- Boost - lists.boost.org

[reference_wrapper] Overloading operator() in reference_wrapper
by Nathan Crookston 02 May '13

02 May '13

Hi all, std::reference_wrapper includes an overload of operator()[1] which allows a wrapped function object to be called without needing to first unwrap: #include <boost/ref.hpp> #include <functional> #include <iostream> int main() { auto f = [](int i) { std::cout << i * 2 << std::endl; }; std::ref(f)(5);//change this to boost::ref and it will not compile. } I think it would be valuable to update boost::ref to match the standard version. On compilers which support variadic templates and rvalue references the code is obvious. Those which support one or neither could still have overloads for some number of arguments. This would be handy in a few places, notably boost::gil::for_each_pixel[2]. I know that boost::bind + reference wrapper could be used instead (boost::bind(boost::ref(f), 5)). Given that implementing operator() is relatively simple, and that the standard object based on boost::reference_wrapper has it (rather than requiring std::bind), I'd argue that this change is desirable. Thanks, Nate [1] http://en.cppreference.com/w/cpp/utility/functional/reference_wrapper/opera… [2]http://comments.gmane.org/gmane.comp.lang.c%2B%2B.isocpp.general/513

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Re: [boost] [gsoc-2013] Boost.Thread/ThreadPool project
by Niall Douglas 02 May '13

02 May '13

> Le 01/05/13 20:39, Niall Douglas a ?crit : > >> I don't see the term "central asynchronous dispatcher" used in any of > >> the links. Could you clarify what it is? > > I have to admit I'm struggling to see where your block is, but Dave Abrahams > > often found the same with me, so it must be me. > It is just that I don't know the term. > As I don't know the domain (the words) you are talking about we can stop > the exchange here if you prefer, or you could continue to explaining me > the things I don't know/understand. Don't worry, it's almost certainly me as native English speakers rarely understand me either. Besides when I lived in Spain I remember only too well the problem with domain terminology, like when a dentist told me I had a "del gasto" which I took to him wanting money because he had high rent :). I'll keep going as long as you need. We'll get there eventually. > > The central means one execution context does the dispatch. The asynchronous > > means that callbacks are processed by recipients asynchronous to the > > dispatcher. And dispatcher, well that dispatches. > In order to be sure I understand what you say could you tell me how a > decentralized asynchronous dispatcher behaves? What are the differences? A centralized dispatcher dispatches from one execution context to many. A decentralized dispatcher dispatches from many execution contexts to one or more contexts. An example of the latter is cloud apps actually, where millions of apps will dispatch events to a load balanced core cluster of servers i.e. many => few. By execution context I mean a thread, a fibre, a coroutine, a handler or even a closure. Generally if it's got its own distinct stack separate from other stacks, it's an execution context. > > I'd take a reasonable guess that MCAS will benefit centralized kernel-based > > threading primitives architectures such as Windows NT more than > > decentralized threading primitive architectures such as POSIX. That said, I > > could see Linux using TM for batch multi-kernel-futex ops, though I'd have > > to say implementing that without breakage would be daunting. > > > Are you saying that current TM technology should be much more useful for > centralized than decentralized asynchronous dispatchers? I'm saying my suspicion is that. Others on SG5 may disagree (they disagree with me about most of my opinions). It's still very early days for TM in C++. > Does this means that the whole application would improve its > performances using always centralized asynchronous dispatchers? I'm saying it's a likely optimization case. Other than a recompile, application need not know the difference. > > You may find N3562 Executors and schedulers coproposed March 2013 for > > Bristol by Google and Microsoft of use to you in understanding the relation > > between thread pools and Boost.ASIO > > (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2013/n3562.pdf) > I know this proposal. Could you explain me how it is related to > Boost.Asio? Could you point me where in the Asio documentation could I > find related information? I think your other post is more relevant, so I'll answer there. But agreed that Asio's documentation assumes the user already understands how it works. If you come from a NT kernel or VMS or libuv programming background, it's obvious. But much less so for everyone else. > > My > > proposed Boost.AFIO library is an implementation of that same N3562 idea, > > albeit I extend Boost.ASIO which is IMHO more C++-y whereas Google and > > Microsoft have gone with proprietary implementations. Also, they include > > timing and many other more general purpose features, and mine does not > > (currently) as it's mainly aimed at maximising input/ouput with highly > > jittery random latency storage. > > > Thanks Niall for all the explanations and sorry if all this is trivial > for you. These types of discussion always add to the collective good. Niall --- Opinions expressed here are my own and do not necessarily represent those of BlackBerry Inc.

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[testing] run.py and cross compilation
by Niall Douglas 02 May '13

02 May '13

> Is there some possibility to compile sources on one platform (x86) and > then run compiled tests on other platform (ARM/Android) using run.py > script? > > This is required, because Android SDK exists only for x86 so there is > no way to compile tests on ARM Android device. I believe we have a related or similar problem with unit testing Boost on BB10. Niall --- Opinions expressed here are my own and do not necessarily represent those of BlackBerry Inc.

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[gsoc2013] Proposal for Boost.Math Bernoulli numbers and special functions project
by Artemy Margaritov 02 May '13

02 May '13

Hi folks! I want to provide my proposal for Boost.Math Bernoulli numbers and special functions poject to the Boost community. Please, lets discuss it! I will be grateful for your advices. -- Best regards, Artemy Margaritov

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Re: [boost] [gsoc-13][proposal] Boost.uBLAS
by Aditya Avinash 02 May '13

02 May '13

On Thu, May 2, 2013 at 1:24 AM, Aditya Avinash <adityaavinash143(a)gmail.com>wrote: > I have updated the proposal. Here it is. > > > On Thu, May 2, 2013 at 1:21 AM, Aditya Avinash <adityaavinash143(a)gmail.com > > wrote: > >> Hi, this is my GSOC 13 proposal on Boost uBLAS. >> >> >> On Wed, May 1, 2013 at 3:15 PM, David Bellot <david.bellot(a)gmail.com>wrote: >> >>> Great. I'm looking forward to it. >>> >>> Best, >>> David >>> >>> >>> On Tue, Apr 30, 2013 at 11:06 PM, Aditya Avinash < >>> adityaavinash143(a)gmail.com >>> > wrote: >>> >>> > I'll upload in 16 hrs. >>> > >>> > On Wed, May 1, 2013 at 2:55 AM, David Bellot <david.bellot(a)gmail.com> >>> > wrote: >>> > >>> > > Hi Aditya, >>> > > >>> > > yes, please send me a written proposal, so that I can help you on >>> that. >>> > > It's definitively something we want to do for ublas. >>> > > >>> > > Best, >>> > > David >>> > > >>> > > >>> > > On Mon, Apr 29, 2013 at 6:56 PM, Aditya Avinash >>> > > <adityaavinash143(a)gmail.com>wrote: >>> > > >>> > > > Hi, I have a proposal for boost in gsoc-13 under boost.ublas >>> > > > >>> > > > *Proposal: SIMD abstraction for uBlas.* >>> > > > >>> > > > >>> > > > - I want to develop SIMD abstraction for uBlas. >>> > > > >>> > > > >>> > > > Goal 1: Develop the Intel SSE & AVX backend for SIMD abstraction in >>> > > uBLAS. >>> > > > >>> > > > Goal 2: Develop AMD SSE backend for SIMD abstraction in uBLAS. >>> > > > >>> > > > Goal 3: Develop frontend for SIMD abstraction in C++. >>> > > > >>> > > > Goal 4: Joining of frontend and backend, so the the code is >>> flexible to >>> > > > implement on both AMD and INTEL. >>> > > > >>> > > > Goal 5: Develop the ARM-NEON backend for SIMD abstraction in >>> uBLAS. >>> > (if >>> > > > time permits). >>> > > > >>> > > > -- >>> > > > ---------------- >>> > > > Atluri Aditya Avinash, >>> > > > India. >>> > > > >>> > > > _______________________________________________ >>> > > > Unsubscribe & other changes: >>> > > > http://lists.boost.org/mailman/listinfo.cgi/boost >>> > > > >>> > > >>> > > _______________________________________________ >>> > > Unsubscribe & other changes: >>> > > http://lists.boost.org/mailman/listinfo.cgi/boost >>> > > >>> > >>> > >>> > >>> > -- >>> > ---------------- >>> > Atluri Aditya Avinash, >>> > India. >>> > >>> > _______________________________________________ >>> > Unsubscribe & other changes: >>> > http://lists.boost.org/mailman/listinfo.cgi/boost >>> > >>> >>> _______________________________________________ >>> Unsubscribe & other changes: >>> http://lists.boost.org/mailman/listinfo.cgi/boost >>> >> >> >> >> -- >> ---------------- >> Atluri Aditya Avinash, >> India. >> > > > > -- > ---------------- > Atluri Aditya Avinash, > India. > -- ---------------- Atluri Aditya Avinash, India.

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[gsoc 2013] draft proposal for chrono::date
by Anurag Kalia 02 May '13

02 May '13

I have prepared a draft proposal for Boost.chrono/date implementation. Could you kindly go through it and tell me of any errors and suggestions? Regards, Anurag Kalia.

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Proposal for Bernoulli numbers
by Gaurav Deshmukh 02 May '13

02 May '13

Mentors for Boost.Math, please review my proposal at the melange site. http://www.google-melange.com/gsoc/proposal/review/google/gsoc2013/gaurav42… Shall I include details about the templates of functions I will have to implement? Or are there any corrections or details needed? Thanking you, Gaurav Deshmukh

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[GSOC] Are we going to participate?
by Antony Polukhin 02 May '13

02 May '13

Hi all, Today starts Google Summer of Code. Is Boost community will become one of the mentoring organizations? What project ideas are we proposing? (As for me, I'd love to see unique_ptr+unique_array implemented using Boost.Move; C++11 features support for MPL, Fusion, Graph, Bind, Optional; BTree library; library for getting system info) -- Best regards, Antony Polukhin

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[Log] Plans to use std::thread?
by Rich E 01 May '13

01 May '13

Hi all, As I've been testing out the newly added Boost.Log library, I noticed it is relying on Boost.Thread even when the C++11 <thread> library is present. Are there any plans to allow the native <thread> library to be used when it is available? I think this can be done with Boost.Config's BOOST_NO_CXX11_HDR_THREAD macro. Thanks, Rich

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Re: [boost] GSoC Boost.Multiprecision project
by Jyotesh Choudhari 01 May '13

01 May '13

Hello, > Hi Jyotesh. >>>> Looking at the project description, I think >>>> I have understood what needs to be implemented >>>> in this project. > Yes, you seem to have a good grasp of the issues. > Good work. >>>> I have also gone through the current >>>> code cpp_bin_float.hpp and I have understood some >>>> part of it. I want to know how >>>> detailed should my proposal be? What details >>>> should I include in my proposal? >>>> What should be the deliverables for the project? > Go ahead and add some details from cpp_bin_float > if you like. You can mention that this is a potential > solution method. Thank you for your valuable feedback. I have written project proposal for the first time in my life. So, I did not know what details to include. I have made some changes to my proposal as per your suggestions. > Other than that, I believe you have found > the right level of detail, with a few more suggestions > from my side below. >> I have attached my proposal with this mail. >> Please have a look at it and let me know your feedback. >> Thanks and regards, > I suggest you move the FFT algorithms to an optional > part, add a bit more time for the elementary transcendental > functions, and add some time for testing the various > milestones in the project. > After that, you should start submitting your proposal. > As far as I know, you can modify your proposal up > to May 03. I have written FFT algorithm as an optional algorithm now and made some changes to schedule. Please let me know if it is fine now. > Keep up the good work. > Sincerely, Chris I was studying the code for cpp_bin_float and I have some doubts in my mind. 1. What are eval_ops_signed_type, eval_ops_unsigned_type and eval_ops_float_type? 2. What is the use of following lines? typedef mpl::list<eval_ops_signed_type> signed_types; typedef mpl::list<eval_ops_unsigned_type> unsigned_types; typedef mpl::list<eval_ops_float_type> float_types; These are not used in the class elsewhere. Similar lines are present in cpp_dec_float.hpp also and not used elsewhere in the class. 3. In the function from_float_type, I think the variable number_of_digits should be initialized to zero before using it in while loop. Lastly, I have seen on mailing list, that some of the students are submitting code samples. As I am busy with my end-semester exams and R&D project, I am not able to send any sample code. As soon as I get free, I will send it. Thanks and regards, Jyotesh Choudhari

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