- Boost - lists.boost.org

Serialisation: Is is_trivial<T> a sufficient precondition to bypass serialisation?
by Niall Douglas 06 Feb '15

06 Feb '15

A library user has raised an interesting question at: https://github.com/BoostGSoC13/boost.afio/commit/ac32ebfceb9a08b133e8c d47000d3b4807bc3e42#commitcomment-9574522 Basically, AFIO v1.3 has new pre-serialisation metaprogramming in response to Robert's comments on his Incubator about it being too hard to serialise and deserialise data with AFIO. AFIO will now consume any STL container and will implicitly auto expand to ASIO scatter gather buffers any: 1. Trivial type T 2. C array of trivial type T 3. STL container of trivial type T, including initializer_list. A free function, to_asio_buffers(T), can be specialised by external code to extend this with custom ASIO scatter gather buffers generation. Note that AFIO explicitly and intentionally expects that anyone interested in async file i/o will be doing their serialisation and endian conversion far away from AFIO code, so to_asio_buffers(T) is really for marking extra types to be treated as implicit auto expand. The user asks the question: Is is_trivial<T> a sufficient precondition for this auto expansion to be safe, or should is_standard_layout<T> also be required? The user notes that is_trivial<T> && is_standard_layout<T> == is_pod<T> which seems a little overkill to me. There is also the possibility that is_trivial<T> is too conservative. Some may argue that is_trivially_copyable<T> would be sufficient. Thoughts? Niall -- ned Productions Limited Consulting http://www.nedproductions.biz/ http://ie.linkedin.com/in/nialldouglas/

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[release-mgt] missing library
by Oliver Kowalke 05 Feb '15

05 Feb '15

Hello, some weeks ago we discussed/decided that the C++11-only version of boost.coroutine should be a new lib -> boost.coroutine2. Daniel has already created a git-submodul inf the boostorg-repo and I've added the sources to branches master and develop. Unfortunately I'm missing coroutine2 (link) in <boost>/lib/coroutine2, entries in <boost>/libraries.htm and <boost>/lib/maintainers.txt. File <boost>/website/blob/master/feed/history/boost_1_58_0.qbk already contains announcement of boost.coroutine2. Could you execute the missing steps to add coroutine2 to release 1.58 please? best regards, Oliver

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boost interval arithmetic
by Павел Кудан 05 Feb '15

05 Feb '15

The difference in behaviour of comparison operators and basic arithmetic operators looks as probable misconception. Default and changeable behaviour of comparison operators consists in throwing exception in intermediate situation (intersecting intervals, ! (a>b) == (a <= b) is not applicable). Great decision for correct migration from float numeric code. The only and unchangeable behaviour of arithmetic operators consists in silent returning only one of possible intervals in intermediate situation (possible return is not single, multiple interval result). The source of mistakes and undesired behaviour at migration from float numeric. At least, throwing exception by arithmetic operators at intermediate situation would provide behaviour unity of comparison and arithmetic operators and functions. Best regards, Pavel Coodan

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[release-mgt] Name of release manager's repository?
by Beman Dawes 05 Feb '15

05 Feb '15

We used to have a directory <boost-root>tools/release that contained scripts used by release managers. As part of the modularization effort, it was separated into its own GitHub repository, boostorg/release. It is not a submodule of the boost super-module as it is primarily of interest only to release managers. That seems to me to be a "good thing". But I'm wondering if the "release" name might be confusing, since it doesn't contain releases or release tags themselves. Would renaming it "release-mgt" or similar be clearer? --Beman

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BOOST_HAS_PRAGMA_ONCE
by Stephen Kelly 05 Feb '15

05 Feb '15

Hello, As of commit 5b20f4910d8b6b48b0b6ad2df693d36edf54cf21 in the interprocess repo, the affected files seem to expect prior include of config by the the includer. Apparently this is not obvious to everyone, so it seems worth pointing out. Thanks, Steve.

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Regression tests stopped on Saturday?
by Neil Groves 05 Feb '15

05 Feb '15

Hi, I know there has been a lot go good work going on updating regression testing, and I might have missed an email. I'm currently waiting for some tests to cycle, but there appear to have been no updates since Saturday. Is this expected? Thanks, Neil Groves

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Boost regression testing on Android
by Dmitry Moskalchuk 04 Feb '15

04 Feb '15

Hi all, We've just published CrystaX NDK 10.1 (https://www.crystax.net/android/ndk) which is a drop-in replacement for the Google's Android NDK, and we've included prebuilt Boost 1.57.0 libraries there, to make life easier for those developers who want to use Boost on Android. The reason I write here is that in CrystaX NDK we were able to build Boost for Android without any changes in Boost sources, just because CrystaX NDK makes Android much more POSIX-conformant than original Android is, and Boost just works on top of it. If you're interested how we did it, please read description of CrystaX NDK release on https://www.crystax.net/android/ndk. Another important point is that we were able to run Boost regression tests on Android devices - again, without any changes in Boost sources, just providing own 'adbrunner' script as tests launcher. The only thing needed is to plug one or more Android devices to USB ports and/or run one or more Android emulators and then run script for Boost testing provided by CrystaX NDK. As long as those devices/emulators are available by ADB, Boost regressions tests will run on all of them. As far as I know, Boost is not yet officially supported on Android platform, mainly because of lack of regular regression testing procedure. I wonder if someone would be interested in our results and, if yes, would he/she like to participate in further Boost-on-Android improvements? -- Dmitry Moskalchuk

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[mixin] Library name
by Borislav Stanimirov 04 Feb '15

04 Feb '15

To those unfamiliar with the Boost.Mixin - it is a new library submitted for review. The docs are here: http://ibob.github.io/boost.mixin/index.html The code is here: https://github.com/iboB/boost.mixin It has been suggested multiple times that perhaps the name "mixin" isn't appropriate, so I was wondering if I can find a better one. The current name, mixin, is, as the library itself, inspired by the mixins in the Ruby programming language. However, it doesn't do exactly what Ruby's mixins do (as mentioned here: http://ibob.github.io/boost.mixin/boost_mixin/introduction.html#boost_mixin… ) My current alternative ideas are: * EntityComponent - not great since it doesn't exactly follow the entity-component-system pattern, although it can be said that it allows the construction of entities from components. * DynamicMixin - to emphasize that it's not to be confused with the CRTP mixins. It still has "mixin" in it's name though. * Trait - since it resembles the traits in Self, Scala, PHP, etc. However, a trait is more a "compile time" feature (even when talking about PHP) * TypeComposition or TyCo - a very vague description * Polymorph - since it allows the composition of polymorphic types at run time, but that's pobably even more vague Other ideas are welcome. Thanks -- Borislav

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A general qurey
by Mudit Sharma 04 Feb '15

04 Feb '15

What can be done to run boost on Dev-C++? What else can be used for boost?

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[chrono][multiprecision][gsoc] Project proposal, looking for feedback and mentor.
by Damian Vicino 03 Feb '15

03 Feb '15

Hi, I’m collaborating with other students working in “Simulation Driven Development” (SimDD), mostly for embed systems. The main idea in SimDD is modelling complete systems (not necessarily software) and make simulations of them. Once the simulation has the expected results start replacing some sub-models (software pieces) by real application code. The pieces that are not replaced are used to provide testing facilities. The main fields where this SimDD is used are robotics and embed systems. Where you can clearly separate models in three groups: the software, the interaction (i.e. sensors) and the environment. The software is what you are developing, the environment is the things the software will interact with and the sensors are what info the software gets from the environment and how. When the software is ready, it interacts with the sensors and the simulated environment for testing. Once tested in simulated environments it can be implemented in real world. In this context, I work in time representation problems for discrete event simulation and I will like to propose some additions to the Boost library as GSOC project. — Adding a clock to chrono for virtual simulation time, so models and real code can both work using same library for time representation. — Adding multi base support for multi-precision library. — Adding the option for an accurate mode to multi-precision (meaning a failure should happen when the result requires to be rounded and, if possible, detected at compile time). — Supporting multi base multi-precision in chrono. — For sure, documentation and tests included for everything. Is anybody interested in these additions? Can you provide some feedback about them? Is anybody interested in be my mentor for GSOC in this project? In the last year, I had being working in a general-purpose Discrete Event Simulation library as a side-project that I hope to contribute to boost. The library was submit for registration to blincubator today and in the following days I will be uploading it. Best regards, Damian Vicino

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