February 2014 - Boost - lists.boost.org

GSoC 2014 Boost.odeint project
by SHANTANU SHAHANE 26 Feb '14

26 Feb '14

Hello, I am a pre-final year engineering student. I am interested in the project of developing implicit routines in odeint library as a part of GSoc 2014. I have experience of C++ programming and also, I have studied basic numerical methods like Euler and Runge-Kutta. I would be grateful if someone would guide me as how to proceed further as in if I need to read some reference or to code some small problem etc. Thanks in advance. Regards: Shantanu Shahane, Fourth Year Undergraduate, Dept. of Mechanical Engineering, Indian Institute of Technology Bombay, Powai, Mumbai-400076 (India). Mobile No.: 9967330927, 9370029097

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Can we consider BOOST_DEDUCED_TYPENAME deprecated?
by Neil Groves 26 Feb '14

26 Feb '14

Hi! I'm finally getting around to spending some decent time tackling tickets on Boost.Range and I'm finding the rather verbose BOOST_DEDUCED_TYPENAME to be considerably worsening the readability of my new code. I believe this existed to cope with very old compilers which we no longer officially support in new versions of Boost. Should I continue to put this in, or is it reasonably to drop a painful workaround for such an old compiler issue? Neil Groves

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[GitHelp] (Mis-)Understanding merge
by Edward Diener 26 Feb '14

26 Feb '14

I was following Modular Boost document "Establishing a merge point after SVN Conversion" (https://svn.boost.org/trac/boost/wiki/PostCvtMergePoint) and everything appeared to go well. I did my 'merge', 'commit', and 'push' specified at the end of the document and things seemed pretty good so I was confident I had established a correct merge point. Knowing that the latest 'develop' had been pushed and tested I determined to update 'master' with the latest 'develop' prior to pushing it. So I did a merge from 'develop' to 'master' and after carefully fixing a few minor conflicts in favor of the 'develop' versions the merge was successful. Yet when I looked at the files involved I noticed that a file which was in 'develop' was not in 'master'. How can this be ? If I merge from 'develop' to 'master' are not any files in 'develop' which are not in 'master' added automatically to 'master' ? If this is not the case it seems that a 'merge' is not doing what I expect it to do. Am I really expected to have to manually add files to 'master' which are in 'develop' and not in 'master' prior to the merge, or I have I missed some 'merge' functionality that would have done this for me automatically ?

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[gsoc14] About "Boost.Functional / Monads"
by Manasij Mukherjee 26 Feb '14

26 Feb '14

Hello everyone, I am interested in working on the Monad idea posted on the project ideas page. I have some academic experience with functional languages like SML and Haskell and find monads interesting. Should I come up with some proof of concept code to show how I'd design it before submitting a proposal when it is time? Or would it be preferrable to follow boost style (which I do not have much idea about) from before starting? In that case, I'd like some pointers to boost code implementing similar stuff. Manasij Mukherjee

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[Boost-users][icl] Icl broken for c++11's hint semantics. Fix provided.
by Joachim Faulhaber 25 Feb '14

25 Feb '14

Dear Icl users, due to a subtle effect of the changed hint semantics for associative containers, the icl library is broken in versions <= 1.55.0 when used with new STL-libraries that implement the new c++11 standard. This bug is fixed in the upcoming Boost 1.56.0. (see regression tests at http://www.boost.org/development/tests/master/developer/icl.html) Since the release of boost 1.56.0 seems to take longer than planned due to restructuring efforts for modular-boost, users of Boost.Icl affected by the problem may choose to pull the fixed Boost.Icl directly from the git repository and replace your_boost_1_55_0/boost/icl with the new code. The libs/icl part does not need an update. Another possibility is to apply the patch-file diff_icl_1_55_0_and_master.patch that is attached to this post to your local boost library 1.55.0: 1. cd to your_boost_1_55_0 root directory. your_boost_1_55_0> 2. From the command line type your_boost_1_55_0> patch -p2 < diff_icl_1_55_0_and_master.patch You may check the patched library by moving to your_boost_1_55_0/libs/icl/test and run your_boost_1_55_0/libs/icl/test> bjam Sorry for the inconvenience. Best regards, Joachim P.S.: For those interested in details of the issue here is a report: The semantics of insertion with hint in associative containers changed in c++11 form insert-after-hint (c++98/03) to insert-before-hint (c++11) see e.g. proposal N1780: http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2005/n1780.html so for an associative container c of type C, a value x and an iterator hint c.insert(hint, x); //tries to insert x right after hint in c++98 c.insert(hint, x); //tries to insert x before hint in c++11 In accordance with this behavior, if using the insert function std::pair<bool, iterator> C::insert(value_type const& x); (success, hint) = c.insert(x); the iterator hint of unsuccessful insertion is the matching hint, pointing to [c++98] the last element y in c that is not greater x, so x can be inserted *after* that hint. [c++11] the first element z in c that is greater than x, so x can be inserted *before* that hint. In Boost.Icl I used the returned hint-iterator of the insert function, that always returned the last overlapping interval y for an inserted interval x given the interval's exclusive-less ordering under c++98. With the changed hint semantics, this returned hint-iterator did not point to the last interval y overlapping x anymore but to the first interval z not overlapping x. Therefore the code was broken and returned false results. -- Interval Container Library [Boost.Icl] http://www.joachim-faulhaber.de

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[testing][jc-bell] Test compilation output truncated
by Andrey Semashev 25 Feb '14

25 Feb '14

Hi, I'm facing the problem with the too low limit for the compiler output size. See here: http://www.boost.org/development/tests/develop/developer/output/FBSD-64%20j… The output contains 2 warnings and part of what may be the actual error. This log is not really helpful, so I have 2 questions: 1. Can this limit be increased? 2. Can I get the full output somehow? Thanks.

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[data-structure] uncompleted data-structure/Algorithm projects
by Prabhat Kumar 23 Feb '14

23 Feb '14

Hello, I'm new to boost community and I don't know where I can find uncompleted projects on data-structure/Algorithms to work on. Please tell where I can find them and how to contribute to those projects. Thanks, Prabhat Kumar

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Boost.Odeint GSoc 2014
by Animesh Gaitonde 23 Feb '14

23 Feb '14

Hi everyone , I am Animesh Gaitonde , 4th year student from Bits-Pilani,India.My major is Electronics & Instrumentation Engineering and I am interested in contributing to Boost during GSoC 2014.I have gone through the different GSoC projects and idea's on Boost' C++ Libraries' homepage for the Summer of Code(SoC). I found the numerical library Boost.Odeint interesting.I have completed a course on Numerical Analysis and also used Boost.Odeint for algorithmic assignments.Moreover,I have been using C++ for around 3 years and I am familiar with STL and to some extent with numerical algorithms. I have gone through the documentation of Odeint and learnt about its structure.I solved a few examples and used different explicit Steppers for solving the ODE's.Currently since Odeint supports only explicit methods it would be better to expand it by adding implicit routines and also to make the existing implicit methods(Euler and Rosenbrock) independent of Boost.uBlas to have greater flexibility.I am learning about the different numeric algorithms for solving ODE's,their implementation in Odeint and along with it solving the ordinary differential equations whose solution cannot be determined analytically. I would like to get in touch with Mario Mulansky or Karsten Ahnert , the mentors for this project to provide me with further pointers for developing the proposal and any tasks which they would like to give me so that I get familiar with Odeint. Regards Animesh Gaitonde 4th year Undergraduate Bits-Pilani,Goa Campus

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[hash] Type trait for hash functions that are well distributed.
by Daniel James 23 Feb '14

23 Feb '14

Hi, I'm thinking about adding a type trait for hash functions to indicate if it's appropriate to use them with a "power of 2" hash table. This would let hash tables be more efficient when using an appropriate hash function, especially when compiling for 64 bit. Any thoughts on how this should be designed? I have a rough design in mind (similar to the allocator_traits propagation traits), but would like to hear other's ideas first. thanks, Daniel

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[testing] No test results?
by Andrey Semashev 23 Feb '14

23 Feb '14

Hi, I'm trying to see test results, but see this error instead: Error extracting file: The specified zipfile was not found. The page is: http://www.boost.org/development/tests/develop/developer/summary.html The same error is for the master branch. Is this a known problem?

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