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error categories point to invalid data with boost log and asio
by priv＠mariusherzog.net 11 Nov '17

11 Nov '17

I have the following problem while using boost asio together with boost log and clang 3.9.0. When I want to print an error code for example passed to me by a asio completion handler, my program crashes. This is because the error category points to invalid data. If I put a breakpoint in get_misc_error category which is called upon program startup, the local static error category already contains junk data. When I compile with gcc 5.4.0 this error does not occur. Also if I do not link against boost log everything works fine as well. I use linux, and link all boost libraries dynamically. Boost version is 1.62.0. Would it help if I maybe link boost log statically? Is there anything else I can do?

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[signals2] Connect to overloaded slots
by Florian Lindner 10 Nov '17

10 Nov '17

Hello, this code compiles just fine: #include <boost/signals2.hpp> #include <iostream> // void slot() { std::cout << "No args slot called." << std::endl; } void slot(int i) { std::cout << "Int " << i << " arg slot called." << std::endl; } int main(int argc, char **argv) { boost::signals2::signal<void(int)> s; s.connect(&slot); return 0; } However, when I uncomment the slot() function, it does not do so, anymore: boostsignals.cpp:78:5: error: no matching member function for call to 'connect' s.connect(&slot); ~~^~~~~~~ /usr/include/boost/signals2/detail/signal_template.hpp:689:18: note: candidate function not viable: no overload of 'slot' matching 'const boost::signals2::signal<void (int), boost::signals2::optional_last_value<void>, int, std::less<int>, boost::function<void (int)>, boost::function<void (const boost::signals2::connection &, int)>, boost::signals2::mutex>::slot_type' (aka 'const slot<void (int), boost::function<void (int)> >') for 1st argument connection connect(const slot_type &slot, connect_position position = at_back) ^ /usr/include/boost/signals2/detail/signal_template.hpp:693:18: note: candidate function not viable: requires at least 2 arguments, but 1 was provided connection connect(const group_type &group, ^ Is there a way to make it working with overloaded slot functions? Thanks, Florian

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(no subject)
by giridhar 08 Nov '17

08 Nov '17

Hi Boost http://bit.ly/2hcH687 giridhar

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Warning "declares a non-template function"
by mahmood n 06 Nov '17

06 Nov '17

Hi, A program needs boost > 1.58. So, I used boost-1.60 with gcc-4.8. However, as I compile the program, I get many warnings similar to /home/mahmood/boost_1_60_0/boost/mpl/set/aux_/item.hpp(47): warning: "char (&operator||(const boost::mpl::s_item<T, Base> &, boost::mpl::aux::type_wrapper<T> *))[boost::mpl::next<Base::order>::type::value]" declares a non-template function -- add <> to refer to a template instance /home/mahmood/boost_1_60_0/boost/mpl/set/aux_/item.hpp(48): warning: "boost::mpl::aux::no_tag operator%(const boost::mpl::s_item<T, Base> &, boost::mpl::aux::type_wrapper<T> *)" declares a non-template function -- add <> to refer to a template instance Lines are BOOST_MPL_AUX_SET_OVERLOAD( order_tag_, ORDER_BY_KEY, s_item, aux::type_wrapper<T>* ); BOOST_MPL_AUX_SET_OVERLOAD( aux::no_tag, IS_MASKED, s_item, aux::type_wrapper<T>* ); Does that mean I have to change that to aux::type_wrapper< >* ? Regards, Mahmood

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Under ubuntu, How to purge default boost-v1.58 then switch to the built version without any damages?
by Alex Luya 06 Nov '17

06 Nov '17

Under ubuntu 16,04 I have*built latest boost 1.65**.1 like this*: |./bootstrap.sh --prefix=/usr/local ./b2 sudo ./b2 install sudo ldconfig ***then when building something against boost,I got the**se errors:* /usr/local/include/boost/serialization/access.hpp: In instantiation of ‘static void boost::serialization::access::serialize(Archive&, T&, unsigned int) [with Archive = boost::archive::text_oarchive; T = std::array<std::__cxx11::basic_string<char>, 10ul>]’: /usr/local/include/boost/serialization/serialization.hpp:68:22: required from ‘void boost::serialization::serialize(Archive&, T&, unsigned int) [with Archive = boost::archive::text_oarchive; T = std::array<std::__cxx11::basic_string<char>, 10ul>]’ /usr/local/include/boost/serialization/serialization.hpp:126:14: required from ‘void boost::serialization::serialize_adl(Archive&, T&, unsigned int) [with Archive = boost::archive::text_oarchive; T = std::array<std::__cxx11::basic_string<char>, 10ul>]’ /usr/local/include/boost/archive/detail/oserializer.hpp:150:40: required from ‘void boost::archive::detail::oserializer<Archive, T>::save_object_data(boost::archive::detail::basic_oarchive&, const void*) const [with Archive = boost::archive::text_oarchive; T = std::array<std::__cxx11::basic_string<char>, 10ul>]’ /usr/local/include/boost/archive/detail/oserializer.hpp:103:1: required from ‘class boost::archive::detail::oserializer<boost::archive::text_oarchive, std::array<std::__cxx11::basic_string<char>, 10ul> >’ /usr/local/include/boost/archive/detail/oserializer.hpp:255:13: required from ‘static void boost::archive::detail::save_non_pointer_type<Archive>::save_standard::invoke(Archive&, const T&) [with T = std::array<std::__cxx11::basic_string<char>, 10ul>; Archive = boost::archive::text_oarchive]’ /usr/local/include/boost/archive/detail/oserializer.hpp:310:22: required from ‘static void boost::archive::detail::save_non_pointer_type<Archive>::invoke(Archive&, const T&) [with T = std::array<std::__cxx11::basic_string<char>, 10ul>; Archive = boost::archive::text_oarchive]’ /usr/local/include/boost/archive/detail/oserializer.hpp:534:18: required from ‘void boost::archive::save(Archive&, T&) [with Archive = boost::archive::text_oarchive; T = const std::array<std::__cxx11::basic_string<char>, 10ul>]’ /usr/local/include/boost/archive/detail/common_oarchive.hpp:70:22: required from ‘void boost::archive::detail::common_oarchive<Archive>::save_override(T&) [with T = const std::array<std::__cxx11::basic_string<char>, 10ul>; Archive = boost::archive::text_oarchive]’ /usr/local/include/boost/archive/basic_text_oarchive.hpp:83:9: required from ‘void boost::archive::basic_text_oarchive<Archive>::save_override(T&) [with T = const std::array<std::__cxx11::basic_string<char>, 10ul>; Archive = boost::archive::text_oarchive]’ /usr/local/include/boost/archive/detail/interface_oarchive.hpp:70:9: required from ‘Archive& boost::archive::detail::interface_oarchive<Archive>::operator<<(const T&) [with T = std::array<std::__cxx11::basic_string<char>, 10ul>; Archive = boost::archive::text_oarchive]’ examples/user_code/openpose_recognition.cpp:867:89: required from here /usr/local/include/boost/serialization/access.hpp:116:9: error: ‘struct std::array<std::__cxx11::basic_string<char>, 10ul>’ has no member named ‘serialize’ t.serialize(ar, file_version); ^ compilation terminated due to -Wfatal-errors. Makefile:478: die Regel für Ziel „.build_release/examples/user_code/openpose_recognition.o“ scheiterte make: *** [.build_release/examples/user_code/openpose_recognition.o] Fehler 1 make: *** Auf noch nicht beendete Prozesse wird gewartet … | |*I think ubuntu is still use default boost that installed by apt-get,so I tried to pur**ge it * sudo apt-get purge libboost1.58-dev| *the output asks me to remove a lot of stuffs **that depend on libboost1.58-dev **like these:* Die folgenden Pakete wurden automatisch installiert und werden nicht mehr benötigt: docutils-common fltk1.3-doc fluid gazebo7 gazebo7-common gazebo7-plugin-base gir1.2-gtk-2.0 libapr1 libapr1-dev libaprutil1 libaprutil1-dev libarmadillo6 libassimp-dev libassimp3v5 libboost-atomic1.58.0 libboost-chrono1.58.0 libboost-context1.58.0 libboost-coroutine1.58.0 libboost-graph-parallel1.58.0 libboost-graph1.58.0 libboost-locale1.58.0 libboost-log1.58.0 libboost-math1.58.0 libboost-mpi-python1.58.0 libboost-mpi1.58.0 libboost-python1.58.0 libboost-random1.58.0 libboost-regex1.58.0 libboost-signals1.58.0 libboost-test1.58.0 libboost-thread1.58.0 libboost-timer1.58.0 libboost-tools-dev libboost-wave1.58.0 libboost1.58-tools-dev libbullet-dev libbulletcollision2.83.6 libbulletdynamics2.83.6 libbulletsoftbody2.83.6 libbz2-dev libcollada-dom2.4-dp-dev libcollada-dom2.4-dp0 libconsole-bridge-dev libconsole-bridge0.2v5 libcurl4-openssl-dev libdap-dev libdap17v5 libdapclient6v5 libdapserver7v5 libepsilon1 libflann-dev libflann1.8 libfltk-cairo1.3 libfltk-forms1.3 libfltk-images1.3 libfltk1.3-dev libfreeimage-dev libfreeimage3 libfreexl1 libgazebo7 libgdal-dev libgdal1i libgeos-3.5.0 libgeos-c1v5 libgeos-dev libgl2ps-dev libgtest-dev libgtk2.0-dev libgts-0.7-5 libgts-bin libgts-dev libhdf4-0-alt libhdf4-alt-dev libhdf5-mpi-dev libignition-math2 libignition-math2-dev libinput-dev libjs-jquery-ui libjsoncpp-dev libjxr0 libkmlbase1 libkmldom1 libkmlengine1 libldap2-dev liblinearmath2.83.6 liblog4cxx-dev liblog4cxx10-dev liblog4cxx10v5 liblz4-dev libminizip1 libnetcdf-c++4 libnetcdf-cxx-legacy-dev libnetcdf-dev libnetcdf11 libogdi3.2 libogre-1.9.0v5 libopenni-dev libopenni-sensor-pointclouds0 libopenni0 ....... ,and it may cause a lot of damage if continuing,so the question is |*How to purge default boost-v1.58 then switch to the built version without any damages?*|

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[asio] Does ssl::stream allow multiple pending async operations?
by Phil Sean 06 Nov '17

06 Nov '17

The documentation for ssl::stream says: "Shared objects: Unsafe. The application must also ensure that all asynchronous operations are performed within the same implicit or explicit strand." Does this mean we have to wait for an async operation to finish before another is started (for read/read, read/write, and write/write)? (Async operations refer to async_read_some() and async_write_some(), not the composed operations.) If so, is the operation said to have finished when the handler is invoked or when the handler returns? That is: void handler( const boost::system::error_code& error, std::size_t bytes_transferred ) { // Does the operation finish here ... } // or here? If not, what's the difference between the async operations of ip::tcp::socket and ssl::stream then (as strand just avoids concurrency for the thread-unsafe)? I came across different views on this problem. This answer[1] suggests that simply using the same strand (ie. no concurrency) will suffice. Another one[2] says multiple pending asynchronous operations can be problematic for ssl::stream even if no concurrency occurs. Thanks. [1] https://stackoverflow.com/questions/27212123/executing-asynchronous-operati… [2] https://stackoverflow.com/questions/15352472/using-boosts-ssl-asio-code-asy…

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Spirit: how to force backtracking
by Stian Zeljko Vrba 04 Nov '17

04 Nov '17

I have the following grammar rule: value = (int_ % ',') | *ascii::print; The intention is to parse either a comma-separated list of integers or a string. The rule as such fails in cases like "123ABC", which should be parsed as string. >From the description of the | operator, I would expect the parser to backtrack and try the other alternative when it sees that the first alternative does not match the input. However, I get a parse error instead (this rule is a part of a larger grammar), I guess because the first alternative matches the single integer but the rest of the grammar cannot be matched. How to rewrite the grammar to resolve this ambiguity, or force spirit to backtrack if the first alternative of 'value' cannot be matched?

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[locale] how to read a local date from an istream?
by Frédéric 02 Nov '17

02 Nov '17

Hi, With boost::locale we can output a localized date: double d=...; std::cout<<boost::locale::as::date<<d; but how can I read a date from a string? std::cin>>boost::locale::as::date>>d; does not work. It stops reading at the first "/". For example, this small program #include <iostream> #include <sstream> #include <boost/locale/formatting.hpp> #include <boost/locale/generator.hpp> int main(int argc, char **argv) { boost::locale::generator gen; gen.categories(); auto loc = gen(""); double date = 5.; // default value to see if it changes std::istringstream iss("2/11/2017"); // November 1st, 2017 in French iss.imbue(loc); iss >> boost::locale::as::date >> boost::locale::as::local_time >> date; std::cout.imbue(loc); std::cout << "as_posix: " << boost::locale::as::posix << date << "\n" << "as_date: " << boost::locale::as::date << date << "\n"; return 0; } outputs as_posix: 2 as_date: 01/01/1970 instead of as_posix: 1509617233 (may be different) as_date: 02/11/2017 F

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Re: [Boost-users] Many undefined references for libboost_filesystem
by mahmood n 01 Nov '17

01 Nov '17

I used another gcc version 4.5 (Ubuntu 11.04) and it works without any problem! I don’t know what is wrong with gcc-4.6. Though the problematic platform was Kubuntuu 12.04. I am know trying with Ubuntu 12.04 which uses gcc-4.6 to see if it is really a gcc problem or the platform! Sent from Mail for Windows 10 From: Alex Perry Sent: Wednesday, October 18, 2017 4:45 PM To: mahmood n Subject: RE: [Boost-users] Many undefined references for libboost_filesystem Actually one other thought (though you may well have solved this by now). Are you sure that the boost libraries you are attempting to link to are using the same abi? Ie how were they built. I only glanced at the github stuff you pointed too but I think I remember that the last commit was 5 years ago or some such – so probably wasn’t using C++11. I note you are using an old (54) version of boost whilst the current is (65) so about 5 years ago as well – but that probably supported being built with c++11.so you might need to rebuild them if they were using a different version of the C++ standard (or any abi breaking change such as 32 vs 64 bit, static runtime vs dynamically loaded etc). Under windows boost normally encodes the abi into the library name and you just automagically (using a msvc extension) link to the appropriate one. That is not the normal way on linux since gcc doesn’t have autolinking so you normally end up sticking them into a separate lib directory and swapping the -L path depending on which abi you want Again though please note this is not boost specific – is just standard C / C++ / Fortran or any obj/link based language issues with building dependencies – (and why most have swapped to using cmake rather than vanilla make to avoid the pain). A. From: Alex Perry Sent: 17 October 2017 16:14 To: 'mahmood n' <nt_mahmood(a)yahoo.com> Subject: RE: [Boost-users] Many undefined references for libboost_filesystem Dropped the rest of the boost list since I’m sure not many are interested! > I didn’t want to have another pain for “finding how the verbose variable is set in the Makefile”!!! Not hard that one… just add it to the command line when you call make make verbose=1 ….. > The libraries do exist, so why on earth it can not link :( > mahmood@vb:AES$ g++ -fPIC -L/home/mahmood/boost_1_54_0/stage/lib -lboost_filesystem -lboost_system -m64 -o /home/mahmood/gpgpu-sim_distribution/ispass2009-benchmarks/bin/release/AES obj/x86_64/release/aescuda.cpp.o obj/x86_64/release/aesCudaUtils.cpp.o obj/x86_64/release/aesHost.cu.o -L/usr/local/cuda/lib64 -L/home/mahmood/NVIDIA_GPU_Computing_SDK/C/src//../lib -L/home/mahmood/NVIDIA_GPU_Computing_SDK/C/src//../common/lib/linux -L/home/mahmood/NVIDIA_GPU_Computing_SDK/C/src//../../shared//lib -lcudart -L/usr/local/cuda/lib64 -L/home/mahmood/NVIDIA_GPU_Computing_SDK/C/src//../lib -L/home/mahmood/NVIDIA_GPU_Computing_SDK/C/src//../common/lib/linux -L/home/mahmood/NVIDIA_GPU_Computing_SDK/C/src//../../shared//lib -lcudart -lcutil_x86_64 -lshrutil_x86_64 …. Nope the computer is telling you they don’t exist on those paths as given – unfortunately the computer is more likely to be correct than you on this! You have a lot of library paths being set there – possibly you have multiple versions of boost libraries so its finding the wrong one first so you have a version conflict Possibly the simplest way is create a noddy test and play with the command line till you work out what the problem is http://rextester.com/live/JDVHT54458 That will give you similar compile errors without -lboost_filesystem -lboost_system added to the compile line. Obviously that is using clang rather than gcc which you are using but the syntax and principles are pretty much the same between any c++ compiler HTH A.

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Boost graph library algorithms - is it possible to use previous solutions to "warm start" a new related problem
by F1E2D3 F1E2D3 29 Oct '17

29 Oct '17

Hello, I am primarily an Operations Researcher, and prior to boost, was writing my own C++ code for specific network flow problems. I am now hoping to transition to boost::graph completely for my network flow problem solution needs. However, I have one major concern. In linear programming (I use CPLEX https://www.ibm.com/us-en/marketplace/ibm-ilog-cplex as my primary linear programming (LP) solver), once a problem is solved, say a Dijkstra's shortest path problem, the solver maintains the optimal basis. Then, if some problem parameter changes, the linear program need not be solved from scratch, but the current basis is first tested for optimality for the new problem as well. An example of this would be an increase in the cost of an arc that does not feature on the optimal path from source to destination in a shortest path problem. This increase in cost does not change the optimal path, and hence, it would be wasteful to solve this problem again from scratch. Does boost::graph have this capability that LP solvers have? I posted this question first on stack overflow and am posting it here now. The question was not completely answered there. A working code and small example are provided there. I am giving the link below. https://stackoverflow.com/questions/46986312/are-boostgraph-algorithms-capa… Any help will be appreciated. Thanks.

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