February 2017 - Boost - lists.preview.boost.org

[config] [atomics] Support for z/OS XL C/C++
by Groke, Paul 21 Feb '17

21 Feb '17

Hi, we're using several Boost libraries in a large cross-platform project. One of the platforms we need to support is z/OS, using the IBM z/OS XL C/C++ compiler (which BTW is a completely different beast from the XL C/C++ compilers for other IBM platforms, which Boost.Config already seems to support). To be able to use Boost we had to write some patches and we'd very much like to contribute them. In more detail: * A minor patch to make the configure script work * Patches to some of the configure tests to fix incorrect feature detections * Compiler-, library- and platform-config header files * A Boost.Atomic implementation * An implementation of Boost.SmartPtr atomic operations This won't result in full support for all Boost libraries, not even close, but it's enough to make an appreciable subset usable on z/OS. I've never contributed code to any open source project so far, so I'd appreciate your help. Where should I start? Do I have to talk to the maintainers of Config/Atomic/SmartPtr? Is there even a maintainer for every specific project? Or should I just fork the Git repos and create pull requests? I'm pretty much lost here, sorry :) Regards, Paul Groke The contents of this e-mail are intended for the named addressee only. It contains information that may be confidential. Unless you are the named addressee or an authorized designee, you may not copy or use it, or disclose it to anyone else. If you received it in error please notify us immediately and then destroy it. Dynatrace Austria GmbH (registration number FN 91482h) is a company registered in Linz whose registered office is at 4040 Linz, Austria, Freistaedterstrasse 313

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Re: [boost] Status of Visual Studio 2017 support
by Nat Goodspeed 20 Feb '17

20 Feb '17

On Feb 20, 2017 5:25 AM, "Olaf van der Spek" <ml(a)vdspek.org> wrote: On Fri, Feb 17, 2017 at 2:57 PM, Nat Goodspeed <nat(a)lindenlab.com> wrote: > In a (non-Boost) project with which I've helped, there's a script that > does the following: > > ... Wouldn't it be much simpler if you let the user pick the right dev environment prompt from the start menu and have all stuff available without having to call extra scripts? It's a command-line build tool. The command-line equivalent to what you suggest is making the user discover, and then type, the correct pathname of the desired VS version.

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Mail List Migration - Update
by Michael Caisse 19 Feb '17

19 Feb '17

The Boost mail lists are now migrated to a new set of servers. This change affected all mail lists and web resources (signing up, changing passwords, moderator access, archives...) that were associated with the domain lists.boost.org . If you are having difficulties, please drop me an email. (Oh the irony) Happy coding! michael -- Michael Caisse Ciere Consulting ciere.com

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Variadic append for std::string
by Olaf van der Spek 19 Feb '17

19 Feb '17

Hi, One frequently needs to append stuff to strings, but the standard way (s += "A" + "B" + to_string(42)) isn't optimal due to temporaries. A variadic append() for std::string seems like the obvious solution. It could support string_view (boost and std), integers, maybe floats but without formatting options.. It could even be extensible by calling append(s, t); append(s, "A", "B", 42); Would this be useful for the Boost String Algo lib? -- Olaf

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Interprocess mutex & condition variable at process termination
by Phil Endecott 18 Feb '17

18 Feb '17

Dear Experts, I've just been surprised by the behaviour of the interprocess mutex and condition variable on abnormal process termination, i.e. they are not automatically released. Google tells me that I'm not the first to be surprised by this; there have been previous posts here, stack overflow questions etc. One often-valid observation is that if a process crashes - or otherwise terminates without executing its destructors - while it holds a lock on a shared data structure then the data is probably now corrupt, so unlocking the mutex that protects it is not very useful. I think there is an important case where that does not apply - when the process that crashes is only reading the shared data. In my case, I had written a "monitor" utility that loops forever, waiting on a shared condition, taking the corresponding mutex, and then dumping the shared data to stdout. I had been running this and stopping it by pressing ctrl-C and it had not occurred to me that this might not work as I expected. My attempt at debugging using this utility was making my problems worse, not better! Modifying this code to run destructors on ctrl-C is non-trivial. I am aware that the SysV shared semaphore is able to undo on process termination (see SEM_UNDO in man semop), and I had assumed that Boost.Interprocess was using this or something like it. I now see that it is using pthreads, which I didn't even realise could work between processes, and I don't think this API has any way to specify process termination behaviour. Anyway, I'd like to suggest that the interprocess docs should make some mention of the behaviour of the synchronisation primitives on process termination, e.g. somewhere near the beginning of http://www.boost.org/doc/libs/1_63_0/doc/html/interprocess/synchronization_… I may now try to implement some primitives that use semop() and unlock automatically. I haven't yet looked at what's involved to implement a condition variable on top of a semaphore, so I may not get very far! Has anyone else ever tried this? Also, I note that Interprocess is using "old style" times, not std::chrono like the std::mutex/condition do. Are there any plans to update this? Thanks, Phil.

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Missing link for Boost.Algorithm documentation
by Alexander Zaitsev 17 Feb '17

17 Feb '17

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Scheduled Outage : Web sites / Trac
by Michael Caisse 17 Feb '17

17 Feb '17

We are planning the final move of services from IU this week. Expect service outages for all web sites including Trac on 17-February-2017 between 16:00 UTC - 00:00 UTC. The mail lists will continue to operate during this time; however, all other sub-domains for boost.org will be affected. Sync'ing bandwidth with IU has been low recently and has caused us to increase the outage window. We will notify these lists when services are available again. Thank you for your patience during the move. -- Michael Caisse Ciere Consulting ciere.com

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Boost.Python sandox or multiple interpreters
by David Bellot 17 Feb '17

17 Feb '17

Hi, I'm using Boost.Python to load and use plugins in Python. Each plugin can define a few functions which are are pre-determined, so that my C++ software knows what to call. However, the mistake I've made was to think that the Python interpreter could be initialized many times, so that each plugins was existing and running into a separate interpreter. It's of course not the case and therefore, each time I load a new plugin, its functions overwrite the functions of the same name from the previous plugin (the one which was loaded just before), and so on. Is there a possibility to either : - have as many independent Python interpreters at the same time ? - or encapsulate each plugin in an independent "environment" ? - or any other solution which would elegantly solve this problem ? :-D Thanks for your help, David

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[trac] how close trac for bug reports
by Oliver Kowalke 17 Feb '17

17 Feb '17

Hello, how can I close boost trac for a specific library? Users should report issues only at github. ty, Oliver

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[teeks] Missing winerror.h for MSVC-9
by Andrey Semashev 17 Feb '17

17 Feb '17

Hi, I see lots of tests failing on teeks99-09b-win2012R2-64on64, MSVC-9.0 because winerror.h is missing. Here's an example: http://www.boost.org/development/tests/develop/developer/output/teeks99-09b… I can see that the file is present in Windows SDK 6.0A, which is supposed to be used with this compiler. The tests are passing on my machine. Could this be a tester configuration issue? Also, all MSVC-15 tests are failing on teeks99-09o-win2012R2-64on64 with the error of 'cl' not being found.

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