March 2017 - Boost - lists.preview.boost.org

GSOC Project
by Umar Ali 28 Mar '17

28 Mar '17

I am a Computer Science student trying to apply with MariaDB in GSOC. I have a basic knowledge of SQL and a deeper understanding of C++, and was wondering whether I would have to come up with a project idea inorder to file a proposal or can i submit a proposal inorder to learn without any deeper understanding of programming languages

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[review queue] Beast Review Date - Request
by Michael Caisse 28 Mar '17

28 Mar '17

Hello Wizards! We would like to schedule the Beast review (already in the queue) for the week of July 1 - July 8. Thanks! michhael -- Michael Caisse Ciere Consulting ciere.com

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[release] Boost 1.64.0 Beta 1
by Rene Rivera 27 Mar '17

27 Mar '17

Boost release 1.64.0 beta 1 is now available at: <https://dl.bintray.com/boostorg/beta/1.64.0.beta.1/source/> The SHA256 checksums are as follows: 8f0ba6b73fad15115049f9b3e7e27eae43be10a94b51a57142f3a27e55ef4beb boost_1_64_0_b1.7z b5c5abf127a3f723dafcc7cf55876c1bda9f014fb1b117f6a7f769e3cc407c4f boost_1_64_0_b1.tar.bz2 a7fe98a9a9f615f6fa68d8ea09ce725d19e3a4fe4719c21c9db29dff88b3b6e3 boost_1_64_0_b1.tar.gz 593005661af8dfe132b2b16bc2cd41339e6acd58456913f353d765090d7868f7 boost_1_64_0_b1.zip For details of what's in the release, see < http://www.boost.org/users/history/version_1_64_0.html>. Note that the links to files on this web page are for the final release - use the link above to get the beta files. There are also pre-built libraries provided by Tom Kent here: <https://dl.bintray.com/boostorg/beta/1.64.0.beta.1/binaries/> Please download the beta, give it a try, and report any problems you encounter. Thanks, -- The Boost Release Team -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

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Going insane trying to build boost for android
by Robert Dailey 26 Mar '17

26 Mar '17

How many months has it been of lost google searching, trying to beat b2 into submission. I have no idea at this point how to build boost for Android. Really hoping I get some help here... So to start, here are the versions I'm using: - Android NDK r14b - Boost 1.63.0 I'm doing all of this on Windows 10, through command prompt. I want to use clang and libc++ to build boost for API 15. I figure the easiest way is to generate a standalone toolchain using the NDK, so I did that first: > %ANDROID_NDK%\build\tools\make_standalone_toolchain.py --arch arm --api 15 --stl libc++ "C:\android\_toolchains\arm-api-15" This generated the appropriate toolchain (I think). I then temporarily added this location to PATH: > set PATH=C:\android\_toolchains\arm-api-15\bin;%PATH% Then I ran bootstrap: > bootstrap.bat --with-toolset=clang Then I tried to build boost itself: > b2 --toolset=clang cxxflags="-stdlib=libc++ -std=c++14" threadapi=pthread --prefix=..\boost_android_arm --builddir=./ target-os=linux define=BOOST_FILESYSTEM_VERSION=3 --without-python link=static runtime-link=shared threading=multi variant=release install -j8 However I get failures when it tries to run the clang command: 'C:\code\_third_party\boost_1_63_0\\clang38++.exe' is not recognized as an internal or external command I'm not sure why it's appending that absolute path (that's where my current directory is set to, and where boost source is). It should just be trying to use "clang++" but doesn't look like it is. >From the output, it looks like it's trying to use clang correctly I think: "clang++" -c -x c++ -stdlib=libc++ -std=c++14 -O3 -Wno-inline -Wall -pthread -stdlib=libc++ -std=c++14 -DBOOST_ALL_NO_LIB=1 -DBOOST_FILESYSTEM_VERSION=3 -DBOOST_THREAD_USE_LIB=1 -DNDEBUG -I"." -o "bin.v2\libs\wave\build\clang-linux-android\release\link-static\target-os-linux\threadapi-pthread\threading-multi\cpplexer\re2clex\aq.o" "libs\wave\src\cpplexer\re2clex\aq.cpp" Am I going about this all wrong? How in the heck can I build boost for android using the settings I specified above?

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[SIMD] Pre-review questions
by Artyom Beilis 26 Mar '17

26 Mar '17

Hello, I have several questions regarding Boost.SIMD (for pre-review) 1. What is boost::simd::pack::storage_type I can't find it in documentation. Is it the "native register" like __m128i for pack<int,4>? If the answer is no, how do I get access to underlying type? 2. I can't find in documentation how to performs casts between different types: I see in docs split_low (actually after I grepped for _mm_unpacklo) but I failed to find how to use one - there is no documentation regarding conversion/casting operation or at least I failed to find one. 3. Is there more convenient way to perform basic saturated operation for example if I want to calc abs diff of two bs::pack<unsigned char,16> values a,b I need to write bs::saturated_(be::minus)(a,b) + bs::saturated_(bs::minus)(b,a) It is quite inconvenient especially when most of operations you want to do are saturated. 4. Why Boost.SIMD is restricted to C++11? Most of the stuff is implementable withing C++2003, it severely limits the usability of the library for existing projects that can't trivially switch to new C++ standard (and there are too many in the "real world" industry) Thanks, Artyom

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Boost Logo usage questions
by Antony Polukhin 26 Mar '17

26 Mar '17

Hello, What are the rules for the Boost logo usage? Can I use the Boost logo on a cover of the Boost related book ? What are the permissions for the library logos (for example https://github.com/boostorg/test/blob/develop/doc/html/images/boost.test.lo… )? -- Best regards, Antony Polukhin

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[asio]ssl::detail::stream_core is accessed after destruction
by Takatoshi Kondo 26 Mar '17

26 Mar '17

Hello, I'm using Boost.Asio. I compiled some TLS client with clang address sanitizer. (I attached the result the last part of this mail.) It indicates that the following `expires_at` member function calling is bad: https://github.com/boostorg/asio/blob/boost-1.63.0/include/boost/asio/ssl/d… So I insert debug print "stream_core() address" to the constructor of ssl::detail::stream_core https://github.com/boostorg/asio/blob/boost-1.63.0/include/boost/asio/ssl/d… "~stream_core() address" to the destructor, https://github.com/boostorg/asio/blob/boost-1.63.0/include/boost/asio/ssl/d… and "io stream_core address of core_" to `expires_at` calling point: https://github.com/boostorg/asio/blob/boost-1.63.0/include/boost/asio/ssl/d… And then, I got the following result: stream_core() 0x6120012beb60 constructor ~stream_core() 0x6120012ca6e0 connected. previous session = false stream_core() 0x6120012ba060 ~stream_core() 0x6120012beb60 destructor io stream_core 0x6120012beb60 call Is seems that `expires_at` at https://github.com/boostorg/asio/blob/boost-1.63.0/include/boost/asio/ssl/d… is called after core_ 's destructor is called. The problem happens a part of big project. The client connects to the server as TLS-stream, then server shutdown the stream, then client connects again. The program does the sequence repeatedly. The error happens the client side. I'm trying to write a minimal and complete code that reproduces the problem, but not yet. So I report the result only as the first report. The result of clang address sanitizer ---------------------------------------------------------------------------------- SUMMARY: AddressSanitizer: heap-use-after-free /usr/include/boost/asio/basic_deadline_timer.hpp:344:27 in boost::asio::basic_deadline_timer<boost::posix_time::ptime, boost::asio::time_traits<boost::posix_time::ptime>, boost::asio::deadline_timer_service<boost::posix_time::ptime, boost::asio::time_traits<boost::posix_time::ptime> > >::expires_at(boost::posix_time::ptime const&) Shadow bytes around the buggy address: 0x0c248024fd20: fd fd fd fd fd fd fd fd fd fd fa fa fa fa fa fa 0x0c248024fd30: fa fa fa fa fa fa fa fa fd fd fd fd fd fd fd fd 0x0c248024fd40: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd 0x0c248024fd50: fd fd fd fd fd fd fd fd fd fd fa fa fa fa fa fa 0x0c248024fd60: fa fa fa fa fa fa fa fa fd fd fd fd fd fd fd fd =>0x0c248024fd70: fd fd fd fd fd fd[fd]fd fd fd fd fd fd fd fd fd 0x0c248024fd80: fd fd fd fd fd fd fd fd fd fd fd fa fa fa fa fa 0x0c248024fd90: fa fa fa fa fa fa fa fa fd fd fd fd fd fd fd fd 0x0c248024fda0: fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd fd 0x0c248024fdb0: fd fd fd fd fd fd fd fd fd fd fd fd fa fa fa fa 0x0c248024fdc0: fa fa fa fa fa fa fa fa fd fd fd fd fd fd fd fd Shadow byte legend (one shadow byte represents 8 application bytes): Addressable: 00 Partially addressable: 01 02 03 04 05 06 07 Heap left redzone: fa Heap right redzone: fb Freed heap region: fd Stack left redzone: f1 Stack mid redzone: f2 Stack right redzone: f3 Stack partial redzone: f4 Stack after return: f5 Stack use after scope: f8 Global redzone: f9 Global init order: f6 Poisoned by user: f7 Container overflow: fc Array cookie: ac Intra object redzone: bb ASan internal: fe Left alloca redzone: ca Right alloca redzone: cb ==11437==ABORTING ---------------------------------------------------------------------------------- heap use after free occurs the following code: ---------------------------------------------------------------------------------- ==11437==ERROR: AddressSanitizer: heap-use-after-free on address 0x6120012bebb0 at pc 0x000000749b30 bp 0x7ffccc310470 sp 0x7ffccc310468 READ of size 8 at 0x6120012bebb0 thread T0 #0 0x749b2f in boost::asio::basic_deadline_timer<boost::posix_time::ptime, boost::asio::time_traits<boost::posix_time::ptime>, boost::asio::deadline_timer_service<boost::posix_time::ptime, boost::asio::time_traits<boost::posix_time::ptime> > >::expires_at(boost::posix_time::ptime const&) /usr/include/boost/asio/basic_deadline_timer.hpp:344:27 #1 0x748e21 in boost::asio::ssl::detail::io_op<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> >, boost::asio::ssl::detail::write_op<boost::asio::mutable_buffers_1>, boost::asio::detail::write_op<boost::asio::ssl::stream<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> > >, boost::asio::mutable_buffers_1, boost::asio::detail::transfer_all_t, boost::asio::detail::wrapped_handler<boost::asio::io_service::strand, mqtt::endpoint<boost::asio::ssl::stream<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> > >, boost::asio::io_service::strand, std::mutex, std::lock_guard>::write_completion_handler, boost::asio::detail::is_continuation_if_running> > >::operator()(boost::system::error_code, unsigned long, int) /usr/include/boost/asio/ssl/detail/io.hpp:260:32 #2 0x7590e7 in boost::asio::detail::write_op<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> >, boost::asio::mutable_buffers_1, boost::asio::detail::transfer_all_t, boost::asio::ssl::detail::io_op<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> >,boost::asio::ssl::detail::write_op<boost::asio::mutable_buffers_1>, boost::asio::detail::write_op<boost::asio::ssl::stream<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> > >, boost::asio::mutable_buffers_1, boost::asio::detail::transfer_all_t, boost::asio::detail::wrapped_handler<boost::asio::io_service::strand, mqtt::endpoint<boost::asio::ssl::stream<boost::asio::basic_stream_socket<boost::asio::ip::tcp, boost::asio::stream_socket_service<boost::asio::ip::tcp> > >, boost::asio::io_service::strand, std::mutex, std::lock_guard>::write_completion_handler, boost::asio::detail::is_continuation_if_running> > > >::operator()(boost::system::error_code const&, unsigned long, int) /usr/include/boost/asio/impl/write.hpp:269:9 Thanks, Takatoshi Kondo

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Re: [boost] Formal Review Request: mp11
by Bjorn Reese 25 Mar '17

25 Mar '17

On 03/17/2017 03:06 PM, Peter Dimov via Boost wrote: > https://github.com/pdimov/mp11/ A few comments... Most algorithms take the typelist as the first argument, but others do not, e.g. mp_transform<F, L...>. If possible, I would like to see all algorithms take typelist as the first argument. It looks like the current order is dictated by the requirements of mp_tranform_impl. Would it be possible to swap the types where the algorithm is declared? For example: template<class L, template<class...> class F> using mp_transform = typename detail::mp_transform_impl<F, L>::type; Apropos mp_transform, would it be possible to extend it such that we can pass a type-trait directly to it? For example: using const_list = mp_transform<std::add_const, typelist>; instead of using std::add_const_t. The reason I ask is that I have lots of my own domain-specific type-traits that does not come with a _t version, so this is mainly for convenience. The reference documentation is a bit terse and obscure. For example, the documentation for mp_find tells us in a convoluted way that it returns the index of a type in a typelist. It could also mention that it is the dual algorithm to mp_at, which returns a type at an index in a typelist.

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I want to hire you to write some docs!
by Vinnie Falco 25 Mar '17

25 Mar '17

I'm interested in hiring someone for a contract to finish up the NuDB documentation (repository is here: https://github.com/vinniefalco/NuDB). Its not a tremendous amount of work but I don't want to shift gears from Beast, and this could be a launching point for future doc work. Feel free to reach out to my email, its listed on my GitHub page (https://github.com/vinniefalco) Thanks!!!

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[stacktrace] Review
by Bjorn Reese 25 Mar '17

25 Mar '17

I vote for the unconditional acceptance of Boost.Stacktrace. The design is sound. The separation of stacktrace and frame is just right, and safe_dump_to is an elegant solution to handle async-safety (much better than the fork-exec alternative.) The implementation (I did not look at the Windows parts) looks solid. There are details that looks platform-specific -- e.g. "/proc/self/exe" in detail/addr2line_impls.hpp is not Posix -- but I did not notice anything that cannot be ported if needed. The documentation is well-structured. I appreciate that the reference documentation contains both complexity and async-handler-safety comments. This library is very useful to developers. I spent a couple of hours going through the documentation and source for the review. Prior to that I have followed the development of this library, and used an earlier version in a commercial product. I have in-depth knowledge of the Posix side (having once implemented an async-safe stacktrace.) Wishlist: Make throw_with_trace of the API. Put it in a separate header so there is no dependency on Boost.Exception unless this header is included. In order to be consistent with Boost.Exception I suggest that the throwing function is called stacktrace::throw_exception(). Add an example with basic_stacktrace that uses a custom allocator. Add a simpler example that uses std::terminate(). The current one is rather overwhelming. Notice that I am not asking for the current example to be removed. Minor comments: Add a note to Getting Started that the stored backtrace.dump only is valid if the program has not be re-compiled between runs, as this is what developers do all the time. I have no opinion about windows.h.

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