November 2021 - Boost - lists.preview.boost.org

CMake Announcement from Boost Steering Committee
by Jon Kalb 13 Aug '24

13 Aug '24

The libraries produced by the Boost community have had a greater impact on the way that the C++ community writes code than any other library implementation. The focus of the Boost community will always be on the libraries, but it is undeniable that we are dependent on and often limited by the infrastructure of our trade. Years ago, the move to Git was contentious; yet, it was required to improve development. In a similar vein our build system has become an impediment for many developers and users, existing and prospective. Therefore, we, the Steering Committee, announce to the Boost community our desire and intent to move Boost’s build system to CMake for users and developers alike. We are soliciting comments and proposals from the community to guide the process and the goals. Our desire is that the community can come to consensus by the end of the calendar year with a vision of supporting users and developers. We understand that the actual process of achieving the end goal will be long, time consuming, and not without its share of conflict. We also recognize that the Boost community is comprised of bright and passionate individuals that are eager to get involved and help get work done. The members of the Steering Committee have been encouraged by the discussions and activity surrounding CMake on the mailing lists over the years and know that many people have voiced visions. We hope that each of you rejoins the discussion to support this initiative and contributes to the common goal of improving Boost’s integration into the broader C++ ecosystem. For the Boost Steering Committee, Jon Kalb, Chair jonkalb(a)boost.org

49 199

Boost Governance?
by René Ferdinand Rivera Morell 09 Aug '24

09 Aug '24

A disclaimer: I write this solely as a Boost Library author. And not in any other capacity or representing any other interest. It's now been at least a year since Boost switched from the Software Freedom Conservancy to the Boost Foundation for its governance organization. But have people noticed any difference? Did you know that switch happened? Did you know that they held an election for the Board of Directors and for the Officers? Do you know when that election happened? Do you know who got elected? Do you know how they were selected? Do you know what their responsibilities are? Do you know what their bylaws are? Do you know their financials? More importantly: Did you answer "no" to any of those questions? As a library author, I can say I definitely answered no to many of those questions. This is a problem. As authors, without asking, we should know those answers from the organization that governs our work. We should have input into how that organization governs. In other words, we deserve open and transparent governance; not the closed and opaque status quo. -- -- René Ferdinand Rivera Morell -- Don't Assume Anything -- No Supone Nada -- Robot Dreams - http://robot-dreams.net

10 9

Boost.Text is looking for a (mini-)review manager
by Zach Laine 07 Dec '22

07 Dec '22

I've made all the recommended changes to Boost.Text that came up in the review. Glen, the previous review manager, recommended a mini review of Boost.Text once I'd made those changes. If you'd like to manage the mini-review, please let me know. For everyone, including potential reviewers and review managers, here are the major changes: * All the specific review feedback issues have been addressed. * The string layer is now gone. * The text layer got a major re-work. It is now a set of template-based adaptors (basic_text<>, vs. a text typedef. etc.), which lets everyone get what they want. You can change the underlying storage type (including whatever allocator you prefer), select UTF-8 or UTF-16, and change the normalization form. Glen recommended I drop this layer, but the library is way less useful without this stuff, and these changes address all the concerns raised about the text layer in the review. The updated docs can be found here: https://tzlaine.github.io/text/doc/html/index.html Oh yeah, and I added concept constraints to the whole library when you build in C++20 mode. Zach

17 46

[review][JSON] Review of JSON starts today: Sept 14 - Sept 23
by Pranam Lashkari 09 Aug '22

09 Aug '22

Boost formal review of Vinnie Falco and Krystian Stasiowski's library JSON starts today and will run for 10 days ending on 23 Sept 2020. Both of these authors have already developed a couple of libraries which are accepted in Boost(boost beast and Static String) This library focuses on a common and popular use-case for JSON. It provides a container to hold parsed and serialised JSON types. It provides more flexibility and better benchmark performance than its competitors. JSON highlights the following features in the documentation: - Fast compilation - Require only C++11 - Fast streaming parser and serializer - Easy and safe API with allocator support - Constant-time key lookup for objects - Options to allow non-standard JSON - Compile without Boost, define BOOST_JSON_STANDALONE - Optional header-only, without linking to a library (a point I would like to add in highlight: it has cool Jason logo 😝) To quickly understand and get the flavour of the library take a look at "Quick Look" <http://master.json.cpp.al/json/usage/quick_look.html> You can find the source code to be reviewed here: <https://github.com/CPPAlliance/json/tree/master> You can find the latest documentation here: <http://master.json.cpp.al/> Benchmarks are also given in the document which can be found here: <http://master.json.cpp.al/json/benchmarks.html> Some people have also given the early reviews, the thread can be found here: <https://lists.boost.org/Archives/boost/2020/09/249745.php> Please provide in your review information you think is valuable to understand your choice to ACCEPT or REJECT including JSON as a Boost library. Please be explicit about your decision (ACCEPT or REJECT). Some other questions you might want to consider answering: - 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 which compiler(s)? 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? More information about the Boost Formal Review Process can be found here: <http://www.boost.org/community/reviews.html> Thank you for your effort in the Boost community. -- Thank you, Pranam Lashkari, https://lpranam.github.io/

21 73

[container] Contributing 'stationary_vector' to Boost
by Mehrdad Niknami 13 Jun '22

13 Jun '22

Hi all, Happy new year! New mailing list member here. I've developed an STL-style stationary_vector class that retains elements in-place when growing. Very briefly, it is effectively a piecewise-contiguous vector, with the following advantages over vector: - Appending has O(1) overhead in the *worst* case (e.g., push_back() does not move elements) - Insertion and random-access can be done in parallel, as prior iterators & references remain valid This has a variety of benefits, including better UX (no "hiccups" due to reallocations), and the ability to simplify parallel processing of streaming data. It occurred to me the larger C++ community might find this useful. I was wondering if there would be interest in incorporating it into Boost.Container, and if so, what steps I could take to make that happen? I'm of course happy to discuss the design etc. with anyone who might be interested. Summary: https://github.com/mehrdadn/libvital/blob/master/doc/vital/container/statio… Implementation: https://github.com/mehrdadn/libvital/blob/master/include/vital/container/st… Thank you, Mehrdad

7 19

[release] Boost 1.7.0 beta 1 released
by Marshall Clow 13 Apr '22

13 Apr '22

Boost release 1.77.0 beta 1 is now available at: <https://boostorg.jfrog.io/artifactory/main/beta/1.78.0.beta1/source/> The SHA256 checksums are as follows: 7a3a025451dfa2923129214eef7d16b03c02310a353d02158a549f6caa4284b0 boost_1_78_0_b1.tar.bz2 c491b1dcb916195598aa6581d6708d57fcc750516641c22511c088d572de9c07 boost_1_78_0_b1.tar.gz 35e7a3b0eb412a3933e57c72ba96374eb7d88ff1f89dbec62a16d67ffea2105a boost_1_78_0_b1.7z e6b68feb2f63401c96ca9fe25e939b409189fbe526a6e784e4bd69832c8f09cb boost_1_78_0_b1.zip For details of what's in the release, see <https://www.boost.org/users/history/version_1_78_0.html>. Please download the beta, give it a try, and report any problems you encounter. Thanks, -- The Boost Release Team

2 1

[ASIO] Do I have to use shared_ptrs with ASIO?
by Andrzej Krzemienski 29 Dec '21

29 Dec '21

Hi Everyone, I am looking at an example implementation of an asynchronous TCP echo server in Boost.ASIO library: https://www.boost.org/doc/libs/1_77_0/doc/html/boost_asio/example/cpp11/ech… It uses a shared_ptr in the implementation to store the things related to session: socket handle, data buffers. I tried to modify it in a number of ways to avoid the usage of shared_ptr (and any form of shared ownership), but they all failed. It looks like I have to use a shared_pointer (or equivalent) when I use ASIO sockets. But conceptually, there is never a point in time where two tasks have to access members of this `session` concurrently: they are always sequenced. So, at least conceptually, there should be a way to do this with a session type that is only movable, with unique ownership: a task does its job with the session and then moves it to the subsequent task. So is this necessity to use a shared pointer an unnecessary and suboptimal design choice? Or is there something fundamental that prevents the unique ownership of buffers and socket handles? Or maybe is there a way to do it in ASIO that I overlooked? I am not trying to solve any specific problem. It just strikes me that a shared_ptr is used in a demo example for the library. I was always of the opinion that a shared_ptr is often abused as a way of doing an ad-hoc GC. Regards, &rzej;

8 21

boost.spawn: review requested
by Oliver Kowalke 06 Dec '21

06 Dec '21

Hi, I'd like to propose the new library boost.spawn (https://olk.github.io/) for review. boost.asio's boost::asio::spawn() uses the deprecated and inefficient boost.coroutine library. boost.spawn provides the same functionality while using boost.context's fiber directly. Oliver

12 49

Boost::any typecasting issue(bad_any_cast)
by Daggumati, Rajesh 05 Dec '21

05 Dec '21

Hi Team, While doing typecasting from boost::any to DecodeErrorPayload_t, its throwing bad_any_cast .. class RegisterIONotification { public: enum NotifyType { TypeUnknown, TypeRegTx, TypeRegRx, TypeDecodeError }; NotifyType Type; boost::any Payload; typedef boost::tuple<std::string, BinaryBuffer_t> DecodeErrorPayload_t; RegisterIONotification(NotifyType type;,boost::any payload) { Type(type); Payload(payload); } }; I have called RegisterIONotification from other class function. void RegisterIOThreaded::OnDecodeError( const std::string& error, BinaryBuffer_t data ) { RegisterIONotification notify(RegisterIONotification::TypeDecodeError ,make_tuple(error, data)); ..... .... ... } While testing, I am getting bad_any_cast exception. TEST_F(...,...) { RegisterIONotification notify = sink.GetDataById(ID::NOTIFY_COMMS_STATUS, 0).GetValue<RegisterIONotification>(); ASSERT_EQ(RegisterIONotification::TypeDecodeError, notify.Type); //passed RegisterIONotification::DecodeErrorPayload_t payload; ASSERT_NO_THROW(payload = boost::any_cast<RegisterIONotification::DecodeErrorPayload_t>(notify.Payload));// Here its got failed...Please help me to fix this. } Regards, Rajesh D Please be advised that this email may contain confidential information. If you are not the intended recipient, please notify us by email by replying to the sender and delete this message. The sender disclaims that the content of this email constitutes an offer to enter into, or the acceptance of, any agreement; provided that the foregoing does not invalidate the binding effect of any digital or other electronic reproduction of a manual signature that is included in any attachment.

3 2

[release] 1.78.0 post-beta merges
by Marshall Clow 01 Dec '21

01 Dec '21

The master branch is is now open for post-beta merges, but only as described in the Post-Beta Merge Policy. See <https://github.com/boostorg/wiki/wiki/Releases%3A-Beta-Merge-Policy <https://github.com/boostorg/wiki/wiki/Releases%3A-Beta-Merge-Policy>> Reminder: The master branch closes for the release on Wednesday, December 1st. Full calendar here: https://www.boost.org/development/ <https://www.boost.org/development/> — Marshall P.S Doc changes and test changes do NOT require release manager approval to be merged.

11 36

Re: [boost] boost.spawn: review requested
by Boris Kolpackov 30 Nov '21

30 Nov '21

Oliver Kowalke <oliver.kowalke(a)gmail.com> writes: > Am Mo., 29. Nov. 2021 um 15:54 Uhr schrieb Boris Kolpackov < > boris(a)codesynthesis.com>: > > > FWIW (and I may be out of context), but "spawn" seems like a > > too generic of a name. I, for example, thought this is about > > posix_spawn(). Maybe call it spawn_fiber or some such? > > > > boost.asio named the function spawn() - boost.spawn named it spawn_fiber() Sorry, looks I wasn't clear enough: I am talking about the library name being too generic: Boost.Spawn can mean spawning all kinds of things (processes, threads, fibers, etc). The fact that you called the function spawn_fiber() in a sense confirms this.

1 0

[fusion] add support for view construction from movable view
by herve martin 28 Nov '21

28 Nov '21

Hi, When working with view of boost::fusion I feel something frustrated because of the limited set of possible constructors. Indeed, apart from copy constructor, views usually only provide constructors taken l-value reference on sequence as input. I would like to extend the constructors set of views with some new ones which would also accept r-value references on view as input. This would allow some fancy combination at construction time as for example: vector <https://www.boost.org/doc/libs/1_77_0/libs/fusion/doc/html/fusion/container…><bool> v0(true);vector <https://www.boost.org/doc/libs/1_77_0/libs/fusion/doc/html/fusion/container…><int, char> v1(3, 'x');vector <https://www.boost.org/doc/libs/1_77_0/libs/fusion/doc/html/fusion/container…><std::string, int> v2("hello", 123); using view1 = joint_view< vector <https://www.boost.org/doc/libs/1_77_0/libs/fusion/doc/html/fusion/container…><int, char> , vector <https://www.boost.org/doc/libs/1_77_0/libs/fusion/doc/html/fusion/container…><std::string, int>>;using view = joint_view< vector <https://www.boost.org/doc/libs/1_77_0/libs/fusion/doc/html/fusion/container…><bool> , view1>; view aview = view(v0, view1(v1, v2));std::cout << aview << std::endl; I would be glad to contribute to the boost library by updating the boost::fusion views with some new constructors bu I'm not familiar with development in boost. What would be the next step to give a chance to my proposal to integrate boost ? Best regards, Herve

1 0

Adding my sorting algorithm, ska_sort, to boost, attempt 2
by Malte Skarupke 24 Nov '21

24 Nov '21

Hi everyone, I started a discussion about this in October, but at the time the maintainer of the sort library was busy, then I was busy, so now it's January... I wrote a generalized version of radix sort a couple years ago and gave a talk about it here: https://www.youtube.com/watch?v=zqs87a_7zxw I would like to get a new version of that sorting algorithm into boost. It's faster than what I showed several years ago. It's also even more general and has a new interface that should be easier to extend. I uploaded the code here: https://github.com/skarupke/sort/tree/master The documentation is also already updated with new benchmark results. Let me know what's required to get this into boost. Would you like this in the form of a pull request? One of the big things that probably needs review is the interface, since radix sorting works differently than comparison based sorting. For most normal uses you just need to provide a sort key, but more complicated cases can get more complicated. I tried very hard to make everything easy, but I'd also be curious if others can come up with better ways of doing the interface. Thanks, Malte -- Malte Skarupke malteskarupke(a)fastmail.fm

8 10

[release] 1.78.0 post-beta merges
by Oliver Kowalke 20 Nov '21

20 Nov '21

Hi, I'd like to merge several fixes for boost.context, boost.coroutine, boost.coroutine2 and boost.fiber to branch master. Oliver

2 1

Boost::any bad_any_cast issue
by rajesh daggumati 18 Nov '21

18 Nov '21

Hi Team, While doing typecasting from boost::any to DecodeErrorPayload_t, its throwing bad_any_cast .. class RegisterIONotification { public: enum NotifyType { TypeUnknown, TypeRegTx, TypeRegRx, TypeDecodeError }; NotifyType Type; boost::any Payload; typedef boost::tuple<std::string, BinaryBuffer_t> DecodeErrorPayload_t; RegisterIONotification(NotifyType type;,boost::any payload) { Type(type); Payload(payload); } }; I have called RegisterIONotification from other class function. void RegisterIOThreaded::OnDecodeError( const std::string& error, BinaryBuffer_t data ) { RegisterIONotification notify(RegisterIONotification::TypeDecodeError ,make_tuple(error, data)); ..... .... ... } While testing, I am getting bad_any_cast exception. TEST_F(...,...) { RegisterIONotification notify = sink.GetDataById(ID::NOTIFY_COMMS_STATUS, 0).GetValue<RegisterIONotification>(); ASSERT_EQ(RegisterIONotification::TypeDecodeError, notify.Type); //passed RegisterIONotification::DecodeErrorPayload_t payload; ASSERT_NO_THROW(payload = boost::any_cast<RegisterIONotification::DecodeErrorPayload_t>(notify.Payload));// Here its got failed…Please help me to fix this. } Regards, Rajesh D

2 1

ASIO problem with boost 1.78.0.beta1 ?
by Stefan Heinzmann 13 Nov '21

13 Nov '21

Hi all, I'm observing a problem with boost::asio that has surfaced with the newest beta relative to version 1.77.0, using MSVC 16.11.6. I'm getting the following errors: 1>...src\libs\asio\include\boost/asio/impl/any_io_executor.ipp(26,18): error C2039: 'any_io_executor': is not a member of 'boost::asio::executor' 1>...src\libs\asio\include\boost/asio/executor.hpp(48): message : see declaration of 'boost::asio::executor' 1>...src\libs\asio\include\boost/asio/impl/any_io_executor.ipp(26,34): error C2059: syntax error: ')' 1>...src\libs\asio\include\boost/asio/impl/any_io_executor.ipp(28,1): error C4430: missing type specifier - int assumed. Note: C++ does not support default-int ...and so on. The errors seem rather weird to me, so I might be doing something wrong myself, but the exact same code compiles fine with 1.77.0, using the same compiler. Has anyone got an idea what's wrong? Should I raise an issue in github? Cheers Stefan Heinzmann

1 1

union support in describe
by Gero Peterhoff 12 Nov '21

12 Nov '21

Hello, first of all, thank you very much for the great work. But I miss the support for unions. Is that correct? namespace boost { namespace describe { #define BOOST_DESCRIBE_UNION(C, Public) \ static_assert(std::is_union<C>::value, "BOOST_DESCRIBE_UNION should only be used with union types"); \ BOOST_DESCRIBE_PUBLIC_MEMBERS_(C BOOST_DESCRIBE_PP_UNPACK Public) \ BOOST_DESCRIBE_PROTECTED_MEMBERS_(C) \ BOOST_DESCRIBE_PRIVATE_MEMBERS_(C) } // describe } // boost This version only supports public members. I also miss the support for std::get. Is that correct? namespace boost { namespace describe { #define BOOST_DESCRIBE_GET(C) \ template <std::size_t Index> \ inline constexpr const auto& get(const C& arg) noexcept \ { \ static_assert(std::is_class<C>::value || std::is_union<C>::value, "BOOST_DESCRIBE_GET should only be used with class, struct or union types"); \ using members = boost::describe::describe_members<C, boost::describe::mod_any_access>; \ static_assert(Index < boost::mp11::mp_size<members>()); \ return arg.*boost::mp11::mp_at_c<members, Index>().pointer; \ } \ template <std::size_t Index> \ inline constexpr auto& get(C& arg) noexcept \ { \ static_assert(std::is_class<C>::value || std::is_union<C>::value, "BOOST_DESCRIBE_GET should only be used with class, struct or union types"); \ using members = boost::describe::describe_members<C, boost::describe::mod_any_access>; \ static_assert(Index < boost::mp11::mp_size<members>()); \ return arg.*boost::mp11::mp_at_c<members, Index>().pointer; \ } } // describe } // boost However, the access rights are not taken into account. E.g.: struct A { int i; float f; }; BOOST_DESCRIBE_STRUCT(A, (), (i, f)) namespace std { BOOST_DESCRIBE_GET(A) } // std This also solves a very special problem, provided the compiler supports it: active member of a constexp union. Problem: union U { int64_t i; double d; }; constexpr U u{.d{3.1415}}; constexpr auto i=u.i; -> error In short: namespace std { template <typename Type> inline constexpr bool is_constant_initialized(const Type& arg) noexcept { #if __has_builtin(__builtin_constant_p) return __builtin_constant_p(arg); #elif defined(BOOST_MSVC) ??? #else static_assert(false, "is_constant_initialized not supportet"); return false; #endif } template <typename Type> inline constexpr bool is_constant_initialized_front(const Type& arg) noexcept { return is_constant_initialized(arg); } template <typename Type, size_t Size> inline constexpr bool is_constant_initialized_front(const Type(&arg)[Size]) noexcept { static_assert(Size > 0); return is_constant_initialized(arg[0]); } template <typename Type, size_t Size> inline constexpr bool is_constant_initialized_front(const std::array<Type, Size>& arg) noexcept { static_assert(Size > 0); return is_constant_initialized(arg[0]); } } // std namespace boost { namespace describe { template <typename Type> inline constexpr std::size_t active_index(const Type& arg) noexcept { static_assert(std::is_union_v<Type>); using any = describe_members<Type, mod_any_access>; std::size_t result{0}, index{0}; bool first{true}; boost::mp11::mp_for_each<any>([&](const auto& desc) constexpr noexcept { const auto& elem{arg.*desc.pointer}; if (std::is_constant_initialized_front(elem)) { if (first) { first = false; result = index; } } ++index; }); return first ? 0 : result; } template <auto Value> inline constexpr std::size_t active_index_v = std::integral_constant<std::size_t, active_index(Value)>::value; } // describe } // boost union __mm128_emu { float m128_f32[4]; double m128_f64[2]; int64_t m128_i64[2]; int32_t m128_i32[4]; int16_t m128_i16[8]; int8_t m128_i8[16]; uint64_t m128_u64[2]; uint32_t m128_u32[4]; uint16_t m128_u16[8]; uint8_t m128_u8[16]; }; BOOST_DESCRIBE_UNION(__mm128_emu, (m128_f32, m128_f64, m128_i64, m128_i32, m128_i16, m128_i8, m128_u64, m128_u32, m128_u16, m128_u8)) namespace std { BOOST_DESCRIBE_GET(__mm128_emu) } // std constexpr __mm128_emu m128{.m128_u32{4711}}; constexpr auto arr = std::to_array(std::get<boost::describe::active_index_v<m128>>(m128)); // works with gcc, clang, intel Do you have an idea how to implement __builtin_constant_p for all compilers? thx Gero

2 2

Update on the 1.78.0 beta
by Marshall Clow 11 Nov '21

11 Nov '21

The beta was supposed to be released yesterday. It’s done, but there’s an issue on Jfrog that seems to make it hard to download. I’m talking to the JFrog folks to get this resolved, and when that’s done, I’ll announce that the beta is released. — Marshall

1 0

[release] Boost 1.78.0 Beta 1 Release Candidate 1 is available
by Marshall Clow 09 Nov '21

09 Nov '21

The first release candidates for the 1.78.0 beta release are now available at: <https://boostorg.jfrog.io/ui/native/main/beta/1.78.0.beta1/source <https://boostorg.jfrog.io/ui/native/main/beta/1.78.0.beta1/source>> The SHA256 checksums are as follows: 7a3a025451dfa2923129214eef7d16b03c02310a353d02158a549f6caa4284b0 boost_1_78_0_b1_rc1.tar.bz2 c491b1dcb916195598aa6581d6708d57fcc750516641c22511c088d572de9c07 boost_1_78_0_b1_rc1.tar.gz 35e7a3b0eb412a3933e57c72ba96374eb7d88ff1f89dbec62a16d67ffea2105a boost_1_78_0_b1_rc1.7z e6b68feb2f63401c96ca9fe25e939b409189fbe526a6e784e4bd69832c8f09cb boost_1_78_0_b1_rc1.zip As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. -- The Release managers

3 5

How to get started with contribution
by Anmol Singh 09 Nov '21

09 Nov '21

Respected Sir/Madam, I am Anmol Singh, an Information Technology undergrad. I have just entered my second year at ADGITM, IP University. I am new to open source contributions but I am well aware of C++,C and javascript. I would love to contribute to your organisation but could you please tell me how to get started? Regards Anmol

1 0

conversion of catched exception to shared_ptr
by rajesh daggumati 08 Nov '21

08 Nov '21

rajesh daggumati <rajeshdaggumati9999(a)gmail.com> 09:59 (4 hours ago) to boost-users HI, please help me to solve below issue. Shared pointers are used in my code. class Exception : public virtual std::exception,public virtual boost::exception { --- }; class ExceptionTestException : public Exception { --- }; boost::shared_ptr<Exception> exceptionptr_t; try { Boost_Throw_function(ExceptionTestException("Hiii")); } catch(...) { boost::exception_ptr exceptionptr = boost::current_exception(); try { boost::rethrow(exceptionptr) } catch(boost::exception &e) { //here i need to assign this 'e' to shared pointer but this e is not in heap so then how to assign this e to sharedptr(exceptionptr_t). 1 way is : boost::exception *ep = new ExceptionTestException(e); exceptionptr_t(ep); here we know that exception_ptr is having ExceptionTestException but in some cases, we dont know which type of excepiton we have in exception_ptr in runtime. then how to assign to shared_ptr

4 4

Library category error handling
by Emil Dotchevski 07 Nov '21

07 Nov '21

Should we add a formal category for error handling libraries in https://www.boost.org/development/library_metadata.html?

5 6

Does boost have a way to get type name at compile time?
by Ivan Matek 04 Nov '21

04 Nov '21

I am aware of hacks/magic with __PRETTY_FUNCTION__ <https://stackoverflow.com/questions/69624128/parameter-pack-sorting-or-equi…>but I wonder if there is a portable boost way to do that?

2 1

Header-only libraries linking to compiled libraries...
by Peter Dimov 03 Nov '21

03 Nov '21

... create problems (at least) for CMake users, because a project using a header-only library must link to its compiled dependencies by hand. (Important Note: this is not about the CMake build of Boost. It's about the b2 build of Boost, and the CMake configuration files it generates.) Compiled libraries don't have this problem, because they have CMake targets, and linking to the library target automatically links to the dependencies. For instance, linking to Boost::filesystem would automatically link to Boost::atomic (and on Windows, to bcrypt.lib) as needed. However, as pointed out in https://github.com/boostorg/boost_install/issues/54, header-only libraries such as Process or UUID have no CMake targets. Consequently, it's not possible for the CMake project to link to Boost::uuid and automatically inherit the dependency to bcrypt.lib, or to link to Boost::process and automatically acquire a dependency to Boost::filesystem. Since the CMake configuration files that are generated by `b2 install` define CMake targets based on the b2 targets, it's not possible to fix this just on the boost-install side. If we want Boost::process to appear as a target in CMake, we need boost_process to appear as a target in b2, that is, we need libs/process/build/Jamfile to exist. The easiest way to fix it - if we decide to do something about it - is to create dummy compiled libraries for each such header-only library that isn't really header-only because of dependencies. A number of Boost libraries are already header-only with a stub library for backward compatibility (System, DateTime, Regex), so this wouldn't be something novel.

6 17

Reminder: The master branch will be closing for the 1.78.0 beta release TOMORROW
by Marshall Clow 02 Nov '21

02 Nov '21

If you have changes for the beta, they need to be merged to master before the end of day tomorrow. See https://www.boost.org/development/index.html <https://www.boost.org/development/index.html> for the full calendar — The Release managers

1 0

Boost libraries packaged for build2
by Boris Kolpackov 02 Nov '21

02 Nov '21

We have added support for the build2 build systems to 136 out of 145 Boost libraries and version 1.77.0 is now available from the cppget.org package repository. For details, see: https://build2.org/blog/build2-boost.xhtml Folks on this mailing list may be particularly interested in the "Implementation Details" section where we go deeper into how this conversion was accomplished: https://build2.org/blog/build2-boost.xhtml#impl-details (There is also the README-DEV file in the repository linked from this section which has even more details.) Also, let me add that this is not a call to convert Boost to build2. While we would gladly assist with this effort if the Boost community so wishes, we are also happy to continue our work out of tree.

1 0