October 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

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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

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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

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[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/

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[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

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[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;

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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

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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

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boost::trim_copy(boost::string_view()); // error
by Olaf van der Spek 31 Oct '21

31 Oct '21

Hi, Why does the overload for boost::string_view not work? The std one works. Could it be made to work? #include <boost/algorithm/string.hpp> #include <boost/utility/string_ref.hpp> #include <boost/utility/string_view.hpp> #include <iostream> #include <string_view> int main() { boost::trim_copy(boost::string_view()); // error boost::trim_copy(std::string_view()); } $ g++ t0.cpp In file included from /usr/include/boost/algorithm/string.hpp:19, from t0.cpp:1: /usr/include/boost/algorithm/string/trim.hpp: In instantiation of ‘SequenceT boost::algorithm::trim_copy_if(const SequenceT&, PredicateT) [with SequenceT = boost::basic_string_view<char, std::char_traits<char> >; PredicateT = boost::algorithm::detail::is_classifiedF]’: /usr/include/boost/algorithm/string/trim.hpp:343:49: required from ‘SequenceT boost::algorithm::trim_copy(const SequenceT&, const std::locale&) [with SequenceT = boost::basic_string_view<char, std::char_traits<char> >]’ t0.cpp:10:19: required from here /usr/include/boost/algorithm/string/trim.hpp:319:20: error: no matching function for call to ‘boost::basic_string_view<char, std::char_traits<char> >::basic_string_view(const char*, const char*&)’ 319 | return SequenceT( | ^~~~~~~~~~ 320 | detail::trim_begin( | ~~~~~~~~~~~~~~~~~~~ 321 | ::boost::begin(Input), | ~~~~~~~~~~~~~~~~~~~~~~ 322 | TrimEnd, | ~~~~~~~~ 323 | IsSpace), | ~~~~~~~~~ 324 | TrimEnd | ~~~~~~~ 325 | ); | ~ In file included from t0.cpp:3: /usr/include/boost/utility/string_view.hpp:97:9: note: candidate: ‘template<class Allocator> boost::basic_string_view<charT, traits>::basic_string_view(const std::__cxx11::basic_string<charT, traits, Allocator>&) [with Allocator = Allocator; charT = char; traits = std::char_traits<char>]’ 97 | basic_string_view(const std::basic_string<charT, traits, Allocator>& str) BOOST_NOEXCEPT | ^~~~~~~~~~~~~~~~~ /usr/include/boost/utility/string_view.hpp:97:9: note: template argument deduction/substitution failed: In file included from /usr/include/boost/algorithm/string.hpp:19, from t0.cpp:1: /usr/include/boost/algorithm/string/trim.hpp:319:20: note: mismatched types ‘const std::__cxx11::basic_string<char, std::char_traits<char>, Allocator>’ and ‘const char*’ 319 | return SequenceT( | ^~~~~~~~~~ 320 | detail::trim_begin( | ~~~~~~~~~~~~~~~~~~~ 321 | ::boost::begin(Input), | ~~~~~~~~~~~~~~~~~~~~~~ 322 | TrimEnd, | ~~~~~~~~ 323 | IsSpace), | ~~~~~~~~~ 324 | TrimEnd | ~~~~~~~ 325 | ); | ~ In file included from t0.cpp:3: /usr/include/boost/utility/string_view.hpp:110:23: note: candidate: ‘constexpr boost::basic_string_view<charT, traits>::basic_string_view(const charT*, boost::basic_string_view<charT, traits>::size_type) [with charT = char; traits = std::char_traits<char>; boost::basic_string_view<charT, traits>::size_type = long unsigned int]’ (near match) 110 | BOOST_CONSTEXPR basic_string_view(const charT* str, size_type len) | ^~~~~~~~~~~~~~~~~ /usr/include/boost/utility/string_view.hpp:110:23: note: conversion of argument 2 would be ill-formed: In file included from /usr/include/boost/algorithm/string.hpp:19, from t0.cpp:1: /usr/include/boost/algorithm/string/trim.hpp:324:17: error: invalid conversion from ‘boost::range_detail::extract_const_iterator<boost::basic_string_view<char, std::char_traits<char> >, true>::typ’ {aka ‘const char*’} to ‘boost::basic_string_view<char, std::char_traits<char> >::size_type’ {aka ‘long unsigned int’} [-fpermissive] 324 | TrimEnd | ^~~~~~~ | | | boost::range_detail::extract_const_iterator<boost::basic_string_view<char, std::char_traits<char> >, true>::type {aka const char*} In file included from t0.cpp:3: /usr/include/boost/utility/string_view.hpp:107:23: note: candidate: ‘constexpr boost::basic_string_view<charT, traits>::basic_string_view(const charT*) [with charT = char; traits = std::char_traits<char>]’ 107 | BOOST_CONSTEXPR basic_string_view(const charT* str) | ^~~~~~~~~~~~~~~~~ /usr/include/boost/utility/string_view.hpp:107:23: note: candidate expects 1 argument, 2 provided /usr/include/boost/utility/string_view.hpp:78:23: note: candidate: ‘constexpr boost::basic_string_view<charT, traits>::basic_string_view(const boost::basic_string_view<charT, traits>&) [with charT = char; traits = std::char_traits<char>]’ 78 | BOOST_CONSTEXPR basic_string_view(const basic_string_view &rhs) BOOST_NOEXCEPT | ^~~~~~~~~~~~~~~~~ /usr/include/boost/utility/string_view.hpp:78:23: note: candidate expects 1 argument, 2 provided /usr/include/boost/utility/string_view.hpp:73:23: note: candidate: ‘constexpr boost::basic_string_view<charT, traits>::basic_string_view() [with charT = char; traits = std::char_traits<char>]’ 73 | BOOST_CONSTEXPR basic_string_view() BOOST_NOEXCEPT | ^~~~~~~~~~~~~~~~~ /usr/include/boost/utility/string_view.hpp:73:23: note: candidate expects 0 arguments, 2 provided In file included from /usr/include/boost/algorithm/string.hpp:19, from t0.cpp:1: /usr/include/boost/algorithm/string/trim.hpp: In instantiation of ‘SequenceT boost::algorithm::trim_copy_if(const SequenceT&, PredicateT) [with SequenceT = std::basic_string_view<char>; PredicateT = boost::algorithm::detail::is_classifiedF]’: /usr/include/boost/algorithm/string/trim.hpp:343:49: required from ‘SequenceT boost::algorithm::trim_copy(const SequenceT&, const std::locale&) [with SequenceT = std::basic_string_view<char>]’ t0.cpp:11:19: required from here /usr/include/boost/algorithm/string/trim.hpp:324:17: error: invalid conversion from ‘boost::range_detail::extract_const_iterator<std::basic_string_view<char>, true>::type’ {aka ‘const char*’} to ‘std::basic_string_view<char>::size_type’ {aka ‘long unsigned int’} [-fpermissive] 324 | TrimEnd | ^~~~~~~ | | | boost::range_detail::extract_const_iterator<std::basic_string_view<char>, true>::type {aka const char*} In file included from /usr/include/c++/11/bits/basic_string.h:48, from /usr/include/c++/11/string:55, from /usr/include/boost/algorithm/string/std/string_traits.hpp:15, from /usr/include/boost/algorithm/string/std_containers_traits.hpp:19, from /usr/include/boost/algorithm/string.hpp:18, from t0.cpp:1: /usr/include/c++/11/string_view:137:56: note: initializing argument 2 of ‘constexpr std::basic_string_view<_CharT, _Traits>::basic_string_view(const _CharT*, std::basic_string_view<_CharT, _Traits>::size_type) [with _CharT = char; _Traits = std::char_traits<char>; std::basic_string_view<_CharT, _Traits>::size_type = long unsigned int]’ 137 | basic_string_view(const _CharT* __str, size_type __len) noexcept | ~~~~~~~~~~^~~~~ -- Olaf

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VS2022 release date is Nov 8
by Peter Dimov 30 Oct '21

30 Oct '21

The Visual Studio 2022 (msvc-14.3) release date is Nov 8, which is right in the middle of our beta master freeze (Nov 3 - Nov 10). Since VS2022 is now RC2, which means that it won't change much if at all, we probably need to start testing our libraries with it now, so that the issues are ironed out before 1.78 beta.

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The deadline for new libraries and breaking changes in Boost 1.78.0 is Friday, October 29
by Marshall Clow 27 Oct '21

27 Oct '21

Sorry for the late notice; the deadline was supposed to be today, but I'm extending it to Friday. See https://www.boost.org/development/index.html <https://www.boost.org/development/index.html> for the full calendar Next deadline: Boost 1.78.0 closed for beta Wednesday, Nov 3, 2021 — The Release Managers

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Header-only Boost.System
by Ashish Singh 25 Oct '21

25 Oct '21

Hi All, In my application, I'm trying to use Boost ASIO via boost 1.66 and defining the following two macros in the Makefile. Basically trying to use the header-only approach. CFLAGS += \ -DBOOST_ERROR_CODE_HEADER_ONLY \ -DBOOST_SYSTEM_NO_DEPRECATED But then I came across this thread: https://lists.boost.org/Archives/boost/2017/10/239106.php "In header only mode, multiple instances may appear and thus no longer be proper singletons. Stuff breaks in this situation, badly." Is the above applicable to 1.66 too?How can I safely use the header-only approach in boost 1.66? Thanks,Ashish

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Boost.URL: Something Wicked This Way Comes! (Was: Needs Review)
by Vinnie Falco 21 Oct '21

21 Oct '21

Folx: Well, I was on a pause but I picked Boost.URL back up and whipped it into shape. The good news, this Belle is ready for the Ball ! I invite you to kick the tires and light the fires on the next major component in my line of network and protocol libraries: Repository <https://github.com/CPPAlliance/url/> Documentation <https://master.url.cpp.al/> Docs are still being worked on, of course (docs are never "done"). `url_view`, `url`, `static_url`, and `authority_view` should be completely solid and ready to get beat up. And I'm ready for all that lovely negative feedback !!! If a kind soul would like to volunteer to be the review manager, that would be swell. I'm very happy to answer any questions about the library, and happy to get feedback regarding the design and implementation. -- Regards, Vinnie Follow me on GitHub: https://github.com/vinniefalco

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Opinions on introduction of string_view in Core
by Andrey Semashev 21 Oct '21

21 Oct '21

Hi, Recently, a new implementation of string_view was introduced in Boost.Core: https://github.com/boostorg/core/blob/d5bd40e5280487fb29a108eb42e6c4f0bef69… Most of you probably know there is also a string_view implementation in Boost.Utility: https://github.com/boostorg/utility/blob/05e0d1688dcfcd3fdd65bdb6884b7edd1a… The main motivation for introducing the new implementation is adding conversions to/from std::string_view, which were proposed to Boost.Utility and rejected a while ago: https://github.com/boostorg/utility/pull/51 Another notable deviation of boost::core::string_view from std::string_view and boost::string_view is that it only accepts the character type in template parameters and not char_traits. This choice was made to simplify implementation. I have concerns that introducing yet another string_view type (3rd in Boost, after boost::string_ref and boost::string_view, not counting std::string_view) is not good for the ecosystem and interoperability, as this will require adding explicit support in some code bases. One example that I readilly have is Boost.Log: https://github.com/boostorg/log/blob/4c54e4ca4c31f18ce2e451e8d0abf88054242d… std::string_view was supposed to make user's code simpler by removing the need to provide a multitude of function overloads accepting string arguments. boost::string_view (and boost::string_ref before it) was a prototype implementation before introduction of std::string_view and served a similar purpose. In the age with std::string_view, boost::string_view is still useful as a drop-in replacement for std::string_view to lower C++ requirements in libraries and projects, like this: #if !defined(BOOST_NO_CXX17_HDR_STRING_VIEW) using std::basic_string_view; using std::string_view; using std::string_view; #else using boost::basic_string_view; using boost::string_view; using boost::string_view; #endif Introducing boost::core::string_view, which is not a drop-in replacement, does not make users' code simpler as it requires adding yet another set of overloads and specializations to users' APIs. I should stress that I'm not opposing because I don't want to make changes to Boost.Log, I'm opposing because I don't think those changes will be for the better, and because I view this as potentially destructive to the wide adoption of one common string_view type (be it std::string_view or boost::string_view, depending on the conventions taken in the project) to accept string arguments. Please, express your opinions on this matter, in particular: - Do you think it is good/ok/bad to have yet another string_view in Boost? - Is it ok that boost::core::string_view is not a drop-in replacement for std::string_view? Should it be changed to be one? - Should we, perhaps, do something with boost::string_view from Boost.Utility? Deprecate? - Should we reopen the discussion to add conversion to/from std::string_view to boost::string_view, which led to this fork? Perhaps, hold a vote to make this change as widely requested? - Any other course of action or thoughts? Thanks. PS: This post was made after an initial discussion in this commit: https://github.com/boostorg/core/commit/95924b1329da49e70c9c8485b87e066895d…

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hash_value( complex<T> )
by Peter Dimov 19 Oct '21

19 Oct '21

At the moment, boost::hash_value for complex<T> is specified as When T is a built in type and val.imag() == 0, the result is equal to hash_value(val.real()). Otherwise an unspecified value, except that equal arguments shall yield the same result. This is a bit odd; the natural implementation for a two-argument point/tuple type is std::size_t seed = 0; boost::hash_combine( seed, v.real() ); boost::hash_combine( seed, v.imag() ); return seed; Can anyone offer an opinion on whether or why the original behavior is preferable?

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regarding boost::exception
by rajesh daggumati 18 Oct '21

18 Oct '21

Hi Team, I need to create an object for catched exception . class exception: virtual public std::exception ,virtual public boost::exception {} inside my application code, try{ boost::rethrow_exception(exceptr)} catch(std::exception &e) { std::exception *e = stacktoHeapObject(e); } static std::exception* stacktoHeapObj(std::exception* e) { if (dynamic_cast<std::bad_alloc*>(e)) { return new std::bad_alloc(*(dynamic_cast<std::bad_alloc*>(e))); } else if (dynamic_cast<std::bad_cast*>(e)) { return new std::bad_cast(*(dynamic_cast<std::bad_cast*>(e))); } else if (dynamic_cast<std::bad_typeid*>(e)) { return new std::bad_typeid(*(dynamic_cast<std::bad_typeid*>(e))); } else if (dynamic_cast<std::bad_exception*>(e)) { return new std::bad_exception(*(dynamic_cast<std::bad_exception*>(e))); } else if (dynamic_cast<std::domain_error*>(e)) { return new std::domain_error(*(dynamic_cast<std::domain_error*>(e))); } else if (dynamic_cast<std::invalid_argument*>(e)) { return new std::invalid_argument(*(dynamic_cast<std::invalid_argument*>(e))); } else if (dynamic_cast<std::length_error*>(e)) { return new std::length_error(*(dynamic_cast<std::length_error*>(e))); } else if (dynamic_cast<std::out_of_range*>(e)) { return new std::out_of_range(*(dynamic_cast<std::out_of_range*>(e))); } else if (dynamic_cast<std::overflow_error*>(e)) { return new std::overflow_error(*(dynamic_cast<std::overflow_error*>(e))); } else if (dynamic_cast<std::range_error*>(e)) { return new std::range_error(*(dynamic_cast<std::range_error*>(e))); } else if (dynamic_cast<std::underflow_error*>(e)) { return new std::underflow_error(*(dynamic_cast<std::underflow_error*>(e))); } else if (dynamic_cast<std::runtime_error*>(e)) { return new std::runtime_error(*(dynamic_cast<std::runtime_error*>(e))); } else if (dynamic_cast<std::exception*>(e)) { return new std::exception(*(dynamic_cast<std::exception*>(e))); } } I have coded by taking order reference of below pic. please help me to get classes names in boost:exception which are not in std::exception . if they are in boost::exception only then how to catch that and send to stackToHeapObj and what order i need to follow to add those if checks. try { boost::rethrow_exception(exptr) } here in catch block , we don't know which exception type we have in exptr(ie. std:: or boost:;) then How to catch them. if i use std::exception in catch block then if exptr throws boost::exception type then ... and viceversa..? Please help me to clarify above queries [image: image.png]

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Opinions on merging Assert, StaticAssert, ThrowException into Core
by Nikita Kniazev 17 Oct '21

17 Oct '21

Recently Core grew with additional dependencies on StaticAssert (in 1.76) and ThrowException (in the next release), previously it was only depending on Assert and Config. That made a lot of libraries checkout the same four repositories, three of them containing only a few headers. Merging into a single dependency will affect mostly positive about 100 libraries and negative 1: StlInterfaces (depends on Assert, and will on Core). Please leave a comment at https://github.com/boostorg/core/issues/97 if you think it is a good idea, or have concerns against doing that.

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No more cycles going forward
by Glen Fernandes 16 Oct '21

16 Oct '21

Boost 1.77.0 released with no dependency cycles between libraries. This wasn't easy to achieve and we want to preserve it, going forward. We should not regress and allow libraries to introduce dependency cycles in any future Boost release. i.e. Doing so should be considered a release blocker. Currently, such a regression exists (introduced last month in Context): Asio -> Coroutine -> Context -> Asio It should be fixed before we lock the branches for the 1.78 release, or we should not take this change in the release. Glen

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[Q] Help needed with boost::log, filters and a custom sink backend
by Volker 15 Oct '21

15 Oct '21

Dear Boost experts! I'm new to this list, so please have mercy if I'm not yet familiar with your best practices. Recently, I have been pulling my hair out while trying to use boost::log for a severity-logger-type functionality where the sink backend is not compatible with std::ostream. Best bet was to implement a custom sink backend that does the job in its consume() member. However, I can't get the attribute value for the severity level extracted to an int. For sure, there's something totally obvious I'm missing... Here's the source code (slightly abbreviated): #include <string> #include <boost/log/core.hpp> #include <boost/log/expressions.hpp> #include <boost/log/sinks/basic_sink_backend.hpp> #include <boost/log/sinks/sync_frontend.hpp> #include <boost/log/sources/logger.hpp> #include <boost/log/sources/severity_logger.hpp> #include <boost/log/trivial.hpp> #include <boost/smart_ptr/make_shared_object.hpp> #include <boost/smart_ptr/shared_ptr.hpp> namespace logging = boost::log; namespace sinks = boost::log::sinks; void SomeLogChannel(int severity, const std::string& message) {} class SinkBackend : public sinks::basic_sink_backend<sinks::synchronized_feeding> { public: explicit SinkBackend() {} void consume(logging::record_view const& rec) { std::string message = *rec[boost::log::expressions::smessage]; int severity = 0; if (rec.attribute_values().count("Severity")) { // severity = rec.attribute_values()["Severity"].extract<int>(); // cannot convert from 'boost::log::v2s_mt_nt6::value_ref<T,TagT>' to 'int' with T=int, TagT=void } SomeLogChannel(severity, message); } }; void init_logging() { typedef sinks::synchronous_sink<SinkBackend> sink_t; boost::shared_ptr<logging::core> core = logging::core::get(); boost::shared_ptr<SinkBackend> backend(new SinkBackend()); boost::shared_ptr<sink_t> sink(new sink_t(backend)); core->add_sink(sink); core->set_filter(logging::trivial::severity >= logging::trivial::error); } int main(int, char* []) { init_logging(); boost::log::sources::severity_logger< logging::trivial::severity_level > lg; BOOST_LOG_SEV(lg, logging::trivial::trace) << "Trace message"; BOOST_LOG_SEV(lg, logging::trivial::error) << "Error message"; return 0; } If this is a clumsy approach and there's a more elegant solution to feed log messages into SomeLogChannel() (in reality, it's a bit more complex because it involves a class, a couple interfaces, etc.), don't hesitate to comment as well. I'm still trying to wrap my mind around the topic. Thanks a bunch in advance and greets, Volker -- @: boost(a)bartheld.net

1 0

regarding spurious wakeup in boost 1.76
by Daggumati, Rajesh 13 Oct '21

13 Oct '21

HI Team, I have been facing an issue regarding conditionvariable.timed_wait() This function is returning false everywhere in my code(windows platform). It not waiting for notify signal. conditionvariable.timed_wait(lock1,boost::posix_time::milliseconds(100)) I have found same issue information in google. [Thread] thousands of spurious wakeups from timed_wait() per second (narkive.com)<https://boost-users.boost.narkive.com/xu7advkY/thread-thousands-of-spurious…> did this issue get fixed in boost 1.76.0? Please help me how to fix this issue. 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.

1 2

Evolving Boost.ContainerHash
by Peter Dimov 13 Oct '21

13 Oct '21

I've been thinking of updating and evolving Boost.ContainerHash, so I e-mailed Daniel James to see what his thoughts on that are. He says he's not going to come back to it, since he's moved on from C++. (Why would anyone do so is beyond me. :-)) More specifically, what I'm envisaging is updating boost::hash to take a seed: template<class T> struct hash { hash(); // as before explicit hash( size_t seed ); size_t operator()(T const& v) { return detail::hash_combine(seed, hash_value(v)); } }; The public hash_combine then becomes: template<class T> void hash_combine( size_t& seed, T const& v ) { return hash<T>(seed)(v); } This allows passing seeded hashes to unordered containers, without any changes to the latter: std::unordered_map<std::string, int, boost::hash<std::string>> map( 0, boost::hash<std::string>( 0x12345678 ) ); Seeding user-exposed hash tables is a good security practice which prevents (or makes less likely) some DoS attacks. The combiner function, detail::hash_combine, will also need to be updated to something that is state of the art for 2021, rather than for 2004. (ContainerHash is already using a more modern implementation of hash_combine, but not in all cases.) The implementation can be cleaned up by removing the C++98 era workarounds for compilers not supporting partial specialization, function template ordering, or argument-dependent lookup. The documentation is also due to a refresh, as the mentions of TR1 are no longer relevant. I also think that Boost.ContainerHash should just be renamed to Boost.Hash as that's what it is - it defines boost::hash. So, I am thinking of taking over ContainerHash and doing all that, if there are no objections.

2 3

[CMake] Can/should we specify optional dependencies
by John Maddock 11 Oct '21

11 Oct '21

I have a regex bug report relating to linking to ICU when using CMake: https://github.com/boostorg/regex/issues/143 Is there a correct way to specify in the CMake file that if you use header X, then you should also link to library Y, but otherwise not? Thanks, John. -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

5 9

Boost::posixtime issue
by mahesh pramod 07 Oct '21

07 Oct '21

Hi , I am getting false always for this timed_wait function . does posix_time supports in windows as its not looking for notify signal. scoped_lock_t lock(m_mutex); EXPECT_TRUE(m_condition_variable.timed_wait(lock, boost::posix_time::milliseconds(500))) << "Should get signalled (true) not time out";

1 0

boost::posix_time issue
by mahesh pramod 06 Oct '21

06 Oct '21

Hi , I am getting false always for this timed_wait function . does posix_time supports in windows as its not looking for notify signal. scoped_lock_t lock(m_mutex); EXPECT_TRUE(m_condition_variable.timed_wait(lock, boost::posix_time::milliseconds(500))) << "Should get signalled (true) not time out";

1 0

MSYS2 - MinGW64 - Windows 10 Pro - GCC 10.2.0 - undefined references
by Jens Kallup 05 Oct '21

05 Oct '21

Hello Community, I running Windows 10 Pro. MSYS2 - MinGW64-bit with gcc/g++ 10.2.0. I have download the 1_77 Version of Boost, compile it with b2 in the msys2 shell terminal. I could not replace cxx11 to cxx17. All options to build.bat, and b2.exe/sh to switch to cxx17 have not be worked. I downwrite the simple "Boost.program_options" example. I could compile it without any errors or warnings. But I ran into trouble at link stage. I have tried libs for x32/64, single/multi thread, debug/release, static/dynamic. All ends up with the same error of undefined reference explained below. Here comes the known source code to the problem: ---%<--- # include <boost/program_options.hpp> # include "common.h" namespace po = boost::program_options; int main(int argc, char *argv[]) { try { po::options_description desc("Allowed Options"); desc.add_options() ("help", "shows the help page") ("compression", po::value<int>(), "set compression level") ; po::variables_map vm; po::store(po::parse_command_line(argc, argv, desc), vm); po::notify(vm); if (vm.count("help")) { std::cout << desc << std::endl; return SUCCESS; } if (vm.count("compression")) { std::cout << "Compression level was set to " << vm["compression"].as<int>() << "." << std::endl; } else { std::cout << "Compression level was not set." << std::endl; } } catch(...) { std::cerr << "caugth a error.\n"; return FAILURE; } return SUCCESS; } --->%--- Here is a list of the files that are generated during the build time: devlab1@rk1700 MINGW64 /e/Projekte/news $ dir ../boost_1_77_0/stage/lib/ cmake libboost_atomic-mgw10-mt-d-x32-1_77.a libboost_atomic-mgw10-mt-d-x64-1_77.a libboost_atomic-mgw10-mt-s-x64-1_77.a libboost_atomic-mgw10-mt-x32-1_77.a libboost_atomic-mgw10-mt-x64-1_77.a libboost_chrono-mgw10-mt-d-x32-1_77.a libboost_chrono-mgw10-mt-d-x64-1_77.a libboost_chrono-mgw10-mt-s-x64-1_77.a libboost_chrono-mgw10-mt-x32-1_77.a libboost_chrono-mgw10-mt-x64-1_77.a libboost_container-mgw10-mt-d-x32-1_77.a libboost_container-mgw10-mt-d-x64-1_77.a libboost_container-mgw10-mt-s-x64-1_77.a libboost_container-mgw10-mt-x32-1_77.a libboost_container-mgw10-mt-x64-1_77.a libboost_context-mgw10-mt-d-x32-1_77.a libboost_context-mgw10-mt-d-x64-1_77.a libboost_context-mgw10-mt-s-x64-1_77.a libboost_context-mgw10-mt-x32-1_77.a libboost_context-mgw10-mt-x64-1_77.a libboost_contract-mgw10-mt-d-x32-1_77.a libboost_contract-mgw10-mt-d-x64-1_77.a libboost_contract-mgw10-mt-s-x64-1_77.a libboost_contract-mgw10-mt-x32-1_77.a libboost_contract-mgw10-mt-x64-1_77.a libboost_coroutine-mgw10-mt-d-x32-1_77.a libboost_coroutine-mgw10-mt-d-x64-1_77.a libboost_coroutine-mgw10-mt-s-x64-1_77.a libboost_coroutine-mgw10-mt-x32-1_77.a libboost_coroutine-mgw10-mt-x64-1_77.a libboost_date_time-mgw10-mt-d-x32-1_77.a libboost_date_time-mgw10-mt-d-x64-1_77.a libboost_date_time-mgw10-mt-s-x64-1_77.a libboost_date_time-mgw10-mt-x32-1_77.a libboost_date_time-mgw10-mt-x64-1_77.a libboost_exception-mgw10-mt-d-x32-1_77.a libboost_exception-mgw10-mt-d-x64-1_77.a libboost_exception-mgw10-mt-s-x64-1_77.a libboost_exception-mgw10-mt-x32-1_77.a libboost_exception-mgw10-mt-x64-1_77.a libboost_fiber-mgw10-mt-d-x64-1_77.a libboost_fiber-mgw10-mt-s-x64-1_77.a libboost_fiber-mgw10-mt-x64-1_77.a libboost_filesystem-mgw10-mt-d-x32-1_77.a libboost_filesystem-mgw10-mt-d-x64-1_77.a libboost_filesystem-mgw10-mt-s-x64-1_77.a libboost_filesystem-mgw10-mt-x32-1_77.a libboost_filesystem-mgw10-mt-x64-1_77.a libboost_graph-mgw10-mt-d-x32-1_77.a libboost_graph-mgw10-mt-d-x64-1_77.a libboost_graph-mgw10-mt-s-x64-1_77.a libboost_graph-mgw10-mt-x32-1_77.a libboost_graph-mgw10-mt-x64-1_77.a libboost_iostreams-mgw10-mt-d-x32-1_77.a libboost_iostreams-mgw10-mt-d-x64-1_77.a libboost_iostreams-mgw10-mt-s-x64-1_77.a libboost_iostreams-mgw10-mt-x32-1_77.a libboost_iostreams-mgw10-mt-x64-1_77.a libboost_json-mgw10-mt-d-x32-1_77.a libboost_json-mgw10-mt-d-x64-1_77.a libboost_json-mgw10-mt-s-x64-1_77.a libboost_json-mgw10-mt-x32-1_77.a libboost_json-mgw10-mt-x64-1_77.a libboost_locale-mgw10-mt-d-x32-1_77.a libboost_locale-mgw10-mt-d-x64-1_77.a libboost_locale-mgw10-mt-s-x64-1_77.a libboost_locale-mgw10-mt-x32-1_77.a libboost_locale-mgw10-mt-x64-1_77.a libboost_log-mgw10-mt-d-x32-1_77.a libboost_log-mgw10-mt-d-x64-1_77.a libboost_log-mgw10-mt-s-x64-1_77.a libboost_log-mgw10-mt-x32-1_77.a libboost_log-mgw10-mt-x64-1_77.a libboost_log_setup-mgw10-mt-d-x32-1_77.a libboost_log_setup-mgw10-mt-d-x64-1_77.a libboost_log_setup-mgw10-mt-s-x64-1_77.a libboost_log_setup-mgw10-mt-x32-1_77.a libboost_log_setup-mgw10-mt-x64-1_77.a libboost_math_c99-mgw10-mt-d-x64-1_77.a libboost_math_c99-mgw10-mt-s-x64-1_77.a libboost_math_c99-mgw10-mt-x64-1_77.a libboost_math_c99f-mgw10-mt-d-x64-1_77.a libboost_math_c99f-mgw10-mt-s-x64-1_77.a libboost_math_c99f-mgw10-mt-x64-1_77.a libboost_math_c99l-mgw10-mt-d-x64-1_77.a libboost_math_c99l-mgw10-mt-s-x64-1_77.a libboost_math_c99l-mgw10-mt-x64-1_77.a libboost_math_tr1-mgw10-mt-d-x64-1_77.a libboost_math_tr1-mgw10-mt-s-x64-1_77.a libboost_math_tr1-mgw10-mt-x64-1_77.a libboost_math_tr1f-mgw10-mt-d-x64-1_77.a libboost_math_tr1f-mgw10-mt-s-x64-1_77.a libboost_math_tr1f-mgw10-mt-x64-1_77.a libboost_math_tr1l-mgw10-mt-d-x64-1_77.a libboost_math_tr1l-mgw10-mt-s-x64-1_77.a libboost_math_tr1l-mgw10-mt-x64-1_77.a libboost_nowide-mgw10-mt-d-x32-1_77.a libboost_nowide-mgw10-mt-d-x64-1_77.a libboost_nowide-mgw10-mt-s-x64-1_77.a libboost_nowide-mgw10-mt-x32-1_77.a libboost_nowide-mgw10-mt-x64-1_77.a libboost_prg_exec_monitor-mgw10-mt-d-x32-1_77.a libboost_prg_exec_monitor-mgw10-mt-d-x64-1_77.a libboost_prg_exec_monitor-mgw10-mt-s-x64-1_77.a libboost_prg_exec_monitor-mgw10-mt-x32-1_77.a libboost_prg_exec_monitor-mgw10-mt-x64-1_77.a libboost_program_options-mgw10-mt-d-x32-1_77.a libboost_program_options-mgw10-mt-d-x64-1_77.a libboost_program_options-mgw10-mt-s-x64-1_77.a libboost_program_options-mgw10-mt-x32-1_77.a libboost_program_options-mgw10-mt-x64-1_77.a libboost_python39-mgw10-mt-d-x32-1_77.a libboost_python39-mgw10-mt-d-x64-1_77.a libboost_python39-mgw10-mt-x32-1_77.a libboost_python39-mgw10-mt-x64-1_77.a libboost_random-mgw10-mt-d-x32-1_77.a libboost_random-mgw10-mt-d-x64-1_77.a libboost_random-mgw10-mt-s-x64-1_77.a libboost_random-mgw10-mt-x32-1_77.a libboost_random-mgw10-mt-x64-1_77.a libboost_regex-mgw10-mt-d-x32-1_77.a libboost_regex-mgw10-mt-d-x64-1_77.a libboost_regex-mgw10-mt-s-x64-1_77.a libboost_regex-mgw10-mt-x32-1_77.a libboost_regex-mgw10-mt-x64-1_77.a libboost_serialization-mgw10-mt-d-x32-1_77.a libboost_serialization-mgw10-mt-d-x64-1_77.a libboost_serialization-mgw10-mt-s-x64-1_77.a libboost_serialization-mgw10-mt-x32-1_77.a libboost_serialization-mgw10-mt-x64-1_77.a libboost_stacktrace_basic-mgw10-mt-d-x32-1_77.a libboost_stacktrace_basic-mgw10-mt-x32-1_77.a libboost_stacktrace_noop-mgw10-mt-d-x32-1_77.a libboost_stacktrace_noop-mgw10-mt-d-x64-1_77.a libboost_stacktrace_noop-mgw10-mt-s-x64-1_77.a libboost_stacktrace_noop-mgw10-mt-x32-1_77.a libboost_stacktrace_noop-mgw10-mt-x64-1_77.a libboost_stacktrace_windbg-mgw10-mt-d-x64-1_77.a libboost_stacktrace_windbg-mgw10-mt-s-x64-1_77.a libboost_stacktrace_windbg-mgw10-mt-x64-1_77.a libboost_stacktrace_windbg_cached-mgw10-mt-d-x64-1_77.a libboost_stacktrace_windbg_cached-mgw10-mt-s-x64-1_77.a libboost_stacktrace_windbg_cached-mgw10-mt-x64-1_77.a libboost_system-mgw10-mt-d-x32-1_77.a libboost_system-mgw10-mt-d-x64-1_77.a libboost_system-mgw10-mt-s-x64-1_77.a libboost_system-mgw10-mt-x32-1_77.a libboost_system-mgw10-mt-x64-1_77.a libboost_test_exec_monitor-mgw10-mt-d-x32-1_77.a libboost_test_exec_monitor-mgw10-mt-d-x64-1_77.a libboost_test_exec_monitor-mgw10-mt-s-x64-1_77.a libboost_test_exec_monitor-mgw10-mt-x32-1_77.a libboost_test_exec_monitor-mgw10-mt-x64-1_77.a libboost_thread-mgw10-mt-d-x32-1_77.a libboost_thread-mgw10-mt-d-x64-1_77.a libboost_thread-mgw10-mt-s-x64-1_77.a libboost_thread-mgw10-mt-x32-1_77.a libboost_thread-mgw10-mt-x64-1_77.a libboost_timer-mgw10-mt-d-x32-1_77.a libboost_timer-mgw10-mt-d-x64-1_77.a libboost_timer-mgw10-mt-s-x64-1_77.a libboost_timer-mgw10-mt-x32-1_77.a libboost_timer-mgw10-mt-x64-1_77.a libboost_type_erasure-mgw10-mt-d-x32-1_77.a libboost_type_erasure-mgw10-mt-d-x64-1_77.a libboost_type_erasure-mgw10-mt-s-x64-1_77.a libboost_type_erasure-mgw10-mt-x32-1_77.a libboost_type_erasure-mgw10-mt-x64-1_77.a libboost_unit_test_framework-mgw10-mt-d-x32-1_77.a libboost_unit_test_framework-mgw10-mt-d-x64-1_77.a libboost_unit_test_framework-mgw10-mt-s-x64-1_77.a libboost_unit_test_framework-mgw10-mt-x32-1_77.a libboost_unit_test_framework-mgw10-mt-x64-1_77.a libboost_wave-mgw10-mt-d-x32-1_77.a libboost_wave-mgw10-mt-d-x64-1_77.a libboost_wave-mgw10-mt-s-x64-1_77.a libboost_wave-mgw10-mt-x32-1_77.a libboost_wave-mgw10-mt-x64-1_77.a libboost_wserialization-mgw10-mt-d-x32-1_77.a libboost_wserialization-mgw10-mt-d-x64-1_77.a libboost_wserialization-mgw10-mt-s-x64-1_77.a libboost_wserialization-mgw10-mt-x32-1_77.a libboost_wserialization-mgw10-mt-x64-1_77.a Here comes the command line for compile/link the application $ /mingw64/bin/x86_64-w64-mingw32-g++ -o winperm.exe ./tmp/main.o ./tmp/network.o ./tmp/threading.o ./tmp/translator.o ./tmp/tv_tui.o ./tmp/permutation.o -fopenmp -MD -I/E/Projekte/boost_1_77_0/stage/lib -L../boost_1_77_0/stage/lib -L../tvision/build -L/mingw64/lib -L/mingw64/x86_64-w64-mingw32/lib -ltvision -lkernel32 -luser32 -lwinmm -lws2_32 -lintl -lpthread -lboost_iostreams-mgw10-mt-x64-1_77 -lboost_program_options-mgw10-mt-x64-1_77 And here comes the error output from the linker LD: E:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32 /bin/ld.exe: ./tmp/main.o:main.cc: (.text$_ZN5boost15program_options25basic_command_line_parserIcE12extra_parserENS_9 function1ISt4pairISsSsERKSsEE[_ZN5boost15program_options25basic_command_line_parserIcE12 extra_parserENS_9function1ISt4pairISsSsERKSsEE]+0x41): undefined reference to `boost::program_options::detail::cmdline::set_additional_parser(boost::function1 <std::pair<std::string, std::string>, std::string const&>)' E:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32 /bin/ld.exe: ./tmp/main.o:main.cc: (.text$_ZN5boost15program_options11to_internalISsEESt6vectorISsSaISsEERKS2_IT_Sa IS5_EE[_ZN5boost15program_options11to_internalISsEESt6vectorISsSaISsEERKS2_IT_Sa IS5_EE]+0x48): undefined reference to `boost::program_options::to_internal (std::string const&)' E:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64- mingw32/bin/ld.exe: ./tmp/main.o:main.cc: (.text$_ZN5boost15program_options25basic_command_line_parserIcEC1EiPKPKc [_ZN5boost15program_options25basic_command_line_parserIcEC1EiPKPKc]+0xaf): undefined reference to `boost::program_options::detail::cmdline::cmdline(std::vector<std::string, std::allocator<std::string> > const&)' E:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32 /bin/ld.exe: ./tmp/main.o:main.cc:(.text.startup.main+0xb8): undefined reference to `boost::program_options::options_description::options_description(std::string const&, unsigned int, unsigned int)' E:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32 /bin/ld.exe: ./tmp/main.o:main.cc:(.text.startup.main+0x281): undefined reference to `boost::program_options::abstract_variables_map::operator[](std::string const&) const' E:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32 /bin/ld.exe: ./tmp/main.o:main.cc: (.text$_ZN5boost15program_options10validators17get_single_stringIcEERKSbIT_St11 char_traitsIS3_ESaIS3_EERKSt6vectorIS7_SaIS7_EEb[_ZN5boost15program_options10validators17 get_single_stringIcEERKSbIT_St11char_traitsIS3_ESaIS3_EERKSt6vectorIS7_SaIS7_EEb]+0xa1): undefined reference to `boost::program_options::validation_error::get_template(boost::program_options:: validation_error::kind_t)' E:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32 /bin/ld.exe: ./tmp/main.o:main.cc: (.text$_ZN5boost15program_options10validators17get_single_stringIcEERKSbIT_St11 char_traitsIS3_ESaIS3_EERKSt6vectorIS7_SaIS7_EEb[_ZN5boost15program_options10validators17 get_single_stringIcEERKSbIT_St11char_traitsIS3_ESaIS3_EERKSt6vectorIS7_SaIS7_EEb]+0xba): undefined reference to `boost::program_options::error_with_option_name::error_with_option_name(std::string const&, std::string const&, std::string const&, int)' E:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32 /bin/ld.exe: ./tmp/main.o:main.cc: (.text$_ZN5boost15program_options10validators17get_single_stringIcEERKSbIT_St11 char_traitsIS3_ESaIS3_EERKSt6vectorIS7_SaIS7_EEb[_ZN5boost15program_options10 validators17get_single_stringIcEERKSbIT_St11char_traitsIS3_ESaIS3_EERKSt6vectorIS7_SaIS 7_EEb]+0x199): undefined reference to `boost::program_options::validation_error::get_template(boost::program_options:: validation_error::kind_t)' E:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32 /bin/ld.exe: ./tmp/main.o:main.cc: (.text$_ZN5boost15program_options10validators17get_single_stringIcEERKSbIT_St11 char_traitsIS3_ESaIS3_EERKSt6vectorIS7_SaIS7_EEb[_ZN5boost15program_options10validators17 get_single_stringIcEERKSbIT_St11char_traitsIS3_ESaIS3_EERKSt6vectorIS7_SaIS7_EEb]+0x1b2): undefined reference to `boost::program_options::error_with_option_name::error_with_option_name(std::string const&, std::string const&, std::string const&, int)' E:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32 /bin/ld.exe: ./tmp/main.o:main.cc: (.text$_ZN5boost15program_options8validateIicEEvRNS_3anyERKSt6vectorISbIT0_St11 char_traitsIS5_ESaIS5_EESaIS9_EEPT_l[_ZN5boost15program_options8validateIicEEvRNS_3any ERKSt6vectorISbIT0_St11char_traitsIS5_ESaIS5_EESaIS9_EEPT_l]+0x5db): undefined reference to `boost::program_options::invalid_option_value::invalid_option_value(std::string const&)' E:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32 /bin/ld.exe: ./tmp/main.o:main.cc: (.rdata$_ZTVN5boost10wrapexceptINS_15program_options20invalid_option_valueEEE[_ZTVN5 boost10wrapexceptINS_15program_options20invalid_option_valueEEE]+0x60): undefined reference to `boost::program_options::error_with_option_name::substitute_placeholders(std::string const&) const' E:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32 /bin/ld.exe: ./tmp/main.o:main.cc: (.rdata$_ZTVN5boost10wrapexceptINS_15program_options16validation_errorEEE[_ZTVN5boost10 wrapexceptINS_15program_options16validation_errorEEE]+0x60): undefined reference to `boost::program_options::error_with_option_name::substitute_placeholders(std::string const&) const' E:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32 /bin/ld.exe: ./tmp/main.o:main.cc: (.rdata$_ZTVN5boost15program_options16validation_errorE[_ZTVN5boost15program_options16 validation_errorE]+0x30): undefined reference to `boost::program_options::error_with_option_name::substitute_placeholders(std::string const&) const' E:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32 /bin/ld.exe: ./tmp/main.o:main.cc: (.rdata$_ZTVN5boost15program_options20invalid_option_valueE[_ZTVN5boost15 program_options20invalid_option_valueE]+0x30): undefined reference to `boost::program_options::error_with_option_name::substitute_placeholders(std::string const&) const' E:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32 /bin/ld.exe: ./tmp/main.o:main.cc: (.rdata$_ZTVN5boost15program_options11typed_valueIicEE[_ZTVN5boost15 program_options11typed_valueIicEE]+0x38): undefined reference to `boost::program_options::value_semantic_codecvt_helper<char>::parse(boost::any&, std::vector<std::string, std::allocator<std::string> > const&, bool) const' E:/msys64/mingw64/bin/../lib/gcc/x86_64-w64-mingw32/10.2.0/../../../../x86_64-w64-mingw32 /bin/ld.exe: ./tmp/main.o:main.cc: (.rdata$.refptr._ZN5boost15program_options3argE[.refptr._ZN5boost15program_options3 argE]+0x0): undefined reference to `boost::program_options::arg' collect2.exe: error: ld returned 1 exit status Did I miss something ? The question is now, how can I use boost under msys2 with mingw64 ? Thanks for helping hands, paule32

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cybersecuriy for boost
by rajesh daggumati 04 Oct '21

04 Oct '21

HI, Is there any group who supports on cyber security while we are using boost 1.76.0

4 3

queries regarding usage of boost 1.76.0 .
by mahesh pramod 04 Oct '21

04 Oct '21

Hi, I have below queries regarding boost 1.76.0. I have been faced these below queries. 1.how to check boost is statically binded or dynamically binded with my code? is this binding related to virtual concept? 2.how boost interacts with any software? 3. does boost takes our data for any use? ex: when we use sql servers they take our data for testing purpose. Like that does boost take?

2 1