February 2015 - Boost - lists.preview.boost.org

[voronoi] Issue with boost::polygon::voronoi_diagram<> as class variable
by duke 08 Feb '15

08 Feb '15

For some reason when I have a voronoi_diagram as a class variable (which it needs to be in this case), I get this error on compile: Error 49 error C2248: 'boost::polygon::voronoi_diagram<T>::operator =' : cannot access private member declared in class 'boost::polygon::voronoi_diagram<T>' I'm new to C# so it may be something obvious. - George

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[MPL] Advice on how to proceed with a bugfix pull request
by Bruno Dutra 08 Feb '15

08 Feb '15

Hello everyone, I've found a fix to this bug <https://svn.boost.org/trac/boost/ticket/7769#no3>, which is based on BOOST PP library and thus should be supported across the various platforms, even though I just tested for a specific set up as I mentioned on my comment there. I've added some code snippets, from which it is straightforward to develop a patch, but I guess it would be best if I just issued a pull request myself. Since this is my first time contributing to MPL and to BOOST itself for all that matters, I'd like to first hear some advice on how to do this properly. For instance, to which branch should I issue the pull request? By the way, is this indeed the best way to proceed at all? Kind regards, *Bruno C. O. Dutra*

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A proposal
by Mudit Sharma 08 Feb '15

08 Feb '15

After creating QR,LU and Cholesky for Boost..can we develop algorithms for determining which of QR,LU,Cholesky..etc. should be used in solving linear equations based on analyzing the running time and numerical stability specific to the problem. Is it feasible? Thanks!

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Re: [boost] A proposal
by Ganesh Prasad 08 Feb '15

08 Feb '15

LU is already implemented in UBLAS. As of QR, SVD and Cholesky you might want to spend more time in debugging and testing for any one or two of the algorithms. https://github.com/GnsP/viennacl-dev/tree/master/viennacl/linalg you can find some useful sources here. Best wishes Ganesh

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[c++11] MSVC does not define __cplusplus?
by Oliver Kowalke 07 Feb '15

07 Feb '15

Hi, I encountered that '__cplusplus < 201103L' evaluates on MSVC (14.0 ...) to true?! At least on GCC + CLANG this test works - what about MSVC? best regards, Oliver

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[new libraries] [sort] New Library Check list updated
by Beman Dawes 07 Feb '15

07 Feb '15

As we started through the process of adding the sort library as a module, it became obvious the docs for how to do this were quite out-of-date. The best document for adding new libraries is https://svn.boost.org/trac/boost/wiki/ReleasePractices/ManagerCheckList#New…, and that section has now been updated. Although this document is written from the perspective of release managers, the New Library Checklist section serves as a roadmap for what is expected as a new library goes through the stages of being added to a Boost distribution. Comments and corrections welcome, --Beman

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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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