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Log: Coloring logging output
by Florian Lindner 04 Jul '17

04 Jul '17

Hello, I try to create a formatter that can display logging messages (or just prints the severity level in different colors). Given a format string like: default_formatter = "%SeverityFormat% %Message%"; /// A custom formatter that handles the Severity formatting class severity_formatter_factory : public boost::log::formatter_factory<char> { public: formatter_type create_formatter(boost::log::attribute_name const& name, args_map const& args) { namespace expr = boost::log::expressions; return expr::stream << "|" << "\033[32m" << expr::attr<boost::log::trivial::severity_level >("Severity") << "|"; } }; and register with bl::register_formatter_factory("SeverityFormat", boost::make_shared<severity_formatter_factory>()); it basically works, i.e. the output is colored (all green) and the severity name is printed. But how can I get the actual severity of the message that is about to be formatted inside the formatter? So I can act on that and color warn messages red and info messages green? What I found on the internets, e.g. https://stackoverflow.com/questions/38309479/how-to-add-color-coding-to-boo… http://www.boost.org/doc/libs/1_64_0/libs/log/doc/html/log/tutorial/formatt… was using the sink->set_formatter method, which gives me, afaik, no possbility to configure using a format string. But I'm open to any ideas... Thanks, Florian

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Why cannot asio tcp socket server detect TCP disconnection when the client device lost power?
by jupiter 03 Jul '17

03 Jul '17

Hi, The asio tcp server can detect the disconnection when the client program stop. But I have small device when it lost power, the server won't be able to detect the TCP disconnection. Does the boost socket has TCP timeout? What is an effective way to handle this situation other than running heartbeat in user level? Thank you. Kind regards, - j

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[review][beast] Review of Beast starts today : July 1 - July 10
by Michael Caisse 01 Jul '17

01 Jul '17

The formal review of Vinnie Falco’s Beast library will take place from July 1 through July 10, 2017. Please consider participating in this review. The success of Boost is partially a result of the quality review process which is conducted by the community. You are part of the Boost community. I will be grateful to receive a review based on whatever level of effort or time you can devote. Beast is a C++ header-only library serving as a foundation for writing interoperable networking libraries by providing low-level HTTP/1, WebSocket, and networking protocol vocabulary types and algorithms using the consistent asynchronous model of Boost.Asio. Beast is designed for: * Symmetry: Algorithms are role-agnostic; build clients, servers, or both. * Ease of Use: Boost.Asio users will immediately understand Beast. * Flexibility: Users make the important decisions such as buffer or thread management. * Performance: Build applications handling thousands of connections or more. * Basis for Further Abstraction: Components are well-suited for building upon. A branch has been made for the review. You can find Beast for review at these links: * Documentation : <http://vinniefalco.github.io/stage/beast/review/> * Source code : <https://github.com/vinniefalco/Beast/tree/review> * The FAQ answers real questions that come up : <http://vinniefalco.github.io/stage/beast/review/beast/design_choices/faq.ht…> A lightning talk from CppCon 2016 introducing Beast can be found here: <https://www.youtube.com/watch?v=uJZgRcvPFwI> Please provide in your review whatever information you think is valuable to understand your final choice of ACCEPT or REJECT including Beast as a Boost library. Please be explicit about your decision. Some other questions you might want to consider answering: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With which compiler(s)? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? More information about the Boost Formal Review Process can be found here: <http://www.boost.org/community/reviews.html> Thank you for your effort in the Boost community. Happy coding - michael -- Michael Caisse Ciere Consulting ciere.com

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Boost_1_64_0 compile errors - gcc 5.3.0
by Michael Miller 30 Jun '17

30 Jun '17

Hello, Qt Creator 4.3.1 Based on Qt 5.9.1 gcc version 5.3.0 Trying to use Boost in my program. I’m getting the following compile errors. Any suggestions, Please. Regards In file included from C:\boost\boost_1_64_0/boost/numeric/ublas/vector.hpp:21:0, from C:\boost\boost_1_64_0/boost/numeric/ublas/matrix.hpp:18, from lib\math/lc_quadratic.h:30, from lib\engine\rs_arc.cpp:37: C:\boost\boost_1_64_0/boost/numeric/ublas/storage.hpp: In member function 'void boost::numeric::ublas::unbounded_array<T, ALLOC>::serialize(Archive&, unsigned int)': C:\boost\boost_1_64_0/boost/numeric/ublas/storage.hpp:299:18: error: 'make_array' is not a member of 'boost::serialization' ar & serialization::make_array(data_, s); ^ C:\boost\boost_1_64_0/boost/numeric/ublas/storage.hpp: In member function 'void boost::numeric::ublas::bounded_array<T, N, ALLOC>::serialize(Archive&, unsigned int)': C:\boost\boost_1_64_0/boost/numeric/ublas/storage.hpp:494:18: error: 'make_array' is not a member of 'boost::serialization' ar & serialization::make_array(data_, s); ^ In file included from C:\boost\boost_1_64_0/boost/numeric/ublas/vector.hpp:21:0, from C:\boost\boost_1_64_0/boost/numeric/ublas/matrix.hpp:18, from lib\math/lc_quadratic.h:30, from lib\engine\rs_circle.cpp:42: C:\boost\boost_1_64_0/boost/numeric/ublas/storage.hpp: In member function 'void boost::numeric::ublas::unbounded_array<T, ALLOC>::serialize(Archive&, unsigned int)': C:\boost\boost_1_64_0/boost/numeric/ublas/storage.hpp:299:18: error: 'make_array' is not a member of 'boost::serialization' ar & serialization::make_array(data_, s); ^ C:\boost\boost_1_64_0/boost/numeric/ublas/storage.hpp: In member function 'void boost::numeric::ublas::bounded_array<T, N, ALLOC>::serialize(Archive&, unsigned int)': C:\boost\boost_1_64_0/boost/numeric/ublas/storage.hpp:494:18: error: 'make_array' is not a member of 'boost::serialization' ar & serialization::make_array(data_, s); ^ In file included from lib\math/lc_quadratic.h:30:0, from lib\engine\rs_circle.cpp:42: C:\boost\boost_1_64_0/boost/numeric/ublas/matrix.hpp: In member function 'void boost::numeric::ublas::c_matrix<T, M, N>::serialize(Archive&, unsigned int)': C:\boost\boost_1_64_0/boost/numeric/ublas/matrix.hpp:5977:18: error: 'make_array' is not a member of 'boost::serialization' ar & serialization::make_array(data_, N); ^

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[poly_collection] Boost.PolyCollection release version ready
by Joaquin M López Muñoz 29 Jun '17

29 Jun '17

Hello, For those who are following the development of this lib, I'd like to announce that the release version of Boost.PolyCollection for Boost 1.65 is already committed to the master branch of Boost. Much of the to-do list prepared by Ion at the end of the review has been implemented. The main features left as roadmap are listed at: http://www.boost.org/doc/libs/master/doc/html/poly_collection/future_work.h… As for the improvements already included, let me comment on what I feel are the most important: * The implementation has been refactored to avoid internal virtual calls at places where the type of the segment involved is known at compile time. Also, segment lookup (the process to get to the segment for U from typeid(U)) has been greatly sped up by means of a std::type_info* cache. These two improvements result in a combined reduction of around 25-30% in insertion times. There's an API breaking change though: no longer is std::type_index used and const std::type_info &'s have to be directly provided instead --this is likely to go unnoticed by those of you already using the lib. * Polymorphic collections now satisfy standard requirements on allocator use as stated in [container.requirements.general]/3 (or, more precisely, the natural interpretation for polymorhpic containers of this clause). This is explicitly described in the reference. As a result, polymorphic collections can now use std::scoped_allocator_adaptor without any problem. * Added segment(typeid(U))/segment<U>() convenience funtions returning a range object over the selected segment. This allows us to write: for(const auto& x:c.segment(typeid(warrior))){ ... } * Collection-level max_size() and capacity() have been removed as I didn't seem to find sensible semantics for them. Segment-level max_size() and capacity() are kept, of course. * Hopefully the tutorial section on boost::function_collection is a bit clearer now. The library works OK for MSVC>=14.0,GCC>=5.0,Clang>=3.7. Unfortunately, Intel fails for test_algorithm: https://lists.boost.org/Archives/boost/2017/06/236016.php If someone's interested in helping fix that, please step up. Thank you, Joaquín M López Muñoz

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C++11 ABI stability
by Marek Skalický 29 Jun '17

29 Jun '17

Hi, mongo-cxx-driver notices this: "Important note about C++11/C++14: The boost libraries do not offer a stable ABI across different versions of the C++ standard. As a result, you must ensure that your application, the C++ driver, and boost are all built with the same language standard. In particular, if you are building the C++ driver with C++11 enabled, you must also build your application with C++11 enabled, and link against a C++11 compiled boost. " [1] Is it true? What changes with new standard? (or is this only related to ABI change in gcc introduced by c++11?) I'm interested mainly in libraries: filesystem, chrono, thread, system and regex Thanks, Marek [1] http://mongodb.github.io/mongo-cxx-driver/legacy-v1/installation/#s cons-options-when-compiling-the-c-driver

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[boost] [beast] Formal "review" branch frozen
by Vinnie Falco 29 Jun '17

29 Jun '17

The "review" branch of Beast is now available and frozen for modifications. It contains the snapshot of the repository which will undergo the Boost formal review starting on July 1 and lasting for 10 days. Currently the review branch is even with the master branch, at version 70. The review branch repository is here: https://github.com/vinniefalco/Beast/tree/review The review documentation snapshot: http://vinniefalco.github.io/stage/beast/review/ Autobahn WebSocket Implementation Test Report: http://vinniefalco.github.io/autobahn/index.html Beast is a C++ header-only library serving as a foundation for writing interoperable networking libraries by providing low-level HTTP/1, WebSocket, and networking protocolvocabulary types and algorithms using the consistent asynchronous model of Boost.Asio. Beast empowers users to create their own libraries, clients, and servers using HTTP/1 and WebSocket. Code will be easier and faster to implement, understand, and maintain, because Beast takes care of the low-level protocol details. Please don't forget to "star" the repository on GitHub, the increased exposure will vitalize Beast and Boost with the new generation of programmers! Thanks! -- Follow me on Github: https://github.com/vinniefalco

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Regression in Boost.Variant with gcc6.3 in C++03 mode
by dariomt＠gmail.com 28 Jun '17

28 Jun '17

Hi, This is the simplest possible repro I could get: #include <boost/variant.hpp> class A {}; class B : private A {}; typedef boost::variant<A, B> variant_t; int main() { B b; variant_t v (b); } This used to work with Boost 1.59.0 but fails with 1.64.0 Using wandbox I've found that: - it started failing in 1.62.0 - clang does not have this problem - newer and older versions of gcc do have the same problem The error is miles long. I think the important parts are: boost/type_traits/is_convertible.hpp:149:53: error: 'A' is an inaccessible base of 'B' error: no matching function for call to 'boost::variant<A, B>::variant(B&)' It seems the metaprogramming messes up due to the private inheritance, and decides that the variant<A,B> is *not* constructible from B Workarounds are very welcome! Switching to C++14 is not an option (yet). Regards

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Compiling Boost_1_6_0 under linux.
by Michael Miller 27 Jun '17

27 Jun '17

Hello, I’m trying to compile Boost_1_64_0 under linux, without success. Debian 9 gcc version 6.3.0 Terminal commands:- cd tools/build ./bootstrap.sh ./b2 install --prefix=~/boost/boost_1_64_0 No Boost (executable) appears. Am I missing something? Regards

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Build error C3083
by James 26 Jun '17

26 Jun '17

Hi, I am trying to build an application that uses the boost libraries. I am seeing build error C3083 in bind_mf_cc.hpp. The error states: Error C3083 'core': the symbol to the left of a '::' must be a type This is the offending code section : template<class Rt2, class R, class T, class A1> typename boost::enable_if_c<!boost::core::is_same<Rt2,R>::value, _bi::bind_t<Rt2, _mfi::BOOST_BIND_MF_NAME(mf0)<R,T>, typename _bi::list_av_1<A1>::type>>::type BOOST_BIND(R(BOOST_BIND_MF_CC T::*f) (), A1 a1) { typedef _mfi::BOOST_BIND_MF_NAME(mf0)<R, T> F; typedef typename _bi::list_av_1<A1>::type list_type; return _bi::bind_t<Rt2, F, list_type>(F(f), list_type(a1)); } And the line giving the trouble is the line beginning: typename boost::enable_if_c<!boost::core::is_same<Rt2,R>::value, Can anyone help me correct the line to fix this issue please? Thanks.

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