March 2015 - Boost - lists.boost.org

[MPL lite or MPL 2] A modest proposal
by Robert Ramey 07 Mar '15

07 Mar '15

I've been looking at another thread which address the problems of maintaining and/or finding a maintainer for MPL. I've come up with an idea for a proposal which I've laid out here: Library Idea MPL lite or MPL2 <http://rrsd.com/blincubator.com/bi_suggestion/mpl-lite-or-mpl2/> -- View this message in context: http://boost.2283326.n4.nabble.com/MPL-lite-or-MPL-2-A-modest-proposal-tp46… Sent from the Boost - Dev mailing list archive at Nabble.com.

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[asio] Massive regression failures
by Aparna Kumta 07 Mar '15

07 Mar '15

I am running the regression tests on the develop branch with Oracle Solaris Studio12.4 on Solaris 11.2 OS. Tests for asio fail as follows: ../boost/system/config.hpp", line 34: Error: #error Must not define both BOOST_SYSTEM_DYN_LINK and BOOST_SYSTEM_STATIC_LINK. I looked at the developer issues on http://www.boost.org/development/tests/develop/developer/issues.html and see that asio tests fail similarly. I'm not sure what causes both BOOST_SYSTEM_DYN_LINK and BOOST_SYSTEM_STATIC_LINK. to be defined on the command line. Any idea on how this can be fixed? Thanks, Aparna

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[move] unique_ptr: problems with move-assign constructor when used with base/derived classes in C++03
by Adam Romanek 06 Mar '15

06 Mar '15

Hi, There is a problem with move-assignment constructor in boost::movelib::unique_ptr when used with a pair of base/derived classes in C++98/03 mode [1] (uncomment the code to see the compiler error). Is it a known issue? Or a limitation of the emulation? I discovered the issue when I wanted to use boost::movelib::make_shared in an answer to a question on StackOverflow [2], i.e. return boost::movelib::make_shared<Derived>(); Where the return value is boost::movelib::unique_ptr<Base>, but unfortunately because of this issue, in C++03 we need to use: return unique_ptr<Base> x(new Derived()); I can create a ticket if that is desired. Nevertheles, thanks for boost::movelib::unique_ptr anyway! BTW, note how the appearance of boost::movelib::unique_ptr makes the most voted answer on the question [3] invalid. This is where my answer comes in. Best regards, Adam Romanek [1] http://melpon.org/wandbox/permlink/8Rvk2g7LJ0Ey0BQL [2] http://stackoverflow.com/a/28193068/1776942 [3] http://stackoverflow.com/q/2953530/1776942

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GSoC 2015 project " Enhanced vector and deque containers "
by ahmad samir 06 Mar '15

06 Mar '15

Good morning I wish to contribute in this project, now I am working on programming competency test. I want to ask about Is there specific or preferable method to show you my work or just upload my code in any online compiler or Github?.

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[random] Quantization effects in generating floating point values
by John Maddock 05 Mar '15

05 Mar '15

First off, I notice there are no examples for generating floating point values in Boost.Random, so maybe what follows is based on a misunderstanding, or maybe not... Lets say I generate values in [0,1] like so: boost::random::mt19937 engine; boost::random::uniform_01<boost::random::mt19937, FPT> d(engine); FPT d = d(); //etc Where FPT is some floating point type. Now my concern is that we're taking a 32-bit random integer and "stretching" it to a floating point type with rather more bits (53 for a double, maybe 113 for a long double, even more in the multi-precision world). So quantization effects will mean that there are many values which can never be generated. It's true that I could use independent_bits_engine to gang together multiple random values and then pass that to uniform_01, however that supposes we have an unsigned integer type available with enough bits. cpp_int from boost.multiprecision would do it, and this does work, but the conversions involved aren't particularly cheap. It occurs to me that an equivalent to independent_bit_engine but for floating point types could be much more efficient - especially in the binary floating point case. So I guess my questions are: Am I worrying unnecessarily? and What is best practice in this area anyway? Thanks, John.

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[build] adding a rquirement for Cygwin only?
by Peter Dimov 05 Mar '15

05 Mar '15

Is it possible to add, for example, <threadapi>pthread to a project's requirements, but only for Cygwin? This works: <toolset>gcc,<target-os>windows:<threadapi>pthread but it also applies to MinGW. This only applies to MinGW: <toolset-gcc:flavor>mingw:<threadapi>pthread but Cygwin has no <flavor>. This: <toolset>gcc,<target-os>windows:<threadapi>pthread <toolset-gcc:flavor>mingw:-<threadapi>pthread doesn't work. There are references to <target-os>cygwin in gcc.jam, but <target-os> is actually 'windows'.

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Call for Papers Meeting C++ 2015
by Jens Weller 05 Mar '15

05 Mar '15

Hello boost community! I'd like to inform you that the call for papers for this years Meeting C++ conference is running! It will end at April 5th, boost related talks are very welcome! This years conference will be again at the Andels Hotel in Berlin, on the 4th and 5th december. It will feature 2 keynotes and 4 Tracks a 7 Talks, this years theme track is "embedded and IoT". There is again also a student program, which will be announced later. Call for Papers: http://meetingcpp.com/index.php/newsreader/items/call-for-papers-for-meetin… Announcement: http://meetingcpp.com/index.php/newsreader/items/announcing-meeting-c-2015.… kind regards, Jens Weller

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GSOC 2015 : Introduction
by roopal nahar 05 Mar '15

05 Mar '15

Hi, I am Roopal, an undergraduate student from IIIT, Hyderabad, India. I would like to express my candidature as an applicant for GSOC, 2015. This is my first time contributing to an open source organization. I have been studying the list of ideas proposed so far and "Boost.uBLAS a library for matrix computations" has caught my attention. Before contacting you, the following is the spade work I have done so far : 1.) The Panda Libraries <http://pandas.pydata.org/pandas-docs/dev/generated/pandas.DataFrame.html> 2.) R package <http://cran.r-project.org/web/packages/data.table/index.html> Apart from the competency test(which I believe, will be submitted at the proposal time), what are your expectations from me and what can I do to prove my seriousness for the candidature before the proposal deadline? I will be joining the IRC channel as soon as my college proxy starts to work(A good time to invest in VPN! :P ) Cheers, Roopal

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GSoc 2015 libraries
by Ágota Horváth 05 Mar '15

05 Mar '15

Hello, I'm Ágota Horváth and I'd like to choose one of the Boost C++ Libraries project this year, because of the language and the interesting projects. However, I haven't really worked with libraries yet, so I'd appreciate if you could tell me how to get started. Thanks, Ágota

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[release 1.58] additional example
by Oliver Kowalke 05 Mar '15

05 Mar '15

Hello, I'd like to add an additional example to boost.context - do I get the permission? best regards, Oliver

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