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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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