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Re: [boost] [fixed_point] First presentation from GSoC 2015 and more
by John McFarlane 13 Oct '16

13 Oct '16

Hi Christopher. I'm actually the main culprit behind P0037. :) Date: Wed, 12 Oct 2016 18:32:26 +0000 (UTC) > From: Christopher Kormanyos <e_float(a)yahoo.com> > To: "boost(a)lists.boost.org" <boost(a)lists.boost.org> > Subject: Re: [boost] [fixed_point] First presentation from GSoC 2015 > and more > Message-ID: <1026507022.4306136.1476297146580(a)mail.yahoo.com> > Content-Type: text/plain; charset=UTF-8 > > > I'm a bit surprised I didn't see this work before. > > Are you aware that SG14, the gamedev, real-time simulations, embedded > > software and financing study group for the standard > > is working on fixed point real proposal too? > > Here is a version of the proposal:>http://johnmcfarlane > .github.io/fixed_point/papers/p0037r2.html and>http://johnmcfarlane.githu > b.io/fixed_point/papers/p0381r0.html > > I will notify SG14 in case they missed your work too. > Thanks for the information. > We became aware of your work unfortunately very late inthe project. Much > of our fixed_point work stems from myearly prototyping dating from 2011 - > 2013. > I see a lot of similarities in the two bodies of work.Maybe we could > identify the strengths of each work.I don't know if it makes sense to > combine them,but maybe share some concepts or interface ideaswould make > sense. > I discuss P0106R0 (a revision to N3352) in my paper, the latest draft of which is always available here: https://github.com/ johnmcfarlane/fixed_point/blob/master/doc/p0037.md#p0106 I'm honestly not sure which approach is preferable overall. The set of features and qualities requested during SG14 and SG6 meetings is large and conflicting. It includes minimal build times, minimal run-time overhead, every rounding and overflow strategy listed in P0105, decimal radix and support for specialized fixed-point instructions on embedded architectures. > > In your work I've been experiencing some trouble withthe division routine. Can you elaborate? Was this recently? I've been trying out numerous strategies for arithmetic operators. My current preferred approach is to pad the left-hand operand before performing the division but that's only been checked in for a few months. > I also had some problems compilingon VC12 (but you don't target that > compiler anyway).So that's no big deal. > You will need a C++11-compliant compiler as sg14::fixed_point<> creates literal types. Lack of support for features like constexpr constructors is the main obstacle to compiling under VC++ 2013 and earlier. > In your work you are using wrapped versions of elementarytranscendental > functions designed for built-in float.You might appreciate our hand-crafted > functionsdesigned to be highly efficient in several digit ranges. > Yes! I would be very interested in seeing if I could adapt those function. Mine are placeholders and I've deliberately postponed the non-trivial task of adding cmath equivalents. It's come up - maybe a couple of times - whether these functions are desired and the response has been to just keep the proposal narrow so they are not included. There are interesting questions regarding how to implement some functions. For example, you surely don't always want the same inputs and outputs from functions involving angles. And hopefully these functions can be constexpr - unlike existing functions. Also, how have you approached the trade-off between speed and accuracy? I went for a very simple sqrt function which is adequate if the value is calculated at compile time but is likely not desirable at run-time. This isn't a problem that floating-point variants face. > I have also benched our fixed_point on bare-metalembedded systems both > 8-bit and 32-bit with verysatisfying efficiency results. This is a key > featurefor our embedded users that might also be interestingfor SG14. > My current aim is to match integer performance for common arithmetic operations when using built-ins. This leads to some situations where overflow is a big problem - but no worse than dealing with raw integers. I'm curious how you deal with multiplying two int-sized values together without resorting to wider, slower types.I was under the impression that P0106 types always widen to fit their values. > > Thank you and best regards, Chris > > And thank you. Keep up the good work! John > > On Tuesday, October 11, 2016 11:37 PM, Klaim - Jo?l Lamotte < > mjklaim(a)gmail.com> wrote: > > > On 6 October 2016 at 12:07, Paul A. Bristow <pbristow(a)hetp.u-net.com> > wrote: > > > > -----Original Message----- > > > From: Boost [mailto:boost-bounces@lists.boost.org] On Behalf Of > > Christopher Kormanyos > > > Sent: 05 October 2016 23:07 > > > To: boost(a)lists.boost.org > > > Subject: Re: [boost] [fixed_point] First presentation from GSoC 2015 > and > > more > > > > > > >> A partial implementation of fixed-point in a Boost-like > > > >> style based on proposal N3352 is now available. > > > > > > > ... But your links don't work, > > > > Indeed :-( ( > > > > The correct link to the docs for some years used to be > > > > https://dl.dropboxusercontent.com/u/43940943/modular-boost/ > > libs/fixed_point/doc/html/index.html > > > > but sadly this no longer works for reasons that so far escape me (but I > > suspect some change at Dropbox?). > > > > Meanwhile here is a PDF version to whet your appetite until I get a html > > version publicly available. > > > > https://dl.dropboxusercontent.com/u/43940943/modular-boost/ > > libs/fixed_point/doc/fixed_point.pdf > > > > Boost.Fixed_point ? > > =============== > > > > A partial implementation of fixed-point in a Boost-like style based on > > proposal N3352 is now available. > > > > This work is the result of developments from 2013-2016, including efforts > > from GSoC 2015. > > > > The source code is available at: https://github.com/ > > BoostGSoC15/fixed_point > > > > (The master branch will be stable for a while but the develop branch may > > be updated in the light of your feedback). > > > > Preliminary docs are available at: > > > > https://dl.dropboxusercontent.com/u/43940943/modular-boost/ > > libs/fixed_point/index.html > > > > We are potentially interested in submitting this work for inclusion in > > Boost. > > > > We are now requesting comments and suggestions for improvements, > > corrections and any > > further test results if these become available. > > > > Some key library features include: > > > > * proper C++ header-only implementation > > * full numeric_limits and <cmath> functions > > * flexible template choice of split between resolution and range > > * automatic selection of underlying integral representation > > * portability and high efficiency for bare metal microcontrollers > > * interoperation with Boost.Math > > * seamless extension to high-precision using Boost.Multiprecision > > * extensive test suite > > > > Thank you for your consideration. > > Best regards, > > > > Christopher Kormanyos > > > > And apologies from Paul. > > > > > Hi, > > I'm a bit surprised I didn't see this work before. > Are you aware that SG14, the gamedev, real-time simulations, embedded > software and financing study group for the standard > is working on fixed point real proposal too? > Here is a version of the proposal: > http://johnmcfarlane.github.io/fixed_point/papers/p0037r2.html and > http://johnmcfarlane.github.io/fixed_point/papers/p0381r0.html > I will notify SG14 in case they missed your work too. > > Jo?l Lamotte > > _______________________________________________ > Unsubscribe & other changes: http://lists.boost.org/mailman > /listinfo.cgi/boost > > > >

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Re: [boost] : Curiousity question
by Brian Wood 13 Oct '16

13 Oct '16

Edward Diener writes: > I would like to ask a design question for any Boost developers or anyone > on this mailing list who might care to answer. > > You are designing or working on a library, perhaps for Boost, perhaps > for fun, and part of the design of the library has some public > functionality taking a shared pointer as input. You: > > 1) Use boost::shared_ptr > 2) Use std::shared_ptr > 3) Use both boost::shared_ptr and std::shared_ptr with the same > functionality > 4) Use neither, you roll your own shared pointer-like functionality > 5) You don't lke shared pointers and use raw pointers instead > > I really am curious about this. I haven't put any limitation on your > library or made any presumption on who your library is for, on purpose. > Thanks for anyone answering ! I avoid shared pointers. I'll use a unique_ptr if a raw pointer won't work. -- Brian Ebenezer Enterprises - In G-d we trust. http://webEbenezer.net

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[qvm] Doesn qvm contain any sse/avx etc optimizations?
by Viktor Sehr 12 Oct '16

12 Oct '16

If not, is it planned for utilizing it? /Viktor

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Boost library incubator URL address
by Edward Diener 12 Oct '16

12 Oct '16

Is the Boost Library Incubator web site down or removed ? I cannot get to it anymore via a URL. I have this URL, http://www.rrsd.com/software_development/blincubator/index.htm, but it just hangs on me.

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Announcing version 3 of the cxx_dual library
by Edward Diener 11 Oct '16

11 Oct '16

I have created version 3 of the cxx_dual library. version 3 is a large rewrite of the documentation to simplify the use of the library, as well as a change in the directory structure so that the basic usage of the library is through a single header file and the use of a namespace alias, and not through the macro interface. As in: #include <boost/cxx_dual/regex.hpp> void SomeFunction() { cxxd_regex_ns::regex re("A regular expression etc."); bool result(cxxd_regex_ns::regex_match("Some string...",re)); // etc. } What ! No macros ! Actually a few macros still exist for testing which dual library has been chosen and overriding the dual library chosen, but the basic functionality means almost no macros in user code. The library is available at https://github.com/eldiener/cxx_dual.git. What is it ? The Cxx Dual library, or CXXD for short, is a C++ macro header-only library which chooses between using a Boost library or its C++ standard equivalent library for a number of different C++ implementations, while allowing the end-user to use the same code to program either choice. An implementation is a Boost library which has a C++ standard library equivalent whose public interfaces are nearly the same in both cases. An 'implementation' is called a 'mod' for short and each of the possible Boost or C++ standard implementations for that mod are called a 'dual library'. The Cxx Dual library does this by automatically choosing either the Boost library or the C++ standard library for a particular mod, including the correct header file(s) needed for the dual library chosen, and creating a namespace alias for the namespace of the dual library chosen. CXXD also provides a macro-based solution for distinguishing between the Boost version and the C++ standard version of a dual library so that specific code for a particular dual library choice may be written in those cases where the public interfaces diverge.

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Announcing version 3 of the cxx_dual library
by Edward Diener 11 Oct '16

11 Oct '16

I have created version 3 of the cxx_dual library. version 3 is a large rewrite of the documentation to simplify the use of the library, as well as a change in the directory structure so that the basic usage of the library is through a single header file and the use of a namespace alias, and not through the macro interface. As in: #include <boost/cxx_dual/regex.hpp> void SomeFunction() { cxxd_regex_ns::regex re("A regular expression etc."); bool result(cxxd_regex_ns::regex_match("Some string...",re)); // etc. } What ! No macros ! Actually a few macros still exist for testing which dual library has been chosen and overriding the dual library chosen, but the basic functionality means almost no macros in user code. What is it ?

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Re: [boost] [beast] Request for Discussion
by Vinnie Falco 10 Oct '16

10 Oct '16

There's some great programming and design discussion related to Beast and HTTP going on in the GitHub issues for the project. And there are some interface changes looming. Stakeholders and interested parties should consider participating in these discussions if they would like to influence the outcome: Some of the discussions: HTTP 1 versus 2 namespacing https://github.com/vinniefalco/Beast/issues/121 HTTP/2 design https://github.com/vinniefalco/Beast/issues/122 Expect: 100-continue https://github.com/vinniefalco/Beast/issues/123 `basic_headers` to make better use of allocators and string_ref https://github.com/vinniefalco/Beast/issues/124

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[git] some fetch errors
by Raffi Enficiaud 09 Oct '16

09 Oct '16

Hi all, I see the following errors: """ Fetched in submodule path 'libs/python', but it did not contain 0ca7db361b8a70540c5683ae3ba2219c3352f721. Direct fetching of that commit failed. """ while my agents were checking out version aa407db3a22120496d6c49d2e3bc0b494b5ceb76 of the boost superproject. Does anyone know why am I seeing this? I cannot find rev 0ca7db361b8a70540c5683ae3ba2219c3352f721 in libs/python Thanks, Raffi

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[python] Missing test file.
by Rene Rivera 09 Oct '16

09 Oct '16

FYI.. The testing CI sanity check is failing with this missing file error: error: Unable to find file or target named error: 'printer.py' error: referred to from project at error: '../libs/python/test' <https://travis-ci.org/boostorg/boost/jobs/166196326#L6960> Please fix ASAP. -- -- Rene Rivera -- Grafik - Don't Assume Anything -- Robot Dreams - http://robot-dreams.net -- rrivera/acm.org (msn) - grafikrobot/aim,yahoo,skype,efnet,gmail

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Re: [boost] [beast] Request for Discussion
by Vinnie Falco 09 Oct '16

09 Oct '16

To get this topic hopping again, I'll share a bit of news. With help from Howard Hinnant I've opened an issue against the Networking TS to make sure that its algorithms do not place unnecessary requirements on user-defined types: http://cplusplus.github.io/LWG/lwg-active.html#2779 This will affect Beast's buffer sequence adapters (such as buffer_cat).

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