- Boost - lists.preview.boost.org

Poor performance on windows with logging sinks::file_collector when two file logs use same directory. Thoughts?
by Nicholas Neumann 24 Jun '21

24 Jun '21

I've got two different rotating file logs that point to the same directory (with different file name patterns). Is this in general just a bad idea? They end up sharing the same file_collector, which seems wrong, so perhaps that is a clue that I shouldn't have my logs set up like this. In production I've got a service that compresses, archives, and manages the size of the logs. But in dev, I don't, so the number of files in the directory slowly grew. But the startup time for my program grew much faster. On windows the scan_for_files function in the collector has a loop that is O(mn), where m is the number of files in the directory, and n is the number that matched in previous calls to the scan_for_files function This means the scan_for_files for the first rotating file log in the directory has no issue (n is 0), but the second can be problematic. It iterates over the files in the directory and for each file in the directory, it calls filesystem::equivalent on all of the matches from previous scan_for_files calls. On windows, filesystem::equivalent is particularly heavy, opening handles to both files. Thoughts? Is the two file logs getting the same collector the real issue? Or is it my pointing two file logs to the same directory? I see some ways to mitigate the slowdown in scan_for_files - e.g., filesystem::equivalent could be called after all of the method/match_pattern check, but the two file logs sharing the same collector feels like the real issue.

3 3

The deadline for new libraries and breaking changes in Boost 1.77.0 is this Wednesday, June 23
by Marshall Clow 21 Jun '21

21 Jun '21

See https://www.boost.org/development/index.html <https://www.boost.org/development/index.html> for the full calendar — The Release Managers

1 0

Re: [boost] What has become of John Maddock's implementation of the Remez algorithm for Chebychev approximation?
by Bjorn Reese 18 Jun '21

18 Jun '21

On 6/15/21 11:48 PM, Joachim Wuttke via Boost wrote: > Until v1.53, Boost Math had doc pages [1,2] on the Remez algorithm. > This algorithm [3] computes the coefficents of the Chebyshev polynomial > that approximates a given function. Page [2] refers to actual code In addition to John's reply, I wanted to add that Boost.Math has direct support for Chebyshev polynomials now: https://www.boost.org/doc/libs/release/libs/math/doc/html/math_toolkit/sf_p…

4 5

What has become of John Maddock's implementation of the Remez algorithm for Chebychev approximation?
by Joachim Wuttke 16 Jun '21

16 Jun '21

Until v1.53, Boost Math had doc pages [1,2] on the Remez algorithm. This algorithm [3] computes the coefficents of the Chebyshev polynomial that approximates a given function. Page [2] refers to actual code in directory libs/math/minimax. This code can still be found on GitHub [4], but maintenance status and dependences are unclear. Anybody around who knows anything about this code? Kind regards, Joachim [1] https://www.boost.org/doc/libs/1_53_0/libs/math/doc/sf_and_dist/html/math_t… [2] https://www.boost.org/doc/libs/1_53_0/libs/math/doc/sf_and_dist/html/math_t… [3] https://en.wikipedia.org/wiki/Remez_algorithm [4] https://github.com/boostorg/math/tree/develop/tools/minimax -- Dr. Joachim Wuttke group leader Scientific Computing Forschungszentrum Jülich GmbH Jülich Centre for Neutron Science at MLZ https://computing.mlz-garching.de https://jugit.fz-juelich.de/mlz

2 1

Using Boost.Test header-only from CMake
by Peter Dimov 15 Jun '21

15 Jun '21

Some libraries (I encountered this when porting the tests of Signals2) use Boost.Test in header-only mode, by including <boost/test/included/unit_test.hpp> without linking to anything. This worked in the "legacy" structure where all headers are always available, but doesn't work under CMake where you have to link to header-only libraries in order to get the proper include path. Should we make an attempt to support this use by declaring a special header-only target in Boost.Test (e.g. Boost::included_unit_test), or is that a waste of time? One can as well link to the proper Boost::unit_test_framework (and then even use it header-only, although there's not much point in doing so.) I'm inclined towards "waste of time".

10 34

Re: [boost] boost-json apt-get packge
by Vollaro, John 14 Jun '21

14 Jun '21

Date: Fri, 11 Jun 2021 01:42:18 +0300 From: "Peter Dimov" <pdimov(a)gmail.com> To: <boost(a)lists.boost.org> Subject: Re: [boost] boost-json apt-get packge Message-ID: <05f001d75e49$decba2f0$9c62e8d0$(a)gmail.com> Content-Type: text/plain; charset="utf-8" Vollaro, John wrote: > Is their a apt package that includes boost-json? For what distro? debian > This apt packages did not include boost-json > > apt-get install libboost1.76-all-dev Should be libboost1.76-json-dev. Could not find this package. This e-mail, including attachments, may include confidential and/or proprietary information, and may be used only by the person or entity to which it is addressed. If the reader of this e-mail is not the intended recipient or his or her authorized agent, the reader is hereby notified that any dissemination, distribution or copying of this e-mail is prohibited. If you have received this e-mail in error, please notify the sender by replying to this message and delete this e-mail immediately.

2 1

CMake minimum version to support
by Peter Dimov 11 Jun '21

11 Jun '21

I suppose the time has come to have the discussion on the minimum CMake version we will support for building Boost. Currently that's set to 3.5, which kind of works, but is fairly inconvenient. The interesting options are - CMake 3.8: required for use of the compile features cxx_std_11, cxx_std_14, cxx_std_17, etc. Also allows source_group(TREE, which is used by Json and PropertyTree. - CMake 3.9: required by Nowide, I'm not sure why. Also, required for FindMPI to define an imported target. Building Boost.MPI is optional though. - CMake 3.13: required for Boost installation support. - CMake 3.14: required for FindPython to be modern enough to make building Boost.Python reasonably easy. (Building Boost.Python is optional, though.) There are also less important nice-to-have things such as - CMake 3.10: adds include_guard() - CMake 3.12: adds CONFIGURE_DEPENDS to file(GLOB - CMake 3.15: adds VERBOSE/DEBUG to message( Opinions?

15 40

boost-json apt-get packge
by Vollaro, John 10 Jun '21

10 Jun '21

Is their a apt package that includes boost-json? This apt packages did not include boost-json apt-get install libboost1.76-all-dev ____________________________ John Vollaro 185 Asylum St 6th Floor, Hartford, CT 06103 O: 860-702-8563 | M: 860-919-9443 | john.vollaro(a)optum.com<mailto:john.vollaro@optum.com> This e-mail, including attachments, may include confidential and/or proprietary information, and may be used only by the person or entity to which it is addressed. If the reader of this e-mail is not the intended recipient or his or her authorized agent, the reader is hereby notified that any dissemination, distribution or copying of this e-mail is prohibited. If you have received this e-mail in error, please notify the sender by replying to this message and delete this e-mail immediately.

2 1

Re: [boost] Using Boost.Test header-only from CMake
by Glen Fernandes 10 Jun '21

10 Jun '21

On Sun, Jun 6, 2021 at 9:51 PM Peter Dimov wrote: > For completeness, the libraries using the deprecated boost/test/minimal.hpp are: > > foreach > graph > graph_parallel > iterator > logic > numeric/conversion > numeric/interval > property_map > tokenizer > units > yap > > These need to migrate to either LWT or the non-deprecated Boost.Test. I've migrated all of the above to LWT. Graph is still a PR that needs to be merged. Glen

1 0

Fwd: Interested in contribution to this organisation.
by Chandrakant Jena 16 09 Jun '21

09 Jun '21

---------- Forwarded message --------- From: Chandrakant Jena 16 <chandrakant.barcelona(a)gmail.com> Date: Wed, Jun 9, 2021 at 9:47 AM Subject: Interested in contribution to this organisation. To: <boost(a)lists.boost.org> hello devs, I am chandrakant jena currently studying computer science in utkal university, bhubaneshwar,Odisha. my current interest is c++ and I found this organisation really interesting and suitable for me. I want to know how can I get started? here are some of my profile links: linked in: https://www.linkedin.com/in/chandrakant-jena-5aab131a7/ github profile: https://github.com/chandrakant100

2 1

[cmake] Problem with dependencies for configure checks
by Andrey Semashev 08 Jun '21

08 Jun '21

Hi, I've been having this problem with CMake in Boost.Filesystem, where I need to have the Boost::library targets available before Boost::filesystem target is defined. This is needed in order to perform configuration checks that will affect how Boost::filesystem will be defined. For example, see the check_cxx_source_compiles calls: https://github.com/boostorg/filesystem/blob/af6ac28b5785820b93a2af7dd6e9b80… For the check_cxx_source_compiles calls, I would have liked to add targets like Boost::config and Boost::winapi to CMAKE_REQUIRED_LIBRARIES so that the checks are compiled with include directories of those dependencies added in the command line. This doesn't work because these targets may not be defined at the point when the configuration checks are performed. My current workaround, as you can see, is to add the Boost root to CMAKE_REQUIRED_INCLUDES, where the boost directory with the common headers tree is located. However, this will not work if we're going to make that directory optional or remove it. Also, you can see that I'm reusing checks implemented in Boost.Config, for which I also had to hard code its relative location from Boost.Filesystem. If we're going to allow different libraries located in separate directory trees, this will also break. My question is, can this be fixed and how? I was wondering if it is possible to make the target generation two-stage, where the first stage identifies library locations, including directories with their headers, and the second stage would define build targets. This way all library directories would be available to the second stage. Although I can already see the problem with second order dependencies with this approach...

5 34

CMake progress report
by Peter Dimov 06 Jun '21

06 Jun '21

At the moment, we're down to the following libraries missing CMake support on develop: asio locale log numeric/odeint numeric/ublas parameter_python python sync I've asked Chris how we can proceed with adding a CMakeLists.txt file to ASIO so that we can unblock Log (and Beast.) In addition, the following libraries are currently disabled as having incompatible CMakeLists.txt files in their root directories: beast callable_traits compute gil hana hof safe_numerics static_string stl_interfaces yap I'm working on documenting the CMake support infrastructure, but I'm not done yet.

2 3

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

2 2

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.

1 0

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

2 2

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).

14 40

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.

6 12

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

3 3

[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.

1 0

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

6 10

[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.…

3 9

Final Notice: BinTray is shutting down 1-May (that's SATURDAY)
by Marshall Clow 07 May '21

07 May '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

5 6

[GSoC] - Boost.Multiprecision Quad Double
by Γιάννης Γονιδέλης 07 May '21

07 May '21

Hello! Christopher, Unfortunately, due to some urgent issues I won't be able to contribute during the summer. Thus, in case you have been considering picking me I would ask you to make a new choice. Apologies, Giannis

2 1

Google Summer of Code 2021
by David Bellot 05 May '21

05 May '21

Hi Boost community, The mentors are now finalizing their selection of the students. Google has been very generous this year with the number of slots we were allocated and we are happy to say that we will again have a nice (and large) team of incredible students developing with us this summer (or winter if you're down under like me). Stay tuned because we will announce the list of projects very soon. Best regards, David

1 0

[Math] Standalone beta release
by John Maddock 05 May '21

05 May '21

Just a heads up that Boost.Math now has a (beta) standalone release at https://github.com/boostorg/math/releases/tag/v1.76-standalone-beta We would very much appreciate any interested parties giving it a whirl and reporting back. With many thanks to Matt Borland and Nick Thompson for making this possible! Best, John Maddock. -- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus

3 4