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Proposed for inclusion in boost: a C++11 span
by Hans Dembinski 17 Jun '19

17 Jun '19

Dear all, I started to work on a C++11 implementation of std::span. The interface will be an exact mirror of std::span, https://en.cppreference.com/w/cpp/container/span. Having a drop-in replacement of std::span for systems with older compilers in Boost seems like a very good idea. Is anyone else already working on this? I am happy to join forces. Coding down the span took me an hour, but several more hours will go into unit testing and documenting. Best regards, Hans

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Re: [boost] [Boost.Config] Detect compiler support for std::current_exception
by dariomt＠gmail.com 17 Jun '19

17 Jun '19

> > > > > However, in my test I throw and catch exceptions: > > But the CI jobs have gcc and clang configured to compile without > exception > > support! > I have two questions: > > > > 1) Where are exceptions disabled in the CI jobs? I can't find it in > > the .travis.yml, > > but I can see e.g. clang being invoked with -fno-exceptions > > It's in the test/Jamfile.v2 file, look for <exception-handling>off. > Thanks! > > > 2) How can I test proper support for std::current_exception() and > > std::rethrow_exception() if exceptions are disabled for the test? > > You should probably condition your test on BOOST_NO_EXCEPTIONS and make > the test no-op when exceptions are disabled. > But that defeats the whole purpose of having tests. I think I should at least use the type std::exception_ptr, and make sure the functions std::current_exception() and std::rethrow_exception() exist (even if I cannot test that they actually work as expected at runtime). I think the following should work, and at least the test tests something when exceptions are off: using std::exception_ptr; auto current = &std::current_exception; auto rethrow = &std::rethrow_exception; What do you think?

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CI: clang installation broken in current Travis build images
by John Maddock 17 Jun '19

17 Jun '19

Currently, pretty much all attempts at installing clang on the travis build images is failing: https://travis-ci.org/boostorg/config/builds/546084433?utm_source=github_st…. And since all the boost libraries have pretty much copied each others .travis.yml files, this means that most PR's for most libraries will be failing. Anyone any ideas? Thanks, John. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

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[boostrap.bat] compilation error
by Raffi Enficiaud 16 Jun '19

16 Jun '19

I have the following during the compilation of bootsrap/b2: d:\bamboo_build_dir\rs-bcb233-vc2008win\library\tools\build\src\engine\sysinfo.h(41) : error C2864: 'b2::system_info::cpu_core_count_' : only static const integral data members can be initialized within a class d:\bamboo_build_dir\rs-bcb233-vc2008win\library\tools\build\src\engine\sysinfo.h(42) : error C2864: 'b2::system_info::cpu_thread_count_' : only static const integral data members can be initialized within a class Current develop (yesterday), Raffi

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[Range] pr for bug in any_range / development/maintenance status
by Max Jendruk 14 Jun '19

14 Jun '19

Hello everyone, I submitted a bugfix on Github about a month ago that fixes an issue where passing a (non-reference) value type as Reference parameter to any_range could lead to undefined behaviour. The issue has been known for a while (5 years). I would like to know when I can expect this to be merged. Also, is there a general review cycle that I'm not aware of? There are still a couple of other pull requests open, some of which were opened over a year ago. Just by looking at the activity on Github, it's difficult to determined how actively Boost.Range is still being maintained. What is the development/maintenance status of the library? I'm wondering whether it would be worth the time implementing a few more adaptors similar to those in the C++20 standard like take_view, join_view, and all_view, which I'd be happy to do. Are additions to the library still being accepted at this point? Best regards, Max

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[regression tests] Regression test pages not updating since June 4th
by Joaquin M López Muñoz 11 Jun '19

11 Jun '19

Thank you, Joaquín M López Muñoz

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[out_ptr] Review scheduled for June 16 to June 26
by Zach Laine 10 Jun '19

10 Jun '19

This is a heads-up that out_ptr has been scheduled for review, starting next Sunday, June 16. From JenHeyd's earlier post about the library: " Documentation: https://github.com/ThePhD/out_ptr/blob/master/docs/out_ptr.adoc Repository: https://github.com/ThePhD/out_ptr <https://github.com/ThePhD/out_ptr/blob/master/docs/out_ptr.adoc> Standards Proposal: https://thephd.github.io/vendor/future_cxx/papers/d1132.html boost.out_ptr is a library for making it easy to interoperate between smart pointers and traditional C-style initialization and allocation interfaces. It also enables doing so in a way that allows library authors to opt into speed optimizations for their smart pointers that give them performance equivalent to typical C pointers (see benchmarks ( https://github.com/ThePhD/out_ptr/blob/master/docs/out_ptr/benchmarks.adoc) and the Standard C++ proposal for more details). " Please consider checking out the library now, and doing a review next week. It's a pretty small library; reviews should be pretty quick to do. Zach

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Re: [boost] [Boost.Stringify] Yet another formatting library.
by Roberto Hinz 09 Jun '19

09 Jun '19

On Sat, Jun 8, 2019 at 9:53 AM Helmut Zeisel <HZ2012(a)gmx.at> wrote: > Actually I did not check your library, but I would be interested in a > formatting library that is not based on functions, but on function objects. > > The usage would not be something like > > std::string s1 = to_string("base10", 15); > std::string s2 = to_string("base16", 42); > > but > > stringifier dec; > dec.set_base(10); > std::string s1=hex(15); > stringifier hex; > hex.set_base(16); > std::string s2=hex(42); > > To format values in Boost.Stringify, one does like this, for example: namespace strf = boost::stringify; int v = 255; std::string s = strf::to_string(v, " in hexadecimal is ", strf::hex(v)); assert(s == "255 in hexadecimal is ff"); So could maybe lambdas solve your need ? auto hex = [](int v){return strf::to_string(strf::hex(v)); }; auto dec = [](int v){return strf::to_string(v); }; auto s1 = hex(15); auto s2 = dec(42); assert(s1 == "f"); assert(s2 == "42"); > With a function object based interface, one could easily store and reuse > different formating options in parallel. > Not clear to me what you mean by that. Could you explain better ?

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[Boost.Stringify] Yet another formatting library.
by Roberto Hinz 08 Jun '19

08 Jun '19

Dear Boost Community, Naturally, any interest in a new formatting library must be lower now that fmtlib is approved into C++20. Still, I'm confident that the library I'm working on has great potential, so I would like to know your opinions. https://github.com/robhz786/stringify This is a locale-independent formatting library that: - has great performance ( almost twice as fast as fmtlib ) - can do things that others can't, like encoding conversion. - is highly customizable. Through "facets" you can specify things like numeric punctuation, encoding error handling, and the width calculation algorithm. - is highly extensible. Not only you can add new input types with own formatting options and facets, but also easily add new output types. The doc has an example of how to extend the library to write to QString ( from Qt ). Actually, I did announce this library about two years ago. But the design is much enhanced now. I believe it will be ready for review by the end of this year. But it may take longer. I much appreciate any feedback. Thank you. Roberto

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Setting up linter for boost library development
by Sagnik Dey 07 Jun '19

07 Jun '19

If someone has a linter setup with appropriate settings, can you please share details? I'm working on Boost.Real and would like to have a linter to help with coding style consistency. Help is appreciated. Thank You

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