February 2014 - Boost - lists.preview.boost.org

DRYing BOOST_FUSION_ADAPT_STRUCT with decltype/Boost.TypeOf ?
by Damien Buhl 05 Mar '14

05 Mar '14

Hi dear Boost Fusion developers, I was asking myself if there were already plan to improve BOOST_FUSION_ADAPT_STRUCT to benefit from C++11 features like decltype ? This would be interesting to avoid the risk encountered that the types definitions can get out-of-sync. And would avoid typing type declarations twice. Currently there is BOOST_FUSION_DEFINE_STRUCT to avoid repeating the type information for each field. However this is something that makes most developer I know unhappy, as it obliges to modify the readable C++ aggregate types definition (i.e. Could be public headers) with this macro. Then there is the nice choice of BOOST_FUSION_ADAPT_STRUCT which obliges retyping the type and adds the risk that some field type information could get out-of-sync between the struct definition and the BOOST_FUSION_ADAPT_STRUCT listing. I think it would be valuable to add macros that would enable to select the fields that we want to adapt to a Random Access Sequence without requiring to repeat the type information. I would find more comfortable to write the example provided here http://www.boost.org/doc/libs/1_55_0/libs/fusion/doc/html/fusion/adapted/ad… as follow : namespace demo { struct employee { std::string name; int age; }; } // demo::employee is now a Fusion sequence BOOST_FUSION_ADAPT_STRUCT_EXT( demo::employee, (name) (age)) And a naïve implementation of BOOST_FUSION_ADAPT_STRUCT_EXT could be: #include <boost/typeof/typeof.hpp> #include <boost/fusion/include/adapt_struct.hpp> #include <boost/preprocessor/seq/for_each.hpp> #define ATTRIBUTE_DEFINITION(r, data, elem) \ (BOOST_TYPEOF(data::elem), elem) \ #define BOOST_FUSION_ADAPT_STRUCT_EXT(NAME, ATTRIBUTES) \ BOOST_FUSION_ADAPT_STRUCT(NAME, \ BOOST_PP_SEQ_FOR_EACH(ATTRIBUTE_DEFINITION, NAME, ATTRIBUTES)) #endif The same could certainly be achieved for BOOST_FUSION_ADAPT_TPL_STRUCT, while I didn't check. Thanks for the really great job done in Boost.Fusion. Cheers, -- Damien Buhl alias daminetreg

3 7

[testing][teeks99] Missing headers in boost checkout
by Andrey Semashev 04 Mar '14

04 Mar '14

Hi, I'm seeing test compilation errors saying that some headers are missing. For example: http://www.boost.org/development/tests/develop/developer/output/teeks99-01a… says that boost/smart_ptr/intrusive_ptr.hpp does not exist. There are other missing headers. The tester is teeks99-01a-win2008-64on64. Is this a known problem?

4 5

Boost.Convert. Take 2.
by Vladimir Batov 03 Mar '14

03 Mar '14

Another day I came across a topic called "String to T conversions - getting it right this time <http://groups.google.com/a/isocpp.org/group/std-proposals/t/a9905ba8e4f33f3e>" on the "ISO C++ Standard - Future Proposals <https://groups.google.com/a/isocpp.org/forum/#%21forum/std-proposals>" that got me interested/curious. Unfortunately, it seemed more of a discussion rather than a proposed/deployable solution to the string conversion issue. Then, I searched Boost archives to see if there was any development in that string-to-type conversion domain since my unsuccessful proposal about three years ago: From: Edward Diener <eldiener <at> tropicsoft.com> Subject: [Review] Boost.Convert, review manager analysis <http://news.gmane.org/find-root.php?message_id=iq12fm%24k6c%241%40dough.gma…> Newsgroups: gmane.comp.lib.boost.devel <http://news.gmane.org/gmane.comp.lib.boost.devel>, gmane.comp.lib.boost.user <http://news.gmane.org/gmane.comp.lib.boost.user> Date: 2011-05-06 15:01:06 GMT (2 years, 39 weeks, 6 days, 23 hours and 47 minutes ago) Unfortunately I was not able to find anything. Apologies if I missed something major/serious (I was not exactly closely monitoring the list). Is anyone aware of any work done in the area? If not, then I am thinking if we could revisit the issue the original (and failed) Boost.Convert tried to address. I am not sure about others but for me that quite essential and seemingly simple task is still quite important. I was watching the development of the lexical_cast but did not see it going beyond its original frugal design. So, maybe we might have another look at the code that Boost.Convert has become and that I've been using/working on?.. Convert V2... From past experience calling it Boost.Convert seems quite premature. :-) I only put Boost.Convert in the title as a reminder for those who participated in the original review. So, the code is at https://github.com/yet-another-user/boost.xtra. The docs are old (from the original proposal) so, if anyone interested, I'd suggest jumping right to the test/example code in libs/convert/test. Apologies for the inconvenience but for now I'll try to see if I should put any effort updating the docs for possible submission. The main difference from the original proposal is that the complicated blob was split in to two separate components -- Convert API facade and a converter. Here it seems very similar to (same as?) boost::lexical_cast which provides a uniform API facade which in turn deploys additional functionality (op<<, op>>). Similarly, Convert V2 requires a converter to be specified for conversion: boost::cstringstream_based_converter ccnv; // char converter boost::wstringstream_based_converter wcnv; // wchar_t converter Then, int a000 = convert<int>::from(not_int_str, -1, ccnv); int a001 = convert<int>::from(std_str, -1, ccnv); int a002 = convert<int>::from(c_str, -1, ccnv); int a003 = convert<int>::from(wstd_str, -1, wcnv); int a004 = convert<int>::from(wc_str, -1, wcnv); Now all the configuration (formatting, locales, etc.) is separate from the API facade and provided (or not) by the plugged in converter. The only available converter tringstream_based_converter allows something like: std::locale rus_locale (rus_locale_name); std::locale eng_locale (""); // Set locale, case, precision, ccnv(std::setprecision(4))(std::scientific)(std::nouppercase); string double_rus = convert<string>::from(double_v01, ccnv(rus_locale)).value(); string double_eng = convert<string>::from(double_v01, ccnv(eng_locale)).value(); Gosh, it's getting too long... cutting it short. The above is probably sufficient for those who participated in the original review. Those who did not might have a look at the (original and old) docs and the test/example code. V.

9 45

[assert] Assert library? - Was: [regression] Where's boost/assert.hpp ??
by Klaim - Joël Lamotte 01 Mar '14

01 Mar '14

On Sat, Feb 22, 2014 at 9:39 PM, Andrey Semashev <andrey.semashev(a)gmail.com>wrote: > It's been moved to a new Boost.Assert library (libs/assert submodule). Is there a discussion or documentation about what is this new library exactly? Is it just to isolate the assert.hpp header or are there other plans? (I'm secretly hoping that someone would propose an implementation of n3877[1] to boost, as I don't have the time to do it myself) [1] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2014/n3877.pdf

5 17

Review request for Boost.Align
by Glen Fernandes 28 Feb '14

28 Feb '14

Source: http://github.com/glenfe/align Documentation: http://glenfe.com/align/doc/ Motivation: Tiny library to be used for all common alignment related chores found in a few Boost libraries. (e.g. we have some in Boost.Smart_Ptr). Provides: 1. Function boost::align, a pointer alignment function, for implementations that do not yet provide std::align. (Uses std::align if available) 2. Functions boost::aligned_alloc and boost::aligned_free, for aligned allocation and deallocation. (Use platform specific functions, such _aligned_malloc or posix_memalign, or otherwise uses std::malloc with the above boost::align) 3. Class template boost::aligned_allocator as a replacement for std::allocator that respects over-aligned types. (Up to the extent the implementation supports over-alignment) Many thanks to Peter Dimov for his feedback on the design and implementation of this library. Notes: Small enough that it might satisfy the requirements for a fast-track review. Glen

9 24

JSON Parsing Library for GSoC 14
by Ganesh Prasad 28 Feb '14

28 Feb '14

I already have done some work over such a library, but this library by me has limited features and need to be improvised. And hence, I am thinking about doing this work during this GSoC 14. But I have certain questions about it. 1) Who will be taking the design decisions for the development of the library ? Whether the student or the mentor will be responsible for the decisions ? 2) To which formats should the library parse the JSON ? The current library by me parses JSON to Maps and Vectors. I am intending to provide flexibility, but if some specifications will be available it'll be helpful. 3) Is the library to be kept as simple as possible in terms of User Interface ? Or, should we use factory patterns to provide more flexibility to the advanced users ? Have a nice day, everybody. Best wishes Ganesh Prasad

5 5

Re: [boost] Review request for Boost.Align
by Glen Fernandes 28 Feb '14

28 Feb '14

Rob Stewart wrote: > Actually, you need Review Wizard approval as a review manager, and then the rest follows. *Nod*. I let Ronald know that Ahmed was kind enough to volunteer to be the review manager, and inquired about his approval, a few days ago. Hoping to hear back soon. Glen

1 0

clang support for __sync_* intrinsics
by Peter Dimov 28 Feb '14

28 Feb '14

Does anyone know what is the earlier version of Clang that supports the __sync_* intrinsics?

2 2

contributing to boost.ublas in gsoc 2014
by Rishabh Kumar 28 Feb '14

28 Feb '14

hello, myself Rishabh Kumar .currently I am pursuing my masters in applied mathematics from iit roorkee. I have a firm knowledge of c++ and python. i would like to contribute to boost.ublas and aspire to be one of the students of gsoc 2014.To start with , i have been following your ideas page for quite some time and i found the linear algebra vision very tempting. i have started working the library . looking forward for a good discussion on the idea and guidance from the respective mentor.

1 0

[GSoC-2014] Has Boost been retained?
by Vicente J. Botet Escriba 28 Feb '14

28 Feb '14

Hi, all is in the title, Vicente

4 4

[mpl] Pull request - Add constexpr to conversion operator for integral constants
by pfultz2 28 Feb '14

28 Feb '14

Hi, I added constexpr to conversion operator for integral constants, so the type traits will more closely match the type traits in C++14. Here is the pull request: https://github.com/boostorg/mpl/pull/1 Thanks, Paul Fultz II -- View this message in context: http://boost.2283326.n4.nabble.com/mpl-Pull-request-Add-constexpr-to-conver… Sent from the Boost - Dev mailing list archive at Nabble.com.

2 1

[interprocess] windows_intermodule_singleton breaks when calling a Debug dll from a Release executable
by Lars Hagström 27 Feb '14

27 Feb '14

Some time ago I reported this bug https://svn.boost.org/trac/boost/ticket/9262. Any ideas? /Lars

2 1

Problem in thread or chrono: boost::this_thread::sleep_for() sometimes returns immediately on win32
by Lars Hagström 27 Feb '14

27 Feb '14

Hi, As I've just described in https://svn.boost.org/trac/boost/ticket/9720 I've had a problem with boost::this_thread::sleep_for. I'm guessing that this could be a problem with either chrono or thread. Just thought I'd post here since I don't know how much the devs check the tickets. Cheers Lars

1 0

BGL in shared memory
by Alexandre Motin 27 Feb '14

27 Feb '14

Hello, I would like to know if BGL works in a shared memory environement. I would like to build a graph (with BGL) in a shared memory area in order to enable multiple processes to access the graph. Best regards, Alexandre Motin

3 3

GSoC 2014 Implementation of Algorithms for Boost.
by Tejas Nikumbh 27 Feb '14

27 Feb '14

Hi Guys, I am Tejas Nikumbh, a Senior UG at IIT Bombay. I am very much interested in contributing to Boost this year. I'm primarily interested in implementing Algorithms and Data Structures or both. I have considerable experience template based data structures as well as algorithms. I'll shortly post a link to the relevant code as this discussion goes on further. Besides the traditional DS and Algos I also have in mind implementation of certain awesome data structures (like say, KDTree) to extend the Boost Libraries capabilities. I found the following algorithms to be of importance to Boost [as from the ideas page on SVN] - Radix sort - Approximate string matching - Full text search - Near Duplicate Detection (shingling) - Parallel algorithms (sort, for_each) - Algorithms for gpgpu - Kinetic scrolling I know some of the algorithms in this list and would research and provide a in depth proposal for implementation of these into boost. As of now, I'd like to know about the potential mentors for this kind of project and whether it is something that Boost is looking forward to. I am pretty enthusiastic about this project so I would like to know how high the project is on Boost's priority list. Also, I wish to start early and get a head start by implementing one simple algorithm for Boost before GSoC so that I increase my chances of being selected. Please let me know what you guys think. -- Tejas Nikumbh, Fourth Year Undergraduate, Electrical Engineering Department, IIT Bombay.

3 10

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

2 3

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

2 1

[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 ?

3 8

[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

2 2

[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

1 0

[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.

2 4

[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

2 1

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

1 0

[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

1 0

[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?

2 1