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Best way to hash_combine a bool?
by John Maddock 05 Jun '21

05 Jun '21

What's the best way to combine a hash value with a bool? Specifically, if you're generating a hash value for a class which has a one member a bool. Normally I would just boost::hash_combine all the class members together, but doing that with a bool member leads to: 1>d:\data\boost\boost\boost\multiprecision\detail\hash.hpp(20,88): warning C4805: '^': unsafe mix of type 'T' and type 'size_t' in operation 1> with 1> [ 1> T=bool 1> ] Followed by a long instantiation backtrace (this is from Boost.Multiprecision). Since there's only one bool in this class, I could just apply a unary ~ to the value when the bool is true, but obviously that wouldn't work for classes with multiple bool's. Should we modify hash_combine for this use case? Cheers, John. -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

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license violations
by tom.beacon 03 Jun '21

03 Jun '21

To whom should possible license violations be reported? Sent with [ProtonMail](https://protonmail.com) Secure Email.

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Reviewing my first file transfer using Asio
by Farbod Ahmadian 01 Jun '21

01 Jun '21

Hi everyone, I was learning Boost.Asio recently and to learn by doing a project, I decided to write a simple file transfer. So I wrote an *Async TCP Server* and a *Sync TCP Client; *you can use a client to send any kind of file to the server. This is how it works: 1) Clients connect to the server. 2) Clients send the file name to the server. 3) If everything is okay, the server will return an "OK" to that client and wait for that client to send the file. 4) If the client received "OK", it'll send the file. 5) If everything goes well, the file is received by server and the connection will be closed. I will attach the source codes in this email. So here are my questions: 1) Would you mind please review my code and say the problems? I'm a newbie in Asio ;) 2) How to make my client and server talk with a special protocol? Let's say HTTP. (If a socket server understands HTTP, will it be a web server? something like Nginx and Apache.) 3) What is the next step? How can I improve this? What should I learn/do next? Anything is kindly appreciated :) With best regards, Farbod

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Adding CMakeLists.txt files
by Peter Dimov 31 May '21

31 May '21

I'm adding CMakeLists.txt files (mostly generated by `boostdep --cmake <libname>` to libraries that don't have one yet. Apologies (in advance) to all the maintainers for not going through the proper procedure, but this is much easier done in bulk (and order matters).

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Tool maintenance
by Edward Diener 27 May '21

27 May '21

There is a list of maintainers for Boost libraries at libs/maintainers.txt. Is there likewise a list of maintainers for Boost tools ? I have discovered a serious bug with BoostBook and nested namespaces, created an issue, but fear that no one will respond. I would like to e-mail anybody who is a maintainer for BoostBook who might be able to look at the issue and fix it, but there is no list of maintainers for Boost tools which I can find. The person who appears to have worked with BoostBook in the past, Daniel James, is no longer active with Boost so I have no idea who might be able to fix the issue.

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Develop Regression Tests Failing
by Tom Kent 26 May '21

26 May '21

Since sometime yesterday, all the gcc/clang develop runners I maintain (not sure about Visual Studio, that machine has been down for updates) have been failing, before the tests suite can even start running. Master still looks good. They end with the following: - bzip2 : yes [30] - lzma : yes [30] - zstd : no [30] - lzma : yes (cached) [30] - has_lzma_cputhreads builds : no [2] - auto_ptr : yes [3] error: Unable to find file or target named error: '/python//numpy' error: referred to from project at error: '../libs/python/build' I believe this is because of the python ( https://github.com/boostorg/python/pull/362) and build ( https://github.com/boostorg/build/pull/726) pull requests that were merged in around that time. The question is, why is this causing an issue....I have some vague memory of the regression test suite always using build from master? Am I remembering this correctly? If so, I think we may need to back out the python change until build's develop branch merges to master? I'm seeing this across multiple docker images, one that has been rather stable is this: https://hub.docker.com/layers/teeks99/boost-cpp-docker/clang-11/images/sha2… running with this user-config.jam: https://github.com/teeks99/boost-cpp-docker/blob/master/clang-11/user-confi… and numpy installed for both python 2 and 3. Thoughts? Tom

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[boostbook] Doxygen nested namespaces entities not being handled
by Edward Diener 20 May '21

20 May '21

I am seeing an issue where nested namespace doxygen documented entities are not being generated by BoostBook for the final documentation of a reference section in a library's documentation. I am using the quickbook -> boostbook -> html set of tools in the doc jamfile. If I just use doxygen directly to generate the documentation the nested namespace entities are there, so this appears to be a BoostBook problem. Has this problem always existed ? Has anyone else ever encountered it ? I first reported this as a Boost Build issue at https://github.com/bfgroup/b2/issues/18, but then reported this at https://github.com/boostorg/boostbook/issues/10.

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Boost Governance?
by René Ferdinand Rivera Morell 18 May '21

18 May '21

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

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Re: [boost] Boost Governance?
by Glen Fernandes 18 May '21

18 May '21

Rene wrote: > It's now been at least a year since Boost switched from the Software Freedom Conservancy to the Boost Foundation for its governance organization. 13:14 <glenfe> @grafikrobot The Software Freedom Conservancy never governed the Boost C++ Libraries, nor did the Boost Steering committee, nor does the Boost Foundation. Only the Boost community does that. 13:15 <grafikrobot> Hopefully you'll clarify that on the dev list. i.e. The "Boost Steering Committee"[1] became "Boost Foundation"[2]. [1] https://sites.google.com/a/boost.org/steering/home [2] https://sites.google.com/a/boost.org/steering/boost-foundation It still deals with the C++Now conference, providing the mailing lists, hosting, etc. But any decision making and governance of the Boost libraries is still the domain of the Boost community (i.e. you, me, and the other Boost library authors and maintainers). Glen

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[sync] Optimizing Boost's sync using futex2
by André Almeida 15 May '21

15 May '21

Hi there, I'm the author of futex2[0], a WIP new set of Linux's syscalls that allows userspace to write efficient sync mechanisms. I would like to hear from Boost's developers if the project would benefit from this new interface. >From Boost/sync's codebase, I can see that you are already familiar with futexes, but just in case: * What's futex? futex stands for "fast userspace mutexes". It's a syscall that basically exposes a wait queue, where userspace can ask to put threads to sleep and to wake them. The index of such queue is an unsigned int address (that is usually called a futex). It's value doesn't mean anything for the kernel, userspace is responsible to defining the rules of it and implementing the logic. * Why futex2? futex has long standing issues that seems impossible to be solved in the current interface, so we are designing a new set of syscalls taking those problems in account (more on that at [0]). It's not merged yet, and I'm researching some uses cases to validate and get feedback about the API. The new API has the following new features: * Variable sized futexes (6, 16, 32 and 64 bits): we aren't restrict to only 32 bits anymore, and this can be used for decreasing memory usage or to wait on an address * Wait for multiple futexes: this function enables userspace to wait on a list of futexes and wake on the first that triggers a wake. Our current use case for this is for game engines and to emulate WaitForMultipleObjects from WinAPI in Wine * NUMA-awarenes: current futex has a single global hash table that is allocated in some node. Every futex() call that happens on the other nodes will have a access penalty. At futex2, there'll be a single table per node, so you can specify which one you want to operate on to increase locality. The detailed description of the API can be seen in the documentation patch[1]. Do you think that Boost would benefit from it? Thanks, André - futex2 talk at OpenSource Summit: https://www.youtube.com/watch?v=eG6GMBTcPQ8 [0] https://lore.kernel.org/lkml/20210427231248.220501-1-andrealmeid@collabora.… [1] https://lore.kernel.org/lkml/20210427231248.220501-7-andrealmeid@collabora.…

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