- Boost - lists.boost.org

1.86 release
by Andrey Semashev 01 Jul '24

01 Jul '24

Hi, Are we behind the 1.86 release schedule?

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In Response to Mr. Falco's June 2024 Letter
by Kristen Shaker 01 Jul '24

01 Jul '24

Hello Boost Community, My name is Kristen. Admittedly, I am not the most active participant on the boost mailing list. However, I do serve on the Boost Foundation Board of Directors as Board Chair. It is lovely to e-meet you; Hopefully I'll have the opportunity to get to know you better during the course of my tenure. Recently, we became aware of a letter that was circulated to the Boost developer community. The Boost Foundation Board of Directors have penned the following note in response to that letter. _____________________________________ Dear Boost Community Members, Recently, Mr. Falco distributed a letter indicating intent to a) rescind his offer of hosting a new boost.org website, b) retract his agreement to retire the @BoostLibraries account on X in favor of the established @Boost_Libraries, c) create a new set of Boost mailing lists on boost.io, and d) attempt to purchase the boost.org domain name from Beman Dawes’s estate. While we are surprised and saddened by this turn of events, we agree with Mr. Falco that cutting ties between the C++ Alliance and the Boost Foundation is in everyone’s best interests. That being said, we want to acknowledge Mr. Falco and his employees’ tremendous contributions toward a modernized Boost website and significant investment in maintaining and extending the Boost Libraries. On March 28th, 2024, the Foundation voted to point the boost.org domain name at Mr. Falco’s new site. Given that we had every intention to move forward we were shocked to hear that Mr Falco felt we were “holding [his] work hostage.” The Boost Foundation was entirely unaware of Mr. Falco’s attempts to purchase the boost.org domain name. We were not consulted until it became clear to Mr. Falco that to proceed with the transaction, he would need the login credentials for the domain name provider. At that point, Mr. Falco did contact a board member requesting the credentials, which were not provided to him. We were hesitant to discuss these events publicly, but since Mr. Falco has openly described his attempts to purchase the boost.org domain name, this public response seems appropriate. The fact that he took these steps without coordinating with—or even notifying— the Boost Foundation, has shaken our confidence in the Alliance and Mr. Falco. While we very much appreciate Mr. Falco's financial investment, nonprofits like Boost are not—nor should they be—beholden to their largest financial contributors. We are committed to continuing to foster a collaborative environment where C++ developers can contribute great ideas to the open source community. Boost's consensus-based process is not always the fastest way to the best result, but it is consistent with that commitment. Ideally, Mr. Falco would be interested in contributing financially to a worthy cause without assuming control over the Libraries, but his letter indicates otherwise. Therefore, we agree with Mr. Falco’s assessment that there is no viable path forward for further coordination between The C++ Alliance and The Boost Foundation. We do, however, wish Mr. Falco and the Alliance all the best in their continued efforts to improve the C++ ecosystem. Sincerely, The Boost Foundation Board of Directors

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boost::any_cast gives build errors with VS2022, boost v1.82 and C++17
by Bhuyan, Jyotideep 01 Jul '24

01 Jul '24

Hi, I was using VS2019, boost v1.78, and C++14 version and the below code was working well. Same code gives build error with VS2022, boost v1.82, and C++17 due to "o << *boost::any_cast<T>(&a); " Instruction. I wanted to know why it behaves differently. Code : class any_out { struct streamer { virtual void print(std::ostream& o, const boost::any& a) = 0; virtual streamer* clone() = 0; virtual ~streamer() {} }; public: any_out() : m_streamer(nullptr) { } ~any_out() { delete m_streamer; } template <typename T> any_out(const T& value) : m_streamer(new streamer_imp<T>), m_object(value) { } any_out(const any_out& a) : m_streamer(a.m_streamer ? a.m_streamer->clone() : nullptr), m_object(a.m_object) { } template <typename T> any_out& operator=(const T& r) { any_out(r).swap(*this); return *this; } any_out& operator=(const any_out& r) { any_out(r).swap(*this); return *this; } any_out& swap(any_out& r) noexcept { std::swap(m_streamer, r.m_streamer); std::swap(m_object, r.m_object); return *this; } friend std::ostream& operator<<(std::ostream& o, const any_out& a) { if(a.m_streamer) { a.m_streamer->print(o, a.m_object); } return o; } boost::any& get() { return m_object; } const boost::any get()const { return m_object; } bool empty() const { return m_object.empty(); } private: template <typename T> struct streamer_imp : public streamer { virtual void print(std::ostream& o, const boost::any& a) { try { if (a.empty()) { o << "<empty>"; } else { o << *boost::any_cast<T>(&a); } } } virtual streamer* clone() { return new streamer_imp<T>(); } }; // Members streamer* m_streamer; boost::any m_object; }; I have migrated to VS2022, boost v1.82, and C++17, and due to a build error, I have changed the code below. virtual void print(std::ostream& o, const boost::any& a) { try { if (a.empty()) { o << "<empty>"; } else { o << boost::any_cast<T*>(a); } } } any_out anyTest; anyTest = 100; std::string actualStr; actualStr = make_string() << anyTest; actualStr prints nullptr (0000000) instated of value 100 for VS2022, boost v1.82 and C++17 Best Regards, Jyotideep (JD) Please be advised that this email may contain confidential information. If you are not the intended recipient, please notify us by email by replying to the sender and delete this message. The sender disclaims that the content of this email constitutes an offer to enter into, or the acceptance of, any agreement; provided that the foregoing does not invalidate the binding effect of any digital or other electronic reproduction of a manual signature that is included in any attachment. Confidential - Company Proprietary

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FYI: recent VS2022 17.10.x gives "Boost toolset is unknown (compiler MSVC 19.40.33808.0)" warning - due to Microsoft changing of the toolset version
by Dennis Luehring 21 Jun '24

21 Jun '24

...using Boost only CMake configure The MSVC toolset will increment its minor version number from|19.39|(VS 2022 v17.9) to|19.40|(VS 2022 v17.10). https://devblogs.microsoft.com/cppblog/msvc-toolset-minor-version-number-14… is still useable - did not check if building boost is a problem

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[boost.QVM] can you explain quaternions in the docs?
by Andrzej Krzemienski 19 Jun '24

19 Jun '24

Hi Everyone, I landed on this library docs when trying to learn what quarterions are for. Although the library has a vast documentation it doesn't explain what quaternions are and why they are used. When I was taught algebra for the purpose of computer graphics, vectors and matrices were on the table, but no quaternions. The examples show that I need to create a quaternion only to turn it into a rotation matrix. I am pretty sure there has to be more to it. Could I request an introduction section in the docs that would explain what quaternions are and why one would want to use them? The corresponding GitHub issue: https://github.com/boostorg/qvm/issues/51 Regards, &rzej;

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CppCast: Boost, The Beman Project and Beyond
by Niall Douglas 16 Jun '24

16 Jun '24

Given that some on here were expressing surprise at recent goings on, I thought in case nobody had seen it yet listening to this might be useful: https://cppcast.com/boost-the_beman_project_and_beyond/ Our own Zach Laine explains some of what's been going on behind the scenes. Niall

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[Newbie] Problem receiving data with asio::serial_port
by Stefano Mora 14 Jun '24

14 Jun '24

Hi all, I’m writing a Qt application running on both Windows and MacOs platforms. The application is based on CMake project that includes boost-asio package 1.84.0 by vcpkg packager. The application must communicate with a board by USB cable = virtual serial port. I’m handling the communication with a small wrap around the asio::serial_port object, found in sample https://github.com/fedetft/serial-port/tree/master/2_with_timeout The problem is on MacOS platform; Windows version works correctly. The problem is that after some data exchanges (they are correct) the program does not receive a reply (with the TIMEOUT exception) and, after that, it receives only system_error = 89. This is a chunk of my log: ... ( I send a command and I receive the reply) [ReceiveLog] start [TP] start SendCommand 'log export' [WriteCommand] Byte[] Write - cmd: 'log export' [WaitForResponse] ms 1000 RX [34] : ' log export -> XModem receive file' [SendCommand] response: ' log export -> XModem receive file' [ReceiveLog] response1: 'XModem receive file' matching: 'XModem receive file' [ReceiveLog] ok -> XMODEM (now I send a byte to start the data from the board - 3 attempts) > Write BEGIN DATA RECEIVE .. [WaitForXModemResponse] ms 4000 [WaitForXModemResponse] TIMEOUT TO diff: 4 > Write BEGIN DATA RECEIVE .. [WaitForXModemResponse] ms 4000 [ToSerial][readCompleted] error system:89 [ToSerial][readCompleted] byteTransf 0 [WaitForXModemResponse] Boost System_error > Write BEGIN DATA RECEIVE .. [WaitForXModemResponse] ms 4000 [ToSerial][readCompleted] error system:89 [ToSerial][readCompleted] byteTransf 0 [WaitForXModemResponse] Boost System_error [TP][ReceiveLog] start XMODEM: 0 (now I sent an ACK, just to try ...) [WaitForXModemResponse] ms 1000 [ToSerial][readCompleted] error system:89 [ToSerial][readCompleted] byteTransf 0 [WaitForXModemResponse] Boost System_error [dlThread] ReceiveLog ret: 0 The read function is simply set the timeout and read 133 bytes: ... _serialPort.setTimeout( boost::posix_time::millisec(timeout)); char data[XMODEM_PACKET_LENGTH]; try { _serialPort.read( data, XMODEM_PACKET_LENGTH); ... } catch(timeout_exception){ ... } catch(boost::system::system_error){ ...} Please what error 89 means (in MACos context)? Any idea on how to exit from this situation? Thanks! Regards

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CMake and Boost
by Robert Ramey 12 Jun '24

12 Jun '24

I'm trying to figure out how to switch to CMake to build and test my libraries. I have some experience with this as I've made such files on sort of an experimental/prototype basis. However it's been some time since I messed with this so a forgot a lot. Now I'm getting serious so I have some questions. I've looked over the official CMake documentation. It seems complete but some stuff is not well explained. I've spent some time studying https://github.com/boostorg/cmake at I'm beginning to see what I have to do. Never-the-less, I still have a few questions: 1) The first lines show mkdir __build cd __build cmake .. cmake --build . Does this presume that one starts from the library directory? Does this syntax work for out of source tree builds? That is, would the following work? mkdir /temp/__build cd /temp/__build cmake .. cmake --build . (very confusing usage of leading __) ahhhh - I see a problem. I'm thinking of starting from within the directory of a particular library. I'm presuming "modular boost". Is this supported? 2) BOOST_INCLUDE_LIBRARY I would like my CMakeLists.txt file to explicitly list the direct antecedent libraries (dependencies - bad word usage). So I'd expect to see something like add_directory(../filesystem) add_directory(../regex) ... So I could just cd to .../libs/serialization cmake --build and have it build the antecedent if and only if required. 3) CMAKE_INSTALL_INCLUDEDIR I would prefer not to "install" (copy) the include files but just use the ones from their original locations. 4) BUILD_TESTING I would prefer to have my library source to look like: ... libs/serialization CMakeLists.txt // includes add_directory for subdirectorys build, test, example, profile and ... // includes add_directory for antecedent libraries like add_directory(../libs/filesystem) include // directory with include files for users of serialization library build(or src) // source files for library build CMakeLists.txt // to build library test CMakeLists.txt example CMakeLists.txt profile CMakeLists.txt Maybe the add_directory would be conditioned on a CMAKE variable. So if I invoke CMake --build test_polymorphic_binary_archive It would recursively (re)build everything necessary and nothing not necessary If I didn't specify a list of targets, it would recursively (re)build everything that needs (re)building. This seems totally reasonable and natural to me - it work like make - but better. It would dovetail with efforts to "modularize" boost. Users would only have to download libraries they actually use - if that's what they want. I realized I've glossed over a couple of details, in particular recursive inclusion of header files and likely some other stuff. I've also experimented with CMake enough to have a feeling that what I want to do is not possible. And this is the short version of what I'd like to do. Any thoughts on this?

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[container] Draft development plan for Boost.Container
by Ion Gaztañaga 11 Jun '24

11 Jun '24

Hi to all, Boost.Container was accepted in 2011 when container classes were spun off from Boost.Interprocess to form a new library. At that time it offered new features like emulated move semantics for "classic" STL-like containers and some new classes like flat_map and stable_vector. During these years more containers/main features were added: - The scoped allocator Model was added in Boost 1.50 (2012) - static_vector was added in Boost 1.54 (2013) - small_vector was added in Boost 1.58 (2015) - Polymorphic Memory Resources were added in Boost 1.60 (2015) - devector was added in Boost 1.75 (2020) Lately I've been collecting some ideas about how to improve the library and keep it interesting/useful both for other Boost libraries and Boost users. I've somewhat formalized a bit some of those ideas and I'd like to share them here in order to obtain feedback from the developers. Here's the document: https://docs.google.com/document/d/1VdMTheFUczC946dP3VKPseOoUq3sVKjU73oMvK8… Note that this document does not outline a schedule for all those ideas, it's an initial description of possible developments that should be evaluated/prioritized, as developing a substantial subset of the proposals would be a huge task. Thanks in advance for your attention and comments. Best, Ion

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b2 headers failing on windows?
by John Maddock 10 Jun '24

10 Jun '24

In latest CI runs, see: https://github.com/boostorg/math/actions/runs/9427754774/job/25973291514?pr… Any ideas? Thanks! John.

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