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remove cached feature checks
by Oliver Kowalke 17 Feb '16

17 Feb '16

Hi, how is it possible to remove the cached feature checks? Boost.Config Feature Check: cxx11_constexpr : no (cached) b2 -a toolset=clang cxxflags="-std=c++11" does not re-check the features. Oliver

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[block_ptr] 20% speed boost
by Phil Bouchard 17 Feb '16

17 Feb '16

> If I try out the latest modifications and I disable the threads then on > Linux I have: > > make: > auto_ptr: 2458626 ns > shared_ptr: 2685224 ns > block_ptr: 28300624 ns > > new: > auto_ptr: 2383605 ns > shared_ptr: 4992185 ns > block_ptr: 7979659 ns So I just added a specialization of the pool for GCC x86 and now block_ptr<> speeds up by 20%: make: auto_ptr: 2511658 ns shared_ptr: 2695469 ns block_ptr: 22547960 ns new: auto_ptr: 2369312 ns shared_ptr: 4991352 ns block_ptr: 6443925 ns Thanks, -Phil

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[Fit] Purpose and Use Cases
by Artyom Beilis 17 Feb '16

17 Feb '16

Hello, Before the formal review begins I would really like to understand the purpose of Boost.FIT It isn't clear to me from the documentation what are the real world use cases? What can't be done today (for example composition) with simple C++11 lambdas? I'd love to see several real world examples and use cases of Boost.FIT - because at least for me I don't really understand why it is useful. Artyom

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Re: [boost] [block_ptr] Request for a review manager
by Bjorn Reese 17 Feb '16

17 Feb '16

On 02/04/2016 03:02 AM, Phil Bouchard wrote: > On the other hand I code completed the deterministic block_ptr in 2011 > and I am wondering if there is anything I am missing to get it through > the review process because this is one of the most important subject in > computer science: > https://svn.boost.org/svn/boost/sandbox/block_ptr/libs/smart_ptr/doc/index.… Do you have any performance measurements comparing block_ptr<T> with shared_ptr<T>? Btw, in the overview section you claim that shared_ptr<T> has to manage counters when it is dereferenced. I am not entirely sure that is correct.

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Boost.Python gsoc project
by Barun Parruck 16 Feb '16

16 Feb '16

Hi! I'm a student looking to get involved with the open source through boost. I was looking through the gsoc projects, and the one involving Boost.python, by Stefan Seefeld piqued my interest! I was wondering what sort of student you'd be looking for for the project, more details about what the project would entail, and what sort of programming competency test I would have to pass.

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stupid github question
by Robert Ramey 16 Feb '16

16 Feb '16

I want to add a contributer to the serialization library - but I can't figure out how to do this on github. I believe this has something to do with the fact that the serialization library is a sub project. It shouldn't be a big deal as I see there are already 31 contributors on the list - many of whom I don't recognise. Robert Ramey

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Alternative remove, erase, and partition algorithms
by Brent Friedman 15 Feb '16

15 Feb '16

Hello, I'd like to propose the following for inclusion in Boost.Algorithm. *semistable_partition* partitions a range into 'good' and 'bad' elements, as partition. 'Good' elements maintain their order, while 'bad' elements are left in unspecified order. stable_partition has either linear additional storage or performs 3NlogN move operations, whereas semistable_partition has constant memory overhead and at most 3N move operations. Requires forward iterators. *unstable_remove ( _if )* removes elements from a range but without maintaining element order. Performs at most N/2 moves as compared to N for remove. Requires bidirectional iterators. *unstable_erase* erases an iterator or range from a container ( as vector::erase ) without maintaining element order. Intuitively, this fills in the hole created by the erase operation by moving elements from the end. Limited to containers with bidirectional iterators (possibly random-access). The following documents describe and explore these algorithms: https://groups.google.com/a/isocpp.org/forum/#!topic/sg14/2uwOmXWqa2E (unstable_erase, unstable_remove) https://iterator.wordpress.com/2016/01/31/algorithms_0/ (unstable_remove, semistable_partition) I have been pursuing standardization, but it seems like there is value in getting community experience with these algorithms first in order to make for easier justification. -Brent Friedman

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[block_ptr] Works on MSVC + Boost.Pool bug
by Phil Bouchard 15 Feb '16

15 Feb '16

It looks like I was able to fix a bug which makes it run correctly under MSVC 2015 Express. Although I do have a crash in the boost::pool: Project2.exe!boost::simple_segregated_storage<unsigned int>::try_malloc_n(void * & start, unsigned int n, unsigned int partition_size) Line 333 C++ Project2.exe!boost::simple_segregated_storage<unsigned int>::malloc_n(unsigned int n, unsigned int partition_size) Line 363 C++ Project2.exe!boost::pool<boost::default_user_allocator_new_delete>::ordered_malloc(unsigned int n) Line 801 C++ Project2.exe!boost::singleton_pool<boost::detail::bp::pool,1,boost::default_user_allocator_new_delete,boost::details::pool::null_mutex,32,0>::ordered_malloc(const unsigned int n) Line 149 C++ Project2.exe!boost::detail::bp::pool::allocate(unsigned int s) Line 148 C++ Project2.exe!boost::detail::bp::block<int>::operator new(unsigned int s) Line 283 C++ Project2.exe!boost::detail::bp::make_block<int,int>(const int & t0) Line 520 C++ > Project2.exe!main() Line 119 C++ When I try this example: https://github.com/philippeb8/block_ptr/blob/master/example/block_ptr_test2… Thanks, -Phil

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Re: [boost] [block_ptr] Request for a review manager
by Peter Dimov 15 Feb '16

15 Feb '16

> Phil Bouchard wrote: > > > I added the new repository with the right folder structure: > > https://github.com/philippeb8/block_ptr > > You should update this to work with the latest Boost, because currently > block_base is abstract as it doesn't implement > > virtual void * get_untyped_deleter() = 0; It also doesn't work with -DBOOST_DISABLE_THREADS, which makes it inconvenient to test as it requires Boost.Thread.

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[dll] dbghelp.hpp in detail/winapi
by Andrey Semashev 14 Feb '16

14 Feb '16

Hi, I've noticed that Boost.Dll provides boost/detail/winapi/dbghelp.hpp header. boost/detail/winapi is the directory of Boost.WinAPI submodule, and I generally don't expect anyone else putting his header in that directory. Could dbghelp.hpp be moved somewhere inside boost/dll?

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