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

[autoindex] Default building with an Index
by Edward Diener 22 Dec '15

22 Dec '15

The documentation for VMD supports building with an index but I had not made this the default situation. This is my mistake. Can I assume the official build of the docs for a release supports building with an index via autoindex ? If so I will change the jamfile to support this as the default for the future and assume any end-user wishing to regenerate the docs has autoindex support also as part of the distribution as long as my jamfile is setup correctly for autoindex.

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[doc] Releases 1.59 and 1.60 missing some tools documentation
by Edward Diener 22 Dec '15

22 Dec '15

In the 1.60 release, and I also just noticed in at least the 1.59 release also, the documentation links to the Release and Regression tools go to an invalid URL. Also while the documentation link to Boost.Build goes to a general explanation page the subsequent documentation link to Documentation goes to an invalid URL. Is this what we want, and that the end-user should have to "build" the documentation ? It seems doubtful, considering what a trial it often is for developers themselves to build the documentation given the tools available to do so. I think that this needs to be corrected in upcoming releases.

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[regression] run.py merge option
by Antony Polukhin 22 Dec '15

22 Dec '15

Hi, How hard would it be to add a --merge option to run.py? Motivation: I'm experimenting with running all the regression tests on TravisCI https://github.com/apolukhin/boost_indirect_testing. Unfortunately, it has some hard limits, so a task can not work more than 2 hours. I've ended up splitting all the Boost tests by libraries and running tests on per library basis. Unfortunately, when the test results are send to server, only one library result is displayed in resulting matrix (search http://www.boost.org/development/tests/develop/developer/summary.html for indirect_travisci_tests) So I'd like to get a --merge option, that will allow merge of all the results by tester_name+revision. For example if results for 'geometry' and 'any' are sent with tester name `indirect_travisci_tests` and revision 74f85d, then show them in a single column. This may be also useful for those test runners that run tests on embedded or emulated devices (running all the Boost tests on emulated MIPS device may take a few weeks; running the tests on multiple emulated MIPS devices will speed up things) -- Best regards, Antony Polukhin

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Software Freedom Conservancy Support
by Jon Kalb 22 Dec '15

22 Dec '15

This is not a technical message, but instead focuses on Boost Administration. Software Freedom Conservancy in a Financial Fight for its Life Software Freedom Conservancy, the non-profit home of Boost is facing an existential threat. Historically, Conservancy has been funded by corporate donations. This works great when it works, but a management shake-up, change in priorities, or a bad quarter at a large donor can derail the organization¹s programs. It has become obvious that Conservancy must move to a Supporter-driven funding model, where individuals who believe in Conservancy¹s mission of supporting open source projects, such as Boost, make a personal commitment to support that effort. Conservancy's fundraiser, found at https://sfconservancy.org/supporter/, is centered around asking individuals who care about the work that Conservancy does to donate $120/year, or just $10/month, to support the organization. Conservancy seeks about 2,500 Supporters to continue its current work, and 750 Supporters to continue a ³bare minimum² of services to its projects. What does this mean to Boost? Boost receives a myriad of important services (see https://sfconservancy.org/members/services/ ) from Conservancy. We¹ve relied on Conservancy since 2007 to provide them. Here are some of the things that Conservancy does for Boost that are in the ³bare minimum² category: * Dealing with all the financial and contractual details regarding our annual C++ Now conference. It was BoostCon that brought Boost and Conservancy together. C++Now 2016 will the the tenth annual BoostCon and it is a tribute to what we¹ve accomplished working together. * Handle our Google Summer of Code payments and travel, including handling all financial transactions with Google to receive and then disperse the money. * Coordinating travel reimbursements for Boost contributors (both developers and students) to attend conferences. * Receiving and tracking all donations to Boost. * Keeping the non-profit status for us so that we don't have to form our own org and file our own paperwork. As the Chair of the Boost Steering Committee, I cannot overstate how important this is to our existence as an organization. Here are some of the services Boost has received in the wider category: * Dealing with questions from the community (including license-governing bodies like OSI) about Boost's license. * Discussing the issue of copyright governance and contributions with large corporations who want their employees to contribute to Boost but need legal assurances or have questions relating to Boost's license or contribution policies. * Reviewing and handling licensing terms of third-party software that relate to Boost in some way, and giving us feedback and answers about issues related to it. * General legal consulting on issues that we run into as an open source non-profit. As you can see, Boost really relies on the important work of Conservancy. Support from Boost Boost, like all of Conservancy¹s projects, contributes 10% of our revenue to Conservancy¹s general fund. (The other 90% is maintained and administered by Conservancy at the direction of the Boost Steering Committee to advance the Boost project.) But that 10% of revenue from all Conservancy¹s member projects doesn¹t add up to enough to even employee one full time person, let alone the already overworked staff of three that Conservancy has. Donors must make up the difference. When Conservancy launched its fundraising effort, I sent out a request to past BoostCon/C++Now attendees asking for support and I¹m proud and delighted to say that a number of Boost community members have already stepped up. One told me that her company will be matching her support. Boost is one of Conservancy¹s oldest and largest projects, so it is right that Boost community members make up a fair proportion of its supporters. I encourage you to choose Conservancy as one of your charitable gifts this holiday season. (Conservancy is a 501(c)(3) charity incorporated in New York, and donations are typically deductible on U.S. taxes.) Please visit: https://sfconservancy.org/supporter/ If you are able to join the others from the Boost community that are making this gift, please let me know. I¹d like to personally thank you. Jon Kalb Chair, Boost Steering Committee

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Becoming Maintainer of the Iterator Library
by Nathan Wilson 21 Dec '15

21 Dec '15

Hi all, There was talk on the mailing list a few months back, and was apparently discussed at CppCon in September, about becoming a Library Maintainer. This was pertaining to Libraries which are either being maintained by the CMT, or as Edward Diener mentioned, Libraries which aren't in the CMT's hands but the current maintainer(s) don't have time to devote to maintaining the particular library. That said, after having discussed it with a few people outside the mailing list, I would like to volunteer to become a Maintainer of Boost's Iterator Library. I have not been active on Boost's mailing list, but have participated in the C++ Standardization Process with the paper Delimited Iterators (http://open-std.org/jtc1/sc22/wg21/docs/papers/2014/n4257.html) which will be in the Library Technical Specification 2. I have also submitted/committed some Patches in Clang as well. I just wanted to mention those couple of things as a point of reference so this didn't seem entirely random. Anyway, I'd be really excited to help contribute and help Boost by becoming a Maintainer of the Iterator Library. I do have some concern about compiling on various versions of Windows/OSX though. I have a Windows 8.1 machine and could obviously use Visual Studio, but I'm not too sure about verification of older Windows/OSX versions. On Linux I can certainly create VMs for various distros. If anyone has some best practices or advice about handling different OS distros/versions, that would be great. Please let me know if there are any questions. Thank you, Nathan

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[smart_ptr] Moving cast for unique_ptr
by Karolin Varner 21 Dec '15

21 Dec '15

Hi all! There is the family of boost pointer cast (boost::static_pointer_cast, boost::dynamic_pointer_cast, ...) that allow a developer to write generic code by casting pointers regardless of whether they are some smart pointer (e.g. shared_ptr) or plain pointers. However, those functions have not been implemented for unique_ptr, because they create a copy of their pointer and unique_pointers can not be copied. In my case I still needed to cast some unique_ptr and since it's ok to move unique_ptrs I wrote a function that does exactly that. The code is below – Comments are very, very welcome. It works for my case, but I am sure it is not as generic and safe as it should be ;) . Specifically, for a library, it should be made to work on any kind of smart/plain pointer. Not just unique_ptr. Is there any interest to include a boost::static_moving_pointer_cast and the other types of casts in boost? Best, Karolin /// Dynamic cast a unique_ptr. /// /// This function shall move the pointer in in_ptr, into /// a new unique_pointer of the desire type, dynamic_casting /// it in the process. /// In given pointer shall contain a NULL pointer afterwards. /// /// If unsuccessful, function shall throw an error and leave /// in_ptr unmodified. /// /// This behaviour contrasts a bit with the behaviour of the /// normal dynamic_cast: /// 1. dynamic_cast copies objects, this moves them since /// unique_pointers can not be copied. /// 2. dynamic_cast returns a NULL pointer if the pointer to /// cast is of an incomplete type, this throws /// incomplete_cast instead, to ease error handling. /// /// @tparam T The type to convert to (as non-pointer) /// @tparam F The type to convert from (as non-pointer) /// @param in_ptr The unique_ptr to cast /// @return in_ptr, cast to the desired type template<typename T, typename F> std::unique_ptr<T> dynamic_moving_pointer_cast(std::unique_ptr<F> &in_ptr) { // Exception safety: If The dynamic cast throws an error, // or of we throw incomplete_cast, in_ptr will still be // unmodified T *plain_out_ptr = dynamic_cast<F*>(in_ptr.get()); if (plain_out_ptr == NULL && in_ptr.get() != NULL) throw incomplete_cast(); // Exception safety: Both operations are noexcept in_ptr.release(); return std::unique_ptr<T>(plain_out_ptr); }

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safe::map
by Karen Pease 21 Dec '15

21 Dec '15

Hi everyone - I'm new to boost-devel, and am a bit intimidated ;) I recently finished a project and I don't know if the boost community would have any interest in it, whether it's really "boost material" or not: https://github.com/KarenRei/safe-map The page goes into more detail, but the short of it is: after searching and a long conversation on StackExchange, I discovered that while there are threadsafe ordered-map containers out there, the threadsafety was a bit weak. For example, if you have Thread A iterating across the map and Thread B thread just happens to delete an element as A is passing by, A's iterator becomes invalidated and the program crashes - even in a supposedly "threadsafe" map. For the type of multithreaded cache that I needed, I needed a structure that had the thread safety level of a filesystem - you know, where multiple processes can have file descriptors open at a time and one process might even potentially delete a file that another is accessing, without leading to a system crash. And that's basically what I implemented: safe::map, which not only ensures that basic operations on the container itself are threadsafe, but that everything you do with the iterators - even deleting elements out of the map that other iterators are pointing to - is also threadsafe. It does this by implementing reference counting on the elements in the map and flagging elements for deletion rather than deleting them immediately. A more detailed description of usage, performance, implementation, use cases, etc is on the project page. The project comes with a test suite which launches a number of threads that endlessly randomly tweak and iterate around the map with every function available to them. Does this sound like something that might be useful in boost (after whatever changes would be required)? If there's no interest, no harm done :) - kv, Karen

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[Travis] All boostorg builds stalled?
by Louis Dionne 20 Dec '15

20 Dec '15

Hi, All of Hana's builds are currently stalled [1]. It has been like this for 2 or 3 days. I tried contacting Travis' support, but they are in vacation until January 4th. It also seems like the builds for Predef have been stalled for a while [2]. Perhaps other libraries are also touched. Strangely, builds for non-Boost repositories are not stalled, since I can build personal projects just fine. Does anyone know what might be happening? Louis [1]: https://travis-ci.org/boostorg/hana/builds [2]: https://travis-ci.org/boostorg/predef/builds/97532851

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[gsoc]Seeking Guidance
by Ibrahim Dalal 20 Dec '15

20 Dec '15

Hi I am a sophomore, majoring in Computer Science. I am also a GSoC'16 aspirant. Its the first time I would be contributing to an open source project. Can someone please guide to a small project/patch suitable for a beginner? I have familiarity with C++ programming language along with basic understanding of C and Python. Also have some elementary knowledge of Git. Thanks

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Boost 1.60.0 has been released
by Marshall Clow 18 Dec '15

18 Dec '15

Release 1.60.0 of the Boost C++ Libraries is now available. These open-source libraries work well with the C++ Standard Library, and are usable across a broad spectrum of applications. The Boost license encourages both commercial and non-commercial use. This release contains one new library and numerous enhancements and bug fixes for existing libraries. New Libraries * VMD: Variadic Macro Data library, from Edward Diener For details, including download links, see http://www.boost.org/users/news/version_1.60.0 You can also download directly from SourceForge: http://sourceforge.net/projects/boost/files/boost/1.60.0/ Tom Kent has made pre-built windows binaries, and they are available at: https://sourceforge.net/projects/boost/files/boost-binaries/1.60.0/ To install this release on your system, see http://www.boost.org/doc/libs/release/more/getting_started/index.html Thanks, --The Boost release team Vladimir Prus Rene Rivera Marshall Clow Eric Niebler Daniel James Beman Dawes

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