_math_c99l-vc140-mt-gd-x32-1_68.dll 'mt' is not recognized as an internal or external command, operable program or batch file. if exist "build15\boost\bin.v2\libs\math\build\msvc-14.0\debug\threading-multi\boost_math_c99l-vc140-mt-gd-x32-1_68.dll.manifest" ( call "build15\boost\bin.v2\standalone\msvc\msvc-14.0\msvc-setup.bat" x86 >nul mt -nologo -manifest "build15\boost\bin.v2\libs\math\build\msvc-14.0\debug\threading-multi\boost_math_c99l-vc140-mt-gd-x32-1_68.dll.manifest" "-outputresource:build15\boost\bin.v2\libs\math\build\msvc-14.0\debug\threading-multi\boost_math_c99l-vc140-mt-gd-x32-1_68.dll;2" ) ...failed msvc.manifest.dll build15\boost\bin.v2\libs\math\build\msvc-14.0\debug\threading-multi\boost_math_c99l-vc140-mt-gd-x32-1_68.dll build15\boost\bin.v2\libs\math\build\msvc-14.0\debug\threading-multi\boost_math_c99l-vc140-mt-gd-x32-1_68.lib build15\boost\bin.v2\libs\math\build\msvc-14.0\debug\threading-multi\boost_math_c99l-vc140-mt-gd-x32-1_68.pdb... Am I missing some incantation? Oddly when I run a VS2015 Developer Command Prompt it also doesn't know where to find mt.exe. A VS2017 Developer Command Prompt finds it at C:\Program Files (x86)\Windows Kits\10\bin\10.0.17134.0\x86\mt.exe. (I'm not having any apparent problems compiling projects within VS2015, but possibly I haven't given it a thorough workout since recently upgrading VS2017.) On another machine (which only has VS2015 installed), the VS2015 Developer Command Prompt finds it at C:\Program Files (x86)\Windows Kits\8.1\bin\x86\mt.exe. I do have that same path and file on my PC, but it's not being found for some reason? Adding it to my PATH before running b2 doesn't help; I assume it's overriding this. It looks like the VS2015 Developer Prompt is putting C:\Program Files (x86)\Windows Kits\10\bin\x86 into my PATH, which exists but doesn't contain any tools. I managed to "fix" the VS2015 Developer Prompt by commenting out the line in "C:\Program Files (x86)\Microsoft Visual Studio 14.0\Common7\Tools\vcvarsqueryregistry.bat" that looks for the Windows 10 SDK. (Thereby allowing it to find the 8.1 SDK, which contains mt.exe.) After deleting the build15 directory and adding --reconfigure to the b2 incantation above, this seems to have allowed Boost to compile as well, but I find the whole thing a bit troubling. Is there a better way to resolve this?

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Re: [Boost-users] [release] Boost 1.68.0 Beta 1 -> warnings in gil, locale, geometry, asio, ublas, interprocess, atomic
by Frédéric 09 Aug '18

09 Aug '18

Here are some more warnings while using the libraries: * gil: boost/gil/extension/toolbox/image_types/indexed_image.hpp:190:5: warning: les qualificatifs de type sont ignorés sur le type retourné par la fonction [-Wignored-qualifiers] const std::size_t num_colors() const { return _num_colors; } ^~~~~ boost/gil/extension/dynamic_image/any_image_view.hpp:41:63: warning: unused parameter 'v' [-Wunused-parameter] template <typename T> result_type operator()(const T& v) const { return num_channels<T>::value; } boost/gil/extension/dynamic_image/algorithm.hpp:147:70: warning: unused parameter 'src' [-Wunused-parameter] template <typename V, typename Value> static void apply(const V& src, const Value& val) { throw std::bad_cast();} ^ boost/gil/extension/dynamic_image/algorithm.hpp:147:88: warning: unused parameter 'val' [-Wunused-parameter] template <typename V, typename Value> static void apply(const V& src, const Value& val) { throw std::bad_cast();} ^ boost/gil/extension/dynamic_image/image_view_factory.hpp:178:140: warning: unused parameter 'cc' [-Wunused-parameter] typename color_converted_view_type<any_image_view<ViewTypes>, DstP, CC>::type color_converted_view(const any_image_view<ViewTypes>& src,CC cc) {~ ^ boost/gil/extension/dynamic_image/image_view_factory.hpp:201:144: warning: unused parameter 'cc' [-Wunused-parameter] typename color_converted_view_type<any_image_view<ViewTypes>, DstP, CC>::type any_color_converted_view(const any_image_view<ViewTypes>& src,CC cc) {~ ^ boost/gil/io/device.hpp:446:31: warning: unused parameter 'data' [-Wunused-parameter] void write( const byte_t* data ^ boost/gil/io/device.hpp:447:31: warning: unused parameter 'count' [-Wunused-parameter] , std::size_t count ) ^ boost/gil/io/device.hpp:471:35: warning: unused parameter 'data' [-Wunused-parameter] std::size_t read( byte_t* data ^ boost/gil/io/device.hpp:472:35: warning: unused parameter 'count' [-Wunused-parameter] , std::size_t count ) ^ * locale: boost/locale/utf.hpp:224:17: warning: cette instruction peut poursuivre son chemin [-Wimplicit-fallthrough=] c = (c << 6) | ( tmp & 0x3F); ^ boost/locale/utf.hpp:225:13: note: ici case 2: ^~~~ boost/locale/utf.hpp:231:17: warning: cette instruction peut poursuivre son chemin [-Wimplicit-fallthrough=] c = (c << 6) | ( tmp & 0x3F); ^ boost/locale/utf.hpp:232:13: note: ici case 1: ^~~~ * geometry: boost/geometry/formulas/vertex_longitude.hpp:340:32: warning: unused parameter 'lon1' [-Wunused-parameter] static inline CT apply(CT& lon1, ^ boost/geometry/formulas/vertex_longitude.hpp:341:32: warning: unused parameter 'lat1' [-Wunused-parameter] CT& lat1, ^ boost/geometry/formulas/vertex_longitude.hpp:343:32: warning: unused parameter 'lat2' [-Wunused-parameter] CT& lat2, ^ boost/geometry/formulas/vertex_longitude.hpp:344:38: warning: unused parameter 'vertex_lat' [-Wunused-parameter] CT const& vertex_lat, ^ boost/geometry/formulas/vertex_longitude.hpp:345:32: warning: unused parameter 'alp1' [-Wunused-parameter] CT& alp1, ^ boost/geometry/formulas/vertex_longitude.hpp:346:44: warning: unused parameter 'azimuth_strategy' [-Wunused-parameter] Strategy const& azimuth_strategy) ^ boost/geometry/strategies/spherical/intersection.hpp:544:81: warning: unused parameter 'b2' [-Wunused-parameter] Point2 const& b1, Point2 const& b2, // in ^ boost/geometry/algorithms/detail/envelope/segment.hpp:156:61: warning: unused parameter 'lon1' [-Wunused-parameter] static inline void compute_box_corners(CalculationType& lon1, ^ boost/geometry/algorithms/detail/envelope/segment.hpp:158:61: warning: unused parameter 'lon2' [-Wunused-parameter] CalculationType& lon2, ^ boost/geometry/strategies/spherical/intersection.hpp:544:81: warning: unused parameter 'b2' [-Wunused-parameter] Point2 const& b1, Point2 const& b2, // in ^ * asio (windows 32 and 64 bits with mingw w64 + g++ 8.2.0) : /softs/win32-mingw-8.2.0/release/boost/include/boost/asio/detail/impl/win_iocp_socket_service_base.ipp: Dans la fonction membre « boost::system::error_code boost::asio::detail::win_iocp_socket_service_base::cancel(boost::asio::> /softs/win32-mingw-8.2.0/release/boost/include/boost/asio/detail/impl/win_iocp_socket_service_base.ipp:253:51: warning: transtypage entre types de fonctions incompatibles de « FARPROC » {aka « int (__attribute__((stdcall)) *)()> cancel_io_ex_t cancel_io_ex = (cancel_io_ex_t)cancel_io_ex_ptr; ^~~~~~~~~~~~~~~~ * ublas: /softs/lin64-gcc-8.2.0/debug/boost/include/boost/numeric/ublas/matrix_expression.hpp:2224:17: warning: cette instruction « if » ne protège pas… [-Wmisleading-indentation] if (it2_ != it2_end_) ^~ /softs/lin64-gcc-8.2.0/debug/boost/include/boost/numeric/ublas/matrix_expression.hpp:2227:21: note: …cette instruction, mais l'indentation de cette dernière est trompeuse car elle fait croire qu'elle est gardée par le « if » if (it2_ != it2_end_) { ^~ boost/numeric/ublas/functional.hpp:1673:57: warning: unused parameter 'size_i' [-Wunused-parameter] size_type upper_element (size_type i, size_type size_i, size_type j, size_type size_j) { ^ boost/numeric/ublas/functional.hpp:1673:88: warning: unused parameter 'size_j' [-Wunused-parameter] size_type upper_element (size_type i, size_type size_i, size_type j, size_type size_j) { ^ * interprocess (windows mingw-w64 + g++ 8.2.0 32/64 bits): In file included from boost/interprocess/errors.hpp:41, from boost/interprocess/exceptions.hpp:24, from boost/interprocess/sync/file_lock.hpp:24, from Progs/delypse-transfer.cpp:32: boost/interprocess/detail/win32_api.hpp:189:8: warning: « struct boost::interprocess::winapi::IUnknown_BIPC » a des fonctions virtuelles et un destructeur non virtuel accessible [-Wnon-virtual-dtor] struct IUnknown_BIPC ^~~~~~~~~~~~~ boost/interprocess/detail/win32_api.hpp:200:8: warning: la classe de base « struct boost::interprocess::winapi::IUnknown_BIPC » a un destructeur non virtuel accessible [-Wnon-virtual-dtor] struct IWbemClassObject_BIPC : public IUnknown_BIPC ^~~~~~~~~~~~~~~~~~~~~ boost/interprocess/detail/win32_api.hpp:200:8: warning: « struct boost::interprocess::winapi::IWbemClassObject_BIPC » a des fonctions virtuelles et un destructeur non virtuel accessible [-Wnon-virtual-dtor] boost/interprocess/detail/win32_api.hpp:306:8: warning: la classe de base « struct boost::interprocess::winapi::IUnknown_BIPC » a un destructeur non virtuel accessible [-Wnon-virtual-dtor] struct IWbemContext_BIPC : public IUnknown_BIPC ^~~~~~~~~~~~~~~~~ boost/interprocess/detail/win32_api.hpp:306:8: warning: « struct boost::interprocess::winapi::IWbemContext_BIPC » a des fonctions virtuelles et un destructeur non virtuel accessible [-Wnon-virtual-dtor] boost/interprocess/detail/win32_api.hpp:345:8: warning: la classe de base « struct boost::interprocess::winapi::IUnknown_BIPC » a un destructeur non virtuel accessible [-Wnon-virtual-dtor] struct IEnumWbemClassObject_BIPC : public IUnknown_BIPC ^~~~~~~~~~~~~~~~~~~~~~~~~ boost/interprocess/detail/win32_api.hpp:345:8: warning: « struct boost::interprocess::winapi::IEnumWbemClassObject_BIPC » a des fonctions virtuelles et un destructeur non virtuel accessible [-Wnon-virtual-dtor] boost/interprocess/detail/win32_api.hpp:369:8: warning: la classe de base « struct boost::interprocess::winapi::IUnknown_BIPC » a un destructeur non virtuel accessible [-Wnon-virtual-dtor] struct IWbemServices_BIPC : public IUnknown_BIPC ^~~~~~~~~~~~~~~~~~ boost/interprocess/detail/win32_api.hpp:369:8: warning: « struct boost::interprocess::winapi::IWbemServices_BIPC » a des fonctions virtuelles et un destructeur non virtuel accessible [-Wnon-virtual-dtor] boost/interprocess/detail/win32_api.hpp:518:8: warning: la classe de base « struct boost::interprocess::winapi::IUnknown_BIPC » a un destructeur non virtuel accessible [-Wnon-virtual-dtor] struct IWbemLocator_BIPC : public IUnknown_BIPC ^~~~~~~~~~~~~~~~~ boost/interprocess/detail/win32_api.hpp:518:8: warning: « struct boost::interprocess::winapi::IWbemLocator_BIPC » a des fonctions virtuelles et un destructeur non virtuel accessible [-Wnon-virtual-dtor] In file included from boost/interprocess/errors.hpp:41, from boost/interprocess/exceptions.hpp:24, from boost/interprocess/sync/file_lock.hpp:24, from Progs/delypse-transfer.cpp:32: boost/interprocess/detail/win32_api.hpp: Dans la fonction « bool boost::interprocess::winapi::get_system_time_of_day_information(boost::interprocess::winapi::system_timeofday_information&) »: boost/interprocess/detail/win32_api.hpp:1676:58: warning: transtypage entre types de fonctions incompatibles de « boost::interprocess::winapi::farproc_t » {aka « int (__attribute__((stdcall)) *)() »} vers « boost::interprocess:> dll_func::get(dll_func::NtQuerySystemInformation); ^ boost/interprocess/detail/win32_api.hpp: Dans la fonction « bool boost::interprocess::winapi::unlink_file(const char*) »: boost/interprocess/detail/win32_api.hpp:1892:78: warning: transtypage entre types de fonctions incompatibles de « boost::interprocess::winapi::farproc_t » {aka « int (__attribute__((stdcall)) *)() »} vers « boost::interprocess:> (NtSetInformationFile_t)dll_func::get(dll_func::NtSetInformationFile); ^ boost/interprocess/detail/win32_api.hpp:1894:94: warning: transtypage entre types de fonctions incompatibles de « boost::interprocess::winapi::farproc_t » {aka « int (__attribute__((stdcall)) *)() »} vers « boost::interprocess:> NtQueryObject_t pNtQueryObject = (NtQueryObject_t)dll_func::get(dll_func::NtQueryObject); ^ boost/interprocess/detail/win32_api.hpp:1966:85: warning: transtypage entre types de fonctions incompatibles de « boost::interprocess::winapi::farproc_t » {aka « int (__attribute__((stdcall)) *)() »} vers « boost::interprocess:> NtOpenFile_t pNtOpenFile = (NtOpenFile_t)dll_func::get(dll_func::NtOpenFile); ^ boost/interprocess/detail/win32_api.hpp:1967:73: warning: transtypage entre types de fonctions incompatibles de « boost::interprocess::winapi::farproc_t » {aka « int (__attribute__((stdcall)) *)() »} vers « boost::interprocess:> NtClose_t pNtClose = (NtClose_t)dll_func::get(dll_func::NtClose); ^ boost/interprocess/detail/win32_api.hpp: Dans la fonction « bool boost::interprocess::winapi::get_file_mapping_size(void*, long long int&) »: boost/interprocess/detail/win32_api.hpp:2413:63: warning: transtypage entre types de fonctions incompatibles de « boost::interprocess::winapi::farproc_t » {aka « int (__attribute__((stdcall)) *)() »} vers « boost::interprocess:> (NtQuerySection_t)dll_func::get(dll_func::NtQuerySection); ^ boost/interprocess/detail/win32_api.hpp: Dans la fonction « bool boost::interprocess::winapi::get_semaphore_info(void*, long int&, long int&) »: boost/interprocess/detail/win32_api.hpp:2426:86: warning: transtypage entre types de fonctions incompatibles de « boost::interprocess::winapi::farproc_t » {aka « int (__attribute__((stdcall)) *)() »} vers « boost::interprocess:> (winapi::NtQuerySemaphore_t)dll_func::get(winapi::dll_func::NtQuerySemaphore); ^ boost/interprocess/detail/win32_api.hpp: Dans la fonction « bool boost::interprocess::winapi::query_timer_resolution(long unsigned int*, long unsigned int*, long unsigned int*) »: boost/interprocess/detail/win32_api.hpp:2437:98: warning: transtypage entre types de fonctions incompatibles de « boost::interprocess::winapi::farproc_t » {aka « int (__attribute__((stdcall)) *)() »} vers « boost::interprocess:> (winapi::NtQueryTimerResolution_t)dll_func::get(winapi::dll_func::NtQueryTimerResolution); ^ boost/interprocess/detail/win32_api.hpp: Dans la fonction « bool boost::interprocess::winapi::query_performance_counter(long long int*) »: boost/interprocess/detail/win32_api.hpp:2444:57: warning: transtypage entre types de fonctions incompatibles de « boost::interprocess::winapi::farproc_t » {aka « int (__attribute__((stdcall)) *)() »} vers « boost::interprocess:> dll_func::get(dll_func::QueryPerformanceCounter); ^ boost/interprocess/detail/win32_api.hpp: Dans la fonction « bool boost::interprocess::winapi::query_performance_frequency(long long int*) »: boost/interprocess/detail/win32_api.hpp:2451:59: warning: transtypage entre types de fonctions incompatibles de « boost::interprocess::winapi::farproc_t » {aka « int (__attribute__((stdcall)) *)() »} vers « boost::interprocess:> dll_func::get(dll_func::QueryPerformanceFrequency); ^ * atomic (OSX): boost/include/boost/atomic/detail/ops_gcc_x86_dcas.hpp:269:113: warning: unused parameter 'order' [-Wunused-parameter] static BOOST_FORCEINLINE storage_type exchange(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT

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[release] Boost 1.68.0
by Marshall Clow 09 Aug '18

09 Aug '18

Release 1.68.0 of the Boost C++ Libraries is now available. These open-source libraries work well with the C++ Standard Library, and are usable across a broad spectrum of applications. The Boost license encourages both commercial and non-commercial use. This release contains 1 new libraryand numerous enhancements and bug fixes for existing libraries. For details, including download links, see <https://www.boost.org/users/news/version_1.68.0> You can also download directly from: <https://dl.bintray.com/boostorg/release/1.68.0/> To install this release on your system, see <https://www.boost.org/doc/libs/release/more/getting_started/index.html> Thanks to everyone who participated in this release. Thanks, -- The Boost Release Team

2 1

[release] Boost 1.68.0 Release Candidate 1
by Marshall Clow 08 Aug '18

08 Aug '18

The release candidates for the 1.68.0 release are now available at: <https://dl.bintray.com/boostorg/release/1.68.0/source/> The SHA256 checksums are as follows: 59804d8fad02cf3b09485f3dbc0f9097c05fc1e0123f0c133b35a6c6f601109a boost_1_68_0_rc1.7z 7f6130bc3cf65f56a618888ce9d5ea704fa10b462be126ad053e80e553d6d8b7 boost_1_68_0_rc1.tar.bz2 da3411ea45622579d419bfda66f45cd0f8c32a181d84adfa936f5688388995cf boost_1_68_0_rc1.tar.gz 3b1db0b67079266c40b98329d85916e910bbadfc3db3e860c049056788d4d5cd boost_1_68_0_rc1.zip As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. The web site will be updated today as well.

3 4

[boost.beast] Example REST api's
by Sean Farrow 07 Aug '18

07 Aug '18

Hi, Does anyone have or know of any example rest api's written with boost.beast? Any help appreciated. Kind regards Sean.

1 0

Any plans to fix C++11 nullptr issues?
by James Walker 04 Aug '18

04 Aug '18

When Clang is compiling C++11 code, there may be a warning (-Wzero-as-null-pointer-constant) when 0 or NULL is used instead of nullptr. I've seen these warnings from Smart Ptr and Tokenizer in particular, but I suppose it's all over. This is still the case in 1.68.0 beta 1.

1 0

[boost.interprocess] Construct boost::basic_string with managed_shared_memory as memory soure crash.
by Zhiming Wang 03 Aug '18

03 Aug '18

Hi, I am using boost 1.65.1 interprocess lib, and tried to construct a string that is safe to store in a managed_shared_memory. Types are defined as below: using namespace boost::interprocess; using ShmSegment_t = boost::interprocess::managed_shared_memory; using SegmentMgr_t = boost::interprocess::managed_shared_memory::segment_manager; template <typename T> using Allocator_t = boost::interprocess::allocator<T, SegmentMgr_t>; using String_t = boost::interprocess::basic_string<char, std::char_traits<char>, Allocator_t<char>>; Code in problem is as below: using namespace boost::interprocess; ShmSegment_t segment(open_or_create, "Test", 1L << 31); const std::string stdStr("std_str"); String_t ipcStr( stdStr.c_str(), segment.get_segment_manager()); *// oops, crashed! * Crash backtrace is as below: #0 0x00007ffff7ab735c in boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void, long, unsigned long, 0ul>, 0ul>::get_size (this=0x441f0ff40024) at /usr/include/boost/interprocess/mem_algo/rbtree_best_fit.hpp:593 #1 0x00007ffff7ab157a in boost::interprocess::segment_manager_base<boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void, long, unsigned long, 0ul>, 0u l> >::get_size (this=0x441f0ff40024) at /usr/include/boost/interprocess/segment_manager.hpp:113 #2 0x00007ffff7ab002d in boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interprocess::offset_ptr<void, long, unsigned long, 0ul>, 0ul>, boost::interprocess::iset_index> >::max_size (this=0x7fffeeffbe80) at /usr/include/boost/interprocess/allocators/allocator.hpp:164 #3 0x00007ffff7aaf34d in boost::container::allocator_traits<boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_fa mily, boost::interprocess::offset_ptr<void, long, unsigned long, 0ul>, 0ul>, boost::interprocess::iset_index> > >::priv_max_size (a=...) at /usr/include/boost/container/allocator_traits.hpp:397 #4 boost::container::allocator_traits<boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_family, boost::interproc ess::offset_ptr<void, long, unsigned long, 0ul>, 0ul>, boost::interprocess::iset_index> > >::max_size (a=...) at /usr/include/boost/container/allocator_traits.hpp:331 #5 boost::container::container_detail::basic_string_base<boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boost::interprocess::mutex_famil y, boost::interprocess::offset_ptr<void, long, unsigned long, 0ul>, 0ul>, boost::interprocess::iset_index> > >::max_size (this=0x7fffeeffbe80) at /usr/include/boost/container/string.hpp:354 #6 0x00007ffff7aae68a in boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boo st::interprocess::mutex_family, boost::interprocess::offset_ptr<void, long, unsigned long, 0ul>, 0ul>, boost::interprocess::iset_index> > >::max_size (this=0x7fffeeffbe80) at /usr/include/boost/container/string.hpp:1080 #7 0x00007ffff7aadb7a in boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boo st::interprocess::mutex_family, boost::interprocess::offset_ptr<void, long, unsigned long, 0ul>, 0ul>, boost::interprocess::iset_index> > >::priv_reserve (this=0x7fffeeffbe80, res_arg=21, null_terminate=true) at /usr/include/boost/container/string.hpp:2777 #8 0x00007ffff7aad62a in boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boo st::interprocess::mutex_family, boost::interprocess::offset_ptr<void, long, unsigned long, 0ul>, 0ul>, boost::interprocess::iset_index> > >::reserve (this=0x7fffeeffbe80, res_arg=21) at /usr/include/boost/container/string.hpp:1141 #9 0x00007ffff7aacbdf in boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boo st::interprocess::mutex_family, boost::interprocess::offset_ptr<void, long, unsigned long, 0ul>, 0ul>, boost::interprocess::iset_index> > >::assign (this=0x7fffeeffbe80, first=0x7fff5c000d60 "std_str", last=0x7fff5c000d75 "") at /usr/include/boost/container/string.hpp:1494 #10 0x00007ffff7aac719 in boost::container::basic_string<char, std::char_traits<char>, boost::interprocess::allocator<char, boost::interprocess::segment_manager<char, boost::interprocess::rbtree_best_fit<boo st::interprocess::mutex_family, boost::interprocess::offset_ptr<void, long, unsigned long, 0ul>, 0ul>, boost::interprocess::iset_index> > >::basic_string (this=0x7fffeeffbe80, s=0x7fff5c000d60 "std_str", a=...) at /usr/include/boost/container/string.hpp:741 I tried "p m_header" within GDB at /usr/include/boost/interprocess/mem_algo/rbtree_best_fit.hpp:593, and GDB told me the memory is not accessable. What's worse is that the issue seems not happening in very code path, that's it sometimes works and sometimes fails. Any insight is appreciated. Thanks.

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Re: [Boost-users] ASIO: custom service which works with spawn/yield
by Vinnie Falco 03 Aug '18

03 Aug '18

On Thu, Aug 2, 2018 at 1:02 PM, Richard Hodges <hodges.r(a)gmail.com> wrote: > I think it's worth mentioning that although your code is very well written > and laid out, the horrid internals of asio mean that only ultra-experts can > read it. It really doesn't 'flow'. > > Surely something can be done (in asio and networking TS) in terms of > providing a cleaner, more logical interface for io_object and service > developers? I have thought about this for a few years and even made efforts to provide algorithms and types to make authoring code easier, but they were not successful. I don't think a "grand unifying theory" exists. However, I also think there is a LOT of room for documentation to grow and mature, and there is opportunity for authors to develop strong, well commented examples (something I strive for in Beast). With Networking TS as part of C++20 (or later), at last there will be one correct interface for doing asynchrony. This will incentivize book publishers and library authors to focus specifically on this networking interface to provide educational resources. In my Cppcon 2018 presentation I am also dedicating a couple of slides with guidance on how to learn Asio effectively and write correct programs. Regards

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Serialization and class versioning
by tim＠raisedbar.net 02 Aug '18

02 Aug '18

Hi, I have an application that uses serialization for data storage/retrieval, based on Boost 1.67.0. I've implemented class versioning as per: https://www.boost.org/doc/libs/1_67_0/libs/serialization/doc/tutorial.html#v ersioning The overall archive stores a number of sub-classes, nested within the XML. However, I get a run-time exception thrown that I can't catch when one of my sub-classes (DisplayDefinition) returns from being read in. A bit of debugging found that the problem was caused by the class version number having a value of 0, whilst the file being read had a version number of 3 for the class in question. Here's the bit of the class responsible for the archiving: class DisplayDefinition: public MessageDefinition { ... private: friend std::ostream & operator<<(std::ostream &os, const DisplayDefinition &DD); friend std::istream & operator>>(std::istream &is, const DisplayDefinition &DD); friend class boost::serialization::access; template<class Archive> void serialize(Archive & myArchive, const unsigned int version) { try { const char * cLabelTag = "Label"; myArchive & boost::serialization::make_nvp( cLabelTag, wstrLabel); const char * cAddressBytesTag = "SysExAddressBytes"; myArchive & boost::serialization::make_nvp( cAddressBytesTag, vSysExAddressBytes); const char * cActionsTag = "Actions"; myArchive & boost::serialization::make_nvp( cActionsTag, myActions); const char * cStatesTag = "StateNames"; myArchive & boost::serialization::make_nvp( cStatesTag, StateLabels); const char * cLineCountTag = "LineCount"; myArchive & boost::serialization::make_nvp( cLineCountTag, nDisplayLineCount); const char * cLineLengthTag = "LineLength"; myArchive & boost::serialization::make_nvp( cLineLengthTag, nDisplayLength); const char * cStripCountTag = "StripCount"; myArchive & boost::serialization::make_nvp( cStripCountTag, nStripCount); const char * cIsLEDLampTag = "LEDLamp"; myArchive & boost::serialization::make_nvp( cIsLEDLampTag, blnIsLEDLamp); const char * cTranslationTag = "TranslationID"; myArchive & boost::serialization::make_nvp( cTranslationTag, strTranslationID); const char * cCursorOffsetTag = "CursorOffset"; myArchive & boost::serialization::make_nvp( cCursorOffsetTag, nCursorOffset); if(version > 0) { const char * cCursorFromLeftTag = "CursorFromLeft"; myArchive & boost::serialization::make_nvp( cCursorFromLeftTag, blnCursorFromLeft); } if(version > 1) { const char * cUniCodeTag = "Unicode"; myArchive & boost::serialization::make_nvp( cUniCodeTag, blnIsUniCode); } if(version > 2) { const char * cLinkedHashTag = "LinkedTo"; myArchive & boost::serialization::make_nvp( cLinkedHashTag, strLinkedDisplayHash); } } // end try catch (...) { throw ID_LOAD_DATA_EXCEPTION; } // end catch } ... }; // end of class definition BOOST_CLASS_VERSION(DisplayDefinition, 3); I'm clueless as to why the BOOST_CLASS_VERSION macro doesn't seem to be setting the version number correctly. Can anybody advise me, please? Best wishes. Tim Burgess Raised Bar Ltd. E: <mailto:tim@raisedbar.net> tim(a)raisedbar.net M: +44 (0)7989 486976

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ASIO: custom service which works with spawn/yield
by Cristian Morales Vega 02 Aug '18

02 Aug '18

Hi, I have implemented a custom service using Boost 1.67 which works mostly OK, but I have noticed it always returns success when using spawn/yield. The following simplified sample shows the problem: ------------------------------------------------ #include <boost/asio.hpp> #include <boost/asio/spawn.hpp> #include <boost/beast/core/bind_handler.hpp> #include <iostream> class Service : public boost::asio::io_context::service { public: static boost::asio::io_context::id id; typedef int implementation_type; Service(boost::asio::io_context &io_context) : boost::asio::io_context::service(io_context) {} void construct(implementation_type &) {} void destroy(implementation_type &) {} }; boost::asio::io_context::id Service::id; template <typename Service> class BasicObject : protected boost::asio::basic_io_object<Service> { public: explicit BasicObject(boost::asio::io_context &io_context) : boost::asio::basic_io_object<Service>(io_context) {} template <typename ConnectHandler> auto async_method(ConnectHandler &&handler) { BOOST_ASIO_CONNECT_HANDLER_CHECK(ConnectHandler, handler) typeCheck; boost::asio::async_completion<ConnectHandler, void(const boost::system::error_code &)> init(handler); boost::system::error_code ec = boost::asio::error::already_started; boost::asio::post( boost::beast::bind_handler(std::move(init.completion_handler), std::move(ec))); return init.result.get(); } }; int main() { boost::asio::io_context ioContext; BasicObject<Service> myObject(ioContext); #if 1 boost::asio::spawn(ioContext, [&](boost::asio::yield_context yield) { boost::system::error_code ec; myObject.async_method(yield[ec]); std::clog << ec << std::endl; }); #else myObject.async_method([](const boost::system::error_code &ec) { std::clog << ec << std::endl; }); #endif ioContext.run(); return 0; } ------------------------------------------------ The version not using spawn prints "system:114", the one using spawn prints "system:0". What am I doing wrong? Thanks.

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