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[statechart] Passing parameters from event to State Local Storage
by Christophe Bourez 16 Nov '16

16 Nov '16

I need to maintain a parameter into the state local storage. This parameter is initially contained in the event that causes the transition to the target state. I give hereafter a small illustrative example. typename sc = boost::statechart; class EvTest : public sc::event<EvTest> { public: EvTest(std::size_t val) : value(val) {} std::size_t getValue() const { return this->value; } private: std::size_t value; }; class MyStateMachine; class StSource; class StTarget; class StSource : public sc::simple_state<StSource, MyStateMachine> { public: typedef sc::custom_reaction<EvTest> reactions; sc::result react(const EvTest &event) { // How to pass event.getValue() to the target state ? transit<StTarget>(); } }; class StTarget : public sc::simple_state<StTarget, MyStateMachine> { public: StTarget(std::size_t val) : val(value) {} private: std::size_t value; }; Thanks, Christophe

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Help needed for boost polygon get trapezoid
by Lei Yin 15 Nov '16

15 Nov '16

Hello all, I recently moved to use boost.polygon for doing non-manhattan shape boolean operation, and I'm using get_trapezoids() function to convert output polygons to trapezoids. There're two problems I'm facing and couldn't overcome: 1. Somehow boost.polygon not always give me the largest polygon as possible. In the result, frequently I saw there are two trapezoids are neighboring each other, and they can be perfectly combined into one big trapezoid, but for some reason, boost.polygon give me separated two instead of one. 2. It maybe due to floating point snapping issue (I'm operating on integer base), for some special cases, I got very slim trapezoid like 1 db unit in width. Preferably, this trapezoid Any suggestion to solve above issues would be much appreciated! Thanks in advance. Lei

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How to get response of the questions I posted?
by Bruce 15 Nov '16

15 Nov '16

Hi, I am not familiar with emails list. First time use or I don't known where to post boost.log questions. I found I can't receive the response of my thread by email. I have to check the boost.user archive and I can't response in the archive list. I do subscribed to this list or I can't post. Anybody can help me? Many thanks.

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Questions about extending boost::log sink backend based on app_luncher example
by Bruce 15 Nov '16

15 Nov '16

Hi,I am extending the boost::log backend sink to show log record into GUI ListBox control, which is gui_logger. I modify based on the app_luncher example which extends backend sink of :basic_formatted_sink_backend. Below are the questions that I have for now: 1) when modifying the consume function, I don't know how to get the message body. void consume(logging::record_view const& rec, string_type const& command_line); I using TRACE of visualstudio 2015 to first log the message out into vs2015 console. But I don't know how the get the message from record_view? 2) When I TRACE(command_line.c_str()) of consume function, I logged every record out into vs2015 console. I need to set a filter to only output some of the log. How to set filters with gui_logger? I notice there is sink->set_filter function, but I don't know how to set in my situation.In my scenario, I setup a src::severity_channel_logger (db_logger) with keywords::channel = "dblog", which output to db.log file. I want to use gui_logger to show the latest 200 records on the ListBox. gui_logger should use the same filter with db_logger. gui_logger log the latest 200 records into gui ListBox. db_logger log all the records into text file. So I need to set the same filter with db_logger. 3) I read settings from the ini file for db_logger. I want also to read setting from ini file for gui_logger. How to do it?

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How to wrap boost::log class to user?
by Bruce 14 Nov '16

14 Nov '16

Hi, I am coding a project and I use boost::log. I need to supply the log function to user, but I don't want the user use boost::log directly. I want to wrap the boost::log into my class. But I still want to keep the << cascade feature. Basically, I need to implement a MyLogger class, which support: MyLogger(info) << bla bla bla; MyLogger(trace) << bla bla bla; and in the operator << function, I can use: BOOST_LOG_SEV macro. I don't know how to implement the operator << in MyLogger class. Can anybody helps me, Thanks.

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How to use boost::log to setup multiple logger?
by 刘宝良 14 Nov '16

14 Nov '16

Hi, I want to use boost::log to setup 3 logger for different purpose. Not one logger to have multiple output file. And I also want one logger to have one file output and a GUI output to be viewed by the end user. How to do it? -Bruce

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boost::filesystem::path::iterator and libstdc++ std::search
by Oleksandr Senkovych 11 Nov '16

11 Nov '16

Hi guys. Several days ago I've faced a strange issue with boost::filesystem::path::iterator - it segfaults when used in some STL algorithms. Here's a sample code that crashes: http://melpon.org/wandbox/permlink/58aIbfJWeGgMKMdF I looked at the issue a little bit and discovered that the reason for that is this part of iterator code: const path& dereference() const { return m_element; } So when using std::search libstdc++ has to convert binary predicate to unary for later use in std::find_if: __first1 = std::__find_if(__first1, __last1, __gnu_cxx::__ops::__iter_comp_iter(__predicate, __first2)); It does this by capturing dereferenced value of second iterator (__first2 in a piece of code above) but since iterator is passed by-value, this wrapper holds dangling reference to local member of iterator.m_element. Now according to C++ standard part 24.2.1 [iterator.requirements.general]: 10. Destruction of an iterator may invalidate pointers and references previously obtained from that iterator. So this looks like a violation of a standard by libstdc++ library. Unfortunately I couldn't get my account registered at https://gcc.gnu.org/bugzilla/ and was not able to file a bug, so can I ask you to help me with it?

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boost::filesystem::native
by Christopher J. Pisz 10 Nov '16

10 Nov '16

I did a Google search to see how to check if a given path is valid, preferably using boost. It brought me here: http://stackoverflow.com/questions/10426671/how-to-check-if-path-is-valid-i… Great! I say to myself. I then Google up the boost doc here: http://www.boost.org/doc/libs/1_62_0/libs/filesystem/doc/portability_guide.… I then write myself a test: #include <iostream> #include <sstream> #include <boost/filesystem.hpp> int main() { const std::string test1 = "D:\\Programing Projects\\Git Workspace\\Common\\x64\\Debug"; const std::string test2 = "D:\Programing Projects\\Git Workspace\\Common\\x64\\Debug\\"; const std::string test3 = "D:/Programing Projects/Git Workspace/Common/x64/Debug"; const std::string test4 = "D:/Programing Projects/Git Workspace/Common/x64/Debug/"; if (!boost::filesystem::native(test1)) { std::cout << "Boost says the following path is not valid for the native operating system: " << test1 << std::endl; } if (!boost::filesystem::native(test2)) { std::cout << "Boost says the following path is not valid for the native operating system: " << test2 << std::endl; } if (!boost::filesystem::native(test3)) { std::cout << "Boost says the following path is not valid for the native operating system: " << test3 << std::endl; } if (!boost::filesystem::native(test4)) { std::cout << "Boost says the following path is not valid for the native operating system: " << test4 << std::endl; } return 0; } The Test's Output: Boost says the following path is not valid for the native operating system: D:\Programing Projects\Git Workspace\Common\x64\Debug Boost says the following path is not valid for the native operating system: D:Programing Projects\Git Workspace\Common\x64\Debug\ Boost says the following path is not valid for the native operating system: D:/Programing Projects/Git Workspace/Common/x64/Debug Boost says the following path is not valid for the native operating system: D:/Programing Projects/Git Workspace/Common/x64/Debug/ What is wrong with that path that it says it is not valid for my native Windows 10 operating system?

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Boost.ASIO stuck on some requests?
by Matthieu Brucher 10 Nov '16

10 Nov '16

Hi, I have an app that serves different clients and it is based on Boost.ASIO. My current issue is that if the first client is fast enough (a continuous fast loop with Python module requests), then the other clients may time out with no good reason when trying to connect. Is there a way of figuring out who is actually waiting on who? Maybe the clients are starved because of an issue on their box, or there is an issue in ASIO that serves always the first connection? Or is it Windows? I tried multithreading the server, but that didn't help, and a run with VTune Amplifier shows me that the app is mainly waiting. But if I add a 100ms sleep between requests, then everything is fine. But this is not an acceptable solution, as the clients in real life will want to launch requests all the time. Regards, Matthieu Brucher -- Information System Engineer, Ph.D. Blog: http://blog.audio-tk.com/ LinkedIn: http://www.linkedin.com/in/matthieubrucher

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[boost][process] Formal review results
by Antony Polukhin 09 Nov '16

09 Nov '16

The Boost.Process library is accepted. Congratulations to Klemens, and thanks to everybody who reviewed the library! The votes were as follows: + Johannes - Niall Douglas +/- Tom Kent +/- Nat Goodspeed + Paul A. Bristow +/- Bjorn Reese + Edward Diener + Boris Schäling +/- Raphaël Londeix + Klaim - Joël Lamotte Legend: + accept - decline +/- accept conditionally Separate thanks to Gavin Lambert for providing a solution to deadlocking problem. Additional thanks to Nat Goodspeed, Niall Douglas, Gavin Lambert, Raphaël Londeix and Bjorn Reese for spending significant amount of time on discussing, reviewing or testing the library. -- Quick review summary -- During the review multiple technical issues were raised and as far as I know, Klemens already working on them. The biggest win of the review - is a fix for possible deadlock with pipes. The most controversial part of the library is it's interface. Many comments were addressing: * passing arguments * starting process right in `system(...)` function Current approaches have benefits and drawbacks, other approaches have different benefits and drawbacks. At this point some people agree that the current approach is the lesser evil. Reviewers also wished to have better/richer documentation. P.S.: Please continue with the discussion and report issues that would help to improve the library. -- Best regards, Antony Polukhin

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Visual Studio "15" Preview Update 5 configuration
by csiga.biga＠aol.com 09 Nov '16

09 Nov '16

Hi fellow users! This is my first message to this list, so take it easy if something’s not right. I wanted to build Boost with the latest Visual Studio spin, dubbed „15” Update 5 (RC coming sometime in November), but the configuration scripts do not quite work. Because _MSC_VER is 1910, I get the unkown compiler pragma warning, but what is more vexing, is that the configuration is not right, I get compilation errors in boost::functional, because std::unary_function has been deprecated since C++11, and VS „15” has removed this function from the STL. The _MSC_FULL_VER is 191024516, and I wanted to use the new toolset, because it has significantly improved in terms of conformance, most notably support for generalized constexpr. (See full list in the link) Can someone help with patching the configuration scripts? I would rather not start defining things to get deprecated features into scope again, but if nothing else works as a hotfix, than so be it. Thanks in advance, Máté

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Help in calculating the size of a boost::unordered_map
by Ram 08 Nov '16

08 Nov '16

Hi, I would like to calculate the size of my filled up boost::unordered_map including the house keeping. I was thinking of sizeof(boost:unordered_map mymap). I asked this question on stackoverflow but they say that wont help. Can somebody tell me an easy way to find the size including the housekeeping that it takes? The boost::unordered_map stores a std::string as the key and a pointer to my class object as the value. Thanks, Ram

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An Asio based header-only asynchronous MySQL client library
by Cheng Lian 07 Nov '16

07 Nov '16

Hey all, Here is an Asio based header-only asynchronous MySQL client library called Amy (*A*synchronous *My*SQL). https://github.com/liancheng/amy In short, this library enables you to work with MySQL in both asynchronous and blocking ways. Links to examples are included in the README file. Haven't got time and energy to write comprehensive documents, though. The interesting thing is that, I wrote this library years ago as an exercise, open sourced it, and then basically forgot about it. However, recently an European developer contacted me and said that they used it in one of their game projects in production and it was "amazing". So I decided to spend some time to polish it a little bit and send it out here to see whether there are anyone else who are interested in it. Please let me know what you think about it. Thanks! Best, Cheng

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Problem compiling a code that uses Boost
by Fernando E Alva Manchego 04 Nov '16

04 Nov '16

Hello, I'm trying to compile a code that uses boost. The code is this one: http://people.eng.unimelb.edu.au/tcohn/t3.html The version of boost installed in the machine is: 1.41 The machine where I'm running this code is a Scientific Linux release 6.8 (Carbon). The detailed error message that I get can be seen here: http://pastebin.com/ADj4j6k0 Basically, the errors messages are like this: undefined reference to `boost::program_options::options_description::options_description(...) undefined reference to `boost::program_options::validation_error::get_template(...) -lboost_program_options is in the compilation line. And I've checked using 'locate' that /usr/lib64 (as appears in the compilation line) contains: /usr/lib64/libboost_program_options-mt.so /usr/lib64/libboost_program_options-mt.so.5 /usr/lib64/libboost_program_options.so /usr/lib64/libboost_program_options.so.5 I would really appreciate any help you could help me with this error. Best, Fernando

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Re: [Boost-users] build of datetime library fails
by LAMOTTE Thierry 03 Nov '16

03 Nov '16

Dear Andreas and Marcel, I checked my Visual Studio 13 Update : it is Update 5, so on this side it is ok. But Andreas you were perfectly right : as soon as I get Boost release 1.56, compilation completes with no warning and no error. I retry Boost 1.62 but it still does not work : it claims for a msvc internal error C1001. Sorry I won't keep investigating since I do not have time for that. I get at least one that works and for now it is enough to help me move on on my project matters that are quite far for boost. I greatly thank both of you for your help, I really appreciate. Best regards, Thierry Note: I do no know why I could not login with my email/password and reply directly on http://boost.2283326.n4.nabble.com/build-of-datetime-library-fails-td468 9472.html#a4689486

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build of datetime library fails
by LAMOTTE Thierry 03 Nov '16

03 Nov '16

Dear Boost community, For the purpose of a project that uses Boost libraries, I tried rebuild Boost but I failed. I would please need some help to complete that building. My context is Microsoft Windows 7, 32 bits, Visual Studio 13 (msvc-12), Boost 1.54.0 My goal is to the create static libraries : libboost_chrono, regex, system, thread and datetime. I initially used a tutorial from the Nordic's github to build Boost : https://github.com/NordicSemiconductor/pc-ble-driver My last try was with Boost 1.54.0 (the one used in the mentioned tuto), the build of datetime library fails (I attached the ouput) and frankly speaking I do not know where I should start looking for. If anyone could help me ? For note, at early stage, I tried with Boost 1.62.0, but the outcome was even worse, I gave up. Best regards, Thierry

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Microsoft and hana
by Dan Bloomquist 31 Oct '16

31 Oct '16

I'm sorry, I take it back. Things were fine until I included <boost/hana.hpp> I had been testing with <boost/hana/core/when.hpp> and the likes of: template<class T> constexpr T pi = T(3.1415926535897932385); // variable template which would not work until I patched. And to quote: In this release, we've updated the C++ compiler and standard library with enhanced support for C++11 and C++14 features, as well as preliminary support for certain features expected to be in the C++17 standard. The most notable compiler changes include complete support for generalized constexpr. Maybe next time.... Best, Dan.

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Microsoft and hana
by Dan Bloomquist 29 Oct '16

29 Oct '16

I did a quick search here and didn't find anything on this. But I just patched up VS2015 with 'Visual Studio "15" Preview 5' <https://www.visualstudio.com/news/releasenotes/vs15-relnotes> and downloaded boost_1_62_0 The compiler now handles variable templates and I've compiled and run some simple hana tests. I did have to comment line 74 in "..\boost\hana\config.hpp". I just thought I'd drop a heads up for those, like me, that wanted to use hana with the Microsoft compiler. Best, Dan.

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Re: [Boost-users] Boost Coroutine
by Emile Cormier 29 Oct '16

29 Oct '16

On 16-10-19 02:57 AM, Oliver Kowalke wrote: > > I'm not the maintainer of boost.asio, so I don't know if an upgrade is > planed - you might ask Christopher Kohlhoff. > This is a bit worrisome to me. We are using the Boost.Asio + Boost.Coroutine integration _extensively_ in our project. Did the API change from Coroutine1 to Coroutine2? Is it simply a matter of including from boost/coroutine2/xxx instead of boost/coroutine/xxx based on some preprocessor macro being defined?

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boost 1.50 unable to make regex_match to work
by MAURICE Jean 27 Oct '16

27 Oct '16

1) Hi Kai, I wrote const_iterator BOOST_REGEX_CALL end()const { // JME 27/10/16 pour savoir si on passe là, je crée une division par 0 en // esperant que le compilateur ne la détecte pas int ijme1, ijme2; ijme2 = 1; ijme1 = 2; --ijme2; ijme1 = ijme1 / ijme2; return (!this->m_status ? 0 : this->m_expression + this->m_expression_len); // return (this->m_status ? 0 : this->m_expression + this->m_expression_len); JME 26/10/16 } Hoping the divide by 0 error would be thrown but it never appears. So I don't think this bug is annoying me. 2) As I am new to boost and regex I tried a simple test : string pattern = "GHI+"; string chaineatester = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; boost::regex boost_pattern( pattern ); boost::smatch what; int errjme = boost::regex_match( chaineatester, what, boost_pattern ); if (errjme == 1) { *outputLog << "test 1: GHI+ a été trouvé" << endl; } else { *outputLog << "test 1: GHI+ n'a pas été trouvé" << endl; // what[0] contains the whole string // what[1] contains the response code // what[2] contains the separator character // what[3] contains the text message. *outputLog << " what[0]:" << what[0] << endl \ << " what[1]:" << what[1] << endl \ << " what[2]:" << what[2] << endl \ << " what[3]:" << what[3] << endl; } string pattern2 = "GHI"; boost::regex boost_pattern2( pattern2 ); errjme = boost::regex_match( chaineatester, what, boost_pattern2 ); if (errjme == 1) { *outputLog << "test 1bis: GHI a été trouvé" << endl; } else { *outputLog << "test 1bis: GHI n'a pas été trouvé" << endl; *outputLog << " what[0]:" << what[0] << endl \ << " what[1]:" << what[1] << endl \ << " what[2]:" << what[2] << endl \ << " what[3]:" << what[3] << endl; } And here is what I get : test 1: GHI+ n'a pas été trouvé what[0]: what[1]: what[2]: what[3]: test 1bis: GHI n'a pas été trouvé what[0]: what[1]: what[2]: what[3]: What am I doing wrong ? Jean

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[geometry] Stable and fast rtree serialize/de-serialize
by 邓尧 27 Oct '16

27 Oct '16

Hi all, How can I serialize/deserialize a Boost.Geometry rtree reliably and efficiently ? I tried the experimental rtree serialization support built-in (-DBOOST_GEOMETRY_INDEX_DETAIL_EXPERIMENTAL=1), I found that the implementation was unstable and failed to deserialize sometimes. I don't even know whether it corrupted any of the tree nodes. I also implemented a slow hack: save all tree nodes during serialization and rebuild the rtree during deserialization. I want something faster. Serialization time isn't important to me, I just need a faster deserialization (as fast as the experimental implementation) Thanks

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Building Boost with VS15 Preview 5
by Trueman, Chris 26 Oct '16

26 Oct '16

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Can't catch Boost.Asio exceptions inside coroutines
by Sergey Shpikin 25 Oct '16

25 Oct '16

I have this little example of Boost.Asio code: http://codepad.org/tuQedXI7 It works as expected on Linux producing 1 2 Caught Host not found (authoritative) but on Windows it crashes with: 1 2 terminate called after throwing an instance of 'boost::system::system_error' what(): Unknown error Tested on Windows Server 2008, Windows 7 and Wine, everything is the same. I'm compiling on Linux for Windows with MXE ( http://mxe.cc/ ) on GCC 4.9.4, Boost version is 1.60.0. I'm really stuck at this point as nothing in Google looks a valid solution for the case and I already have a working application on Linux but it crashes on any network error on Windows. On Windows coroutines prevent any exceptions from being caught when the program is compiled with -O1/2/3 but they're caught with -O0 or -Os (see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=54267 — this is about GCC on FreeBSD but the same seemingly applies to MinGW). However, boost's own exceptions, like the aforementioned boost::system::system_error, still can't be caught.

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boost @ Meeting C++ 2016
by Jens Weller 24 Oct '16

24 Oct '16

Hello boost community, a short and final reminder, that the Meeting C++ conference is just a few weeks away! A few tickets are still available, here is the schedule: https://meetingcpp.com/index.php/schedule16.html The schedule also has the link to the student program and diversity tickets! Also there is still a few places available in the boost workshop with Boris Schäling and Michael Caisse. I plan to have a meetup for boost users in one of the breaks in the upper lounge, so that the boost communtiy is able to actually meet at Meeting C++! thanks, Jens Weller

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boost asio ssl read issue
by Ananth 24 Oct '16

24 Oct '16

Hi, I have posted the question here at StackForge with all the details. http://stackoverflow.com/questions/40163626/boost-asio- ssl-not-working-as-expected-when-used-with-null-buffers Basically, http://www.boost.org/doc/libs/1_40_0/doc/html/ boost_asio/overview/core/reactor.html did not work when used with ssl. With plain-tcp steam socket, it works fine. o If we do ssl_socket->lowest_layer().async_read_some(null_buffers(), read_cb), then we do get all data in read_cb, but read_cb keep getting called endlessly (and read_some then returns 0, with error 11 resource unavailable) (This causes cpu remain over-utilized for ever) If we do ssl_socket->async_read_some(null_buffers(), read_cb), then it works fine with small amounts of data. When larger data is to be received (~20MB or so), then not all data is received. around 1% of data towards the end is never received by the application. My guess is that data is sitting in openssl library some where I tried with latest ssl and boost code, but that did not help either. Can some one please help ? Thanks, Ananth

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