September 2018 - Boost-users

[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

1 0

[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

1 0

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

2 1

[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.

1 0

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

1 0

[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

3 5

[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

1 0

[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

2 2

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!

3 2

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.

1 0