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Help with a compilation error [Boost/Math]
by Peder Lon Hauge 04 Aug '22

04 Aug '22

Hi, I'm trying to use Boost in order to find values of a 2F3 hypergeometric function. Just to check that I am using the package the correct way, I tried to compile the small test file below (using the example from the pFq docs), with the command $ g++ -o test.exe test.cpp -I /home/peder/boost/boost_1_79_0 As far as I understand, the library is header-only, so I didn't expect the compilation error below. I don't where I've made a mistake, and I'd greatly appreciate any help with figuring out the error. I'm running Ubuntu 20.04.04 on WSL and using gcc 9.4.0. Best regards, Peder Test program: #include <iostream> #include <boost/math/special_functions/hypergeometric_pFq.hpp> int main() { double z = -9; double h = boost::math::hypergeometric_pFq({2,3,4}, {5,6,7,8}, z); // Calculate 3F4 std::cout << h << std::endl; return 0; } Error message: $ g++ -o test.exe test.cpp -I /home/peder/boost/boost_1_79_0 /usr/bin/ld: /tmp/ccp4Lm8m.o: in function `std::pair<long double, long double> boost::math::detail::hypergeometric_pFq_checked_series_impl<std::initializer_list<int>, long double, boost::math::policies::policy<boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy>, boost::math::detail::iteration_terminator>(std::initializer_list<int> const&, std::initializer_list<int> const&, long double const&, boost::math::policies::policy<boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy> const&, boost::math::detail::iteration_terminator const&, long long&)': test.cpp:(.text._ZN5boost4math6detail38hypergeometric_pFq_checked_series_implISt16initializer_listIiEeNS0_8policies6policyINS5_14default_policyES7_S7_S7_S7_S7_S7_S7_S7_S7_S7_S7_S7_EENS1_20iteration_terminatorEEESt4pairIT0_SB_ERKT_SF_RKSB_RKT1_RKT2_Rx[_ZN5boost4math6detail38hypergeometric_pFq_checked_series_implISt16initializer_listIiEeNS0_8policies6policyINS5_14default_policyES7_S7_S7_S7_S7_S7_S7_S7_S7_S7_S7_S7_EENS1_20iteration_terminatorEEESt4pairIT0_SB_ERKT_SF_RKSB_RKT1_RKT2_Rx]+0xeef): undefined reference to `boost::math::tools::promote_args<long double, float, float, float, float, float>::type boost::math::lgamma<long double, boost::math::policies::policy<boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy> >(long double, boost::math::policies::policy<boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy> const&)' /usr/bin/ld: test.cpp:(.text._ZN5boost4math6detail38hypergeometric_pFq_checked_series_implISt16initializer_listIiEeNS0_8policies6policyINS5_14default_policyES7_S7_S7_S7_S7_S7_S7_S7_S7_S7_S7_S7_EENS1_20iteration_terminatorEEESt4pairIT0_SB_ERKT_SF_RKSB_RKT1_RKT2_Rx[_ZN5boost4math6detail38hypergeometric_pFq_checked_series_implISt16initializer_listIiEeNS0_8policies6policyINS5_14default_policyES7_S7_S7_S7_S7_S7_S7_S7_S7_S7_S7_S7_EENS1_20iteration_terminatorEEESt4pairIT0_SB_ERKT_SF_RKSB_RKT1_RKT2_Rx]+0xfe5): undefined reference to `boost::math::tools::promote_args<long double, float, float, float, float, float>::type boost::math::expm1<long double, boost::math::policies::policy<boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy> >(long double, boost::math::policies::policy<boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy> const&)' /usr/bin/ld: /tmp/ccp4Lm8m.o: in function `int boost::math::detail::log_pochhammer<int, boost::math::policies::policy<boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy> >(int, unsigned int, boost::math::policies::policy<boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy>, int*)': test.cpp:(.text._ZN5boost4math6detail14log_pochhammerIiNS0_8policies6policyINS3_14default_policyES5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_EEEET_S7_jT0_Pi[_ZN5boost4math6detail14log_pochhammerIiNS0_8policies6policyINS3_14default_policyES5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_EEEET_S7_jT0_Pi]+0x3d): undefined reference to `boost::math::tools::promote_args<int, float, float, float, float, float>::type boost::math::lgamma<int, boost::math::policies::policy<boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy> >(int, int*, boost::math::policies::policy<boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy> const&)' /usr/bin/ld: test.cpp:(.text._ZN5boost4math6detail14log_pochhammerIiNS0_8policies6policyINS3_14default_policyES5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_EEEET_S7_jT0_Pi[_ZN5boost4math6detail14log_pochhammerIiNS0_8policies6policyINS3_14default_policyES5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_EEEET_S7_jT0_Pi]+0x57): undefined reference to `boost::math::tools::promote_args<int, float, float, float, float, float>::type boost::math::lgamma<int, boost::math::policies::policy<boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy> >(int, int*, boost::math::policies::policy<boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy, boost::math::policies::default_policy> const&)' collect2: error: ld returned 1 exit status

3 3

[Query] Does boost support concurrent hash map, for ip fragment reassemble
by Jiany Wu 02 Aug '22

02 Aug '22

Hello, I want to use boost concurrent hash map to do fragment reassemble, does it support concurrent hash map? Or is there any similar concurrent data structure, which can support it? Thanks in advance! Best regards Dave

1 0

sgn/sign-function
by Gero Peterhoff 31 Jul '22

31 Jul '22

Hi John, i think your sign-function (boost/math/special_functions/sign.hpp) is incomplete. Because the resulttype is int, not all cases can be covered correctly (nan, inf, -0). With my implementation this works and it follows the std-conventions (sgn(FP) -> FP, sgn(INT/BOOL) -> double). I also tried to optimize them (branch-free, vectorizable). sgn(FP) -> FP ±0/±1 sgn(FP nan/inf) -> FP nan/inf sgn(INT) -> double +0/±1 sgn(UINT/BOOL) -> double +0/+1 regards Gero

1 0

C++11 or C++14?
by Vinnie Falco 29 Jul '22

29 Jul '22

I'm considering bumping up the C++ language requirement for Boost.URL from C++11 to C++14. I have concerns about doing this, because it affects all my downstream libraries (HTTP.Proto, HTTP.IO, Websocket.Proto, Websocket.IO, and any examples or complete clients/servers that I write). My main fear is that there are still a considerable number of individuals or corporations who, for whatever reason, cannot build with -std=c++14 or later despite having access to newer compilers. I don't mind if there is a small percentage of loss but I do mind if 20% or more of potential users will be locked out. The questions are: 1. Would you or your company be prevented from using Boost.URL if it required C++14? 2. Do you know any other organizations who cannot use C++14 or later? 3. Do you know of any regional or global metrics on who _cannot_ use libraries which require C++14? See also, this reddit thread on r/cpp: <https://www.reddit.com/r/cpp/comments/w6zuo5/c11_or_require_c14/> -- Regards, Vinnie Follow me on GitHub: https://github.com/vinniefalco

6 6

gcc 12 and clang 14
by Matt Hurd 28 Jul '22

28 Jul '22

Curious as to if gcc-12 and clang-14 may make it to the release compiler list for 1.80? (https://www.boost.org/users/history/version_1_80_0.html) Is that just a formality? I see the regression tests for both look in pretty good shape: https://www.boost.org/development/tests/develop/developer/summary.html Thanks all for your great work. Much appreciated, --Matt _______________ matthurd(a)acm.org

1 0

boost::asio::ssl::context::use_certificate_chain_file and boost::asio::ssl::context::use_certificate_file Methods Give "bad method" Error
by Osman Zakir 21 Jul '22

21 Jul '22

Hello. Message for update to previously-reported issue. It turns out that the "bad method" error was because of the boost::asio::ssl::context object methods I mentioned in the subject of this email. Reading the certs in from the files into std::strings manually and using use_certificate and use_certificate_chain instead is better, at least from what I saw. I still have an error in the browser (code: ERR_SSL_PROTOCOL_ERROR) when I try to visit my running app saying that the connection for the site isn't secure and that it gave back an invalid response. And running the command openssl s_client -connect <ip_address>:5501 -servername dragonosman.dynu.net gave this result: CONNECTED(00000148) 11784:error:1409442E:SSL routines:ssl3_read_bytes:tlsv1 alert protocol version:ssl\record\rec_layer_s3.c:1544:SSL alert number 70 --- no peer certificate available --- No client certificate CA names sent --- SSL handshake has read 7 bytes and written 322 bytes Verification: OK --- New, (NONE), Cipher is (NONE) Secure Renegotiation IS NOT supported Compression: NONE Expansion: NONE No ALPN negotiated Early data was not sent Verify return code: 0 (ok) and when command exits, I see this error in my server console window: Lines 625 and 626: handshake: unsupported protocol (SSL routines, tls_early_post_process_client_hello) Lines 646 and 647: read: unspecified system error I'm assuming this is a HTTP/2 upgrade request inside a TLS ClientHello message, but is that enough reason for the SSL error I'm getting in my browser? Anyway, I've sent an email on the OpenSSL users mailing list to ask how to parse the ClientHello message, so hopefully I'll get something from there.

1 0

[container] flat_set using a reversed small_vector
by Phil Endecott 20 Jul '22

20 Jul '22

Dear Experts, I currently have: template <typename KEY, typename VALUE, size_t SZ> using small_flat_map = boost::container::flat_map< KEY, VALUE, std::less<KEY>, boost::container::small_vector< std::pair<KEY,VALUE>, SZ > >; This works OK, but one thing that I do with it quite often is auto i = m.upper_bound(...); m.erase(m.begin(),i); Erasing items at the start of the vector is of course the worst thing you can do for performance with a flat_map. So I was wondering if I can have a flat_map that stores its elements in the reverse order in the underlying vector. Question: can anyone think of a way to do this that doesn't require changing all of the downstream code? For a few milliseconds I thought I could just change std::less for std::greater but that reverses the externally-visible behaviour. Is there some Boost utility that can wrap the implementation vector to work in reverse? Thanks, Phil.

1 0

Server App using Boost.Beast, Sending Only One Certificate out of Chain
by Osman Zakir 16 Jul '22

16 Jul '22

Hi, everyone. I upgraded my server app to Boost 1.79.0 and tried running it, but there are issues: 1. I renewed my Let's Encrypt certs, but when I try to check them, I see it's only sending one cert out of a chain of three. And I'm loading the certs and the RSA private key using the SSL context methods to load the cert chain and key from files, too. 2. The read operation on line 640 in the do_session function in currency_converter.cpp gave a "bad method" error before, but mostly gives "the connection was forcibly closed by the remote host" error. I have the source code on GitHub here: https://github.com/DragonOsman/currency_converter.

1 0

[release] Boost 1.80.0 beta 1 released
by Glen Fernandes 14 Jul '22

14 Jul '22

Boost release 1.80.0 beta 1 is now available at: https://boostorg.jfrog.io/artifactory/main/beta/1.80.0.beta1/source/ The SHA256 checksums are: boost_1_80_0_b1.tar.bz2 - b29191c1bd4504511f9b1155c6f79f06cc7044444780392ed7358f5778ac7d16 boost_1_80_0_b1.tar.gz - ad3df9f63acd667dcf13375fa0e90e7303f851251e91d1505974bdbbf1f94907 boost_1_80_0_b1.7z - 7bfdf705b1d058c3525be90ed5cb47aacf919cd74aa7d5752d55e78aa60880ba boost_1_80_0_b1.zip - 1b509ed848f153086984658d4d4a57af6230f496a53bf88aba805bb49039012d Release notes (still need updates): https://www.boost.org/users/history/version_1_80_0.html Please try the beta and report any problems you encounter. Thanks, -- Boost Release Team

1 0

Higher than expected memory usage by boost::iostreams::gzip_compressor
by Alex Petty 13 Jul '22

13 Jul '22

Hello, I'm looking at adopting boost::iostreams for reading/writing compressed streams. I'm testing with textual files commonly on the order of a couple of GB uncompressed, and a couple hundred MB compressed. I noticed during some initial testing that using a gzip_compressor to write a compressed stream through boost::iostreams results in significant memory usage, I'm seeing hundreds of MB per compressed stream. It looks like internally the gzip_compressor must be doing some GC-type behavior, because I see its memory usage increase to just under 1GB per stream with a gzip_compressor, and then decrease again. Is there any way to control the memory that gzip_compressor is using? I've tried both increasing and decreasing the buffer size when gzip_compressor is constructed, but that buffer is tiny and cannot be what's driving the increased memory usage. Thanks, Alex

1 0

[Graph] Can users on Xcode 7-10 help out?
by Jeremy Murphy 12 Jul '22

12 Jul '22

Dear Boost.Graph users, Is anyone that uses old Xcode 7-10 able to help out with some curious compilation errors? https://github.com/boostorg/graph/issues/298 We'll do our best to fix them but I assume it might be easier for someone that actually uses these particular platforms. Thanks, cheers. Jeremy

1 0

xpressive: How to combine vector of regex to one?
by Anton Sergunov 08 Jul '22

08 Jul '22

Hello Boost Users! I'm seeking some help from the community because can't see answer in documentation or in source code. I need to find which regex of N my string matches. I don't like to compare them one by one, to speed up the process. It's easy to implement if I have them compile time: ```cpp sregex re = (s1 = re1)|(s2 = re2)|(s3=re3); ... std::set<int> foo(const std::string& str) { std::set<int> result; smatch match; if(regex_match(str, match, re)) { for(int i = 0; i<3; ++i) if(match[i+1]) result.insert(i); } return result; } ``` But I have a vector: ```cpp std::set<int> foo(const std::string& str, const std::vector<sregex>& reVector) { sregex re; int index = 1; for(auto&& item : reVector) { re |= (mark_tag(index++) = item); // (1) } std::set<int> result; smatch match; if(regex_match(str, match, re)) { for(int i = 0; i<reVector; ++i) if(match[i+1]) result.insert(i); } } return result; } ``` There at (1) `|=` doesn't work as I expect for some reson, It didn't catch some values. If I replace it with ```cpp re = re | (mark_tag(index++) = item); ``` it just crashes. If I replace with: ```cpp auto t = re; re = t | (mark_tag(index++) = item); ``` it making captures of previous tags to be subexpresions matches. So code doesn't work as I want. Is it any way to prevent sub-expression capture isolation? As I understand it should be some intermediate type before sregex to express expression under construction. So it will not isolate matches of existing part. I'm using v1.65.1 https://github.com/boostorg/xpressive/issues/24

1 0

Embedded install paths in CMake files for Boost 1.79
by Alex 05 Jul '22

05 Jul '22

Apologies if this is the wrong list. I tried boost-build but I'm not sure if my message was verified (I don't see it in the archive). I'm trying to make a build of Boost that includes the generated CMake files. For my case, I need to install the files to a staging area before packaging them up for installation in the target environment. I've tried "b2 --stagedir <dir> stage" but the generated CMake files still include the stagedir path in them, instead of the install prefix specified during bootstrap, which triggers errors in the packaging system I need to use. I'm also not sure if it's then possible to just install the headers to the same staging location. Is there a way to install to a staging location while the CMake files have the paths to the final install location? CMake uses CMAKE_STAGING_PREFIX for this but I can't find an equivalent for b2. I guess it must be required for cross-compiling though, if you want to support CMake on the target? Regards, Alex

1 0

Excessive dynamic allocation when using boost::split(..., boost::is_any_of(", "))?
by Dominique Pellé 05 Jul '22

05 Jul '22

Hi This following program shows many allocations coming from boost::split(..., boost::is_any_of(",")): ``` $ cat split.cpp #include <string> #include <cstdio> #include <boost/algorithm/string.hpp> #include <boost/container/small_vector.hpp> int main() { std::string str = "foo,bar,foobar,quux"; std::size_t s = 0; for (int i = 0; i < 100; ++i) { boost::container::small_vector<std::string, 4> v; #ifdef USE_IS_ANY_OF boost::split(v, str, boost::is_any_of(",")); #else boost::split(v, str, [](const char c) { return c == ',';}); #endif s += v.size(); } fprintf(stderr, "%zu\n", s); } ``` When using boost::is_any_of(","), there are 7 dynamic allocations per loop iteration whereas when using the lambda predicate, there are 0 dynamic allocation per loop as shown below: ``` $ clang++ -std=c++14 -DUSE_IS_ANY_OF split.cpp $ heaptrack ./a.out ... allocations: 702 $ clang++ -std=c++14 split.cpp $ heaptrack ./a.out ... allocations: 2 ``` I suspect that there are potential optimizations in Boost here to avoid so many allocations when boost::is_any_of(",") is used. Regards Dominique

3 2

Boost.URL review planned for 13-22 August 2022
by Mateusz Loskot 29 Jun '22

29 Jun '22

Folks, Klemens Morgenstern kindly volunteered [1] as the Review Manager (thanks Klemens!) for the Boost.URL [2], so we have planned the review shortly after the upcoming release of the Boost 1.80. Check the Review Schedule [3] for details! [1] https://lists.boost.org/Archives/boost/2022/06/253225.php [2] https://lists.boost.org/Archives/boost/2022/04/252814.php [3] https://www.boost.org/community/review_schedule.html Best regards, -- The Boost Review Wizards Mateusz Loskot

2 2

Boost Twitter is Blowing Up!!!
by Vinnie Falco 21 Jun '22

21 Jun '22

Greetings fellow users, library authors, maintainers, review wizards, release wizards, and Boost Foundation Board members! As part of our ongoing effort to continue the revitalization of Boost, a handful of us have taken the reins to post about Boost on social media. We have postings on Reddit and Hacker news, blog posts about the new efforts in Boost.Unordered, and new tweets. However, we could use your help! Right now the Boost Twitter account has a measly 957 followers. It would be great to increase our reach, so I'm asking everyone if they could be so kind as to Follow the official Boost Twitter account here: <https://twitter.com/Boost_Libraries> and then amplify our messages by Liking and Retweeting. Starting with this pinned tweet, which everyone will see when they visit the Boost Libraries Twittter profile page: <https://twitter.com/Boost_Libraries/status/1539003321939202048> Following the Boost Twitter account will give you up-to-date information about what is going on with Boost, including articles and mentions on other social media sites. Here is what we have so far: <https://www.reddit.com/r/cpp/comments/vfdcrz/advancing_the_state_of_the_art…> <https://www.reddit.com/r/cpp/comments/vbdr3z/new_boostunordered_containers_…> <https://twitter.com/hackernewstop10/status/1538622706035343364> <https://news.ycombinator.com/item?id=31801814> To summarize, engaging with Boost related content on social media will enhance our profile - any help is appreciated! -- Regards, Vinnie Follow me on GitHub: https://github.com/vinniefalco

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[JSON] Vote for Boost.JSON in this poll!
by Vinnie Falco 21 Jun '22

21 Jun '22

There's an online poll asking about which JSON library you use. If you use Boost.JSON consider voting for it: <https://meetingcpp.com/mcpp/survey/?q=2> Also, consider voting for it if you _don't_ use Boost.JSON, but you want to. -- Regards, Vinnie Follow me on GitHub: https://github.com/vinniefalco

1 0

[Locale] IBM437 encoding not supported in wconv
by Arnold, Stefan 14 Jun '22

14 Jun '22

Why is the IBM437 encoding not supported in boost::locale with the Win32 API ("wconv") backend? The following call will fail with a boost::locale::conv::invalid_charset_error when using the Win32 API backend: boost::locale::conv::to_utf<char>("abc", "IBM437") This is because "ibm437" is not contained in the all_windows_encodings variable in wconv_codepage.ipp (nor is "cp437" or another alias). As per Win32 API documentation (https://docs.microsoft.com/en-us/windows/win32/api/stringapiset/nf-stringap…, https://docs.microsoft.com/en-us/windows/win32/intl/code-page-identifiers) this encoding is supported in Win32 API. Furthermore, IBM437 is the legacy encoding of filenames in ZIP files, so it should be quite common.

1 1

Any objections to making C++14 the current baseline for Boost support and testing?
by John Maddock 10 Jun '22

10 Jun '22

Pursuant of discussion elsewhere: Does anyone have any concrete objections to Boost moving to a C++14 baseline? This would mean: * Library authors can drop and remove all support for pre-C++14 compilers after a suitable deprecation notice in place for say 3 releases. * The community maintenance team can likewise drop pre-C++14 support from community maintained / orphan libaries. * CI tests no longer need report pre-C++14 results. * From the next release onward, the boost super-project should clearly announce in our release notes, that C++11 and earlier support may no longer be available from the start of 2023. Thoughts? Thanks, John Maddock.

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[thread] attribute constructor failing to compile
by Jeanette C. 07 Jun '22

07 Jun '22

Hey hey, using boost 1.78 from the Archlinux repository, using the thread constructor with boost::thread::attributes as first argument fails to compile. The relevant code from the small test program is this: void work(bool& done) // simple main function for the thread int main() { bool done = false; boost::thread::attributes attr; // all changes commented out in the program boost::thread th1(attr, work, std::ref(done)); // some code, sleep and set done to true th1.join(); return 0; } g++ 11.2.0 reports the following error: In file included from /usr/include/boost/thread/detail/thread.hpp:33, from /usr/include/boost/thread/thread_only.hpp:22, from /usr/include/boost/thread/thread.hpp:12, from thread_prio.cpp:1: /usr/include/boost/bind/bind.hpp: In instantiation of 'void boost::_bi::list2<A1, A2>::operator()(boost::_bi::type<void>, F&, A&, int) [with F = boost::thread_attributes; A = boost::_bi::list0; A1 = boost::_bi::value<int (*)(bool&)>; A2 = boost::_bi::value<std::reference_wrapper<bool> >]': /usr/include/boost/bind/bind.hpp:1273:18: required from 'boost::_bi::bind_t<R, F, L>::result_type boost::_bi::bind_t<R, F, L>::operator()() [with R = void; F = boost::thread_attributes; L = boost::_bi::list2<boost::_bi::value<int (*)(bool&)>, boost::_bi::value<std::reference_wrapper<bool> > >; boost::_bi::bind_t<R, F, L>::result_type = void]' /usr/include/boost/thread/detail/thread.hpp:120:18: required from 'void boost::detail::thread_data<F>::run() [with F = boost::_bi::bind_t<void, boost::thread_attributes, boost::_bi::list2<boost::_bi::value<int (*)(bool&)>, boost::_bi::value<std::reference_wrapper<bool> > > >]' /usr/include/boost/thread/detail/thread.hpp:118:18: required from here /usr/include/boost/bind/bind.hpp:298:35: error: no match for call to '(boost::thread_attributes) (int (*&)(bool&), std::reference_wrapper<bool>&)' 298 | unwrapper<F>::unwrap(f, 0)(a[base_type::a1_], a[base_type::a2_]); | ~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ The syntax is based on this part of the manual: https://www.boost.org/doc/libs/1_79_0/doc/html/thread/thread_management.htm… Is that perhaps a feature only introduced in version 1.79 of the Boost libraries? Best wishes and thanks for any pointers, Jeanette -- * Website: http://juliencoder.de - for summer is a state of sound * Youtube: https://www.youtube.com/channel/UCMS4rfGrTwz8W7jhC1Jnv7g * Audiobombs: https://www.audiobombs.com/users/jeanette_c * GitHub: https://github.com/jeanette-c Don't care about money It doesn't give me half the thrill <3 (Britney Spears)

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[Compute] Auto-determine work group size
by Stephan Menzel 12 May '22

12 May '22

Hi everyone, perhaps someone can answer a question about Boost.Compute. I have recently switched to it from using native OpenCL. Most of the things work fine except for one quirk: OpenCL allows for auto-determining the work group size when using enqueue_kernel(). As the correct work group size is still a mystery to me after using OpenCl for almost a year now I normally left this parameter to 0 to let OpenCL figure it out. With Boost.Compute and the equivalent function enqueue_nd_range_kernel() this doesn't seem to be possible. I have to use a parameter like boost::compute::extents<2>{ 8, 2 } as local_work_size. Leaving it 0 or using extents<2>{ 0, 0 } doesn't do the trick and I'm getting "Invalid work group size". This forces me to guess values until one works, which is extremely error prone and breaks all the time with images of different resolutions. Does anyone know how I can use OpenCL's auto-work-group-size feature in Boost.Compute? Cheers, Stephan

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Iterating over each point within a geometry::box
by Keith Bennett 11 May '22

11 May '22

I want to iterate over every point within a geometry::model::box<point>. I want to be able to do that with iterators so that I can also use all (or most of) the standard algorithms like for_each or all_of or etc. Initially my code used several loops, one for each axis, like so for a 2d point: for (int x = box.min_corner().template get<0>(); x <= box.max_corner().template get<0>(); ++x) { for (int y = box.min_corner().template get<1>(); y <= box.max_corner().template get<1>(); ++y) { callback(point(x,y)) } } There are several places where this occurs. Some loops have the x axis first, others the y axis first -- and this has performance issues when translating the point to a container. Some loops were erroneously considering right-open intervals with less-than instead of less-than-or-equal-to comparisons. So I've had to fix bounding bugs and performance issues in multiple places that are caused by these manual loops. I've gone and unified a lot of that to use templated functions that basically duplicate some of the functionality in the standard. But that's not tractable and still doesn't use iterators so most of <algorithm> is still off-limits: namespace mynamespace { template <class box, enable_if vomit, blah blah> void for_each(const box& b, const std::function<void(const typename box::point_type&)> callback) { // the manual loops here, not repeated for brevity } } Then I've replaced most of those manual loops with calls to: mynamespace::for_each(box, [](const point& p){ // do some work here }); So I want to instead do: for (const auto& point : box) { callback(point); } Satisfying that would make a lot of places simpler and easier to read. I think it should also help to enable use of a lot of the stuff in the standard <algorithm> I understand that it might be difficult for, eg, a box containing a point with floating point types. But that's fine ... I'm only looping over integral points anyway. I'd also prefer to have the ability to control the axis order ... eg do I want x or y on the inner/outer loop? Do I want to only iterate over the y axis? I'm using C++14 and boost 1.70 at the moment. There's some friction against upgrading. But if this problem is solved in a future version -- like with C++20 ranges -- then that would be a strong point for me to convince my team to upgrade. I could go and write up some iterators myself of course. But before I do that I wondered if someone else has already solved this problem and I just haven't found the solution. Thoughts? -- Keith Bennett

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Fwd: [boost] Boost MySQL Review Starts Today
by Mateusz Loskot 10 May '22

10 May '22

FYI ---------- Forwarded message --------- From: Richard Hodges via Boost <boost(a)lists.boost.org> Date: Tue, 10 May 2022 at 09:14 Subject: [boost] Boost MySQL Review Starts Today To: boost(a)lists.boost.org List <boost(a)lists.boost.org>, <boost-announce(a)lists.boost.org> Cc: Richard Hodges <hodges.r(a)gmail.com> Dear All, The Boost formal review of the MySQL library starts Today, taking place from May 10th, 2022 to May 19th, 2022 (inclusive) - We are starting one day after the announced date and extending the period by one day to compensate. The library is authored by Rubén Pérez Hidalgo (@anarthal in the CppLang slack). Documentation: https://anarthal.github.io/mysql/index.html Source: https://github.com/anarthal/mysql/ The library is built on the bedrock of Boost.Asio and provides both synchronous and asynchronous client connectors for the MySQL database system. Boost.MySQL is written from the ground up, implementing the entire protocol with no external dependencies beyond the Boost library. It is compatible with MariaDB. Connectivity options include TCP, SSL and Unix Sockets. For async interfaces, examples in the documentation demonstrate full compatibility with all Asio completion handler styles, including: Callbacks:- https://anarthal.github.io/mysql/mysql/examples/query_async_callbacks.html Futures :- https://anarthal.github.io/mysql/mysql/examples/query_async_futures.html Boost.Coroutine :- https://anarthal.github.io/mysql/mysql/examples/query_async_coroutines.html C++20 Coroutines :- https://anarthal.github.io/mysql/mysql/examples/query_async_coroutinescpp20… Rubén has also implemented the Asio protocols for deducing default completion token types :- https://anarthal.github.io/mysql/mysql/examples/default_completion_tokens.h… Reviewing a database connector in depth will require setting up an instance of a MySQL database. Fortunately most (all?) Linux distributions carry a MySQL and/or MariaDB package. MySQL community edition is available for download on all platforms here: https://dev.mysql.com/downloads/ Rubén has spent quite some time in order to bring us this library candidate. The development process has no doubt been a journey of discovery into Asio, its concepts and inner workings. I am sure he has become a fount of knowledge along the way. >From a personal perspective, I was very happy to be asked to manage this review. I hope it will be the first of many more reviews of libraries that tackle business connectivity problems without further dependencies beyond Boost, arguably one of the most trusted foundation libraries available. Please provide in your review information you think is valuable to understand your choice to ACCEPT or REJECT including Describe as a Boost library. Please be explicit about your decision (ACCEPT or REJECT). Some other questions you might want to consider answering: - Will the library bring additional out-of-the-box utility to Boost? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - Will the choice of API abstraction model ease the development of software that must talk to a MySQL database? - Are there any immediate improvements that could be made after acceptance, if acceptance should happen? - 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 at: http://www.boost.org/community/reviews.html The review is open to anyone who is prepared to put in the work of evaluating and reviewing the library. Prior experience in contributing to Boost reviews is not a requirement. Thank you for your efforts in the Boost community. They are very much appreciated. Richard Hodges - review manager of the proposed Boost.MySQL library Rubén is often available on CppLang Slack and of course by email should you require any clarification not covered by the documentation, as am I. -- Richard Hodges hodges.r(a)gmail.com tg: @rhodges office: +44 2032 898 513 mobile: +376 380 212 _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost -- Mateusz Loskot, http://mateusz.loskot.net

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[Boost.Asio] [SSL] Can I set the host name before performing a handshake?
by B Aleck 04 May '22

04 May '22

In openssl you call SSL_set_tlsext_host_name to set that Can I do that in boost?

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boost.org domain expired?
by Warren Weckesser 03 May '22

03 May '22

(Hit enter too soon in my last email.) FYI: Attempting to visit https://www.boost.org results in a Network Solutions page, with links for "Renew Now" and "Backorder Domain". Warren

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