January 2020 - Boost - lists.preview.boost.org

Contribution to core library
by anshu khare 13 Jan '20

13 Jan '20

Hello mentors, I would like to contribute to the core library of BOOST. I am working on windows. I cloned boostorg/core library. After cloning I found that there are many folders. Could you please tell which folder should I look up? Thank you Anshu Khare

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Documentation of dynamic cast
by anshu khare 11 Jan '20

11 Jan '20

Hello mentors, Could you please provide the documentation and code of dynamic_cast?

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[Astronomy] GSoC2020
by Pranam Lashkari 10 Jan '20

10 Jan '20

Hello, Earlier I was thinking of resting astronomy library for this GSoC and bring it to its first formal review after some development on my own cause it has been part of GSoC for 2 years now and still not reached to its first review and there are still many pending things before its first review. Since last month, I have started receiving many requests and ideas from the students about this library and many students are taking initiative and this may speed up the process of development. I still would like to know the opinion of the community before including this library in this GSoC. Thank you, Pranam Lashkari

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boost range for non integers
by Wim Leflere 10 Jan '20

10 Jan '20

Hello, I was wondering why the (i)range function is limited to integers. https://www.boost.org/doc/libs/1_72_0/libs/range/doc/html/range/reference/r… It would be nice if it also supported floats. Or any 'incrementable' class, e.g. Date. Regards, Wim Leflere

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New allocator uses global memory
by Frederick Gotham 10 Jan '20

10 Jan '20

I propose a new allocator that uses global (i.e. static duration) memory. Here's my current experimental code: #include <cstddef> /* size_t */ #include <new> /* Only for bad_alloc */ static int this_translation_unit; /* This serves the same purpose as __FILE__ */ template<typename T, std::size_t t_capacity, std::size_t t_counter, int *t_file = &this_translation_unit> class StaticAllocator { protected: static T buf[t_capacity]; public: typedef T value_type; template<typename U> struct rebind { typedef StaticAllocator<U, t_capacity, t_counter, t_file> other; }; T *allocate(std::size_t const n) { if (n > t_capacity) throw std::bad_alloc(); return buf; } void deallocate(T *, std::size_t) { /* Do Nothing */ } }; template<typename T, std::size_t t_capacity, std::size_t t_counter, int *t_file> T StaticAllocator<T, t_capacity, t_counter, t_file>::buf[t_capacity]; using std::size_t; #include <vector> using std::vector; #include <iostream> using std::cout; using std::endl; auto main(void) -> int { vector< char, StaticAllocator< char, 4, __COUNTER__ > > v; v.push_back('a'); v.push_back('b'); v.push_back('c'); v.push_back('d'); for (auto const &elem : v) cout << elem << endl; vector< char, StaticAllocator< char, 4, __COUNTER__ > > v2; v2.push_back('x'); v2.push_back('y'); v2.push_back('z'); for (auto const &elem : v2) cout << elem << endl; // Now try the first vector again for (auto const &elem : v) cout << elem << endl; } The trick I am using with "this_translation_unit" works fine on GNU and Clang, however it fails to compile on Microsoft because the variable has internal linkage. I'm sure we can do this another way using something from the Boost preprocessor library. The preprocessor macro __COUNTER__ is available on every compiler I know of. Frederick P.S. This is my second idea posted to the Boost dev list. My first one was "istream_iterator_limited".

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Willing to participate in GSOC'20 with boost
by soham mukherjee 10 Jan '20

10 Jan '20

Hi, I am Soham Mukherjee. I am willing to participate in GSOC-20 and was looking forward participating with this organization. Can someone please guide me on how to get started and linking me to some easy fixes and also documentations so that I can familiarize myself with the codebase. Thanks

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Clone warnings in lexical_cast
by Tom Kent 09 Jan '20

09 Jan '20

I just ran a: git clone --recursive https://github.com/boostorg/boost boost_root and I got some warnings in lexical_cast: Cloning into 'D:/teeks99-09/boost_root/libs/lambda'... Cloning into 'D:/teeks99-09/boost_root/libs/lexical_cast'... warning: unable to unlink 'D:/teeks99-09/boost_root/.git/modules/lexical_cast/objects/b1/102161720ea50668a5756828409400a4314744.temp': Invalid argument warning: unable to unlink 'D:/teeks99-09/boost_root/.git/modules/lexical_cast/objects/8a/0a6c194259a9a3fa24ea3fb815899bfcbfed64.temp': Invalid argument warning: unable to unlink 'D:/teeks99-09/boost_root/.git/modules/lexical_cast/objects/47/dd68ef6ee5c02257a57d03ac9e611a68893d0d.temp': Invalid argument warning: unable to unlink 'D:/teeks99-09/boost_root/.git/modules/lexical_cast/objects/02/b86ef5bcc4574e5c03b75ed463dbb5ada446c9.temp': Invalid argument warning: unable to unlink 'D:/teeks99-09/boost_root/.git/modules/lexical_cast/objects/c2/b4875ef060ea7de75feceb1f20284766128325.temp': Invalid argument Cloning into 'D:/teeks99-09/boost_root/libs/local_function'... I don't think these are an issue necessarily but it might be something that can be cleaned up. Tom

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[Graph] Large incoming changes to Boost.Graph master.
by John Maddock 08 Jan '20

08 Jan '20

Dear all, Boost.Graph has had no maintainer for some time, but the CMT has been busy fixing bugs none the less. Unfortunately, other than some trivial fixes to docs and some directory refactoring, nothing much has been merged to master in a good while . On the plus side, develop is now in a better tested tested state than IMO it has ever been, however the change set is rather large so the potential to mess up somebodies code is certainly there: https://github.com/boostorg/graph/pull/196. So... this is both a heads up, and a plea: if you have any mission critical code using the Graph library, could you please test against current develop and report any problems? If you don't want to mess about with git, download from https://github.com/boostorg/graph/archive/develop.zip and place zipfile-contents/libs/graph/include in your include path ahead of that for Boost-1.72. Many thanks, John.

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What happened to Boost.Nowide?
by Alexander Grund 08 Jan '20

08 Jan '20

Hi, I'm a user of (a fork of) Boost.Nowide and already fixed some issues I found and was looking into getting them upstream. I also wanted to know, if it is finally in Boost. Unfortunately this does not seem to be the case. I found https://lists.boost.org/Archives/boost//2017/06/236475.php which accepted it into Boost. This is from mid-2017 and nothing has happened since. Does anyone know what the status of Boost.Nowide is? It seems the filestream parts are now incorporated into Boost.FileSystem. So it seems only cin/cout/cerr, the args wrapper and the C-functions (fopen, ...) are missing. Especially the first 2 are very useful in writing cross-platform code. Might those be integrated into some other Boost Library? Thanks, Alex

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Retirement as Review Wizard
by Ronald Garcia 07 Jan '20

07 Jan '20

Dear Boosters and Boost Steering Committee, After roughly 14 years as a Boost Co-Review Wizard, I feel that the time has come for me to step down from the position, and make room for a new face with fresh ideas. It has been my pleasure to serve in this position for this time alongside first Tom Brinkman and now John Phillips. I look forward to seeing what the next 14+ years of Boost brings! Sincerely, Ron Garcia Boost Co-Review Wizard

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