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[GSoC-2019] Guidance about GSoC 2019
by Karthik Kothuri 24 Dec '18

24 Dec '18

Hi, I am Karthik Kothuri, a 2nd year Computer Science and Engineering student at National Institute of Technology, Warangal. I would like to contribute to this organization in view of GSoC 2019. Any mentor is requested to guide me regarding this and tell me where to get started. I am experienced with moderate C++ and have been using it extensively for over an year for my Data Structures and Algorithms course. I also have a basic knowledge of object oriented programming which I will improve over the course of the next few months as part my college curriculum. Thanks.

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[uuid] constexpr uuid from string and ""_uuid literal
by Tobias Loew 24 Dec '18

24 Dec '18

Hi, while searching for constexpr GUID from string generators, I found https://gist.github.com/AlexBAV/b58e92d7632bae5d6f5947be455f796f . Since I still work with VS 2015, I wrote a C++11 constexpr version incl. boost-uuid generators. If there's interest adding this to boost uuid, please have a look at https://github.com/tobias-loew/constexpr-GUID-cpp-11 NB. This is not a finished version to be added to uuid. Comments and BOOST-Macros for constexpr needs to be added. Tobias -- Sent from: http://boost.2283326.n4.nabble.com/Boost-Dev-f2600599.html

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ASIO TCP socket scalability for large scale connections
by hh h 24 Dec '18

24 Dec '18

Hi, In regard to ASIO TCP socket implementation, for each connections the server needs to open and to maintain a session, obviously there need be adequate RAM and CPU resources for supporting large connections, but does ASIO TCP socket itself has any limitation for connecting to large clients which could be over 10000 or more simultaneously? What will be the maximum connections a single ASIO TCP socket server can handle? Thank you.

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Re: [boost] Should pass boost::asio::io_service by raw pointer or smart pointer?
by Vinnie Falco 24 Dec '18

24 Dec '18

On Thu, Dec 20, 2018 at 6:45 PM Richard Hodges <hodges.r(a)gmail.com> wrote: > ...even with Vinnie's easy to follow guide, it requires a hundred lines of > boilerplate to implement what amounts to one async method. Yes, that is kind of irritating. I've been working on some tools to make it easier. The function wrap_handler returns a new completion handler which wraps your function object (lambda) and inherits the allocator and executor of another completion handler: <https://github.com/vinniefalco/beast/blob/8afbc6090bded0cdfda46871d829ea778…> The class template base_handler<> is meant as a base class for composed operations, it holds the handler for you and it provides all the hooks. I notice that you didn't include an overload for asio_handler_invoke in your example, which will certainly cause undefined behavior in some cases: <https://github.com/vinniefalco/beast/blob/8afbc6090bded0cdfda46871d829ea778…> You can see both wrap_handler and handler_base used together to implement a composed operation, a flavor of async_read_some which has a built-in timeout: <https://github.com/vinniefalco/beast/blob/8afbc6090bded0cdfda46871d829ea778…> In particular, handler_base let me leave out all of the boilerplate which is nice. It is possible that with some adaptation these utilities can be used to achieve the result you desire. These experimental features will appear in Boost.Beast version 1.70.0. Regards

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GitHub testing issues
by Cromwell Enage 22 Dec '18

22 Dec '18

Hi, everyone! Starting yesterday, I experienced failures on all my test builds. Their logs contain the following message: travis_time:end:1a83bdea:start=1545229245463720000,finish=1545229258317024000,duration=12853304000 [0Ktravis_fold:end:install.10 [0Ktravis_fold:start:install.11 [0Ktravis_time:start:04d79bf0 [0K$ ./b2 headers boost-install.jam: No such file or directory Jamroot:307: in boost-install ERROR: rule "boost-install.boost-install" unknown in module "Jamfile</Users/travis/build/CromwellEnage/boost-root>". libs/atomic/build/Jamfile.v2:38: in modules.load /Users/travis/build/CromwellEnage/boost-root/tools/build/src/build/project.jam:372: in load-jamfile /Users/travis/build/CromwellEnage/boost-root/tools/build/src/build/project.jam:64: in load /Users/travis/build/CromwellEnage/boost-root/tools/build/src/build/project.jam:89: in load-used-projects /Users/travis/build/CromwellEnage/boost-root/tools/build/src/build/project.jam:75: in load /Users/travis/build/CromwellEnage/boost-root/tools/build/src/build/project.jam:142: in project.find /Users/travis/build/CromwellEnage/boost-root/tools/build/src/build-system.jam:618: in load /Users/travis/build/CromwellEnage/boost-root/tools/build/src/kernel/modules.jam:295: in import /Users/travis/build/CromwellEnage/boost-root/tools/build/src/kernel/bootstrap.jam:139: in boost-build /Users/travis/build/CromwellEnage/boost-root/boost-build.jam:17: in module scope travis_time:end:04d79bf0:start=1545229258327432000,finish=1545229259660893000,duration=1333461000 [0K [31;1mThe command "./b2 headers" failed and exited with 1 during . [0m It's also happening on Appveyor, and just from looking at < https://github.com/boostorg/graph/pull/144>, I'm not the only one who is encountering these errors. Any help would be appreciated. Thanks! Cromwell D. Enage

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New library proposal: Autodiff
by Matt Pulver 21 Dec '18

21 Dec '18

Hello, An automatic differentiation <https://en.wikipedia.org/wiki/Automatic_differentiation> C++ library - Autodiff - is released under the Boost License and is proposed for inclusion into Boost: - Github: https://github.com/pulver/autodiff - Boost Library Incubator: http://blincubator.com/bi_library/autodiff-2/?gform_post_id=1716 Features: - Instances of autodiff variables satisfy Boost's Conceptual Requirements for Real Number Types <https://www.boost.org/doc/libs/1_69_0/libs/math/doc/html/math_toolkit/real_…>. In fact the class and function template definitions are based upon the tables in this page. - No use of dynamic memory. The only member variable is a std::array<>. - Consistent with Boost's type promotion templates. When adding/multiplying/etc. variables of differing dimension number and sizes, the resulting data type is calculated at compile-time. - Single header-only file. - Intuitive and minimal API. Requirements: - C++17 compiler that supports constexpr if statements. There are a fair amount of calculations done at compile-time which would require messy SFINAE hacks to make this C++14-compatible. Todo: - A github build matrix that also includes clang and MSVC. - Additional documentation, including the mathematics. Feedback and endorsements for Boost Library inclusion are welcome and requested. Best regards, Matt

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[parameter] Helping user libraries adjust to recent changes in GitHub develop branch
by Cromwell Enage 20 Dec '18

20 Dec '18

Hi, everyone! I've been contributing upgrades to Boost.Parameter functionality and documentation in the GitHub develop branch for the past couple of months. These upgrades include the addition of code generation macros for Boost.Parameter-enabled function call operators and support for perfect forwarding, and more upgrades are yet to come. It's been an enjoyable experience so far, but understandably there are some growing pains. I've taken pains to ensure that as long as user libraries access only the public interface of Boost.Parameter, they won't be affected by the changes. However, there are several notable libraries that currently use non-public portions of Boost.Parameter, so whenever possible I've submitted PRs to those libraries that either change the usage to access only public portions (preferred) or make quick fixes (temporary). I'm drawing off Peter Dimov's page < https://pdimov.github.io/boostdep-report/develop/parameter.html> as a guide to focus my efforts. As of this writing, I have active PRs for the following libraries: Boost.Convert Boost.Graph Boost.Lockfree I also have my eye on the following libraries, which I know have been broken by the latest changes: Boost.Accumulators Boost.Log I'm willing to help the library maintainers resolve these issues as quickly as possible. This post can serve as a discussion starting point, and I should be able to answer any questions you have about the changes to Boost.Parameter. Cromwell D. Enage

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Feature/cmake-config merged to develop; yml files need to be updated
by Peter Dimov 19 Dec '18

19 Dec '18

I've just merged the superproject branch feature/cmake-config to develop. This updates `b2 install` to export CMake configuration files into the `cmake` subdirectory of the library directory. These configuration files enable a Boost installation to be used from CMake via `find_package(boost_filesystem)`, without relying on FindBoost. Unfortunately, this change adds two necessary submodules to the superproject, `tools/boost_install` and `libs/headers`. As a result, all .travis.yml and appveyor.yml files that rely on a partial checkout need to be updated to perform git submodule update --init tools/boost_install git submodule update --init libs/headers in addition to the usual git submodule update --init tools/build git submodule update --init libs/config I'm sorry for the inconvenience this will cause, or perhaps already has caused.

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Ignoring unused type aliases in concepts
by Mateusz Loskot 18 Dec '18

18 Dec '18

Hi, In concepts, such unused type aliases are not uncommon. What is the best way to ignore compiler warnings about those? Options I'm aware of are: 1. Adjust compile options in build configuration (Jamfile) 2. Use #pragma in headers 3. Use boost::ignore_unused_variable_warning(alias{}) (or little brother boost::ignore_unused) 4. Ignore ignoring them. The options 1 and 2 are mentioned on https://svn.boost.org/trac10/wiki/Guidelines/WarningsGuidelines The option 3 is not and is there any particular reason why? Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

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Error to convert to boost::asio::streambuf to raw buffer char *buffer
by hh h 18 Dec '18

18 Dec '18

boost::asio::streambuf sb; char *raw = sb; error: cannot convert ‘boost::asio::streambuf {aka boost::asio::basic_streambuf<>}’ to ‘char*’ in initialization I've checked the boost::asio::streambuf reference, but could not find anything to fix it, appreciate any clues.

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