September 2017 - Boost - lists.boost.org

Upcoming Boost.Fit Review (September 8th-17th)
by Matt Calabrese 05 Sep '17

05 Sep '17

Hi everyone, This coming Friday, September 8th, marks the start of review of the Fit library by Paul Fultz II. Source: https://github.com/pfultz2/Fit Docs: http://fit.readthedocs.org/ This is the second time that the library will go through the review process, with the previous time being in March of 2016. The result of the initial review can be found here: https://lists.boost.org/Archives/boost/2016/04/228770.php In this second review, those who choose to participate should be as rigorous as they'd be in any other review, but are also encouraged to voice whether or not the concerns from March of 2016 were addressed. The following is a brief description of the library from its author: ========== Fit is a header-only C++11/C++14 library that provides utilities for functions and function objects, which can solve many problems with much simpler constructs than whats traditionally been done with metaprogramming. Fit is: - Modern: Fit takes advantages of modern C++11/C++14 features. It support both constexpr initialization and constexpr evaluation of functions. It takes advantage of type deduction, varidiac templates, and perfect forwarding to provide a simple and modern interface. - Relevant: Fit provides utilities for functions and does not try to implement a functional language in C++. As such, Fit solves many problems relevant to C++ programmers, including initialization of function objects and lambdas, overloading with ordering, improved return type deduction, and much more. - Lightweight: Fit builds simple lightweight abstraction on top of function objects. It does not require subscribing to an entire framework. Just use the parts you need. Fit is divided into three components: - Function Adaptors and Decorators: These enhance functions with additional capability. - Functions: These return functions that achieve a specific purpose. - Utilities: These are general utilities that are useful when defining or using functions. ========== Requirements¶ <http://fit.readthedocs.io/en/latest/doc/src/index.html#requirements> This requires a C++11 compiler. There are no third-party dependencies. This has been tested on clang 3.5-3.8, gcc 4.6-6.2, and Visual Studio 2015. Gcc 5.1 is not supported at all, however, gcc 5.4 is supported. Contexpr support¶ <http://fit.readthedocs.io/en/latest/doc/src/index.html#contexpr-support> Both MSVC and gcc 4.6 have limited constexpr support due to many bugs in the implementation of constexpr. However, constexpr initialization of functions is supported when using the FIT_STATIC_FUNCTION <http://fit.readthedocs.io/en/latest/doc/src/FIT_STATIC_FUNCTION> and FIT_STATIC_LAMBDA_FUNCTION <http://fit.readthedocs.io/en/latest/doc/src/FIT_STATIC_LAMBDA_FUNCTION> constructs. Noexcept support¶ <http://fit.readthedocs.io/en/latest/doc/src/index.html#noexcept-support> On older compilers such as gcc 4.6 and gcc 4.7, noexcept is not used due to many bugs in the implementation. Also, most compilers don’t support deducing noexcept with member function pointers. Only newer versions of gcc(4.9 and later) support this. ========== Please take this time to become familiar with the Fit library before the review takes place and feel free to respond in this thread with any additional questions related to the library or its review. Thanks! -- -Matt Calabrese

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Boost.TR1 silently removed with 1.65?
by Tim Rakowski 04 Sep '17

04 Sep '17

Hi, I noticed that boost 1.65 does not contain the tr1 folder and found that the documentation was updated accordingly: http://www.boost.org/doc/libs/1_64_0/ contains http://www.boost.org/doc/libs/1_64_0/libs/tr1/, while http://www.boost.org/doc/libs/1_65_0/ has no http://www.boost.org/doc/libs/1_65_0/libs/tr1/. But http://www.boost.org/users/history/version_1_65_0.html <http://www.boost.org/users/history/version_1_65_0.htmldoes> does not mention this. Even if it was deprecated, shouldn't this be mentioned somewhere? Googling "site:https://lists.boost.org/Archives/boost/ 1.65 tr1" didn't yield anything either :/ Regards, Tim

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[contract] Ready to release
by Lorenzo Caminiti 04 Sep '17

04 Sep '17

Hello all, I *finally* got around finishing Boost.Contract after the library was reviewed and accepted by Boost about 5 years ago?! (review results: https://groups.google.com/forum/?fromgroups=#!topic/boost-list/jQ7OjAmos_Y) Documentation: https://lcaminiti.github.io/boost-contract/doc/html/index.html Source: https://github.com/lcaminiti/boost-contract * All Contract Programming features (a.k.a., Design By Contract, DBC) are supported: subcontracting, class invariants, postconditions (with old and return values), preconditions, customizable actions on assertion failure (terminate, throw, etc.), optional compilation of assertions, disable assertions while already checking other assertions (to avoid infinite recursion), etc. * Leveraging the convenience of C++11 lambdas, this revision of the library no longer requires "crazy" macros that alter C++ declaration syntax. That makes the library much easier to use, faster to compile, and generates readable compiler errors on misuse. I was thinking to add Boost.Contract to the next, or next next, Boost release... Thanks, -- --Lorenzo

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Boost 1.65.2 Release Candidate 2
by Daniel James 04 Sep '17

04 Sep '17

The second release candidates for the 1.65.1 release are now available at: <https://dl.bintray.com/boostorg/release/1.65.1/> The SHA256 checksums are as follows: df7bea4ce58076bd8e9cd63966562d8cf969b431e1c587969e6aa408e51de606 boost_1_65_1_rc2.7z 9807a5d16566c57fd74fb522764e0b134a8bbe6b6e8967b83afefd30dcd3be81 boost_1_65_1_rc2.tar.bz2 a13de2c8fbad635e6ba9c8f8714a0e6b4264b60a29b964b940a22554705b6b60 boost_1_65_1_rc2.tar.gz d1775aef807bd6a14077b450cce2950d8eacd86aaf51015f79e712917f8cc3c2 boost_1_65_1_rc2.zip As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy.

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To start contributing to boost
by Yaghyavardhan Singh Khangarot 03 Sep '17

03 Sep '17

Hello boost community, My name is Yaghyavardhan Singh, a 3rd year CS undergrad at IIIT, Hyderabad. I have been using Boost C++ Library for quite some time now and I would like to contribute to it. I have sound knowledge of C++(along with STL) and Advanced data structures and algorithms. As I am new to open source, I need some help to get started. I would be interested to add any new algorithms which might not be part of any specific module yet(say some optimized convex hull algorithm in boost.geometry). I am also open to optimization problems. Thank you, Your's Sincerely, Yaghyavardhan Singh

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[build][wave][thread][date-time] 1.65.0 clang on Windows build failures
by Konstantin Ivlev 02 Sep '17

02 Sep '17

Hi, I am trying to compile boost 1.65.0 on Windows via clang 4.0.1 with the following user-config.jam: using clang : 4.0 : "C:/Program Files/LLVM/bin/clang.exe" : <compileflags>-fmsc-version=1910 <ranlib>"C:/Program Files/LLVM/bin/llvm-ranlib.exe" <archiver>"C:/Program Files/LLVM/bin/llvm-ar.exe" <linkflags>-fuse-ld=lld ; and there are few issues. 1. clang.jam ignores ranlib/archiver settings. currently there is the PR https://github.com/boostorg/build/pull/232 against clang-darwin.jam, and I suppose the same should be applied to the clang-linux.jam. 2. there are numerous errors in boost wave: .\boost/wave/grammars/cpp_expression_grammar.hpp:829:18: error: case value evaluates to -804257404, which cannot be narrowed to type 'unsigned int' [-Wc++11-narrowing] case T_CPPCOMMENT: // contains newline (about 100 errors of such kind for various enumerations) 3. WinAPI-related errors in boost::date_time & boost::thread, e.g. In file included from libs\coroutine\src\windows\stack_traits.cpp:23: In file included from .\boost/thread.hpp:13: In file included from .\boost/thread/thread.hpp:12: In file included from .\boost/thread/thread_only.hpp:15: In file included from .\boost/thread/win32/thread_data.hpp:10: In file included from .\boost/thread/thread_time.hpp:10: In file included from .\boost/date_time/microsec_time_clock.hpp:23: .\boost/date_time/filetime_functions.hpp:57:46: error: conflicting types for 'GetSystemTimeAsFileTime' __declspec(dllimport) void __stdcall GetSystemTimeAsFileTime(FILETIME* lpFileTime); ^ C:\Program Files (x86)\Windows Kits\10\include\10.0.15063.0\um\sysinfoapi.h:159:1: note: previous declaration is here GetSystemTimeAsFileTime( ^ seems like stack_traits.cpp unconditionally includes windows.h, while BOOST_USE_WINDOWS_H is not defined in case of clang build, so filetime_functions.hpp defines its own WinAPI prototypes. probably shall be somehow fixed in boost config? any advice on how to proceed with these issues?

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[release] Boost 1.65.1 Release Candidate 1
by Daniel James 02 Sep '17

02 Sep '17

The release candidates for the 1.65.1 release are now available at: <https://dl.bintray.com/boostorg/release/1.65.1/> The SHA256 checksums are as follows: 9b440d8167043c8d70326d8a5d4df98a59abb40be7d68f51e75ea95ea24d84f3 boost_1_65_1_rc1.7z fbd5663c748a88479adb4106c8a12009b149e602dec4b40a4a778381a33cf3ce boost_1_65_1_rc1.tar.bz2 b1b18d658cc0ff8a5030b29f4ed41de1826281fcb52fc1073b106c5802a570bd boost_1_65_1_rc1.tar.gz 542624352b2c3fd6a76c98624f90d2c0e62dd810ec6cc9fdae831677c7aa1fbf boost_1_65_1_rc1.zip As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy.

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[regression] [date_time] Tests table damaged
by Andrey Semashev 01 Sep '17

01 Sep '17

Hi, It looks like Boost.DateTime table got damaged: http://www.boost.org/development/tests/develop/developer/date_time.html One of the table cells contains this text: lin/home/www/live.boost.org/common/code/boost_archive.php:149: Cannot modify header information - headers already sent by (output started at /home/www/live.boost.org/common/code/boost_archive.php:91) and there are no test results visible past this cell.

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[iterator] generator_iterator vs. function_input_iterator
by Andrey Semashev 01 Sep '17

01 Sep '17

Hi, There seems to be two nearly equivalent components in Boost.Iterator: generator_iterator (moved from Boost.Utility) and function_input_iterator. Both are input iterators wrapping a function object, which result is used as the dereferenced value. The difference is: - generator_iterator always creates an instance of the element type while function_input_iterator does that lazily; - function_input_iterator uses result_of while generator_iterator relies on C++03 T::result_type - equality comparison is different: generator_iterators compares equal if both refer to the same generator and cached element instances are equal while function_input_iterator uses an additional state (which can be viewed as an index) for comparison instead of the cached element. So basically, they are the same thing. generator_iterator looks a bit more dated and IMHO its comparison implementation is not as robust as that of function_input_iterator, so maybe we should deprecate it?

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