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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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Re: [boost] [Boost.Config] Detect compiler support for std::current_exception
by dariomt＠gmail.com 06 Jun '19

06 Jun '19

> > >Are there instructions for developers that I've missed? > > There are some instructions here: > > > https://www.boost.org/doc/libs/1_70_0/libs/config/doc/html/boost_config/gui… > > Thanks! I was expecting developer guidelines in the github readme, not in the actual library docs! doh! I have made a PR #285 and after some trial and error (I only have VS2015 and VS2017 available to test locally) I think I have something. However, in my test I throw and catch exceptions: int test() { std::exception_ptr ep; try { throw 42; } catch(...) { ep = std::current_exception(); } try { std::rethrow_exception(ep); } catch(int i) { // return zero on success return i == 42 ? 0 : 1; } return 1; } But the CI jobs have gcc and clang configured to compile without exception support! And I get errors like: libs/config/test/boost_no_cxx11_hdr_exception.ipp:22:5: error: cannot use 'throw' with exceptions disabled throw 42; ^ libs/config/test/boost_no_cxx11_hdr_exception.ipp:20:3: error: cannot use 'try' with exceptions disabled try ^ 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 2) How can I test proper support for std::current_exception() and std::rethrow_exception() if exceptions are disabled for the test? Thanks!

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[ boost.out_ptr ] [ Review Endorsement ] New Library targeting C++11
by JeanHeyd Meneide 04 Jun '19

04 Jun '19

Dear Boost Community, After a lot of work and discussion in-person, via e-mail, and on the Slack, I would like to ask for the library boost.out_ptr <https://github.com/ThePhD/out_ptr/blob/master/docs/out_ptr.adoc> -- targeting C++11 -- to be endorsed for review. Documentation: ascii doc-ready and readable on GitHub <https://github.com/ThePhD/out_ptr/blob/master/docs/out_ptr.adoc> Repository: GitHub <https://github.com/ThePhD/out_ptr> Standards Proposal: p1132 <https://thephd.github.io/vendor/future_cxx/papers/d1132.html> (accepted for and targeting C++20) 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 <https://thephd.github.io/vendor/future_cxx/papers/d1132.html#perf> for more details). Many thanks to the in-person discussion during Library in a Week at C++Now, which helped shape the implementation and yield the final Rationale <https://github.com/ThePhD/out_ptr/blob/master/docs/out_ptr/rationale.adoc>. Many thanks to Ezra (eracpp) for a lot of the quick, easy-to-read examples that became part of the documentation. Sincerely, JeanHeyd Meneide

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Re: [boost] [Boost.Config] Detect compiler support for std::current_exception
by dariomt＠gmail.com 03 Jun '19

03 Jun '19

> > >>> Hi all, > >>> > >>> I'm working on a Boost.Exception issue [1] and I need to detect > compiler > >>> support of std::current_exception. In the issue there is a suggestion > to > >>> use #if __cplusplus > 199711L but that does not work for my use case > >>> (VS2015 reports __cplusplus = 199711L). > >> > >> MSVC defines _MSVC_LANG for this[1]. At least, it used to. However, it > >> would be cleaner to have a dedicated macro in Boost.Config for this. > >> > > Totally agree. > > > >> > >>> Is it possible to add a config macro for this? > >>> Or is there a good enough existing macro I can use? > >> > >> I don't think there is. Something like BOOST_NO_CXX11_HDR_EXCEPTION > >> would be useful. > > > > I would need to detect support for std::current_exception, not the > presence > > of header <exception>, so I would think that > > BOOST_NO_CXX11_CURRENT_EXCEPTION is what I need, right? > > BOOST_NO_CXX11_HDR_EXCEPTION, as all BOOST_NO_CXX11_HDR_* macros, detect > that the header not only exists, but is usable and contains all major > components described by the standard. In case of > BOOST_NO_CXX11_HDR_EXCEPTION, that would mean std::exception_ptr, > std::current_exception, std::rethrow_exception, std::make_exception_ptr, > etc. You need at least std::exception_ptr and std::current_exception. > Thanks, that makes sense! > > Should I open an issue in github for Boost.Config? > > Yes, or better yet - make a PR. > Added github Issue #284 [1], I'll try to come up with a PR. Wondering how deep the rabbit hole goes... ^_^ Regards [1] https://github.com/boostorg/config/issues/284

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Downloads of boost from Bintray.com are temporarily unavailable
by Marshall Clow 30 May '19

30 May '19

Apparently, Boost is being downloaded over 6000 times/day from Bintray, and we've reached the limits of their bandwidth for the month. We're trying to get them to increase our quota (and see if there's someone who is downloading boost over and over again), but at the present time, downloads from bintray are being rejected. Hopefully this will be a temporary situation. -- Marshall (boost release manager)

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disjoint_sets and graph appear to be Link previously defined to another file,
by Paul A. Bristow 30 May '19

30 May '19

I have just done a full GIT update from Boost develop. (and bootstrap to rebuild b2.exe) When I try to recreate the headers or run any b2 run, I now get Performing configuration checks - default address-model : 32-bit - default architecture : x86 - symlinks supported : yes error: Cannot create link ..\..\..\boost\pending\detail\disjoint_sets.hpp to ..\..\graph\include\boost\pending\detail\disjoint_sets.hpp. error: Link previously defined to another file, ..\..\disjoint_sets\include\boost\pending\detail\disjoint_sets.hpp. I deleted all the bin.v2/libs files but this has no effect. I have deleted /disjoint_sets to get going again (as I not using either graph or disjoint_sets). What am I doing wrong? Paul --- Paul A. Bristow Prizet Farmhouse Kendal UK LA8 8AB +44 (0) 1539 561830

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Follow the work on Google summer of code
by David Bellot 30 May '19

30 May '19

Hi Boost community, you can follow the work of our students on this github page https://github.com/BoostGSoC19 They are all working very hard already. Best regards, David

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Re: [boost] Aggregate usage statistics request for Boost
by Dimitri John Ledkov 29 May '19

29 May '19

On Fri, 3 May 2019 at 10:03, Joshua Marshall <jrmarsha(a)mtu.edu> wrote: > > Hello all, > > A few of us with Boost are trying to decide support of different compilers. I know that Ubuntu collects some anonymized statistics which could help us some. Could someone please collect and forward the following bits of information to boost(a)lists.boost.org : > Install base size of Ubuntu 14.04 to 19.04 > Per OS version, what versions of GCC, Clang, and Boost are installed on what percentage of the install base. > -- > ubuntu-devel mailing list > ubuntu-devel(a)lists.ubuntu.com > Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-devel >From Ubuntu development point of view, our biggest concern is that no stable releases of boost claim to be supported or tested with the next GCC compiler. For example, for 19.10 we will be switching to GCC-9 by default, yet boost 1.70.0 primary test compilers do not include GCC-9 for Linux. Ideally, we would like to see boost upstream include next-gcc as part of primary or additional test compilers for every boost release. W.R.T. Install base size ratios and which boosts are in use -> we do not have statistics on what you are asking for. I.e. default compilers are installed on all systems (to support dkms), some boost runtime libraries are also always installed as quite a few packages depend on boost runtimes. And dev packages are not tracked and impossible to tell if they are installed by accident or on purpose. We can say generically, that our LTS releases are used a lot more than non-LTS releases, and thus by extension default compilers and boost versions within those are used more. And LTS cycles do follow an overlap, where for a while after one LTS release, the previous LTS is the most popular, and then it rolls over eventually. Our default compiler is GCC for all packages. LLVM toolchain is used for mesa and intel graphics compiler, and like that's it. Mesa requirements are what drives LLVM toolchain updates in Ubuntu. Next LTS 20.04 -> to be determined Current Development 19.10 -> 1.67.0, gcc 8.3 being switched to gcc 9, clang 8.0 (or newer) Current LTS releases (most popular at the moment) 18.04 -> 1.65.1, gcc 7.4, clang 6.0 16.04 -> 1.58.0, gcc 5.3, clang 3.8 Past basic support, in Extended Maintainance Support LTS (very old, and declining in usage) 14.04 -> 1.54.0, gcc 4.8, clang 3.4 12.04 -> 1.48.0, gcc 4.6, clang 3.0 -- Regards, Dimitri.

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Re: [boost] [Boost.Config] Detect compiler support for std::current_exception
by dariomt＠gmail.com 29 May '19

29 May '19

> > > > Hi all, > > > > I'm working on a Boost.Exception issue [1] and I need to detect compiler > > support of std::current_exception. In the issue there is a suggestion to > > use #if __cplusplus > 199711L but that does not work for my use case > > (VS2015 reports __cplusplus = 199711L). > > MSVC defines _MSVC_LANG for this[1]. At least, it used to. However, it > would be cleaner to have a dedicated macro in Boost.Config for this. > Totally agree. > > > Is it possible to add a config macro for this? > > Or is there a good enough existing macro I can use? > > I don't think there is. Something like BOOST_NO_CXX11_HDR_EXCEPTION > would be useful. > I would need to detect support for std::current_exception, not the presence of header <exception>, so I would think that BOOST_NO_CXX11_CURRENT_EXCEPTION is what I need, right? So that I can #ifndef BOOST_NO_CXX11_CURRENT_EXCEPTION // I can use std::current_exception() unconditionally here #endif Should I open an issue in github for Boost.Config?

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