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Final Notice: BinTray is shutting down 1-May (that's SATURDAY)
by Marshall Clow 29 Apr '21

29 Apr '21

Bintray is “sunsetting” on the 1st of May. At that time, you will be unable to download boost releases from there. Before that time, their service will be occasionally interrupted. The web site has been updated, all the download links now refer to https://boostorg.jfrog.io/artifactory/main/release/ <https://boostorg.jfrog.io/artifactory/main/release/> Example: Instead of downloading from: https://dl.bintray.com/boostorg/release/1.76.0/source/boost_1_76_0.tar.gz <https://dl.bintray.com/boostorg/release/1.76.0/source/boost_1_76_0.tar.gz> You should download from: https://boostorg.jfrog.io/artifactory/main/release/1.76.0/source/boost_1_76… <https://boostorg.jfrog.io/artifactory/main/release/1.76.0/source/boost_1_76…> This applies to all releases from 1.63.0 onward (The pre-1.63 releases are still hosted at SourceForge) — Marshall

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[beast] help with http::dynamic_body and http::buffer_body
by Klebsch, Mario 26 Apr '21

26 Apr '21

Hello, After using boost::asio for several years I thought, I might give beast a try. I need to write a http server processing a POST request with an upload of a big file. So I thought, I could start with libs/beast/example/http/server/async. I soon found the function handle_request() and that I have to add something like if (req.method() == http::verb::post && req.target()=="/xxx" ) to catch the http POST transaction. But since I have to process the upload of a large file, I thought that using a http::string_body might not be the best choice. I found several other body types in the documentation. I thought buffer_body ought to be fine, since the documentation says: ‘This allows for serialization of body data coming from external sources, and incremental parsing of message body content using a fixed size buffer.’. incremental processing of the input stream is what I need. But now, I have no clue, how to change the example to use a buffer_body. I changed http::request<http::string_body> req_ to http::request<http::buffer_body> req_. But now I must process the request message in chunks. How do I get my callback invoked for each chunk? Without additional changes, I get a read error: need buffer. But the documentation on buffer_body does not help me. Buffer_body does not seem to have any methods, that I can call. It does have a member type reader, that is documented as implementation-defined. So there is nothing I can do with this reader. ☹ There is a member type value_type, that does have data, size and more mebers, but I have no idea, how I could et hold of a variable of this type containing a part of my message body. The error message might indicate, that I need to provide a fixed size buffer to the buffer_body, but I have no idea, how to do this. I tried to add the following code to do_read(): req_.body().data = my_buffer; req_.body().size = sizeof(my_buffer); It compiles, so req_body() seems to be the way to get hold on a http::buffer_body::value_type, but simply initializing the two variables does not seem to be sufficient. I also tried to set req_.body().more to false or to true, but it didn’t change anything. I then thought, I might try a dynamic_body. This would store the entire upload in memory, but perhaps I get more familiar with the beat framework, when I try to use this body. And in deed, I managed to write some code, that shows all request headers and the request body on stdout. To get the body, I had to copy the buffer contents into a std::string: std::string body{ boost::asio::buffers_begin(req.body().data()), boost::asio::buffers_end(req.body().data()) }; Since large files have to be handled by my code, this additional copy of the data is to be avoided. So I tried to iterate the body using the iterators: const auto begin = boost::asio::buffers_begin(req.body().data()); const auto end = boost::asio::buffers_end(req.body().data()); for (auto it = begin; it != end; it++) putchar(*it); While it runs fine on the windows box, the loop crashes on linux in the 512th iteration in it++. Program received signal SIGSEGV, Segmentation fault. 0x0000555555592432 in boost::intrusive::list_node_traits<void*>::get_previous (n=@0x7fffffffc118: 0x1ff) at ../boost/boost/intrusive/detail/list_node.hpp:54 54 { return n->prev_; } (gdb) print n $1 = (const boost::intrusive::list_node_traits<void*>::node_ptr &) @0x7fffffffc118: 0x1ff (gdb) Here is the call stack: #0 0x0000555555592432 in boost::intrusive::list_node_traits<void*>::get_previous (n=@0x7fffffffc118: 0x1ff) at ../boost/boost/intrusive/detail/list_node.hpp:54 #1 boost::intrusive::list_iterator<boost::intrusive::bhtraits<boost::beast::basic_multi_buffer<std::allocator<char> >::element, boost::intrusive::list_node_traits<void*>, (boost::intrusive::link_mode_type)0, boost::intrusive::dft_tag, 1u>, true>::operator-- (this=0x7fffffffc118) at ../boost/boost/intrusive/detail/list_iterator.hpp:107 #2 std::__advance<boost::intrusive::list_iterator<boost::intrusive::bhtraits<boost::beast::basic_multi_buffer<std::allocator<char> >::element, boost::intrusive::list_node_traits<void*>, (boost::intrusive::link_mode_type)0, boost::intrusive::dft_tag, 1u>, true>, long> (__i=..., __n=0) at /usr/lib/gcc/x86_64-pc-linux-gnu/10.2.0/include/g++-v10/bits/stl_iterator_base_funcs.h:169 #3 0x000055555558daf0 in std::advance<boost::intrusive::list_iterator<boost::intrusive::bhtraits<boost::beast::basic_multi_buffer<std::allocator<char> >::element, boost::intrusive::list_node_traits<void*>, (boost::intrusive::link_mode_type)0, boost::intrusive::dft_tag, 1u>, true>, long> (__i=..., __n=-1) at /usr/lib/gcc/x86_64-pc-linux-gnu/10.2.0/include/g++-v10/bits/stl_iterator_base_funcs.h:206 #4 0x0000555555589254 in std::prev<boost::intrusive::list_iterator<boost::intrusive::bhtraits<boost::beast::basic_multi_buffer<std::allocator<char> >::element, boost::intrusive::list_node_traits<void*>, (boost::intrusive::link_mode_type)0, boost::intrusive::dft_tag, 1u>, true> > (__x=..., __n=1) at /usr/lib/gcc/x86_64-pc-linux-gnu/10.2.0/include/g++-v10/bits/stl_iterator_base_funcs.h:230 #5 0x0000555555589608 in boost::beast::basic_multi_buffer<std::allocator<char> >::subrange<true>::const_iterator::operator* (this=0x7fffffffc4f8) at ../boost/boost/beast/core/impl/multi_buffer.hpp:384 #6 0x0000555555589b4b in boost::asio::buffers_iterator<boost::beast::basic_multi_buffer<std::allocator<char> >::subrange<true>, char>::increment (this=0x7fffffffc4d0) at ../boost/boost/asio/buffers_iterator.hpp:370 #7 0x0000555555584894 in boost::asio::buffers_iterator<boost::beast::basic_multi_buffer<std::allocator<char> >::subrange<true>, char>::operator++ (this=0x7fffffffc4d0) at ../boost/boost/asio/buffers_iterator.hpp:229 #8 0x000055555557e7c0 in boost::asio::buffers_iterator<boost::beast::basic_multi_buffer<std::allocator<char> >::subrange<true>, char>::operator++ (this=0x7fffffffc4d0) at ../boost/boost/asio/buffers_iterator.hpp:237 #9 0x0000555555579ba8 in handle_request<boost::beast::http::basic_dynamic_body<boost::beast::basic_multi_buffer<std::allocator<char> > >, std::allocator<char>, session::send_lambda&> (doc_root=..., req=..., send=...) at t.cpp:164 I hope anybody can give my a hint on how to use this beast. Right now it feels that it might be easier to write the http server using plain boost::asio. Klebsch Mario Funktion | R&D Tel: +49 (0) 531 38 701 718 Raum: Braunschweig, E20 Diese E-Mail und die an sie angehängten Dateien sind ausschließlich für Personen oder Institutionen bestimmt, deren Namen oben aufgeführt sind. Sie können Informationen enthalten, die durch das Berufsgeheimnis geschützt sind und deren Weitergabe strengstens untersagt ist. Jede elektronische Nachricht kann geändert werden. ACTIA lehnt jede Verantwortung für diese Nachricht ab. Der Inhalt dieser Nachricht stellt keine Verpflichtung seitens unseres Unternehmens dar. Wenn Sie kein Empfänger sind, weisen wir Sie darauf hin, dass das Lesen, Vervielfältigen oder Verteilen strengstens untersagt ist. Wir bitten Sie daher, uns umgehend über diesen Brief zu informieren und diese Nachricht sowie eventuell beigefügte Unterlagen aus Ihrem Postfach zu löschen. Danke. This e-mail and the files attached to it are intended exclusively for persons or institutions whose names are listed above. They may contain information that is protected by professional secrecy and the disclosure of which is strictly prohibited. Any electronic message can be modified. ACTIA declines all responsibility for this message. The content of this message does not represent a commitment on the part of our company. If you are not a recipient, we would like to point out that reading, copying or distribution is strictly prohibited. We therefore ask you to inform us immediately about this letter and to delete this message and any accompanying documents from your mailbox. Thank you.

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Boost + Emscripten: .bc files?
by Rainer Deyke 22 Apr '21

22 Apr '21

I managed to successfully compile a subset of Boost for Emscripten using the emscripten toolset. However, this for some reason produces .bc files for libraries instead of .a files, which causes link errors I try to link my project. How can I get Boost to generate .a files? (Emscripten uses .a files for libraries: https://emscripten.org/docs/compiling/Building-Projects.html#using-libraries) -- Rainer Deyke (rainerd(a)eldwood.com)

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Cannot build 1.76.0 for Windows (wrong path to compiler)
by Andreas Tscharner 22 Apr '21

22 Apr '21

Hello World, I try, according to the "Get started guide" >bootstrap.bat in the main boost directory. I get an error, because "C:\Program Files(x86)" ... contains a space and is not double quoted. So I replace all set "B2_CXX=%CXX% ..." with set "B2_CXX="%CXX%" ..." in tools\build\src\engine\config_toolset.bat After that I have the following problem: D:\Projects\development\QUARTIS-related\boost>.\bootstrap.bat Building Boost.Build engine LOCALAPPDATA=C:\Users\ATs\AppData\Local Found with vswhere C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise Found with vswhere C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise Call_If_Exists "C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\Common7\Tools\..\..\VC\Auxiliary\Build\vcvarsall.bat" AMD64 ********************************************************************** ** Visual Studio 2019 Developer Command Prompt v16.9.4 ** Copyright (c) 2021 Microsoft Corporation ********************************************************************** [vcvarsall.bat] Environment initialized for: 'x64' ### ### Using 'vc142' toolset. ### D:\Projects\development\QUARTIS-related\boost\tools\build\src\engine>"C:/Program Files (x86)/Microsoft Visual Studio/2019/Enterprise/VC/Tools/MSVC/14.27.29110/bin/Hostx64/x64/cl.exe" /nologo /MP /MT /TP /Feb2 /wd4996 /O2 /GL /EHsc -DNDEBUG builtins.cpp class.cpp command.cpp compile.cpp constants.cpp cwd.cpp debug.cpp debugger.cpp execcmd.cpp execnt.cpp filent.cpp filesys.cpp frames.cpp function.cpp glob.cpp hash.cpp hcache.cpp hdrmacro.cpp headers.cpp jam.cpp jamgram.cpp lists.cpp make.cpp make1.cpp md5.cpp mem.cpp modules.cpp native.cpp object.cpp option.cpp output.cpp parse.cpp pathnt.cpp pathsys.cpp regexp.cpp rules.cpp scan.cpp search.cpp jam_strings.cpp startup.cpp subst.cpp sysinfo.cpp timestamp.cpp variable.cpp w32_getreg.cpp modules/order.cpp modules/path.cpp modules/property-set.cpp modules/regex.cpp modules/sequence.cpp modules/set.cpp /link kernel32.lib advapi32.lib user32.lib Das System kann den angegebenen Pfad nicht finden. It tries to start "C:/Program Files (x86)/Microsoft Visual Studio/2019/Enterprise/VC/Tools/MSVC/14.27.29110/bin/Hostx64/x64/cl.exe". Unfortunately at my system, I don't have this path. I have C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\MSVC\14.28.29910... Please note the different number after "MSVC" What is the problem? How can I fix this? TIA and best regards Andreas -- ("`-''-/").___..--''"`-._ `o_ o ) `-. ( ).`-.__.`) (_Y_.)' ._ ) `._ `. ``-..-' _..`--'_..-_/ /--'_.' .' (il).-'' (li).' ((!.-' Andreas Tscharner andy(a)stupidmail.ch ICQ-No. 14356454

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Reminder: BinTray is shutting down 1-May
by Marshall Clow 21 Apr '21

21 Apr '21

Bintray is “sunsetting” on the 1st of May. At that time, you will be unable to download boost releases from there. Before that time, their service will be occasionally interrupted. We will be updating the web site before then, but the new location is: https://boostorg.jfrog.io/artifactory/main/release/ <https://boostorg.jfrog.io/artifactory/main/release/> So instead of downloading from: https://dl.bintray.com/boostorg/release/1.76.0/source/boost_1_76_0.tar.gz You should download from: https://boostorg.jfrog.io/artifactory/main/release/1.76.0/source/boost_1_76… This applies to all releases from 1.63.0 onward — Marshall

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Boost Graph + Compute Libraries
by Muhammad Hassan Khan 20 Apr '21

20 Apr '21

Hi, I am new to boost libraries. I was wondering if I can use boost graph and boost compute libraries in one code to implement graphs on GPUs. Can you give any example if it is possible? or any other solution to it. Thank you. Regards, Hassan Khan

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ASIO: acceptor::async_accept throws "Operation cancelled" after restart io_service
by Joost Kraaijeveld 19 Apr '21

19 Apr '21

Hi, In short my program: - creates an io_service - calls acceptor::async_accept - calls io_service.run - handle several connections OK - calls io_service.stop - the acceptor goes out of scope (i.e. the destructor of the owning object is ran) - calls io_service.restart - calls acceptor::async_accept which then throws "Operation cancelled" Should it be possible to do this? When/under what circumstances does async_accept throw this exception? Could it be connected with the fact that the acceptor's destructors documents that is does some cleanup but actually does nothing, from the source: /// Destroys the acceptor. /** * This function destroys the acceptor, cancelling any outstanding * asynchronous operations associated with the acceptor as if by calling * @c cancel. */ ~basic_socket_acceptor() { } OS: Linux Debian Bullseye, Boost 1.74, gcc 10 TIA Joost

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[release] Boost 1.76.0
by Marshall Clow 17 Apr '21

17 Apr '21

Release 1.76.0 of the Boost C++ Libraries is now available. These open-source libraries work well with the C++ Standard Library, and are usable across a broad spectrum of applications. The Boost license encourages both commercial and non-commercial use. This release contains no new libraries and numerous enhancements and bug fixes for existing libraries. For details, including download links, see <http://www.boost.org/users/news/version_1.76.0> You can also download directly from: <https://boostorg.jfrog.io/artifactory/main/release/1.76.0/> To install this release on your system, see <http://www.boost.org/doc/libs/release/more/getting_started/index.html> Thanks to everyone who participated in this release. Thanks, -- The Boost Release Team Marshall Clow, Michael Caisse, Glen Fernandes

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Boost.Test - test tree is empty
by Olaf Peter 17 Apr '21

17 Apr '21

Hello, I am in despair. The attached source compiles fine, but gives: $ bin/utf_dataset_loader_issue Test setup error: test tree is empty and I don't know why. It is based [Data-driven test cases parametrized from the command line <https://www.boost.org/doc/libs/1_73_0/libs/test/doc/html/boost_test/runtime…>](https://www.boost.org/doc/libs/1_73_0/libs/test/doc/html/boost_test/runtime_config/custom_command_line_arguments.html#boost_test.runtime_config.custom_command_line_arguments.data_driven_test_cases_parametri) but reduced to pure API, no cli parse, file loading etc. Any help is appreciated.

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[release] Boost 1.76.0 Release Candidate 12
by Marshall Clow 14 Apr '21

14 Apr '21

The second release candidates for the 1.76.0 release are now available at: <https://boostorg.jfrog.io/artifactory/main/release/1.76.0/source/ <https://dl.bintray.com/boostorg/release/1.76.0/source/>> The SHA256 checksums are as follows: 7bd7ddceec1a1dfdcbdb3e609b60d01739c38390a5f956385a12f3122049f0ca boost_1_76_0_rc2.tar.gz 0fd43bb53580ca54afc7221683dfe8c6e3855b351cd6dce53b1a24a7d7fbeedd boost_1_76_0_rc2.zip 88782714f8701b6965f3fce087a66a1262601dd5ccd5b2e5305021beb53042a1 boost_1_76_0_rc2.7z f0397ba6e982c4450f27bf32a2a83292aba035b827a5623a14636ea583318c41 boost_1_76_0_rc2.tar.bz2 Changes from RC1: * A missing include was added to a Boost.Regex header. This fixes compilation on gcc 11. 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

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Information about a Fixed Point type
by Emilio Paolini 13 Apr '21

13 Apr '21

Hi everyone, i'm new to Boost. I would like to know if there is a way, using this library, to declare a fixed point type, specifying the number of bits for the fractional part and the behaviour when overflow happens. Thank you very much. Regards, Emilio

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A new home for Boost releases
by Marshall Clow 12 Apr '21

12 Apr '21

We’ve been using BinTray to host our releases for a few years, and it’s worked well for us However, JFrog is shutting down BinTray soon (at the end of this month). We have moved all the releases that were hosted on BinTray over to JFrog Artifactory. They are at https://boostorg.jfrog.io/artifactory/main/release <https://boostorg.jfrog.io/artifactory/main/release> For example, instead of: https://dl.bintray.com/boostorg/release/1.74.0/source/boost_1_74_0.tar.gz <https://dl.bintray.com/boostorg/release/1.74.0/source/boost_1_74_0.tar.gz> You should now use: https://boostorg.jfrog.io/artifactory/main/release/1.74.0/source/boost_1_74… <https://boostorg.jfrog.io/artifactory/main/release/1.74.0/source/boost_1_74…> I’ll be updating the web site soon, but if you have automation that relies on BinTray, you should update it to use the new home. — Marshall P.S. The “nightly” snapshots will live there too, as soon as we get that set up.

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[release] Boost 1.76.0 Release Candidate 1
by Marshall Clow 10 Apr '21

10 Apr '21

IMPORTANT NOTE: This will be the last RC posted on BinTray! The first release candidates for the 1.76.0 release are now available at: <https://dl.bintray.com/boostorg/release/1.76.0/source/> The SHA256 checksums are as follows: aaf920e31ae815ff6b55d70a28bb614a6aa6f5cd2f6e4543461d20a4fe39df4e boost_1_76_0_rc1.7z 5dd0c91e1f0f18d452fcaa772d9c30815e449dd4fe99fadf224cca180d98cee3 boost_1_76_0_rc1.zip 5b9844335bc327272030b8050cf417178d26c8abbc64ed7aefc4d818facc1c10 boost_1_76_0_rc1.tar.gz cea1cf7609daf5bb285a625530e8d660dca51816007da7f5eb3f577b685a888d boost_1_76_0_rc1.tar.bz2 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

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Multiprecision
by shady mohamed 09 Apr '21

09 Apr '21

I need to talk with mentor of this project to discuss the competency test

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does boost::variant support 128 bit integer?
by David Frank 09 Apr '21

09 Apr '21

especially the gnu __int128?Thanks,David.

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Multiprecision
by shady mohamed 07 Apr '21

07 Apr '21

I need to understand the competency test of multiprecision project

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select_stdlib_config.hpp and <version> 1.73
by Allen Sanderson 05 Apr '21

05 Apr '21

Hello, A casual boost user and abuser here. Some specifics on my OS OS X Big Sur 11.2 Xcode 12.4 Compiler clang : Apple land version 12.0.0 Boost 1.73 - forward When select_stdlib_config.hpp is included it gets to this initial code to include the file “version" ... #if defined(__cplusplus) && defined(__has_include) # if __has_include(<version>) // It should be safe to include `<version>` when it is present without checking // the actual C++ language version as it consists solely of macro definitions. // [version.syn] p1: The header <version> supplies implementation-dependent // information about the C++ standard library (e.g., version number and release date). # include <version> ... The issue is that many projects have a file “VERSION” in their top level src directory. On a traditional Linux system the case sensitivity would make sure the right file is included. However, many/most OS X file systems are case insensitive. As such, the file VERSION gets included instead. And does not compile. I have no solution to the issue but wanted to raise it. Cheers, Allen Sanderson SCI Institute University of Utah

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std::any serialization
by Isaac Lascasas 04 Apr '21

04 Apr '21

Hello, I wonder if there is a workaround to serialize std::any objects. I want to replace some old code that had similar functionality and all the types were registered via BOOST_CLASS_EXPORT_GUID. Regards.

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Tried to unzip a file , and followed the example in the boost.org as well, but it doesn't work
by asfskfdjkj kfasjfkasjf 03 Apr '21

03 Apr '21

Hi guys I tried to unzip a file with code below which exactly like the example from boost.org, but it doesn't work the example is in the link which is Zlib Filters | | | | Zlib Filters | | | I tried the code like the below try{ ifstream file("d:\\202012303333629003180526491.txt.zip", ios_base::in | ios_base::binary); boost::iostreams::filtering_streambuf<boost::iostreams::input> in; in.push(boost::iostreams::zlib_decompressor()); in.push(file); boost::iostreams::copy(in, cout); return 0;}catch (const std::exception& error) { std::cerr << error.what() << std::endl; return (EXIT_FAILURE); } it's not working, it get exception when it excuted boost::iostreams::copy(in, cout); I got the zlib error: iostream stream error exception thoughwhat wrong I have done though? thank you

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[Spirit] [Fusion] Concise way to construct attribute object
by Phil Endecott 28 Mar '21

28 Mar '21

Dear Experts, I currently have something like: struct S { string name; string value; }; BOOST_FUSION_ADAPT_STRUCT( S, name, value ) using S_rule = qi::rule<ITER, skipper, S()>; S_rule r %= identifier >> lit(':') >> identifier; Note that I can use %= here and I don't need to write an explicit semantic action to assign to S. Now say I modify S: class S { public: S(string name_, string value_); // May be default-constructable, copyable, assignable etc. // - but name and value are not individually assignable. }; Question: what is the best way to use that with the qi parser rule? I was hoping to find something in Fusion that would allow me to adapt the new class so that it can be used with %= as before, but I don't see anything appropriate. Currently the best that I can think of is: S_rule r = ( identifier >> lit(':') >> identifier ) [ _val = boost::phoenix::construct<S>(_1,_2) ]; How can I improve on that? Thanks, Phil.

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[Core] scoped_enum and template arguments
by Alan Barr 24 Mar '21

24 Mar '21

Hi, I'm a little confused about the following statement in the docs for scoped enum: > The emulated scoped enum can not be used in switch nor in > template arguments. https://www.boost.org/doc/libs/1_75_0/libs/core/doc/html/core/scoped_enum.h… I understand the rationale for the switch statement part (and indeed it won't compile in C++03). However, I'm struggling to grasp the template argument part (and I'll be the first to admit I'm not particularly strong with templates). Unlike the switch case, any basic scenario I've thrown at it compiles. So I'm not sure if this is a case of "should not" vs "can not". When would using a "scoped_enum_type" in a template argument as opposed to "BOOST_SCOPED_ENUM_NATIVE(scoped_enum_type)" become a problem? Or, why should I use "boost::optional<BOOST_SCOPED_ENUM_NATIVE(future_errc)>" over "boost::optional<future_errc>" ? I've got a compiler explorer link with some test code here if it helps: https://godbolt.org/z/dfr6M6vrW Regards, Alan

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Boost 64bit in Embarcadero C++ Builder
by Michael Morelli 17 Mar '21

17 Mar '21

Hi folks, we are testing the Boost.Test-Framework (installed with GetIt-Package Boost). We use C++ Builder 10.4.1 with Boost 1.70.0. We have created a new C++ Console-Application (with VCL enabled). Under Project->Options we have set '_TCHAR as char', because Boost.Test seems to need this mapping. It is not working with ' _TCHAR as wchar_t' The application main-entry-function is imported via #include <boost/test/included/unit_test.hpp>. The application then is run with the params : --log_level=all --report_level=detailed --build_info=true The console-output seems to be fuzzy : 1. Why is the platform win32? We use target-platform win64 and have installed boost 64bit via getit... 2. Paths are outputted with '\' and '/' 3. The fatal-error is correct but the consoleoutput 'St9exception' seems not correctly interpreted (charset ?) Are we doing something wrong or do you have some tipps regarding this ? Thx a lot. This is the console-output : [cid:image001.png@01D71B23.032439B0] Kind regards, Michael Morelli

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[release] Boost 1.76.0 beta 1 released
by Marshall Clow 16 Mar '21

16 Mar '21

Boost release 1.76.0 beta 1 is now available at: <https://dl.bintray.com/boostorg/beta/1.76.0.beta1/source/> The SHA256 checksums are as follows: 39eecd9672e78b95c8e3fdec1430a63788d528a66d3c8799c4639238e5d785bd boost_1_76_0_b1.7z c32edd34f767dd4bb67b86f76ebf58cf76822a5993a9b434c028b2dd08cfeefc boost_1_76_0_b1.zip 3ec1f92fa0a159b7073e39dd88f527a55d1f35e8986a3c560f202a75bdb8d584 boost_1_76_0_b1.tar.gz eb098d6d5352e10b17a3c49d2927ed61f09b6544f7c534627de35dfa2560fe20 boost_1_76_0_b1.tar.bz2 For details of what's in the release, see <https://www.boost.org/users/history/version_1_76_0.html>. Please download the beta, give it a try, and report any problems you encounter. Thanks, -- The Boost Release Team

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[release] Boost 1.76.0 Beta 1 Release Candidate 2
by Marshall Clow 13 Mar '21

13 Mar '21

The second release candidates for the 1.76.0 beta release are now available at: <https://dl.bintray.com/boostorg/beta/1.76.0.beta1/source/> The SHA256 checksums are as follows: c32edd34f767dd4bb67b86f76ebf58cf76822a5993a9b434c028b2dd08cfeefc boost_1_76_0_b1_rc2.zip eb098d6d5352e10b17a3c49d2927ed61f09b6544f7c534627de35dfa2560fe20 boost_1_76_0_b1_rc2.tar.bz2 39eecd9672e78b95c8e3fdec1430a63788d528a66d3c8799c4639238e5d785bd boost_1_76_0_b1_rc2.7z 3ec1f92fa0a159b7073e39dd88f527a55d1f35e8986a3c560f202a75bdb8d584 boost_1_76_0_b1_rc2.tar.gz The only changes from RC1 is an update to Boost.Interprocess, which was failing to compile on Mac OS X. 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

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[release] Boost 1.76.0 Beta 1 Release Candidate 1
by Marshall Clow 11 Mar '21

11 Mar '21

The first release candidates for the 1.76.0 beta release are now available at: <https://dl.bintray.com/boostorg/beta/1.76.0.beta1/source/> The SHA256 checksums are as follows: a222d325cd3c9f66951ec9026eca6ff6f48dd563c9a025911d598d2aca8770ce boost_1_76_0_b1_rc1.tar.bz2 6b90b510a3de38fc30a071ac798da37545fb60a1d6b21aed1130b47c9c598977 boost_1_76_0_b1_rc1.zip b01627bd9ce934b092037da81696bb4482a44e6a31c8791dbed82eafe04b69fa boost_1_76_0_b1_rc1.tar.gz dbef57adbab1d4395d14000f0a2420fc82f87476e10d48359ceff7125a74b77a boost_1_76_0_b1_rc1.7z 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

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(no subject)
by Jinlong Shen 11 Mar '21

11 Mar '21

Dear Madam/Sir, I used the boost::statechart asynchronous_state_machine to create a simple state machine. The state machine, the events and states are regular classes and are not class templates. Everything builds and works well on linux and qnx platform. However, on windows I got message that the the initial state is undefined. I think I have dealt with forward declaration well since it is build on linux and qnx. On Windows microsoft this compiler is used: Microsoft (R) C/C++ Optimizing Compiler Version 19.00.24215.1 for x64 The error message is like this. (ClCompile target) -> C:\Program Files\boost_1_64_0\boost/statechart/state_machine.hpp(701): error C2027: use of undefined type 'xxxx::FirstState' C:\Program Files\boost_1_64_0\boost/statechart/state_machine.hpp(701): error C3861: 'initial_deep_construct': identifier not found Any hint how it could be wrong with Microsoft C++? Best regards,Jinlong Shen

2 1

Boost accepted in Google Summer of Code 2021
by David Bellot 09 Mar '21

09 Mar '21

We're in again! https://github.com/boostorg/wiki/wiki/Google-Summer-of-Code%3A-2021 David

1 0

MSM and multithreading. Not clear what pattern to follow.
by Andrea Fiorito 08 Mar '21

08 Mar '21

Hi, I'm trying to use MSM to implement a client server component for my app. The client is broadcasting a msg, that servers in a local network will detect and respond. The client at that point will connect to one of the servers and interact following the network protocol. For the network and threading I'm using boost ASIO. I have 2 submachines that manage one the discovering part, and the other the connection and dialogue with one server part. I found that would be beneficial to run the submachines in one thread managed by an io_context, with the idea of stopping that context to cancel all the asynchronous operations. Unfortunately there are some weird behaviours with submachines, and not getting if I missed the right way of doing things or else. the description of my last stopper is here: https://github.com/boostorg/msm/issues/37 Is anyone able to point me on the right direction? Regards, Andrea

2 1

CMake's PCH support and boost.test linker error
by Olaf Peter 04 Mar '21

04 Mar '21

Hello Boost users I have here a strange problem which occurs only if I try to build with precompiled headers using CMake. I've configured the project for use with dynamically linking. The error is: /usr/bin/ld: /usr/lib/gcc/x86_64-redhat-linux/10/../../../../lib64/crt1.o: in function `_start': (.text+0x24): undefined reference to `main' Something obvious? Thanks in advance The project's reduce is: ---8<--- test_driver.cpp --- 8< ---- #defineBOOST_TEST_MODULE "My Test Suite" #include<boost/test/unit_test.hpp> --->8------>8------>8--- ---8<--- test_x.cpp --- 8< ---- #include<boost/test/unit_test.hpp> .... --->8------>8------>8--- ---8<--- src/CMakeLists.txt --- 8< ---- ... set_source_files_properties(src/test_xxx.cpp APPEND PROPERTIES COMPILE_DEFINITIONS "BOOST_TEST_DYN_LINK" ) .... --->8------>8------>8------>8------>8------>8--- ---8<--- pch.pp --- 8< ---- #pragma once #include<boost/test/unit_test.hpp> --->8------>8------>8---

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How should a "using zlib ..." jam statement look, for Boost to link to ZLib in the form of SO filename (libz.so) instead of by -lz?
by Bob 03 Mar '21

03 Mar '21

Hello Boost mailing list, I am building a code project in my user home directory on OpenBSD, and doing this involves both a local build of Boost and also a local build of ZLib. I do the whole build using GCC. This is a relatively ordinary build use case, however GCC on OpenBSD (at least in its current version) has a peculiarity to it, which is that it adds to LD the argument "-L/usr/lib" in the leading position, and this means that LD's search for libz.so will find and use the operating system's bundled ZLib binary which is /usr/lib/libz.so ALWAYS, and NEVER use my local libz.so . Can you help me understand if Boost can be customized to link to ZLib in the following way: I can force GCC/LD to use a particular libz.so file, by specifying it by filename, e.g. "gcc ... libz.so ...", "gcc ... /my/dir/libz.so ...", instead of by the conventional "-lz". Boost's build process is hardwired to "-lz" and I ask you to help me understand if there is a way to circumvent that. ZLIB_LIBRARY_PATH will not make "-lz" hit anything else than /usr/lib/libz.so , per the compiler's default -L/usr/lib in leading position, so it will not be of help to solve my problem. To my best awareness ZLIB_INCLUDE has nothing to do with linking, so it will not be of help to solve my problem. ZLIB_NAME would only be to customize the library name would it e.g. to "-lmycustomz", or what is it for? Please clarify so I could figure if it could be of help, though ideally i keep my local ZLib having its default name "libz.so". And this brings me to the path of solving the problem that I imagine could work, but that I don't understand fully from the Boost documentation: There is the possibility to customize ZLib build settings through the JAM configuration, that is user-config.jam . The syntax used is "using zlib ...". Can you please help me understand if this route works, if so how would that "using zlib ..." statement look, such that Boost's build process will NOT build ZLib itself, and then will NOT link to it via "-lz", but will instead link to it by "$MYCUSTOMBUILDDIR/libz.so"?

1 0

Boost.Python + `RecursionError` during deallocation
by Andrew Jones 01 Mar '21

01 Mar '21

Hi, I just raised the following issue on the Python issue tracker: https://bugs.python.org/issue43351 But I'm sharing it here to widen the net ... Basically, when moving from Python 2.7.14 to Python 3.7.5, and when using Boost.Python (Boost version 1.6.9), I'm seeing a crash in finalisation due to: ``` Exception ignored in: <Boost.Python.life_support object at 0x2acf473c5d10> RecursionError: maximum recursion depth exceeded while calling a Python object Fatal Python error: Cannot recover from stack overflow. ``` Everything else with the Python that's running, and the Boost.Python interface, is consistent between 2.7.14 and 3.7.5 -- it is just the Python version that's changing. I should say, Python 3.7.5 does otherwise seem operable, it just falls over when running this certain code (which just walks a linked-list of ~1400 elements via Boost.Python). Has anyone seen anything like this before? Does this list feel this is more likely a Python-proper issue, or a Boost.Python issue? Cheers, Andrew

1 0

[boost::units] Best practices for implementing custom units and quantities
by Alexandru Onea 01 Mar '21

01 Mar '21

Hello community, I am working on a project which works with units such as scale intervals (cents, moria, etc.) depending on the temperament system used (24-EDO, 72-EDO, etc.). My implementation defines a namespace for each tuning system. Within the namespaces I define base units, units and a system, as well as conversion factors between the systems. The base dimension is defined in only one of the namespaces (corresponding to the tuning system which I consider "standard" which is the 1200 cents per octave system). 1. Does such an approach qualify as a good approach in general (leaving aside the musical aspects)? 2. Is it a good practice to place all these namespaces in boost::units (extend boost::units)? Or should I keep them within my own namespaces? Learning the answer to #2 is more interesting to me, even in the absence of an answer to #1. Best regards, Alexandru Onea

2 1

Question about Boost Integer
by Emilio Paolini 28 Feb '21

28 Feb '21

Hi everyone, i'm pretty new to Boost. I need to use as a default type for the CNL. The problem is that i would need an integer type that can assume only 2^4 values (so basically that stays on 4 bits). What i am asking is that if there is a way to define an integer like int128_t but instead of 128 i would need to have 4. Thank you very much for your answers. Emilio

2 2

flyweights, nested flyweights and shared libraries
by Andreas Buykx 25 Feb '21

25 Feb '21

I want to use boost::flyweight to capture some structures containing const data. The documentation states that if flyweights are exported across shared library boundaries that the intermodule holder should be used. Since my flyweights are all created in the same shared library I would prefer to use the static holder but I keep getting crashes. I tried the intermodule holder but I'm having trouble compiling my sources with that. So my thinking was to wrap all flyweight types in accessor classes which are exposed instead, and the accessor classes create the flyweights within the same shared library to store the data. Would that be a valid approach? Also, is it possible to have nested flyweights (when they are wrapped by accessor classes)? And would that cause any additional problems in the above scenario? Below is an example of what I'm trying to achieve... Thanks for your advice! Andreas === Foo.h === struct FooDetails { FooDetails( std::string text_, std::vector<double> values ); std::string text; std::vector<double> values; }; class STUFF_EXPORT Foo { public: Foo( std::string text_, std::vector<double> values ); // rule-of-5 constructors declared, and default-implemented in cpp file const std::string& text() const; const std::vector<double>& values() const; private: boost::flyweight<FooDetails> m_data; }; === Foo.cpp === FooDetails( ( std::string text_, std::vector<double> values_ ) : text(text_), values( values_ ) { } Foo::Foo( std::string text_, std::vector<double> values_ ) m_data( FooDetails( text_, values_ ) ) { } std::string Foo::text() const { return m_data.get().text; } std::vector<double> Foo::values() const { return m_data.get().values; } === Bar.h === struct BarDetails { BarDetails( Foo foo_, std::vector<long> ids_ ); Foo foo; //< Foo holds a flyweight std::vector<long> ids; }; class STUFF_EXPORT Bar { public: Bar( std::string text_, std::vector<double> values_, std::vector<long> ids_ ); // rule-of-5 constructors declared, and default-implemented in cpp file const std::string& text() const; const std::vector<double>& values() const; const std::vector<long>& ids() const; private: boost::flyweight<BarDetails> m_bar; }; === Bar.cpp === BarDetails::BarDetails( Foo foo_, std::vector<long> ids_ ) : foo( foo_ ), ids( ids_ ) { } Bar::Bar( std::string text_, std::vector<double> values_, std::vector<long> ids_ ) : m_bar( Foo( text_, values), ids_ ) { } const std::string& Bar::text() const { return m_bar.get().m_foo.text(); } const std::vector<double>& Bar::values() const { return m_bar.get().foo.values(); } const std::vector<long>& Bar::ids() const { return m_bar.get().ids; }

3 8

Re: [Boost-users] Boost-users Digest, Vol 5456, Issue 1
by philippe DALET 23 Feb '21

23 Feb '21

Hi, I have built some binaries for boost and python https://sourceforge.net/projects/pcpu/files/Boost/ boost 1.71 python3.7&numpy3.7 for ubuntu 20.04 64 bits boost 1.75 python3.789&numpy3.789 for visual studio 2019 mscv14.2 - win10 Ph.DALET Le mar. 23 févr. 2021 à 11:03, <boost-users-request(a)lists.boost.org> a écrit : > Send Boost-users mailing list submissions to > boost-users(a)lists.boost.org > > To subscribe or unsubscribe via the World Wide Web, visit > https://lists.boost.org/mailman/listinfo.cgi/boost-users > or, via email, send a message with subject or body 'help' to > boost-users-request(a)lists.boost.org > > You can reach the person managing the list at > boost-users-owner(a)lists.boost.org > > When replying, please edit your Subject line so it is more specific > than "Re: Contents of Boost-users digest..." > > > Today's Topics: > > 1. Re: Boost cannot find numpy37 on Dockerized Ubuntu 20.04 > (Roy de Bokx) > 2. Re: flyweights, nested flyweights and shared libraries > (Andreas Buykx) > > > ---------------------------------------------------------------------- > > Message: 1 > Date: Mon, 22 Feb 2021 15:49:11 +0100 > From: Roy de Bokx <rdebokx1990(a)gmail.com> > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Boost cannot find numpy37 on Dockerized > Ubuntu 20.04 > Message-ID: > < > CAFLoxwXy8_an1jZh_PQMkjppbOWyixvR5Exw1DCeaUyV9xDfBA(a)mail.gmail.com> > Content-Type: text/plain; charset="utf-8" > > Op vr 19 feb. 2021 om 22:05 schreef Nathan Ernst via Boost-users < > boost-users(a)lists.boost.org>: > > > The missing symbols you quoted come from python itself. It looks like > > you're missing a "-lpython" linker flag. > > > Thanks! That definitely put me on the right track. Eventually I got it > working using the "-lpython3.6m" flag, since I found that the Python3.6 .so > file was situated at /usr/lib/x86_64-linux-gnu/libpython3.6m.so > Many thanks, this is much appreciated! I've pasted the full Dockerfile in > https://github.com/boostorg/boost/issues/462, in case anyone is > interested. > > > > > Regards, > > Nathan > > > > On Fri, Feb 19, 2021, 4:47 AM Roy de Bokx via Boost-users < > > boost-users(a)lists.boost.org> wrote: > > > >> > >> > >> Op wo 17 feb. 2021 om 20:30 schreef Anonymous Maarten < > >> anonymous.maarten(a)gmail.com>: > >> > >>> Thanks for your answer Maarten! > >>>> Please bare with me as I'm a little new to this. Is there some way I > >>>> can change the interpreter that is used for installing boost? Or do > you > >>>> think that adapting the --prefix flag may also work? > >>>> > >>> > >>> When using the pre-built boost packages of a linux distribution > >>> (ubuntu), you're generally stuck with the versions/options that its > >>> packagers have chosen. > >>> A distribution freezes versions to make a more robust experience. > >>> > >>> Adding a `--prefix` will not help because, first of all, it's not a > >>> valid gcc option, and second, ubuntu 18.04 does not provide a > >>> libboost-python-py37 shared/static library. > >>> Do you really need python 3.7? Doesn't 3.6 suffice? > >>> > >> > >> Thanks! This helped me understanding the issue a bit further. I think > 3.6 > >> should suffice indeed, so I tried using 3.6 by removing the 3.7 > >> installation from the Dockerfile and using the -lboost_numpy3 flag > instead. > >> It seems I ran into some linking issue after this. It was able to find > >> the right numpy3.so and libboost_python3-py36.so, but I'm getting a lot > of > >> errors like these: > >> > >> //usr/lib/x86_64-linux-gnu/libboost_numpy3.so: undefined reference to > >> `PyExc_ValueError' > >> > >> //usr/lib/x86_64-linux-gnu/libboost_python3-py36.so.1.65.1: undefined > >> reference to `PyLong_AsLong' > >> > >> //usr/lib/x86_64-linux-gnu/libboost_python3-py36.so.1.65.1: undefined > >> reference to `PyNumber_InPlaceFloorDivide' > >> > >> //usr/lib/x86_64-linux-gnu/libboost_python3-py36.so.1.65.1: undefined > >> reference to `PyBool_Type' > >> etc... > >> > >> I've pasted the full docker file and logs in > >> https://github.com/boostorg/boost/issues/462 > >> Thanks again for any help. > >> > >>> > >>> If you really want to use Boost.Python + python 3.7, you can do 2 > things: > >>> - stay on ubuntu bionic and build boost yourself (or use an alternative > >>> c/c++ package manager, e.g. [conan](https://conan.io/) has a [boost > >>> package](https://conan.io/center/boost)) > >>> - more to a more recent ubuntu release. e.g. ubuntu 20.10 has python > >>> 3.8: > >>> > https://packages.ubuntu.com/groovy/amd64/libboost-python1.71-dev/filelist > >>> > >> I've also given 20.10 a try, however I ran into the same linking issues > >> as mentioned above. > >> > >>> > >>> > >>> > >>> _______________________________________________ > >> Boost-users mailing list > >> Boost-users(a)lists.boost.org > >> https://lists.boost.org/mailman/listinfo.cgi/boost-users > >> > > _______________________________________________ > > Boost-users mailing list > > Boost-users(a)lists.boost.org > > https://lists.boost.org/mailman/listinfo.cgi/boost-users > > >

1 0

Re: [Boost-users] Boost cannot find numpy37 on Dockerized Ubuntu 20.04
by Roy de Bokx 22 Feb '21

22 Feb '21

Op wo 17 feb. 2021 om 20:30 schreef Anonymous Maarten < anonymous.maarten(a)gmail.com>: > Thanks for your answer Maarten! >> Please bare with me as I'm a little new to this. Is there some way I can >> change the interpreter that is used for installing boost? Or do you think >> that adapting the --prefix flag may also work? >> > > When using the pre-built boost packages of a linux distribution (ubuntu), > you're generally stuck with the versions/options that its packagers have > chosen. > A distribution freezes versions to make a more robust experience. > > Adding a `--prefix` will not help because, first of all, it's not a valid > gcc option, and second, ubuntu 18.04 does not provide a > libboost-python-py37 shared/static library. > Do you really need python 3.7? Doesn't 3.6 suffice? > Thanks! This helped me understanding the issue a bit further. I think 3.6 should suffice indeed, so I tried using 3.6 by removing the 3.7 installation from the Dockerfile and using the -lboost_numpy3 flag instead. It seems I ran into some linking issue after this. It was able to find the right numpy3.so and libboost_python3-py36.so, but I'm getting a lot of errors like these: //usr/lib/x86_64-linux-gnu/libboost_numpy3.so: undefined reference to `PyExc_ValueError' //usr/lib/x86_64-linux-gnu/libboost_python3-py36.so.1.65.1: undefined reference to `PyLong_AsLong' //usr/lib/x86_64-linux-gnu/libboost_python3-py36.so.1.65.1: undefined reference to `PyNumber_InPlaceFloorDivide' //usr/lib/x86_64-linux-gnu/libboost_python3-py36.so.1.65.1: undefined reference to `PyBool_Type' etc... I've pasted the full docker file and logs in https://github.com/boostorg/boost/issues/462 Thanks again for any help. > > If you really want to use Boost.Python + python 3.7, you can do 2 things: > - stay on ubuntu bionic and build boost yourself (or use an alternative > c/c++ package manager, e.g. [conan](https://conan.io/) has a [boost > package](https://conan.io/center/boost)) > - more to a more recent ubuntu release. e.g. ubuntu 20.10 has python 3.8: > https://packages.ubuntu.com/groovy/amd64/libboost-python1.71-dev/filelist > I've also given 20.10 a try, however I ran into the same linking issues as mentioned above. > > > >

2 2

Prooblem building software with fstream.hpp
by Mack Wallace 21 Feb '21

21 Feb '21

Hi all. I'm a noob and unfamiliar with boost. It has also been a long time since I have done any C++ programming. In any case, here are the details: I am trying to compile MecnRao/TCP-UDP-Proxy that uses the Boost Library. I am trying to compile this for Windows, ultimately Windows 10, but at the moment trying to compile on my Windows 7 VM. I am using Visual Studio Pro 2019. After trying the latest version of the Boost Library with some errors due to some deprecated members, I bounced around older versions until finding that Version 1.68.0 reduced my compile errors substantially, and of those 20 or so errors, are caused by some typedef problems in fstream.hpp. (I could be wrong, but the errors all seem to be related to fstream_fix.) Specifically, I get the following errors to begin with: 'fstream_fix<std::basic_ifstream<char,std::char_traits<char> > >' is not a variable template 'fstream_fix<std::basic_ofstream<char,std::char_traits<char> > >' is not a variable template This comes from the following lines in the fstream.hpp typedef basic_ifstream<char> ifstream; typedef basic_ofstream<char> ofstream; Where ifstream and ofstream are indicated as being redefined as #define ifstream fstream_fix<std::ifstream> #define ofstream fstream_fix<std::ofstream> Within the program with fstream_fix as template<class T> struct fstream_fix : public T { fstream_fix(){}; template<class T1> fstream_fix(T1 v1){ setlocale(LC_CTYPE, ""); T::open(v1); setlocale(LC_CTYPE, 0); } template<class T1,class T2> fstream_fix(T1 v1,T2 v2){ setlocale(LC_CTYPE, ""); T::open(v1,v2); setlocale(LC_CTYPE, 0); } template<class T1> void open(T1 v1){ setlocale(LC_CTYPE, ""); T::open(v1); setlocale(LC_CTYPE, 0); } template<class T1,class T2> void open(T1 v1,T2 v2){ setlocale(LC_CTYPE, ""); T::open(v1,v2); setlocale(LC_CTYPE, 0); } }; So I'm wondering if this is a newer/different compiler issue? Or the application itself? Or maybe just missing something like uses namespace std. I am hoping someone can help me nip this last problem so I can get this compiled. Thanks, Mack

1 0

boost::asio::read() gets stuck when there's no internet
by Child OfGod 20 Feb '21

20 Feb '21

In TgBot library i use under MSVC++, in tgbot/net/BoostHttpOnlySslClient.cpp, a call to boost::asio::read() does not return when internet is disconnected for a few minutes. I would appreciate any help to get this resolved, i.e. for the read function to return if it fails after some timeout has passed the code block in the tgbot/net/BoostHttpOnlySslClient.cpp file: [code] string BoostHttpOnlySslClient::makeRequest(const Url& url, const vector<HttpReqArg>& args) const { tcp::resolver resolver(_ioService); tcp::resolver::query query(url.host, "443"); ssl::context context(ssl::context::tlsv12_client); context.set_default_verify_paths(); ssl::stream<tcp::socket> socket(_ioService, context); connect(socket.lowest_layer(), resolver.resolve(query)); #ifdef TGBOT_DISABLE_NAGLES_ALGORITHM socket.lowest_layer().set_option(tcp::no_delay(true)); #endif //TGBOT_DISABLE_NAGLES_ALGORITHM #ifdef TGBOT_CHANGE_SOCKET_BUFFER_SIZE #if _arm64 || _WIN64 || __amd64__ || __x86_64__ || __MINGW64__ || __aarch64__ || __powerpc64__ socket.lowest_layer().set_option(socket_base::send_buffer_size(65536)); socket.lowest_layer().set_option(socket_base::receive_buffer_size(65536)); #else //for 32-bit socket.lowest_layer().set_option(socket_base::send_buffer_size(32768)); socket.lowest_layer().set_option(socket_base::receive_buffer_size(32768)); #endif //Processor architecture #endif //TGBOT_CHANGE_SOCKET_BUFFER_SIZE socket.set_verify_mode(ssl::verify_none); socket.set_verify_callback(ssl::rfc2818_verification(url.host)); socket.handshake(ssl::stream<tcp::socket>::client); string requestText = _httpParser.generateRequest(url, args, false); write(socket, buffer(requestText.c_str(), requestText.length())); string response; #ifdef TGBOT_CHANGE_READ_BUFFER_SIZE #if _M_ARM64 || _WIN64 || __amd64__ || __x86_64__ || __MINGW64__ || __aarch64__ || __powerpc64__ char buff[65536]; #else //for 32-bit char buff[32768]; #endif //Processor architecture #else char buff[1024]; #endif //TGBOT_CHANGE_READ_BUFFER_SIZE boost::system::error_code error; while (!error) { std::size_t bytes = read(socket, buffer(buff), error); response += string(buff, bytes); } return _httpParser.extractBody(response); } [/code] Thankyou in advance😀🙏

3 4

(no subject)
by Dk Jack 18 Feb '21

18 Feb '21

Hi, I am using boost 1.58 in my project. Ran into a crash in the boost filesystem library. I've included the relevant stack trace at the end of the email. My code is something like this: boost::filesystem::path fpath(mFilename.c_str()); if (!boost::filesystem::exists(fpath)) { // log a message and return. return; } auto curr_time = boost::filesystem::last_write_time(fpath); <== crash The crash is not consistent and happened randomly. I tested the above code in a small test program with just the above code. I made the input file unreadable etc, even then it was able to successfully read the last write timestamp of the file without any issues. Not sure why this particular call would throw an error. Since it's compiled with -O2, the error code is optimized out in the stack trace. Any ideas? Thanks for your help. Dk. (gdb) bt #0 0x00007f01651ba387 in raise () from /lib64/libc.so.6 #1 0x00007f01651bba78 in abort () from /lib64/libc.so.6 #2 0x00007f0160d087d5 in __gnu_cxx::__verbose_terminate_handler() () from /lib64/libstdc++.so.6 #3 0x00007f0160d06746 in ?? () from /lib64/libstdc++.so.6 #4 0x00007f0160d06773 in std::terminate() () from /lib64/libstdc++.so.6 #5 0x00007f0160d06993 in __cxa_throw () from /lib64/libstdc++.so.6 #6 0x00007f0161171f5f in boost::filesystem::detail::last_write_time(boost::filesystem::path const&, boost::system::error_code*) () from xxx.so #7 0x00007f0161089657 in last_write_time (p=...) at /usr/local/include/boost/filesystem/operations.hpp:594

2 1

Boost cannot find numpy37 on Dockerized Ubuntu 20.04
by Roy de Bokx 17 Feb '21

17 Feb '21

Hi there, I've been trying to get GP-GOMEA running in a dockerized environment <https://github.com/marcovirgolin/GP-GOMEA/issues/2>, which is a project that is built using Boost. As part of the build process, the source code is compiled by the g++ compiler, using the flag -lboost_numpy37, which fails because (it seems) numpy cannot be found. I've reported this also as an issue also in the boost repository <https://github.com/boostorg/boost/issues/462>, but mclow advised me to send this to the boost-users mailinglist too. I've create the following Dockerfile as a minimal test case, which runs into the same problem. I'm a bit of a noob when it comes to Boost and numpy, but from what I found so far on the web, this should work (but it doesn't) FROM ubuntu:20.04 ENV DEBIAN_FRONTEND noninteractive RUN apt-get update && apt-get upgrade -y && apt-get clean RUN apt-get install -y curl python3.7 python3-dev python3-distutils python3-numpy # Install latest boost version RUN apt-get -y install wget g++ RUN wget https://dl.bintray.com/boostorg/release/1.75.0/source/boost_1_75_0.tar.bz2 && \ tar --bzip2 -xf boost_1_75_0.tar.bz2 && \ cd boost_1_75_0 && \ # this will generate ./b2 ./bootstrap.sh --prefix=/usr/local && \ ./b2 --with=all install && \ sh -c 'echo "/usr/local/lib" >> /etc/ld.so.conf.d/local.conf' && \ ldconfig # Check numpy installation RUN find / -name "numpy.hpp" RUN find / -name "libboost_numpy37.so" RUN find / -name "libboost_numpy3.so" RUN find / -name "libboost_numpy.so" RUN ld -lboost_numpy37 --verbose This eventually results in the following error: The command '/bin/sh -c ld -lboost_numpy37 --verbose' returned a non-zero code: 1, because it could not find any libboost_numpy37.so or libboost_numpy37.o file. The full logs are attached in the GH issue linked above. Did anyone encounter something similar, or does anyone have an idea what could cause this? Any help is much appreciated! -Roy

2 2

How to change read/write method of source/sink device in C++ boost::iostreams?
by mostaan fereidooni 16 Feb '21

16 Feb '21

I'm trying to get familiar with boost::iostream, so in a example program I'm writing, I want to read a text from a file and write it to file. I would use my inherited class from file_source/file_sink as device to read/write. In the read method, my class needs to add each character with one and write method needs to subtract one from each character. First of all, I want to make sure that the reading part of the program works properly so you can see the code as follow: #include <boost/iostreams/stream.hpp>#include <fstream>#include "MyFileSource.h"#include <iostream>using namespace std;using namespace boost::iostreams;int main(){ MyFileSource<char> fileSource("source.txt"); stream<MyFileSource<char>> myStream(fileSource); std::cout << myStream.rdbuf(); fileSource.close(); } and my inherited source device code is as follow: template <typename charType>class MyFileSource : public boost::iostreams::file_source {public: MyFileSource(const std::string& path) : boost::iostreams::file_source(path) { file_path = path; if (!is_open()) open(path); seek(0, ios::end); sizeOfFile = seek(0, ios::cur); seek(0, ios::beg); buffer = new charType[sizeOfFile]; } std::streamsize read(charType*, std::streamsize) { std::streamsize readCount = boost::iostreams::file_source::read(buffer, sizeOfFile); if (readCount > 0) { std::string result(buffer, readCount); for (char& c : result) c++; finalResult = result; } return readCount; } private: string file_path; int sizeOfFile; charType* buffer; std::string finalResult; }; unfortunately, the result of *std::cout << myStream.rdbuf()* with above read method is nothing while if I delete the read method of MyFileSource class to use the read method of parent, the result will be correct. Any help will be appreciated.

1 0

How to link boost library DLLs?
by Anand Arumugam 14 Feb '21

14 Feb '21

Hello all, How to properly link boost library DLLs? I have #define-d the following: #define BOOST_ALL_DYN_LINK #define BOOST_DYN_LINK #define BOOST_THREAD_USE_DLL #define BOOST_THREAD_PROVIDES_FUTURE_CONTINUATION #define BOOST_THREAD_VERSION 4 And I still get the following problem: --------------------------- testprogs.exe - System Error --------------------------- The code execution cannot proceed because boost_thread-vc142-mt-gd-x64-1_75.dll was not found. Reinstalling the program may fix this problem. --------------------------- OK --------------------------- I get the same error when I try to run the program using DLLs that I built and while running using the prebuilt binaries. Not sure what step I'm missing. The program runs fine if I build using static libs. The problem is only with DLLs. Any help is much appreciated. Thanks, Anand.

3 3

Boost.Asio as "thread-pool": How to apply back-pressure?
by Dominique Devienne 10 Feb '21

10 Feb '21

Hi, I'm using Boost.ASIO, not for networking, but simply to parallelize work items, with a simple graph of "processing nodes" as detailed below. It's working fine, but uses too much memory. I'd like insights on limiting memory use via "throttling", or what I've also seen called "back-pressure". At a high level, I process two files (A and B) composed of several "entries" each, extracting a subset or a transformation of those entries, that I then write into an output file (C). (those 3 files reach into the many GBs, thus the need for parallelism, and limiting memory use). Extracting entries from A and B are independent operations, implemented single-threaded, producing independent work items (for subsetting or transforming each item), A#1...A#n, and B#1..B#m. That's the "fan-out" part, with each work-item (task) scheduled on any thread of the ASIO pool, since independent. Writing to C is also single-threaded, and needs to "fan-in" the work posted by the A#n and B#m functors, and I serialize that via posting to a C-specific strand (still on any thread, as long as serialized, doesn't matter). Lets call all those tasks writing to C the C#n+m tasks, which are posted to the strand via the A#s and B#s. My issue is that Boost.Asio seems to schedule an awful lots of A# and B# tasks, before getting to the C# tasks, which results in accumulating in memory too many C# tasks, and thus using too much memory. I don't see a way to force more C "downstream" tasks to be scheduled, before processing so much A and B tasks, and accumulating pending C tasks in the work queue, thus using too much memory again. Could someone please recommend a way to have a more balanced flow of tasks in the graph? Or alternative designs even, if what I do above is not ideal. Is Boost.Asio even suitable in this case? Thanks, --DD

7 17

[boost-process] why does my child process not get EOF on stdin
by harald 01 Feb '21

01 Feb '21

Dear community, dear experts! I am trying to use boost::process to call weasyprint to convert HTML to a picture. To do that I wrote a test program (further down in the mail). This worked fine and did what i expected. But it stopped working as soon as I tried to convert two files at the same time by changing new renderer_t(io_context, "<head></head><body></body>"); in main to new renderer_t(io_context, "<head></head><body></body>"); new renderer_t(io_context, "<head></head><body></body>"); Now weasyprint hangs. I changed the call to weasyprint to weasyprint2, which is a short bash script for testing purposes: --------------------------------------------------------------------------------- #! /bin/bash cat > /dev/null echo "This should be a PNG picture" --------------------------------------------------------------------------------- It reads stdin until it gets EOF and then writes something to stdout before terminating. Same result. It seems that my program does not close stdin of the child, so it never gets EOF on stdin. But only when more than one child process is running at the same time. So obviously I am doing something wrong, but I have no idea what! Does anybody have a hint for me? I am on xubuntu 20.10 compiler is g++ (Ubuntu 10.2.0-13ubuntu1) 10.2.0, boost version 1.75.0 compiler command line (from my IDE): g++ -c main.cpp -g -O0 -Wall -Wextra -std=c++17 -o build-Debug/main.cpp.o -I. -I. --------------------------------------------------------------------------------- #include <boost/smart_ptr/intrusive_ptr.hpp> #include <boost/smart_ptr/intrusive_ref_counter.hpp> #include <boost/process.hpp> #include <boost/asio/write.hpp> #include <iostream> namespace bp = boost::process; bool is_eof( std::error_code error) { boost::system::error_code eof = boost::asio::error::eof; return error == eof; } struct renderer_t : public boost::intrusive_ref_counter<renderer_t> { using pointer = boost::intrusive_ptr<renderer_t>; boost::asio::io_context &io_context; const std::string html; bp::child child; bp::async_pipe in; bp::async_pipe out; bp::async_pipe err; std::array<unsigned char, 256> outbuf; std::array<char, 256> errbuf; std::vector<unsigned char> result; std::error_code result_error; std::string errmsg; ~renderer_t() { std::cout << "renderer_t::~renderer_t\n"; if (!errmsg.empty()) std::cerr << "renderer_t::~renderer_t: stderr: " << errmsg << "\n"; } renderer_t( boost::asio::io_context &io_context, const std::string &html) : io_context(io_context), html(html), in(io_context), out(io_context), err(io_context) { post( io_context, [self = pointer(this)]() { self->start(); }); } void start() { std::error_code ec; std::cout << "renderer_t::start\n"; bp::child c( "weasyprint2 -m screen -p -f png - /dev/stdout", bp::std_in < in, bp::std_out > out, bp::std_err > err, bp::on_exit=[self = pointer(this)]( int exit, std::error_code error) { self->on_exit(error, exit); }, bp::start_dir="/data/build/", io_context, ec); if (ec) { std::cerr << "renderer_t::start: creating child failed: " << ec.message() << "\n"; if (!result_error) result_error = ec; return; } child = std::move(c); boost::asio::async_write( in, boost::asio::buffer(html), [self = pointer(this)]( std::error_code error, std::size_t bytes) { self->on_write(error, bytes); }); out.async_read_some( boost::asio::buffer(outbuf), [self = pointer(this)]( std::error_code error, std::size_t bytes) { self->on_read_out(error, bytes); }); err.async_read_some( boost::asio::buffer(errbuf), [self = pointer(this)]( std::error_code error, std::size_t bytes) { self->on_read_err(error, bytes); }); } void on_write( std::error_code error, std::size_t bytes) { std::cout << "renderer_t::on_write\n"; if (error) { std::cerr << "renderer_t::on_write: failed: " << error.message() << "\n"; if (!result_error) result_error = error; return; } if (bytes != html.size()) { std::cerr << "renderer_t::on_write: short write\n"; } boost::system::error_code ec; in.close(ec); if (ec) { std::cerr << "renderer_t::on_write: close failed: " << error.message() << "\n"; } } void on_read_out( std::error_code error, std::size_t bytes) { std::cout << "renderer_t::on_read_out\n"; if (is_eof(error)) { std::cout << "renderer_t::on_read_out: EOF\n"; return; } else if (error) { std::cerr << "renderer_t::on_read_out: failed: " << error.message() << "\n"; if (!result_error) result_error = error; return; } else { result.insert( end(result), begin(outbuf), begin(outbuf) + bytes); out.async_read_some( boost::asio::buffer(outbuf), [self = pointer(this)]( std::error_code error, std::size_t bytes) { self->on_read_out(error, bytes); }); } } void on_read_err( std::error_code error, std::size_t bytes) { std::cout << "renderer_t::on_read_err\n"; if (is_eof(error)) { std::cout << "renderer_t::on_read_err: EOF\n"; return; } else if (error) { std::cerr << "renderer_t::on_read_err: failed: " << error.message() << "\n"; if (!result_error) result_error = error; return; } else { std::string e(begin(errbuf), begin(errbuf) + bytes); std::cerr << "renderer_t::on_read_err: from stderr: " << e << "\n"; errmsg.insert( end(errmsg), begin(errbuf), begin(errbuf) + bytes); err.async_read_some( boost::asio::buffer(errbuf), [self = pointer(this)]( std::error_code error, std::size_t bytes) { self->on_read_err(error, bytes); }); } } void on_exit( std::error_code error, int exit) { std::cout << "renderer_t::on_exit\n"; if (error) { std::cerr << "renderer_t::on_exit: error: " << error.message() << "\n"; if (!result_error) result_error = error; return; } if (exit) { std::cerr << "renderer_t::on_exit: weasyprint returned " << exit << "\n"; if (!result_error) result_error = make_error_code(std::errc::no_such_process); } } }; int main() { boost::asio::io_context io_context; bp::async_pipe in(io_context); new renderer_t(io_context, "<head></head><body></body>"); io_context.run(); return 0; } --------------------------------------------------------------------------------- Regards Harald

1 0

TOMS748 question
by Shriramana Sharma 29 Jan '21

29 Jan '21

Namaste. This is wrt the TOMS748 math root finding implementation: Given that `if(fa == 0)` is handled at: https://github.com/boostorg/math/blob/develop/include/boost/math/tools/toms… … and the function returns in case of the above condition, it is not clear to me what the need is for the `if (fa != 0)` at: https://github.com/boostorg/math/blob/develop/include/boost/math/tools/toms… Note that I do not find the condition being applied at the SciPy implementation of this algorithm at: https://github.com/scipy/scipy/blob/v1.6.0/scipy/optimize/zeros.py#L1220 Now I also note similar checks at: https://github.com/boostorg/math/blob/develop/include/boost/math/tools/toms… https://github.com/boostorg/math/blob/develop/include/boost/math/tools/toms… … but regarding those lines, while I can understand the need for checking there after more bracketing work is done, it is not clear to me why `(fa == 0)` is alone checked for, and not `(fb == 0)` as well. I would have thought the algorithm is not biased towards a or b. Indeed, in the last steps from: https://github.com/boostorg/math/blob/develop/include/boost/math/tools/toms…, … both the conditions are checked for, which is what I would expect even in the intervening steps. Now the lines seem to have originated in the very first commit implementing this algorithm: https://github.com/boostorg/math/commit/79a8199f9c26ba353fb52ec4543f75ffc2a… … but I do not see a way to contact the author jzmaddock other than posting to this list, so I hope someone/they see here and reply. Thanks! -- Shriramana Sharma ஶ்ரீரமணஶர்மா श्रीरमणशर्मा 𑀰𑁆𑀭𑀻𑀭𑀫𑀡𑀰𑀭𑁆𑀫𑀸

2 7

Correct way to handle error in boost::filesystem::recursive_directory_iterator::increment()?
by Dominique Pellé 23 Jan '21

23 Jan '21

Hi I see code like this in an application to iterate over files in a directory with boost::filesystem (v1.70) without using exceptions: boost::filesystem::path dir("somedir"); boost::system::error_code error; boost::filesystem::directory_iterator node(dir, error), end; if (error) { return ...; } for (; node != end; node.increment(error)) { const boost::filesystem::path& path = node->path(); // ... } It appears to work... or mostly work since a crash was reported and the stack points to this area of the code. It's a rare crash that I could not reproduce myself. I suspect that there is a bug in the above code and it should instead be: boost::filesystem::path dir("somedir"); boost::system::error_code error; boost::filesystem::directory_iterator node(dir, error), end; for (; !error && node != end; node.increment(error)) { const boost::filesystem::path& path = node->path(); // ... } In other words, I suspect that we need to check that node.increment(error) in the for loop did not give an error before checking the condition "node != end", or else we may enter the loop in case of error and then it may access node->path() with an invalid node iterator. I could not find in the doc at ... https://www.boost.org/doc/libs/1_75_0/libs/filesystem/doc/reference.html ... what exactly happens when node.increment(error) gives an error. Perhaps the doc deserves clarification or an example illustrating how to reliably iterate over files without using exceptions would be welcome. Thanks Dominique

1 1

Serialization and static Libraries
by Wolfgang Meyerle 20 Jan '21

20 Jan '21

Hi, probably has been asked already thousand of times but I'm stuck currently with some code: Assuming I have the following files (The Base class Action is serialized in the same way): File: Ping.h #include"Action.h" classPing:publicAction{ public: voidoperator()(); Ping(); Ping*clone()const; ~Ping(); template<typenameArchive> voidserialize(Archive&ar,constunsignedint); }; BOOST_CLASS_EXPORT_KEY2(Ping,"Ping"); File: Ping.cpp #include"Ping.h" #include<iostream> #include<boost/serialization/base_object.hpp> #include<boost/serialization/export.hpp> #include<boost/serialization/tracking.hpp> #include"Action.h" #include"system.h" #include"pong.h" #include"serializerdeserializer.h" #include"system.h" #include"connection.h" #include"communication.h" voidPing::operator()(){ } Ping::Ping() { } Ping*Ping::clone()const{ Ping*ping=newPing(*this); returnping; } template<typenameArchive> voidPing::serialize(Archive&ar,constunsignedint){ ar&BOOST_SERIALIZATION_BASE_OBJECT_NVP(Action); } Ping::~Ping(){} BOOST_CLASS_EXPORT_IMPLEMENT(Ping); BOOST_CLASS_TRACKING(Ping,boost::serialization::track_never); If I now compile the project into a library. And link this library to a different project. If I try to serialize the class now it doesn't work. I get the following error: unregistered class - derived class not registered or exported According to the boost documentation I need to use BOOST_CLASS_EXPORT_KEY in the header file and BOOST_CLASS_EXPORT_IMPLEMENT in the corresponding cpp file. What did I miss? Regards, Wolfgang

1 0

[Boost-MPI][Boost-ODEINT] Running odeint within MPI-context without using mpi_state
by Roland Richter 19 Jan '21

19 Jan '21

Hei, I am currently using the odeint-solver for calculating the right hand side of a non-linear equation. For speeding up the calculation of the right hand side, I decided to test the MPI-implementation. Now, after I would prefer to keep the code backwards compatible, I did not want to replace state_type with mpi_state, and instead split up the initial vector by hand before calling odeint without telling odeint that I am operating within an MPI context. I take care of all communications which involve the vectors, and therefore I assumed that this approach should work (especially after it worked correctly in small test programs). Nevertheless, I encountered the issue that after a certain amount of steps the step size between the different threads starts to differ by a small amount, even though I am in the same iteration. As example: step number rank step size n 1 0.00025 n 0 0.00025 //Ok n + 1 1 0.00051152 n + 1 0 0.000511523 //Not ok I checked my program with valgrind for possible memory leaks/corruption which could overwrite something, but nothing relevant came up. The problem is repeatable. Therefore, is the general idea correct at all, or am I doing something wrong here by neglecting a possible communication between the different threads within odeint? Thanks! Regards, Roland

2 2

Conversion numeric::array in numpy::ndarray
by philippe DALET 17 Jan '21

17 Jan '21

Hello, It's my first mail on this maillist. I started to upgrade a package for python 3.7, 3.8, 3.9 (linux and windows): vpython-wx. One file gives me some problems num_util.hpp My context: ubuntu 20.04: boost 1.71 python3.7 windows 10: boost 1.75 python3.7, 3.8, 3.9 I want to create a double_array class: Original version --------------------- namespace cvisual { namespace python { using boost::python::numeric::array; class double_array : public array { public: explicit double_array( const boost::python::handle<>& h ) : array(h) {} }; array makeNum(npy_intp n, NPY_TYPES t =NPY_DOUBLE); New version ----------------- namespace cvisual { namespace python { using boost::python::numpy::ndarray; class double_array : public ndarray { public: explicit double_array( const boost::python::handle<>& h ) : ndarray(h) {} }; ndarray makeNum(npy_intp n, NPY_TYPES t =NPY_DOUBLE); error message with VC2019 community error conversion 'const boost::python::handle<PyObject>' in 'boost::python::detail::borrowed_reference' error message with gcc 9.3 no matching function for call to ‘boost::python::numpy::ndarray::ndarray(const boost::python::handle<>&)’ Thanks a lot for your help. Philippe DALET Laboratoire de Physique Lyp Champollion, Figeac FRANCE

1 0

Re: [Boost-users] boost::regex: regex meta data or AST for regex?
by Frank Bergemann 16 Jan '21

16 Jan '21

On 16.12.20 18:05, Frank Bergemann via Boost-users wrote: > in concrete: > Is it possible to not only get the #no of groups (sub-expressions) via > basic_regex::mark_count(), but also their position (begin() / end() > iterators) in the given regex string (c'tor argument)? > > more general: > Can an AST be created for a the given regex string (c'tor argument)? > E.g with boost::spirit? I am busy with #2 parsers: 1) RegexParser: Intended to be a full regular expression parser https://github.com/F-Bergemann/RegexParser 2) RegexSplitter: to just break up regular expression into substrings for top level regex-group & non-regex-group substrings: https://github.com/F-Bergemann/RegexSplitter It's just a start and so much wrong within, i know. But i have one concrete question for the RegexSplitter: How can i avoid in RegexSplitter.cpp to use #157 ( tok_element >> *tok_element ) [ qi::_val = phx::new_<ASTNode> (qi::_1, qi::_2, ASTNode::COLLECTION_c) ]; I want to pass a SINGLE std::vector<ATSNode *> only to the receiving #51 // COLLECTION_c #52 ASTNode::ASTNode( #53 ASTNode const * first, #54 std::vector<ASTNode *> & others, #55 Type const type) without the SEPARATE parameter 'first'. I.e. i need to "merge" qi::_1 and qi::_2.

1 0

Re: [Boost-users] boost ptr_map memory access violation
by roland kapl 08 Jan '21

08 Jan '21

Dear All! After finding some inspiration on https://stackoverflow.com/questions/4088387/how-to-store-pointers-in-map , I've succeeded storing the property tree pointers in a std::map... std::string TreeizeRelD::writeTree(const std::vector<std::vector<std::string>> &control, const std::vector<std::vector<std::vector<std::string>>> &data, pt::ptree & ptTree) { // now the map is local... typedef std::map<std::string, pt::ptree*> treeMap; std::map<std::string, treeMap> parentTableTrees; .... std::string subRootNode = parentNode + (subnodeOfParent != "" ? "." + subnodeOfParent : ""); std::string tableLookup = subRootNode + "." + rootElemRec; // simply add records if no foreign key name exists (usually the top (root) table) if (foreignKeyName == "") { for (std::pair<std::string, pt::ptree> && keyPair : tables[tableLookup]) { parentTableTrees[subRootNode].insert(std::make_pair(keyPair.first, &ptTree.add_child(subRootNode, keyPair.second))); ... // iterate through all parent key record collections referred to by subtables parentNode (rootnode + optional subnode) for (std::pair<std::string, pt::ptree*> && parentKeysPair : parentTableTrees.find(lookupNode)->second) { // iterate through all records (ptrees) in key collection for (pt::ptree::iterator parentRecPair = parentKeysPair.second->begin(); parentRecPair != parentKeysPair.second->end(); ++parentRecPair) { // important here: assign a reference to parentRecPtree (pointer!), otherwise a copy is created! pt::ptree &parentRecPtree = parentRecPair->second; ... parentTableTrees[subRootNode].insert(std::make_pair(rowsFK, &parentRecPair->second.get_child(subnodeFRec))); ... parentTableTrees[subRootNode].insert(std::make_pair(rowsFK, &parentRecPtree.put_child(subnodeOfParent, foreignRecordset))); The complete source of this: https://github.com/rkapl123/OreControl/blob/master/OreMgr/TreeizeRelD/treei… -regards, Roland ---------------------------------------------------------------------- Message: 1 Date: Wed, 6 Jan 2021 11:49:07 +0000 From: roland kapl <roland.kapl(a)hotmail.com<mailto:roland.kapl@hotmail.com>> To: "boost-users(a)lists.boost.org<mailto:boost-users@lists.boost.org>" <boost-users(a)lists.boost.org<mailto:boost-users@lists.boost.org>> Subject: [Boost-users] boost ptr_map memory access violation (stack/heap problem) Message-ID: <AM0PR03MB424285F7832EDC3C73C96860EDD00(a)AM0PR03MB4242.eurprd03.prod.outlook.com<mailto:AM0PR03MB424285F7832EDC3C73C96860EDD00@AM0PR03MB4242.eurprd03.prod.outlook.com>> Content-Type: text/plain; charset="us-ascii" Dear Boost-Experts! I'm trying to use a ptr_map along with boost property trees. I need to store pointers to specific parts of a built up property tree to access these parts later on for easy insertion there. However, when the ptr_map is cleared/destroyed, I get memory access violations/stack overflow messages for my test cases. The ptr_map (typedef treeMap) is globally defined within a std::map to a ptr_map to property trees as follows (I know this isn't good practice, but passing it as a reference didn't make a difference, so I left it that way): namespace pt = boost::property_tree; typedef boost::ptr_map<std::string, pt::ptree> treeMap; std::map<std::string, treeMap> parentTableTrees; The property tree is defined as follows in this function (this builds a property tree from tabular data in the passed table variable "data" using definitions form table variable "control"): std::string TreeizeRelD::writeTreeAndCreateXML(const std::vector<std::vector<std::string>>& control, const std::vector<std::vector<std::vector<std::string>>>& data, int *result) { std::string resultString; pt::ptree &propTree = pt::ptree(); std::string returnStr = TreeizeRelD::writeTree(control, data, propTree); *result = 0; if (returnStr != "") { *result = 1; return returnStr; } returnStr = TreeizeRelD::createXML(propTree, resultString); if (returnStr != "") { *result = 1; return returnStr; } // here the memory access violation occurs: parentTableTrees.clear(); return resultString; } In function writeTree the propTree (being passed by ref as ptTree) is populated in following three lines: std::string TreeizeRelD::writeTree(const std::vector<std::vector<std::string>> &control, const std::vector<std::vector<std::vector<std::string>>> &data, pt::ptree & ptTree) ... // FIRST LINE parentTableTrees[subRootNode].insert(keyPair.first, &ptTree.add_child(subRootNode, keyPair.second)); ... // iterate through all parent key record collections referred to by subtables parentNode (rootnode + optional subnode) for (treeMap::value_type && parentKeysPair : parentTableTrees.find(lookupNode)->second) { // iterate through all records (ptrees) in key collection for (pt::ptree::iterator parentRecPair = parentKeysPair.second->begin(); parentRecPair != parentKeysPair.second->end(); ++parentRecPair) { pt::ptree &parentRecPtree = parentRecPair->second; ... // SECOND LINE // parentRecPair is an iterator variable from the ptr_map: parentTableTrees[subRootNode].insert(rowsFK, &parentRecPair->second.get_child(subnodeFRec)); ... // THIRD LINE // parentRecPtree is the referenced property tree itself: parentTableTrees[subRootNode].insert(rowsFK, &parentRecPtree.put_child(subnodeOfParent, foreignRecordset)); I already have the suspicion that the memory access violation comes from ptr_map taking ownership of the pointers (references) passed to it in the above three lines and that these are all created on the stack and not the heap, where ptr_map expects them to be. When the ptr_map is finally destroyed, it tries to access memory, that's impossible to access... But I didn't manage to successfully create heap objects that also do NOT copy the property tree objects, which is important as I only need references to the property trees. Any help is appreciated. -regards, Roland

1 0

boost ptr_map memory access violation (stack/heap problem)
by roland kapl 06 Jan '21

06 Jan '21

Dear Boost-Experts! I'm trying to use a ptr_map along with boost property trees. I need to store pointers to specific parts of a built up property tree to access these parts later on for easy insertion there. However, when the ptr_map is cleared/destroyed, I get memory access violations/stack overflow messages for my test cases. The ptr_map (typedef treeMap) is globally defined within a std::map to a ptr_map to property trees as follows (I know this isn't good practice, but passing it as a reference didn't make a difference, so I left it that way): namespace pt = boost::property_tree; typedef boost::ptr_map<std::string, pt::ptree> treeMap; std::map<std::string, treeMap> parentTableTrees; The property tree is defined as follows in this function (this builds a property tree from tabular data in the passed table variable "data" using definitions form table variable "control"): std::string TreeizeRelD::writeTreeAndCreateXML(const std::vector<std::vector<std::string>>& control, const std::vector<std::vector<std::vector<std::string>>>& data, int *result) { std::string resultString; pt::ptree &propTree = pt::ptree(); std::string returnStr = TreeizeRelD::writeTree(control, data, propTree); *result = 0; if (returnStr != "") { *result = 1; return returnStr; } returnStr = TreeizeRelD::createXML(propTree, resultString); if (returnStr != "") { *result = 1; return returnStr; } // here the memory access violation occurs: parentTableTrees.clear(); return resultString; } In function writeTree the propTree (being passed by ref as ptTree) is populated in following three lines: std::string TreeizeRelD::writeTree(const std::vector<std::vector<std::string>> &control, const std::vector<std::vector<std::vector<std::string>>> &data, pt::ptree & ptTree) ... // FIRST LINE parentTableTrees[subRootNode].insert(keyPair.first, &ptTree.add_child(subRootNode, keyPair.second)); ... // iterate through all parent key record collections referred to by subtables parentNode (rootnode + optional subnode) for (treeMap::value_type && parentKeysPair : parentTableTrees.find(lookupNode)->second) { // iterate through all records (ptrees) in key collection for (pt::ptree::iterator parentRecPair = parentKeysPair.second->begin(); parentRecPair != parentKeysPair.second->end(); ++parentRecPair) { pt::ptree &parentRecPtree = parentRecPair->second; ... // SECOND LINE // parentRecPair is an iterator variable from the ptr_map: parentTableTrees[subRootNode].insert(rowsFK, &parentRecPair->second.get_child(subnodeFRec)); ... // THIRD LINE // parentRecPtree is the referenced property tree itself: parentTableTrees[subRootNode].insert(rowsFK, &parentRecPtree.put_child(subnodeOfParent, foreignRecordset)); I already have the suspicion that the memory access violation comes from ptr_map taking ownership of the pointers (references) passed to it in the above three lines and that these are all created on the stack and not the heap, where ptr_map expects them to be. When the ptr_map is finally destroyed, it tries to access memory, that's impossible to access... But I didn't manage to successfully create heap objects that also do NOT copy the property tree objects, which is important as I only need references to the property trees. Any help is appreciated. -regards, Roland

1 0

[statechart] Event dispatching for orthogonal states
by B A 03 Jan '21

03 Jan '21

Hello, I have following code : ///////////////////////////////////////////// #include <iostream> #include <boost/mpl/list.hpp> #include <boost/statechart/simple_state.hpp> #include <boost/statechart/state_machine.hpp> #include <boost/statechart/event.hpp> #include <boost/statechart/transition.hpp> #include <boost/statechart/custom_reaction.hpp> namespace sc = boost::statechart; struct Event1 : sc::event<Event1> {}; struct Event11 : sc::event<Event11> {}; struct Meta; struct Machine : sc::state_machine<Machine, Meta> {}; struct Meta2 : sc::simple_state<Meta2, Machine> { Meta2() { std::cout << "Meta2\n"; } }; struct Inner1; struct Inner2; struct Meta : sc::simple_state<Meta, Machine, boost::mpl::list<Inner1, Inner2>> { Meta() { std::cout << "Meta\n"; } typedef sc::transition<Event1, Meta2> reactions; }; struct Inner11 : sc::simple_state<Inner11, Meta::orthogonal<0>> { Inner11() { std::cout << "Inner11\n"; } typedef sc::custom_reaction<Event1> reactions; sc::result react(const Event1& ev) { std::cout << "Inner1 reaction\n"; return forward_event(); } }; struct Inner1 : sc::simple_state<Inner1, Meta::orthogonal<0>> { Inner1() { std::cout << "Inner1\n"; } typedef sc::transition<Event11, Inner11> reactions; }; struct Inner2 : sc::simple_state<Inner2, Meta::orthogonal<1>> { Inner2() { std::cout << "Inner2\n"; } }; int main() { Machine m; m.initiate(); m.process_event(Event11()); m.process_event(Event1()); return 0; } //////////////////// That gives me output: Meta Inner1 Inner2 Inner11 Meta2 The goal was to get Event1 processed first in Inner11 state and then forward it to outer state Meta for further processing but looks like event dispatching does not work as expected. I can make it work in that way only if I put Event1 handling into Inner1 state. I'm aware of limitation (https://www.boost.org/doc/libs/1_61_0/libs/statechart/doc/rationale.html#Li… #Event dispatch to orthogonal regions) but as far I understand that considers that case when both Inner1 and Inner11 have same event processing, please correct me if I'm wrong. Is current dispatching work correctly for my code? Regards, Andrew

1 0

BOOST_DLL_ALIAS - non Latin AliasName
by Nicholas Yue 02 Jan '21

02 Jan '21

Hi, The examples I have seen so far appears to use ASCII name for AliasName I am considering providing AliasName in languages like Chinese, Korean, Japanese, Thai, Tamil, does Boost DLL allow for wstring/UNICODE as AliasName ? Cheers -- Nicholas Yue Graphics - Arnold, Alembic, RenderMan, OpenGL, HDF5 Custom Dev - C++ porting, OSX, Linux, Windows http://au.linkedin.com/in/nicholasyue https://vimeo.com/channels/naiadtools

1 0

shutdown( ) blocks forever
by Fariya F 30 Dec '20

30 Dec '20

I have a server that accepts ssl connections on port 443. I am using the boost libraries for the server implementation. Below is the code snippet: ssl_socket socket_; { // Open the acceptor with the option to reuse the address (i.e. SO_REUSEADDR). boost::asio::ip::tcp::resolver resolver(io_service_); boost::asio::ip::tcp::resolver::query query(address, port); boost::asio::ip::tcp::endpoint endpoint = *resolver.resolve(query); acceptor_.open(endpoint.protocol()); acceptor_.set_option(boost::asio::ip::tcp::acceptor::reuse_address(true)); acceptor_.bind(endpoint); acceptor_.listen(1000); start_accept(); } void server::start_accept() { new_connection_.reset( new connection(io_service_, connection_manager_, request_handler_, context_)); acceptor_.async_accept(new_connection_->socket(), boost::bind(&server::handle_accept, this, boost::asio::placeholders::error)); } void server::handle_accept(const boost::system::error_code& e) { // Check whether the server was stopped by a signal before this completion // handler had a chance to run. if (!acceptor_.is_open()) { return; } else { start(); } start_accept(); } void server::start() { socket_.async_handshake(boost::asio::ssl::stream_base::server, boost::bind(&connection::handle_handshake, this, boost::asio::placeholders::error)); if (boost::asio::placeholders::error) { // printf("Error is there. Check it\n"); } } void connection::handle_handshake(const boost::system::error_code& error) { if (!error) { DEBUG("async read some"); socket_.async_read_some(boost::asio::buffer(buffer_), boost::bind(&connection::handle_read, shared_from_this(), boost::asio::placeholders::error, boost::asio::placeholders::bytes_transferred)); } else { std::cout << "Error number: " << error.value(); std::cout << " Error message: " << error.message(); std::cout << " Error category: " << error.category().name() << std::endl; delete this; } } When I initiate multiple clients to connect to the server, most of the time the connection succeeds i.e TCP handshake followed by SSL handshake succeeds and I am able to do data transfer. However, there are times when the TCP handshake succeeds (as seen by wireshark) but the SSL request isn't responded to by my server. I am able to see the SSL handshake request coming from the client onto my server, but the server doesn't respond, neither is my handle_accept() function gets called. When I check the output of netstat, I see a lot of data pending in the Recv-Q. Below is the output of netstat -atn command on the server during one such scenario: Active Internet connections (servers and established) Proto Recv-Q Send-Q Local Address Foreign Address State tcp 15 0 0.0.0.0:443 0.0.0.0:* LISTEN tcp 0 213 10.110.112.1:443 10.110.112.2:52363 ESTABLISHED tcp 180 0 10.110.112.1:443 10.110.112.2:52624 ESTABLISHED tcp 180 0 10.110.112.1:443 10.110.112.2:52581 ESTABLISHED tcp 180 0 10.110.112.1:443 10.110.112.2:52646 ESTABLISHED tcp 180 0 10.110.112.1:443 10.110.112.2:52749 ESTABLISHED tcp 180 0 10.110.112.1:443 10.110.112.2:52824 ESTABLISHED tcp 180 0 10.110.112.1:443 10.110.112.2:52805 ESTABLISHED tcp 180 0 10.110.112.1:443 10.110.112.2:52645 ESTABLISHED tcp 0 471 10.110.112.1:443 10.110.112.2:52362 ESTABLISHED tcp 1 0 10.110.112.1:443 10.110.112.3:39129 CLOSE_WAIT tcp 183 0 10.110.112.1:443 10.110.112.3:39130 CLOSE_WAIT tcp 180 0 10.110.112.1:443 10.110.112.2:52595 ESTABLISHED tcp 183 0 10.110.112.1:443 10.110.112.3:39131 CLOSE_WAIT Upon further debugging, I see that the call to ssl socket member function shutdown() blocks sometimes forever and sometimes for at least 5 - 10 minutes due to which no further data is taken in and the recv-q indicates pending bytes. This is how my write handler is. Any help on where I am going wrong would be greatly appreciated: void connection::handle_write(const boost::system::error_code& e) { if (!e) { boost::system::error_code ec; socket_.shutdown(ec); //Code blocks here indefinitely } } Any reasons why the socket_.shutdown( ) blocks. How could I specify a timeout such that the shutdown( ) returns back after some time? Any other way of handling this? ( I know there is async_shutdown( ) but I prefer using shutdown( ) blocking handler) Any help would be greatly appreciated. Regards, Fariya

3 3

[json] Using boost.json with boost.beast
by Sean Farrow 22 Dec '20

22 Dec '20

Hi, Are there any samples of using boost.json to deserialize boost.beast responses? Thanks, Sean.

2 2

[Accumulators] How to extract P90, P99?
by Dominique Devienne 21 Dec '20

21 Dec '20

I'm already using the accumulator below to keep track of request processing times of a server. using ProcAcc = acc::accumulator_set< double, acc::stats< acc::tag::min, acc::tag::max, acc::tag::mean, acc::tag::median, acc::tag::sum > >; But now I'm interested in also extracting the P90 and P99 values, to get insight in how much of an outlier the max could be. AFAIK, the median is the P50, but it's not readily obvious to me what tag to use for the P90 or P(N) in general. Could someone help please? Thanks, --DD PS: Does accumulator allow to keep the top(N) values as well? How?

2 2

boost::hash_value not picking up std::hash specialisations
by Marc Mutz 21 Dec '20

21 Dec '20

Hi, I'm trying to move away from Qt containers in my source code, and Qt 5.15 makes that a bit easier by providing specialisations for some its types. Now I have a struct S { QLatin1String a, b; } that I'd like to hash. I can use boost::hash_combine to implement std::hash<S>, but S is actually a nested type, and with qHash(), I could just write an overload as a hidden friend, and I figured I could do the same with hash_value() (at the cost of having to specify boost::hash<S> as a unordered_map template argument). But hash_combine seems to insist on hash_value which in turn doesn't look at std::hash at all: size_t seed = 0; boost::hash_combine(seed, key.a); // ERROR: no hash_value overload for QLatin1String boost::hash_combine(seed, key.b); // Ditto return seed; expected: calls std::hash<QLatin1String>{}::op() (if it exists). It's trivial to write hash_value(QLatin1String), of course, but what's the general strategy here? Shouldn't hash_combine() look for std::hash<T> first? And, speaking as a Qt developer: do I really need to provide qHash(), std::hash<T> _and_ hash_value(T) for every hashable T?! Thanks, Marc

1 1

Weight as a function of distance at source
by Amit Prakash Ambasta 18 Dec '20

18 Dec '20

Hi, Looking at BGL implementations, weight, compare and combine are used in examine edge(e) as compare(combine(old_distance, get(weight, e)), old_distance) Additionally, old_distance = m_zero to check for negative weights etc. In my implementation, edges have a bundled property struct EdgeProp { Distance weight(Distance start) { ... } }; that returns the cumulative weight on iterating over the edge given a start distance. To use this, I should be able to pass a combine function of the form []<typename BinaryFunction>(DistanceType d, BinaryFunction f) { return f(d); } However, this approach falls apart. I've tried putting together a formal example here, but not sure why this fails. (My actual use case is where weights represent nodes in a transport system and for a person arriving at a vertex at some time Tx, there is a variable weight of using the next outbound transport = waiting_time + travel_time, where waiting_time is a function of Tx #include <boost/graph/adjacency_list.hpp> #include <boost/graph/dijkstra_shortest_paths.hpp> #include <limits> struct VProp {}; struct EProp { int multiplier; int weight(int src_distance) { return src_distance * multiplier; } }; typedef boost:: adjacency_list<boost::vecS, boost::vecS, boost::directedS, VProp, EProp> Graph; template<class G> using Vertex = boost::graph_traits<G>::vertex_descriptor; template<class G> using Edge = boost::graph_traits<G>::edge_descriptor; int main() { Graph graph; auto source = boost::add_vertex(VProp{}, graph); auto target = boost::add_vertex(VProp{}, graph); boost::add_edge(source, target, EProp{ 3 }, graph); auto index_map = get(boost::vertex_index, graph); std::vector<Vertex<Graph>> predecessors(boost::num_vertices(graph)); auto predecessor_map = boost::make_iterator_property_map(predecessors.begin(), index_map); std::vector<int> distances(boost::num_vertices(graph)); auto distance_map = boost::make_iterator_property_map(distances.begin(), index_map); auto compare = [](int lhs, int rhs) -> bool { return lhs < rhs; }; auto combine = []<typename BinaryFunction>(int dst, BinaryFunction f) -> int { return f(dst); }; boost::dijkstra_shortest_paths( graph, source, predecessor_map, distance_map, boost::weight_map(boost::get(&EProp::weight, graph)), index_map, compare, combine, std::numeric_limits<int>::min(), std::numeric_limits<int>::max(), boost::default_dijkstra_visitor()); }

2 3

boost::regex: regex meta data or AST for regex?
by Frank Bergemann 16 Dec '20

16 Dec '20

in concrete: Is it possible to not only get the #no of groups (sub-expressions) via basic_regex::mark_count(), but also their position (begin() / end() iterators) in the given regex string (c'tor argument)? more general: Can an AST be created for a the given regex string (c'tor argument)? E.g with boost::spirit?

1 0

how to get progress indicator during phrase_parse() of boost::spirit::x3?
by Lane 15 Dec '20

15 Dec '20

I am using boost::spirit:x3, shown below. I use it to import/parse some very large files and am trying to find a way to get some sort of progress from it so that I can use for a progress bar in app, but so far I've been unable to see a way. namespace parser { namespace x3 = boost::spirit::x3; using namespace x3; auto const string = lexeme[+graph]; auto const point = rule<struct _p, ast::point> {"point"} = int_ >> double_ >> double_ >> double_; auto const element = rule<struct _e, ast::element> {"element"} = int_ >> string >> int_ >> int_ >> int_ >> eol >> *(int_ >> int_ >> int_); auto lines = [](auto p) { return *(p >> eol); }; auto const input = lines(point) >> lines(element); } And I import a file like so. { namespace x3 = boost::spirit::x3; mapped_file_source map(filePath); std::istringstream iss(map.data()); map.close(); boost::spirit::istream_iterator iter(iss >> std::noskipws), eof; bool ok = phrase_parse(iter, eof, smf::parser::input, x3::blank, types); if (iter != eof) { // ... } } Would anyone have thoughts on how to get some sort of indicator during the parsing?

1 0

[Beast] Client connection times out after 5s. How to avoid?
by Dominique Devienne 15 Dec '20

15 Dec '20

Hi. Continuing my explorations of Boost.Beast. So now I have: * a small Boost.Beast HTTP server (based on async_http_server example), and * a small Boost.Beast HTTP client (based on sync_http_client example). This works, in that I can start the client (wrapped in a helper class), make several requests, and close the client. But until now, the client was short-lived, so no problem. (the server was started too of course, and long lived as expected). Now I'm embedding that HTTP client into another (WebSocket) server, which uses that same wrapper class above, successfully connects to the HTTP server on startup, and now waits for WebSocket connections, at which time it's supposed to make HTTP requests to the HTTP server for various reasons. Problem is, the HTTP client times out after 5s. While I want it to be long lived. I've read Vinnie's answer in https://stackoverflow.com/a/56880415/103724 about sync operation not having timeouts, but I don't want to control timeouts of individual requests here (for now at least), I want to not have the underlying socket not timeout on its own, the same way a WebSocket does not timeout either. Is that possible? Who controls that 5s timeout? Would switching to an async HTTP client make any difference? Sounds to me that it would allow me to control timeouts of requests, but would it make any difference to the socket timeout described above? Thanks, --DD

2 4

[Beast] Slow HTTP connect on Windows. Normal?
by Dominique Devienne 14 Dec '20

14 Dec '20

Hi. I'm writing a small interaction between: 1) a Boost.Beast-based HTTP server (based on http_server_async.cpp example) 2) a Boost.Beast-based HTTP client (based on http_client_sync.cpp example) When I log the time it takes to resolve the server address and connect to it, then issue my HTTP request, it takes over 1 second (Win10, VS2019, C++17, Release, localhost for both client and server): 2020-11-25T09:46:37.473936 Prologue in 0.001s 2020-11-25T09:46:37.482470 Resolved in 0.008s 2020-11-25T09:46:38.506180 Connected in 1.023s 2020-11-25T09:46:38.509607 OK: Authenticated; in 0.003s While the same on Linux (RH7.5) is just over 2ms: 2020-11-25T09:45:45.515926 Prologue in 0.000s 2020-11-25T09:45:45.517083 Resolved in 0.001s 2020-11-25T09:45:45.517550 Connected in 0.000s 2020-11-25T09:45:45.518010 OK: Authenticated; in 0.000s That's a huge difference! Almost 500x... And when I contact the same HTTP server on Windows, but from Chrome this time, it takes about 300ms, and if I hit reload rapidly, the time jumps around to as low as 3ms, and as high as 300ms (the same initial delay), with ~50ms and ~100ms in between. (I also see several different connections being established, for some reason...) I've seen similar differences between Windows and Linux connection times, but with WebSocketPP-based client and server this time, also based on Boost.ASIO. Q1: Am I doing anything wrong? I.e. is this "normal" somehow? Q2: How come Chrome, on Windows too, is 3x faster than ASIO-based clients, with the same Beast-based server? Given the high connect time on Windows, I thought I'd try to keep the connection open on the client, and issue several send-request/read-response pairs, using the Beast-based (sync) HTTP client, but only the first one works correctly, the 2nd errors out with: Error: An established connection was aborted by the software in your host machine I suspect it is a user-error, with the server closing the connection, despite the Keep-Alive HTTP header being present server-side on the request. Q3: Given the Beast HTTP examples I'm based off, would anyone have suggestions on what changes are necessary to allow the client issuing several (non-overlapping) requests to the server, on the same connection? (since connecting is so expensive). Q4: And for better performance, what about overlapping request/response pairs, with HTTP pipelining. How to set that up on the client and server with Beast? Thanks for any help on this. --DD PS: Great examples in Boost.Beast BTW. Thanks Vinnie.

4 9

boost.python and python3 64 bit
by Cruz, Petagay [USA] 14 Dec '20

14 Dec '20

Does Boost Python support using python 3 64 bit? if yes, how do i build say Boost.Python 1.74? What is the 'b2' command and then the bjam command for the tutorial example? Thank you

1 0

Boost Asio support for OpenSSL 1.1.1
by Gehrs, Volker 14 Dec '20

14 Dec '20

Hi all, we are using boost.asio on windows. Does boost.asio support OpenSSL 1.1.1 in any new version? I could not find a hint in the Revision history of boost.asio. https://www.boost.org/doc/libs/1_75_0/doc/html/boost_asio/history.html Thanks in advance!

2 1

unresolved external symbol __DllMainCRTStartup@12
by Cruz, Petagay [USA] 13 Dec '20

13 Dec '20

I have built boost python. I am trying to use the boost_1_74_0\libs\python\example\tutorial example. I keep getting a fail in the build of the dll: msvc.link.dll bin\msvc-14.0\debug\boost_python.dll LINK : warning LNK4001: no object files specified; libraries used LINK : error LNK2001: unresolved external symbol __DllMainCRTStartup@12 bin\msvc-14.0\debug\boost_python.dll : fatal error LNK1120: 1 unresolved externals call "bin\standalone\msvc\msvc-14.0\msvc-setup.bat" x86 >nul link /NOLOGO /INCREMENTAL:NO /DLL /DEBUG /MACHINE:X86 /MANIFEST:EMBED /subsystem:console /out:"bin\msvc-14.0\debug\boost_python.dll" /IMPLIB:"bin\msvc-14.0\debug\boost_python.lib" @"bin\msvc-14.0\debug\boost_python.dll.rsp" Any advice as to what might be wrong. My Visual Studio 2019 does not have the corelibc.lib. I only find that under 'WinCE' libs, and so not found when I compile msvc 14... thanks

1 0

Where to find a complete boost example using ICL (intel 64bit compiler for windows 10)?
by Mehdi Est 13 Dec '20

13 Dec '20

Hi Everyone, Where can I find a complete boost example using ICL (intel 64bit C/C++ compiler for windows)? I would like to do it in header-only mode. Right now, I am compiling and linking using the below-mentioned flags/libraries. However, when I run the code I seem to experience deadlock because the execution stalls. Please let me know your valuable comments. Regards *Compile Flags* icl -I"C:/Program Files (x86)/IntelSWTools/sw_dev_tools/compilers_and_libraries_2020.2.254/windows/compiler/include" -I/../boost_1_73_0 -I../../../boost_1_73_0 -Qstd=c++0x -Qdiag-error-limit:3 -debug:all -Zi -Z7 -ZI -MDd -D_DEBUG -DBOOST_STACKTRACE_USE_WINDBG -Fo:../../Debug/obj/test.obj -c test.cpp *Link Flags* xilink -LIBPATH:"c:\Program Files (x86)\Windows Kits\10\Lib\10.0.19041.0\um\x64" -out:Debug/test.exe test.obj ole32.lib dbgeng.lib

1 0

[release] Boost 1.75.0
by Marshall Clow 11 Dec '20

11 Dec '20

Release 1.54.0 of the Boost C++ Libraries is now available. These open-source libraries work well with the C++ Standard Library, and are usable across a broad spectrum of applications. The Boost license encourages both commercial and non-commercial use. This release contains 1 new library and numerous enhancements and bug fixes for existing libraries. For details, including download links, see <http://www.boost.org/users/news/version_1.75.0> You can also download directly from: <https://dl.bintray.com/boostorg/release/1.75.0/> To install this release on your system, see <http://www.boost.org/doc/libs/release/more/getting_started/index.html> Thanks to everyone who participated in this release. Thanks, -- The Boost Release Team Marshall Clow, Glen Fernandes, Michael Caisse

3 3

Fwd: [Beast] Slow HTTP connect on Windows. Normal?
by Dominique Devienne 11 Dec '20

11 Dec '20

Oops, this was meant for the list of course. --DD ---------- Forwarded message --------- From: Dominique Devienne <ddevienne(a)gmail.com> Date: Fri, Dec 11, 2020 at 6:54 PM Subject: Re: [Boost-users] [Beast] Slow HTTP connect on Windows. Normal? To: Vinnie Falco <vinnie.falco(a)gmail.com> On Wed, Nov 25, 2020 at 7:43 PM Vinnie Falco <vinnie.falco(a)gmail.com> wrote: > On Wed, Nov 25, 2020 at 2:55 AM Dominique Devienne via Boost-users > <boost-users(a)lists.boost.org> wrote: > > Given the high connect time on Windows, I thought I'd try to keep the > connection open on the client, and issue several send-request/read-response > pairs, using the Beast-based (sync) HTTP client, but only the first one > works correctly, the 2nd errors out with: > > > > Error: An established connection was aborted by the software in your > host machine > > This means that the server closed the connection. Are you setting > HTTP/1.1 in the request? For HTTP/1.1 the default is to enable > keep-alive. But for 1.0 the default is to close the connection. > Sorry for the delay. Just getting back to this. Yes, I'm in 1.1, and I verified that the request has Keep-Alive, and I'm (or the example, I don't recall) is setting the same value on the response. > it sounds like your connection is being closed after one request. Beast > definitely supports keep-alive, so this is certainly user error. > Please inspect the request/response messages taking place and post > them on the list unmodified (use a wire sniffer for this if necessary) > if you are still having problems. > Debugging this, I can see that the close arg to on_write is true, despite the Keep-Alive on the response. That response has an empty_body BTW, in case it matters. This route just replies 200 OK or 403 Forbidden, there's no body to return, only the headers matter to the client. The reason why the connection is closed after the 1st request seems to be because of need_eof(). The async server example has something like this in `send()`: template <typename RES> void send(RES&& msg) { // The lifetime of the message has to extend // for the duration of the async operation so // we use a shared_ptr to manage it. auto sp = std::make_shared<RES>(std::move(msg)); // Store a type-erased version of the shared // pointer in the class to keep it alive. res_ = sp; bool need_eof = sp->need_eof(); ctx_.out() << "send: sp->need_eof() = " << need_eof << std::endl; // Write the response http::async_write( stream_, *sp, beast::bind_front_handler( &session::on_write, shared_from_this(), sp->need_eof() ) ); } And `need_eof()` is true indeed. Which thus calls `on_write()` with `bool close = true`, resulting in a `do_close()` instead of waiting for the next request: void on_write( bool close, beast::error_code ec, std::size_t bytes_transferred ) { boost::ignore_unused(bytes_transferred); if (ec) { return; // fail(ec, "write"); } if (close) { // This means we should close the connection, usually because // the response indicated the "Connection: close" semantic. ctx_.out() << "on_write: close()" << std::endl; return do_close(); } // We're done with the response so delete it res_.reset(); // Read another request do_read(); } I stepped into `need_eof()`, and all conditions of the `if` are false, resulting in the `return true` at the end. template<bool isRequest, class Body, class Fields> bool message<isRequest, Body, Fields>:: need_eof(std::false_type) const { // VFALCO Do we need a way to let the caller say "the body is intentionally skipped"? if( this->result() == status::no_content || this->result() == status::not_modified || to_status_class(this->result()) == status_class::informational || has_content_length() || chunked()) return ! keep_alive(); return true; } So is the issue having an empty_body? I'm not supposed to have one on a GET? BTW, I tried commenting out the `do_close()` inside `on_write()`, just to see what happens, and it still doesn't work, with the same error, but an additional delay (timeout?) I think. Here's the response I'm sending: ctx_.out() << "Sending response: 200 OK" << std::endl; http::response<http::empty_body> res{http::status::ok, req_.version()}; res.set(http::field::server, BOOST_BEAST_VERSION_STRING); res.keep_alive(req_.keep_alive()); ctx_.out() << "on_read: res.keep_alive() = " << res.keep_alive() << std::endl; return send(std::move(res)); I'm fairly sure it's user-error, but it's not easy to figure out for a Beast novice like myself. --DD

2 2

Reminder that Outcome v2.2 is to become Boost.Outcome
by Niall Douglas 11 Dec '20

11 Dec '20

After three Boost releases and a year of warning, this is a reminder that Outcome v2.2 is to replace v2.1 as Boost.Outcome. This is a breaking change, all existing Boost.Outcome code shall need to be upgraded as of Boost 1.76 onwards. Changes: https://www.boost.org/doc/libs/1_75_0/libs/outcome/doc/html/changelog/v22.h… Upgrade guide: https://www.boost.org/doc/libs/1_75_0/libs/outcome/doc/html/changelog/upgra… You should see the merge land into boostorg/outcome next few days. It'll take some weeks to upgrade the tutorial and documentation. Niall

1 0

Boost.Beast base64 decode
by Dominique Devienne 11 Dec '20

11 Dec '20

I'm decoding a Java Web Token, composed of 3 separate base64 encoded parts (header.payload.signature). Before I was using Boost.Serialization: using namespace boost::archive::iterators; using It = transform_width<binary_from_base64<std::string::const_iterator>, 8, 6>; std::string tmp(It(std::begin(base64_str)), It(std::end(base64_str))); return boost::algorithm::trim_right_copy_if(tmp, [](char c) { return c == '\0'; }); But since I'm already using Boost.Beast, I thought I'd drop the above dependency, and use this instead: using namespace boost::beast::detail; std::string decoded(base64::decoded_size(base64_str.size()), '\0'); auto rc = base64::decode(decoded.data(), base64_str.data(), base64_str.size()); decoded.resize(rc.first); But turns out some (all?) JWTs do not include the trailing equals that "proper" base64 should have. And in that case, Beast's rc.first does not include the last character, which I can still see in decoded variable prior to the .resize() in the debugger. Here's the payload part: eyJwYXNzd29yZCI6IlAiLCJ1c2VybmFtZSI6IlUifQ What it should decode to: {"password":"P","username":"U"} What Beast's decode yields: {"password":"P","username":"U" Is this on purpose? Could Beast's base64::decode() be changed to be more lenient about the absence of trailing equals from the base64 encoded string? JWT handling seems like a natural fit within the context of Beast, and although this is an implementation detail, it would seem logical for decode() to cope with that, no? Thanks, --DD

3 4

Boost 1.75.0 Release Candidate 1 -- macOS (gcc 10.2.0)
by DV Henkel-Wallace 10 Dec '20

10 Dec '20

> Date: Thu, 3 Dec 2020 06:54:13 -0800 > From: Marshall Clow <mclow.lists(a)gmail.com <mailto:mclow.lists@gmail.com>> > > [release] Boost 1.75.0 Release Candidate 1 > Built fine on macOS 11.0.1 using brew-installed g++-10 ./b2 cxxstd=2a boost.locale.icu=off boost.locale.std=off threading=multi -sNO_COMPRESSION=1 Darwin KA-19.local 20.1.0 Darwin Kernel Version 20.1.0: Sat Oct 31 00:07:11 PDT 2020; root:xnu-7195.50.7~2/RELEASE_X86_64 x86_64 gcc version 10.2.0 (Homebrew GCC 10.2.0) Target: x86_64-apple-darwin19 Lots of deprecated warnings for #pragma GCC diagnostic ignored "-Wdeprecated-copy", use of boost/bind.hpp and boost/detail/iterator.hpp. But otherwise OK. Net: Apple's clang and g++ generated pretty similar warnings. Clang-11 did not.

1 0

Boost 1.75.0 Release Candidate 1 -- macOS (system compiler)
by DV Henkel-Wallace 10 Dec '20

10 Dec '20

> Date: Thu, 3 Dec 2020 06:54:13 -0800 > From: Marshall Clow <mclow.lists(a)gmail.com <mailto:mclow.lists@gmail.com>> > > [release] Boost 1.75.0 Release Candidate 1 > Built fine on macOS 11.0.1 using the system compiler installed with latest Xcode (12.2) ./b2 cxxstd=2a boost.locale.icu=off boost.locale.std=off threading=multi -sNO_COMPRESSION=1 Darwin KA-19.local 20.1.0 Darwin Kernel Version 20.1.0: Sat Oct 31 00:07:11 PDT 2020; root:xnu-7195.50.7~2/RELEASE_X86_64 x86_64 Apple clang version 12.0.0 (clang-1200.0.32.27) Target: x86_64-apple-darwin20.1.0 Lots of deprecated warnings for #pragma GCC diagnostic ignored "-Wdeprecated-copy", use of boost/bind.hpp and boost/detail/iterator.hpp. But otherwise OK.

1 0

Boost 1.75.0 Release Candidate 1 -- macOS
by DV Henkel-Wallace 10 Dec '20

10 Dec '20

> Date: Thu, 3 Dec 2020 06:54:13 -0800 > From: Marshall Clow <mclow.lists(a)gmail.com <mailto:mclow.lists@gmail.com>> > > > [release] Boost 1.75.0 Release Candidate 1 > Built fine on macOS 11.0.1 using llvm 11.0.0 ./b2 cxxstd=2a boost.locale.icu=off boost.locale.std=off threading=multi -sNO_COMPRESSION=1 Darwin KA-19.local 20.1.0 Darwin Kernel Version 20.1.0: Sat Oct 31 00:07:11 PDT 2020; root:xnu-7195.50.7~2/RELEASE_X86_64 x86_64 clang version 11.0.0 Target: x86_64-apple-darwin20.1.0 Lots of deprecated warnings for use of boost/bind.hpp and boost/detail/iterator.hpp as well as using enums as bitfields. But otherwise OK.

2 1

QT MinGW32 : bootstrap stacktrace (header only) not showing function names and lines numbers shows only address
by Mehdi Est 05 Dec '20

05 Dec '20

Hi Everyone, I am trying to print stack-trace using boost *HEADER-ONLY. *I am using descriptions under Configuration and Build <https://www.boost.org/doc/libs/1_74_0/doc/html/stacktrace/configuration_and…> to compile a simple code using QT MinGW32 I also use the below macros to tune boost: -DBOOST_STACKTRACE_USE_WINDBG -DBOOST_STACKTRACE_USE_ADDR2LINE -DBOOST_STACKTRACE_ADDR2LINE_LOCATION I have no clue why the function names and line numbers are not showing up. Any comment is appreciated. Mike *Below are compile and build instructions:* g++ -g3 -DBOOST_STACKTRACE_USE_WINDBG -DBOOST_STACKTRACE_USE_ADDR2LINE -DBOOST_STACKTRACE_ADDR2LINE_LOCATION=C:\Qt_5_12\Tools\mingw730_32\bin\addr2line.exe -I../../../boost_1_73_0 -c main.cpp -omain.o g++ main.o -o stack_traces.exe -L"C:\Program Files (x86)\Windows Kits\10\Lib\10.0.19041.0\um\x86" -L"C:\temp\libbacktrace" -lkernel32 -luser32 -lgdi32 -lwinspool -lcomdlg32 -ladvapi32 -lshell32 -lole32 -luuid -lodbc32 -lodbccp32 -lDbgEng *And here is the output ... * 0# 0x00402C75 in stack_traces 1# 0x00401602 in stack_traces 2# 0x004016CE in stack_traces 3# 0x0040138B in stack_traces 4# _BaseThreadInitThunk in KERNEL32 5# _RtlGetAppContainerNamedObjectPath in ntdll 6# _RtlGetAppContainerNamedObjectPath in ntdll 1 + 2 = 3 *The code (main.cpp)* Is fairly simple as below: #include <iostream> #include <boost/stacktrace.hpp> double add(double a, double b){ std::cout << boost::stacktrace::stacktrace(); std::cout << a << " + " << b << " = " << (a+b) << std::endl; return a+b; } int main(){ add(1,2); return 0; }

2 2

[release] Boost 1.75.0 Release Candidate 1
by Marshall Clow 04 Dec '20

04 Dec '20

[release] Boost 1.75.0 Release Candidate 1 The first release candidates for the 1.75.0 release are now available at: <https://dl.bintray.com/boostorg/release/1.75.0/source/> The SHA256 checksums are as follows: caf36d7c13b3d8ce62282a64a695113945a13b0f1796a45160726d04295f95ed boost_1_75_0_rc1.zip aeb26f80e80945e82ee93e5939baebdca47b9dee80a07d3144be1e1a6a66dd6a boost_1_75_0_rc1.tar.gz 953db31e016db7bb207f11432bef7df100516eeb746843fa0486a222e3fd49cb boost_1_75_0_rc1.tar.bz2 3a8b314871646e7404886736273c053278ba71b11347f72d4751411d65d6d1a5 boost_1_75_0_rc1.7z 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 4

Boost.Numeric.Interval: Please specify rounding control mechanism
by Bastien Commelongue 01 Dec '20

01 Dec '20

Hello, I am building an app for IOS (ARM) and I had this issue while compiling: *Boost.Numeric.Interval: Please specify rounding control mechanism.* C99 version should be used in this case but __USE_ISOC99 is not defined. Modifying the condition with this code (using __cplusplus) fixed the issue: *boost/numeric/interval/hw_rounding.hpp(36)* *#if defined(BOOST_NUMERIC_INTERVAL_NO_HARDWARE) && (defined(__USE_ISOC99) || defined(__MSL__) || (defined __cplusplus && __cplusplus >= 201103L))# include <boost/numeric/interval/detail/c99_rounding_control.hpp>#endif* Let me know if I missed something or if you plan to integrate this modification in a next version. Cheers, Bastien Commelongue

2 1

PolyCollection
by Brian Wood 30 Nov '20

30 Nov '20

Shalom Hey, is anyone using PolyCollection? I have serialization support for it: https://github.com/Ebenezer-group/onwards/tree/master/example/poly If you considered it, but chose an alternative library, what was the reason? Thanks. Brian Ebenezer Enterprises - Enjoying programming again. https://webEbenezer.net

1 0

Re: [Boost-users] [multi_array] Feature request: constructor and resize from values
by DV Henkel-Wallace 30 Nov '20

30 Nov '20

If an object does not have a default constructor what could it mean to have a block of memory holding one that has not been initialized? How would your program know if the object had been properly initialized or not? There are three ways to address this: 1 - A pointer, as already mentioned. A null pointer means the spot does not refer to ("contain") a valid object -- or any object at all. 2 - use a variant 3 - create a default constructor (which you could do by changing the signature of your constructor to something like (int = 0) or (int = -1) assuming those values are invalid). In all cases, regardless of semantics or implementation you'll either have to check at runtime for a valid object OR, if you know for other reasons which locations are valid, use the default constructor with any value you'd like. If you don't want to use pointers there are a couple of other possibilities: > > Date: Sun, 22 Nov 2020 12:06:04 +0100 > From: Eugenio Bargiacchi <svalorzen(a)gmail.com <mailto:svalorzen@gmail.com>> > > Ah, sorry, I thought it would have been automatically clear. Consider this > example: > > class A { > public: > A(int) {} > }; > > boost::multi_array<A,2> array(boost::extents[2][2]); // Compiler error > boost::multi_array<A,2> array(boost::extents[2][2], A(3)); // What I would > like > > array.resize(boost::extents[2][2]); // Again, compiler error > array.resize(boost::extents[2][2], A(2)); // What I would like > > The variable `array` cannot be constructed in any way, as multi_array will > try to default-construct it, and that will fail. Trying to simply create > `array` with its default constructor works (although it will obviously be a > zero-sized array), but when trying to resize it (to actually store things), > the same thing will happen.

2 1

[multi_array] Feature request: constructor and resize from values
by Eugenio Bargiacchi 22 Nov '20

22 Nov '20

I'd love to be able to use multi_array with classes that do not have a default constructor. At the moment, this is impossible, as both the constructor and resize functions only take extents as arguments (and possibly some other options), but no value_type, as for example std::vector does. Thus, trying to store objects without a default constructor in a multi_array results in hard compiler errors, with no workaround that I know of. This happens to me fairly often, as I use multi_array to organize sets of complex objects. If there is a technical reason why this is not possible, I would also be happy to learn it. Best regards, Eugenio Bargiacchi

2 2

[xpressive] I got a crash in after i upgrade from 1.44 to 1.74
by forston_shi＠trendmicro.com 20 Nov '20

20 Nov '20

Hi Boost Users I met a crash in following code after I upgrade from 1.44 to 1.74, When I used "-O1 -DNDEBUG" to compile, it will crash. But when I used "-O1" or "-DNDEBUG" or "-O0 -DNDEBUG", it will not crash. In 1.44, all of them are ok. My GCC version is 4.1.2 and test in redhat-AS 4 32 bit. callstack #0 at ./boost_1_74_0_bk/boost/xpressive/detail/static/transmogrify.hpp:160 160 char const *name_end = m.name_ + std::strlen(m.name_); #1 at ./boost_1_74_0_bk/boost/proto/transform/detail/preprocessed/fold_impl.hpp:80 #2 at ./boost_1_74_0_bk/boost/proto/transform/detail/preprocessed/fold_impl.hpp:80 #3 at ./boost_1_74_0_bk/boost/xpressive/detail/static/compile.hpp:79 #4 at ./boost_1_74_0_bk/boost/xpressive/detail/static/compile.hpp:99 #5 0x08049d5f in main () at ./boost_1_74_0_bk/boost/xpressive/basic_regex.hpp:252 Can you help to check this problem? Best regards Forston callstack Following is source code. #include <boost/xpressive/basic_regex.hpp> #include <boost/xpressive/regex_primitives.hpp> #include <boost/xpressive/match_results.hpp> #include <boost/xpressive/regex_algorithms.hpp> int main(int argc, char* argv[]) { std::wstring uri_string = L"https://192.168.1.1/test"; printf("begin regex_match %ls \n ", uri_string.c_str()); using namespace boost::xpressive; static wsregex const uri_regex = bos >> (s1 = (alpha >> *(alnum | L'+' | L'-' | L'.'))) >> L"://" >> (s2 = *(alnum | L'-' | L'.' | L':' | L'@' | L'[' | L']' | L'_')) >> !(as_xpr(L'/') >> (s3 = (*_))) >> eos ; wsmatch result; try { if (!regex_match(uri_string, result, uri_regex)) { printf( "regex_match failed %ls \n ", uri_string.c_str()); return -1; } } catch (std::exception& e) { printf("regex_match failed %ls \n ", uri_string.c_str()); return -1; } printf("end regex_match success %ls \n ", uri_string.c_str()); return 0; } TREND MICRO EMAIL NOTICE The information contained in this email and any attachments is confidential and may be subject to copyright or other intellectual property protection. If you are not the intended recipient, you are not authorized to use or disclose this information, and we request that you notify us by reply mail or telephone and delete the original message from your mail system. For details about what personal information we collect and why, please see our Privacy Notice on our website at: Read privacy policy<http://www.trendmicro.com/privacy>

1 0

[asio] Prevent socket inheritance on Windows
by Klebsch, Mario 17 Nov '20

17 Nov '20

Hello everybody, I am using boost as communication framework in a library for Windows. I am getting problems, when the client code, that uses our library, creates windows processes and inherits handles, e.g. by using popen(). I currently observing two problems. 1. Even though my library has closed the socket, the peer keeps an active connection. 2. When there is a pending async read operation, calling close() does not lead to the read handler being invoked with an error. My library closes a socket in its shutdown process and because it also terminates the io_service during shutdown, it waits for the termination of the pending read operation. The second problem is the one, that is visible to the client, since our library hands during shutdown. Unfortunately it is not triggered by just inheriting a socket handle to a child process. I know, the socket handle gets inherited to the child process and when I kill the child process, the pending async operation terminates. I also have seen the pending read operation to terminate, then the peer system sends some data. The data seems to be read fine, although the socket has already been closed by our library. The io_service is blocked in the call to GetQueuedCompletionStatus() on its io completion port. It seems, the io completion port still is linked the the socket, although the socket has been closed. The problem is triggered reliably, when using my fully integrated library, but I have not yet managed to write a small simple sand alone program to demonstrate this problem. * Does anybody on this mailing list has a clue, what may cause the 2nd problem, where the async operation does not terminate upon closing the socket. * Does anybody know of a reliable way to prevent an asio socket from being inherited. I found some web pages mentioning WSA_FLAG_NO_HANDLE_INHERIT, but have not found a way to get boots to use this flag other than patching my boost source code. Thanks to everybody, Mario -- Mario Klebsch Actia I+ME GmbH Mario.klebsch(a)ime-actia.de<mailto:Mario.klebsch@ime-actia.de> Dresdenstrasse 17/18 Fon: +49 531 38 701 716 38124 Braunschweig Fax: +49 531 38 701 88 Germany

1 0

[release] Boost 1.74.0 beta 1 released
by Marshall Clow 14 Nov '20

14 Nov '20

Boost release 1.75.0 beta 1 is now available at: <https://dl.bintray.com/boostorg/beta/1.75.0.beta1/source/> The SHA256 checksums are as follows: 3f01d3e5dc822e151892040d4667e364ea808d208d2e49cc7a1802bd4da3d4cc boost_1_75_0_b1.7z 9b75a80f845d4ae312e3c9151ffdfe3fed450973095e0a15c68d0be394f2f2df boost_1_75_0_b1.tar.bz2 123519d4b056fbbd69e452db880abe2c7e55f21779d44a4d6b6c714d5c13c3ee boost_1_75_0_b1.tar.gz b73e01d22d5b3d2ff82f14a371e3974fab30448bf6ff5ac8b9c829539a19c2d7 boost_1_75_0_b1.zip For details of what's in the release, see <https://www.boost.org/users/history/version_1_75_0.html>. Please download the beta, give it a try, and report any problems you encounter. Thanks, -- The Boost Release Team

1 0

[release] Boost 1.75.0 Beta 1 Release Candidate 2
by Marshall Clow 13 Nov '20

13 Nov '20

The second release candidates for the 1.75.0 beta release are now available at: <https://dl.bintray.com/boostorg/beta/1.75.0.beta1/source/> The SHA256 checksums are as follows: 3f01d3e5dc822e151892040d4667e364ea808d208d2e49cc7a1802bd4da3d4cc boost_1_75_0_b1_rc2.7z 9b75a80f845d4ae312e3c9151ffdfe3fed450973095e0a15c68d0be394f2f2df boost_1_75_0_b1_rc2.tar.bz2 123519d4b056fbbd69e452db880abe2c7e55f21779d44a4d6b6c714d5c13c3ee boost_1_75_0_b1_rc2.tar.gz b73e01d22d5b3d2ff82f14a371e3974fab30448bf6ff5ac8b9c829539a19c2d7 boost_1_75_0_b1_rc2.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

Compile issues when cross compiling for iOS with external dependencies
by Ardavon Falls 10 Nov '20

10 Nov '20

When attempting to cross-compile boost 1.69.0 for iOS (with clang) and using external dependencies it fails to compile because when it tests to see if the dependencies are valid, it fails to compile the test program correctly due to it attempting to add incorrect linker flags. I tried modifying the boost.build to not add those flags but it seemed to unravel a rat's nest of issues (attempting to link with librt even though its for iOS, compiled the test program for x86 and not arm, etc.., etc..) The error I keep getting is... ld: unknown option: --start-group Thank you for your help. I am using the following b2 options.. ./b2 --prefix=/Users/afalls/delete-me/build-boost/install/ \ --build-dir=/Users/afalls/delete-me/build-boost/build/ \ --user-config=/Users/afalls/delete-me/build-boost/ios-config.jam \ --with-math \ --with-wave \ --with-container \ --with-contract \ --with-exception \ --with-graph \ --with-iostreams \ --with-locale \ --with-log \ --with-program_options \ --with-random \ --with-regex \ --with-mpi \ --with-serialization \ --with-coroutine \ --with-fiber \ --with-context \ --with-timer \ --with-thread \ --with-chrono \ --with-date_time \ --with-atomic \ --with-filesystem \ --with-system \ --with-graph_parallel \ --with-stacktrace \ --with-test \ --with-type_erasure \ -q \ -j 16 \ toolset=clang \ threading=multi \ architecture=arm \ abi=aapcs \ binary-format=mach-o \ address-model=64 \ cxxflags="${IOS_CXXFLAGS}" \ cflags="${IOS_CFLAGS}" \ target-os=iphone \ link=static \ variant=release \ define=_LITTLE_ENDIAN \ install My user-config.jam file is below... import os ; using clang : : /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/clang++ -arch arm64 -DBOOST_AC_USE_PTHREADS -DBOOST_SP_USE_PTHREADS -Wno-unused-local-typedef -Wno-nullability-completeness -miphoneos-version-min=9.0 -fPIC : <stripper> <root>/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk <architecture>arm <target-os>iphone <include>/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS.sdk/usr/include ; using zlib : 1.2.11 : <include>/Users/afalls/.conan/data/zlib/1.2.11/channel/niantic/package/d522642044ded35b1d89ab2201a41e2c5d74a0b0/include <search>/Users/afalls/.conan/data/zlib/1.2.11/channel/niantic/package/d522642044ded35b1d89ab2201a41e2c5d74a0b0/lib <name>z ; using lzma : 5.2.4 : <include>/Users/afalls/.conan/data/xz_utils/5.2.4/channel/niantic/package/d522642044ded35b1d89ab2201a41e2c5d74a0b0/include <search>/Users/afalls/.conan/data/xz_utils/5.2.4/channel/niantic/package/d522642044ded35b1d89ab2201a41e2c5d74a0b0/lib <name>lzma ; using bzip2 : 1.0.8 : <include>/Users/afalls/.conan/data/bzip2/1.0.8/channel/niantic/package/d522642044ded35b1d89ab2201a41e2c5d74a0b0/include <search>/Users/afalls/.conan/data/bzip2/1.0.8/channel/niantic/package/d522642044ded35b1d89ab2201a41e2c5d74a0b0/lib <name>bz2 ; using zstd : 1.4.4 : <include>/Users/afalls/.conan/data/zstd/1.4.4/channel/niantic/package/d522642044ded35b1d89ab2201a41e2c5d74a0b0/include <search>/Users/afalls/.conan/data/zstd/1.4.4/channel/niantic/package/d522642044ded35b1d89ab2201a41e2c5d74a0b0/lib <name>zstd ;

1 0

Boost version not matching according to the manual
by Arnab Chaudhuri 08 Nov '20

08 Nov '20

To whom it may concern, I have installed boost and to the version is 1.65.1.0ubuntu1 . It is written while installing that the minimum requirement is 1.66. Can you please tell me how to update my version. The commands I used to install boost are as follows: *sudo apt install libboost-dev**sudo apt install libboost-all-dev* *Thanking you,* *Arnab Chaudhuri.*

1 0

Validating downloads on Windows
by Kenneth Porter 08 Nov '20

08 Nov '20

I thought I had a corrupted download and wanted to relate my experience on how to validate the zip file downloads on Windows. The Boost archives (tar, zip, etc.) all have a matching small .json file that contains a SHA256 hash of the archive file. Under Windows 10, you can use certutil.exe from a command line to compute the hash for the archive and compare it to the value in the .json file: C:\Users\ken\Downloads>certutil -hashfile boost_1_75_0_b1_rc1.zip SHA256 SHA256 hash of boost_1_75_0_b1_rc1.zip: 07ddca7c39ea9152bad73bee4f10f2c9c8e3a2d7e153aa945a343f83eca5db59 CertUtil: -hashfile command completed successfully. (I thought my download was corrupted because I was using an ancient version (5.50) of InfoZip's unzip program and it was reporting errors. I updated to version 6 and it unpacked the same file just fine.)

1 0

[release] Boost 1.75.0 Beta 1 Release Candidate 1
by Marshall Clow 07 Nov '20

07 Nov '20

The first release candidates for the 1.75.0 beta release are now available at: <https://dl.bintray.com/boostorg/release/1.75.0.beta1/source/> The SHA256 checksums are as follows: c271f488c7c8de7c147bf8675d578fb2f06c6c171d9547c5a40cddccb9f2a6c4 boost_1_75_0_b1_rc1.7z 0db0944e9d2250907e011900eea304ca055d1c418d38b3fbb1eee692a6b851a6 boost_1_75_0_b1_rc1.tar.bz2 624bd6b03d86bf1387b4e8927dab16b4198f255f15dd71d6a8c1c5ec270584b3 boost_1_75_0_b1_rc1.tar.gz 07ddca7c39ea9152bad73bee4f10f2c9c8e3a2d7e153aa945a343f83eca5db59 boost_1_75_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

2 4

Why did ip::basic_resolver::query get depreciated in 1.66?
by Luke Knoble 06 Nov '20

06 Nov '20

I ask because I replaced its return value with an endpoint in a tcp resolver function and my dns resolution started working..! Cheers, Luke Knoble

1 0

Boost 1.74: Coroutines2 on MSVC 2019 / C++20
by Daniel Petrovic 29 Oct '20

29 Oct '20

Using Boost 1.74. By using coroutines 2 on MSVC 2019 (v16.7.7) with C++20 there is a compilation issue regarding result_of which is replaced by invoke_result in C++20. Is there already some patch for 1.74 or maybe work in progress for 1.75 regarding this issue ? Regards Daniel

2 1

[Signals2] Deprecated header warning VS2017 Boost 1.74
by Peter Barker 27 Oct '20

27 Oct '20

Hi, Just upgraded to Boost 1.74 from Boost 1.71. I'm getting a warning: c:\releases\lib\boost\boost_1_74_0\include\boost\function_output_iterator.hpp(14): note: This header is deprecated. Use <boost/iterator/function_output_iterator.hpp> instead. from this MWE: #include <boost/signals2/signal.hpp> int main() { } I'll have to #define BOOST_ALLOW_DEPRECATED_HEADERS I guess, but I'm surprised Boost libraries are using deprecated Boost headers. Regards, Pete

4 4

A Newbie Boost.Build with Variants Question
by Ryan Heniser 24 Oct '20

24 Oct '20

Hi, I am building Boost 1.61 (we need this old version for other libraries) for the first time at work with Boost.Build (b2). I have successfully built Boost (using b2) for gcc 4.8. If I want to add one or more variants (for example using gcc 6.3), where should I put the Boost header’s include directory? Should one go inside each variant or should just one go at the root directory containing the variant directories? Kind regards, Ryan

2 1

[Newbie][Intrusive] - Beginners question
by Gaier, Bjoern 22 Oct '20

22 Oct '20

Hey everybody, I looked into the boost intrusive container and played around with it a bit. I tried the following code: struct animal : public boost::intrusive::list_base_hook<> { std::string name; int legs; animal(std::string n, int l) : name{std::move(n)}, legs{l} {} }; int main(int argc, char **argv) { std::vector<animal> test; boost::intrusive::list<animal> wuff; for(int n = 0; n < 5; n++) { test.push_back(animal("Katze", 4)); } for(int n = 0; n < 5; n++) { wuff.push_back(test[n]); } for(int n = 0; n < 15; n++) { wuff.push_back(test[n]); } for(auto elem : wuff) { printf("%s\n", elem.name.c_str()); } } This code does crash! I guess this is because "test" relocated the memory and therefor "wuff" lost its references. I would expect the same result if I would have a std::list with pointers to animal structures - this is why I wonder what the benefit of an intrusive container is compared to the same container with just pointers in it. Hope someone can explain me this! Thank you in advance and kind greetings Björn Als GmbH eingetragen im Handelsregister Bad Homburg v.d.H. HRB 9816, USt.ID-Nr. DE 114 165 789 Geschäftsführer: Dr. Hiroshi Nakamura, Dr. Robert Plank, Markus Bode, Heiko Lampert, Takashi Nagano, Junichi Tajika, Ergin Cansiz.

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Does boost promise/future support corroutines?
by David Frank 19 Oct '20

19 Oct '20

Hi, Does boost promise/future support coroutines? For example, the get call only block the running coroutine, instead of the whole thread? Thanks,David

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Boost.MSM: Problem with defered events
by Georg Gast 16 Oct '20

16 Oct '20

Dear Boost users, i am currently writing a driver for the ADS1256 chip with Boost.MSM. Yes, there are other drivers. I do this for training and fun. During the startup phase i need to defer the requests from the user as the SPI bus is not yet available. To model the behaviour the most correct, i tried to model it with MSM. In the transition table, i use the "Defer" action to defer these events. In my Idle state, after the startup phase, there is a transition with this defered event going to the "work" states. In the debugger i can see, that the defered_event_queue holds one defered event and it is of my type but it is not processed. I did use boost 1.67.0 (from debian buster ) and also 1.74.0 (self compiled) to test this. My program can be also compiled under Windows and VS2019 as i handled the hardware interfacing with a abstract class. It works under Windows and 1.74.0. With VS2017 and 1.67.0 it also does not work. Under Linux and gcc it always stops at the Idle state where i wait for the defered event. At the end is my transition table. Any ideas are welcome! Georg // clang-format off struct transition_table : mpl::vector< // +----------------+-------------------+----------------+---------------------------+----------------------+ // Region 0 // +----------------+-------------------+----------------+---------------------------+----------------------+ // Start Event Next Action Guard // +----------------+-------------------+----------------+---------------------------+----------------------+ Row < NotIntialized , ev_Init , WaitDRDYID , none , none >, Row < WaitDRDYID , ev_CheckFlags , ReadID , none , IsDrdy0 >, Row < ReadID , ev_CheckFlags , none , none , none >, Row < ReadID , Spi::Reply , ReadIDFailed , none , IsIDNotOk >, Row < ReadID , Spi::Reply , Idle , none , IsIDOk >, // during the startup phase these event must be defered Row < NotIntialized , ev_MultiStart , none , Defer , none >, Row < WaitDRDYID , ev_MultiStart , none , Defer , none >, Row < ReadID , ev_MultiStart , none , Defer , none >, // +----------------+-------------------+----------------+---------------------------+----------------------+ Row < Idle , ev_CheckFlags , none , none , none >, Row < Idle , ev_MultiStart , MConfigWaitDRDY, none , none >, // +----------------+-------------------+----------------+---------------------------+----------------------+ Row < MConfigWaitDRDY, ev_CheckFlags , MSwitchConfig , none , IsDrdy0 >, Row < MSwitchConfig , ev_CheckFlags , none , none , none >, Row < MSwitchConfig , Spi::Reply , MMuxWaitDRDY , none , IsECNotFailed >, Row < MMuxWaitDRDY , ev_CheckFlags , MSwitchMux , none , IsDrdy0 >, Row < MSwitchMux , ev_CheckFlags , none , none , none >, Row < MSwitchMux , Spi::Reply , MSync , none , IsECNotFailed >, Row < MSync , Spi::Reply , MDataWaitDRDY , none , IsECNotFailed >, Row < MDataWaitDRDY , ev_CheckFlags , MReadData , none , IsDrdy0 >, Row < MReadData , ev_CheckFlags , none , none , none >, Row < MReadData , Spi::Reply , Idle , WorkDone , IsWorkDone >, Row < MReadData , Spi::Reply , MMuxWaitDRDY , RemoveDoneWork , IsStillWorkTodo >, // +----------------+-------------------+----------------+---------------------------+----------------------+ // Region 1 // +----------------+-------------------+----------------+---------------------------+----------------------+ Row < DrdyUndefined , ev_DRDY_0 , Drdy0 , none , none >, Row < DrdyUndefined , ev_DRDY_1 , Drdy1 , none , none >, Row < Drdy0 , ev_DRDY_0 , none , none , none >, Row < Drdy0 , ev_DRDY_1 , Drdy1 , none , none >, Row < Drdy1 , ev_DRDY_0 , Drdy0 , none , none >, Row < Drdy1 , ev_DRDY_1 , none , none , none >, // +----------------+-------------------+----------------+---------------------------+----------------------+ // Region 2 // +----------------+-------------------+----------------+---------------------------+----------------------+ // Start Event Next Action Guard // +----------------+-------------------+----------------+---------------------------+----------------------+ Row < AllOk , Spi::Reply , ErrorMode , none , IsECFailed > // +----------------+-------------------+----------------+---------------------------+----------------------+ > {}; // clang-format on

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[Circular Buffer] Why doesn't have “emplace” interface?
by Марсель Галимуллин 16 Oct '20

16 Oct '20

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Boost configuration for VS Code / MacOS X Catalina
by Stefano Gragnani 12 Oct '20

12 Oct '20

Hi, how should i configure vs code to use Boost? I tried to compile the following example: #include <iostream> #include <boost/multiprecision/float128.hpp> #include <boost/math/special_functions/gamma.hpp> int main() { using namespace boost::multiprecision; // Operations at 128-bit precision and full numeric_limits support: float128 b = 2; // There are 113-bits of precision: std::cout << std::numeric_limits<float128>::digits << std::endl; // Or 34 decimal places: std::cout << std::numeric_limits<float128>::digits10 << std::endl; // We can use any C++ std lib function, lets print all the digits as well: std::cout << std::setprecision(std::numeric_limits<float128>::max_digits10) << log(b) << std::endl; // print log(2) = 0.693147180559945309417232121458176575 // We can also use any function from Boost.Math: std::cout << boost::math::tgamma(b) << std::endl; // And since we have an extended exponent range we can generate some really large // numbers here (4.02387260077093773543702433923004111e+2564): std::cout << boost::math::tgamma(float128(1000)) << std::endl; // // We can declare constants using GCC or Intel's native types, and the Q suffix, // these can be declared constexpr if required: constexpr float128 pi = 3.1415926535897932384626433832795028841971693993751058Q; return 0; } but that's what I get: Executing task: g++-10 -g -std=c++17 '-fext-numeric-literals' main.cpp -L/usr/local/Cellar/gcc/10.2.0/lib/gcc/10/ -lquadmath -o main.out < main.cpp:2:10: fatal error: boost/multiprecision/float128.hpp: No such file or directory 2 | #include <boost/multiprecision/float128.hpp> | ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ compilation terminated. The terminal process "/bin/zsh '-c', 'g++-10 -g -std=c++17 '-fext-numeric-literals' main.cpp -L/usr/local/Cellar/gcc/10.2.0/lib/gcc/10/ -lquadmath -o main.out'" failed to launch (exit code: 1). My task.json is: { // See https://go.microsoft.com/fwlink/?LinkId=733558 <https://go.microsoft.com/fwlink/?LinkId=733558> // for the documentation about the tasks.json format "version": "2.0.0", "tasks": [ { "label": "Build with g++ 10", "type": "shell", "command": "g++-10", "args": [ "-g", "-std=c++17", "'-fext-numeric-literals'", "main.cpp", "-L/usr/local/Cellar/gcc/10.2.0/lib/gcc/10/", "-lquadmath", "-o", "main.out" ], "group": { "kind": "build", "isDefault": true } }, { "label": "Build with Intel ICC", "type": "shell", "command": "icc", "args": [ "-g", "-std=c++17", "main.cpp", "-o", "main.out" ], "group": { "kind": "build", "isDefault": true } }, { "label": "Run Project", "type": "shell", "command": "./main.out", "group": { "kind": "build", "isDefault": true } } ] } And my c_cpp_properties.json is: { "configurations": [ { "name": "Mac", "includePath": [ "${workspaceFolder}/**", "/usr/local/Cellar/boost/1.73.0/include/**" ], "defines": [], "macFrameworkPath": [], "compilerPath": "/usr/local/bin/g++-10", "cStandard": "gnu18", "cppStandard": "gnu++14", "intelliSenseMode": "gcc-x64" } ], "version": 4 } Thanks Stefano Gragnani

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A question about boost::uuid
by Shishir Pandey 10 Oct '20

10 Oct '20

Hi all, I have been trying to figure out how to use murmurhash3 with boost::uuid. Looking at the documentation it is not entirely clear to me if a class implementing murmurhash3 that provides the interface defined by NameHashProvider would be sufficient. If yes, would creating a wrapper over the following implementation work? https://github.com/aappleby/smhasher/blob/master/src/MurmurHash3.cpp Can anyone direct me to some similar implementation perhaps not of using murmurhash3 but of using any other algorithms? Regards, Shishir Pandey -- Necessity is not an established fact, but an interpretation. - Friedrich Wilhelm Nietzsche

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Re: [Boost-users] [Boost-announce] [PFR][review] Result
by Antony Polukhin 09 Oct '20

09 Oct '20

On Thu, Oct 8, 2020, 13:51 Benedek Thaler via Boost-announce < boost-announce(a)lists.boost.org> wrote: <...> > Benedek > review wizard > Many thanks for beeng the review manager! >

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Re: [Boost-users] [Boost-announce] [FPR] Review of FPR starts Today: Sept 28 - Oct 7
by Nat Goodspeed 05 Oct '20

05 Oct '20

On Mon, Sep 28, 2020 at 1:15 PM Benedek Thaler via Boost-announce < boost-announce(a)lists.boost.org> wrote: - How much effort did you put into your evaluation? A glance? A quick > reading? In-depth study? > I have read only the announcement email, but it prompts a very interesting question: does the FPR library facilitate integration with Boost.Serialization? If not yet, how hard would it be to improve the interoperability of those two libraries? If the FPR documentation already addresses this point, a terse reply to that effect will suffice.

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