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

Interest in Base2/16/32/64 Encoding Library?
by Thomas Kemmer 27 Jan '14

27 Jan '14

Dear Boost Developers, I would like to know if there is interest in incorporating a generic Base2/16/32/64 encoding library into Boost. I am the author of such a libray, hosted at http://code.google.com/p/stlencoders/ and would be willing to contribute and make the effort of "Boostifying" it, if the Boost community is interested in such a thing. There have been several suggestions for a Base64 encoding library on this mailing list in the past. Most of them have been dismissed, since Boost already provides a Base64 implementation with Boost.Serialization's "Dataflow Iterators". Though I appreciate the dataflow iterator's design, from personal experience I think that for the basic task of encoding/decoding, a higher-level interface, e.g. one that takes padding and intermittent whitespace (MIME) into account, would benefit many developers. Currently, the stlencoders library - implements the Base16, Base32 and Base64 encoding schemes as defined in RFC 4648. Base2, i.e. binary encoding, is also supported. - implements encoding and decoding operations as generic algorithms that operate on STL-style iterators - supports different encoding alphabets using custom traits classes - supports different character types - lets the user define if/which non-alphabet characters should be ignored via predicates - provides reasonable performance that matches most "plain C" implementations stlencoders is currently designed as a stand-alone library with no dependencies on Boost (or anything but C++03); it would therefore take some effort and guidance from the community to properly integrate it with the rest of Boost. I would therefore appreciate any feedback regarding your interest in this. Kind Regards, Thomas

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Boost candidate similar to asyncplusplus
by Rodrigo Madera 27 Jan '14

27 Jan '14

Hello, I was wondering if there is anything similar to asyncplusplus [1] here in Boost land. I just found out about the library and I specially liked the task chaining syntax [2]: --- async::spawn([] { return 42; }).then([](int result) { return result; }).then([](task<int> parent) { std::cout << parent.get() << std::endl; }); --- This is something I would love to see in Boost. So I ask: 1) Are there any similar Boost candidates for task scheduling? 2) If not, is ASIO up to this with some adaptation? I felt specially inclined to ask this here because of all the discussion taking place over the recently reviewed Fibers library and the fundamentals of asynchronous processing. Very interesting thoughts being discussed there. And something more higher level (but not necessarily IO bound) might be helpful. Best regards, Rodrigo Madera [1] https://github.com/Amanieu/asyncplusplus [2] https://github.com/Amanieu/asyncplusplus/wiki/Tutorial

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[github] boostorg/boost not listed?
by Joaquin M Lopez Munoz 26 Jan '14

26 Jan '14

Hi, After some recent aesthetic changes to https://github.com/boostorg , the repository boostorg/boost does not get listed in either of https://github.com/boostorg https://github.com/boostorg?page=2 https://github.com/boostorg?page=3 https://github.com/boostorg?page=4 https://github.com/boostorg?page=5 https://github.com/boostorg?page=6 even though it certainly exists and can be searched and found through the "Find a repository..." editbox. Before these latest changes to the web, boostorg/boost usualliy appeared #1 in the list as it quickly autoupdated after any subproject did. Thank you, Joaquín M López Muñoz Telefónica Digital

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[atomic] Probable documentation issue: how do we know atomic is safe and/or efficient?
by John Maddock 26 Jan '14

26 Jan '14

I'm looking to use Boost.Atomic for the double-checked-locking-idiom, but I'm having trouble discovering a) Whether the library is correctly implemented. b) How efficient (or otherwise) the library is on various platforms. I'm sure the answer to (a) is that it is correct, but I was surprised that atomic<int> relied on the volatile modifier for thread safe load/stores on MSVC, I had assumed that something more than that would have been required, but I know I'm out of date on this stuff! I can't help thinking that questions like this could be allayed by better documentation - specifically what operations are used to ensure correctness on each supported platform, plus rationale and/or link to reference material. My apologies if this has been covered already in the review, and I realize that documentation is a lot of work, but I can see no way to ensure correctness other than through code inspection, so proper documentation is essential in that case. Regards, John.

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[predef] Suggestion for Boost itself to start using this.
by Fletcher, John P 25 Jan '14

25 Jan '14

I have started to use the Boost predef library. I think it will be a good idea for this to be used within Boost. This is actually contained in the Future Work section of the Boost predef manual. http://www.boost.org/doc/libs/1_55_0/libs/predef/doc/html/predef/introducti… * And obviously there's lots of work to do in reformulating the existing Boost libraries to use the Predef library once it's accepted. I have been attempting to make use of it and one of the problems is that BOOST_VERSION itself is not consistent with it. It would I think break a lot of existing code to change BOOST_VERSION. Instead I suggest having another define a longside it which is consistent with Boost predef. I wnt to make the following suggestions to go into the definition of the version. First check that the version of Boost is recent enough. 1.55.0 is the first to have Boost predef. #include <boost/version.hpp> #if BOOST_VERSION >= 105500 #include <boost/predef.h> #define BOOST_HAVE_BOOST_PREDEF #endif #include <iostream> #include <string> #include <sstream> Then if that is true then construct a new defintion: #ifdef BOOST_HAVE_BOOST_PREDEF #ifdef BOOST_VERSION // The following translates BOOST_VERSION to a BOOST_VERSION_NUMBER!! // BOOST_VERSION % 100 is the patch level // BOOST_VERSION / 100 % 1000 is the minor version // BOOST_VERSION / 100000 is the major version #define BV BOOST_VERSION #define BVN BOOST_VERSION_NUMBER(BV / 100000,BV / 100 % 1000,BV %100) #define BOOST_VERSION_VERSION BVN #undef BVN #undef BV #endif Other libraries can also construct new version codes. John Fletcher

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Re: [boost] [Boost-testing] DrWeb regression test server is going down
by Beman Dawes 25 Jan '14

25 Jan '14

On Thu, Jan 23, 2014 at 5:24 PM, Sergey Cheban <s.cheban(a)drweb.com> wrote: > Dear subscribers, > > Unfortunately, DrWeb regression test server (Visual C++ 9-12, Windows > server 2012) is going down. > Sorry to hear that, but thanks for all your past runs! Is this permanent or will it come back up at some point? --Beman

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inter thread communication with message queues
by Kenneth Adam Miller 25 Jan '14

25 Jan '14

I was reading about message queues with respect to inter thread communication, and I have a specific use case that I want to describe. It's rather complex, so I want to be careful that I design it so that there are no race conditions. Pool A is a buffer (of type 1) handle manager, that feeds buffer handles into thread set 1, and receives old handles from thread set 2. There is only one thread running pool A. Thread set 1 is a set of N threads that fill up buffers of type 1 with regular data. It pushes full buffers to thread set 2. Thread set 2 is a set of M threads that compress buffers of type 1 into data buffers of type 2. Once the buffer of type 1 has be used up, it is cleared and sent back to Pool A. It pulls fresh data buffers of type 2 from Pool B, and sends freshly filled compressed buffers to Pool C. Pool C does something with the buffer, clears it and hands it to Pool B. Can this be done safely using an implementation like what I see here: http://www.justsoftwaresolutions.co.uk/threading/implementing-a-thread-safe… ? Note 1: -= denotes a 1-to-N connect and =- a N-to-1 connect RR = Request reply relationship +--------------------------------------------------------------------+ | | v | Pool A RR Thread Set 1 Router X | PULL-PUSH --==> PULL-read-PUSH ==--> PULL-PUSH --==> PULL Thread Set 2 PUSH \ / +-compress-+ Pool B RR / \ PULL-PUSH --==> PULL PUSH ^ || | || +----------- PUSH-write-PULL <--==++ Pool C Questions: how do I have a separate thread poll on multiple shared message queues? Like, I have a thread pool that both receives requests for buffer handles and that receives old buffer handles to recycle.

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boost condition_variable internals
by Kenneth Adam Miller 25 Jan '14

25 Jan '14

I need to know that boost does not use any kind of locking, mutex or semaphore mechanism within the boost::condition_variable class. I don't know where it is in source, or I would check to make certain. Can someone provide me a yes no verification?

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Re: [boost] Compile time reflection for IPC using
by Brian Wood 25 Jan '14

25 Jan '14

> Ok. I would like to ask you about next > When we should use the RPC architect should we serrialize the call Oleg, Sorry, but I have no idea what you're talking about in your posts. I have some serialization related software on my website that you may be interested in. I'm available to talk on the phone if you like. -- Brian Ebenezer Enterprises - In G-d we trust. http://webEbenezer.net

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Announcing the Boost Community Maintenance mailing list
by Marshall Clow 24 Jan '14

24 Jan '14

The Boost Community Maintenance mailing list (boost-maint) has been created, and you can sign up here: http://lists.boost.org/mailman/listinfo.cgi/boost-maint The goal of the Boost Community Maintenance team is to maintain those libraries whose creators no longer can. The initial proposal for the group is here: https://dl.dropboxusercontent.com/u/9897665/community-maintenance.html I will be posting status and working guidelines here and on the boost-maint mailing list over the weekend. I encourage everyone who wishes to participate to subscribe to the boost-maint mailing list, and we’ll get started by Monday. Thanks in advance! -- Marshall Marshall Clow Idio Software <mailto:mclow.lists@gmail.com> A.D. 1517: Martin Luther nails his 95 Theses to the church door and is promptly moderated down to (-1, Flamebait). -- Yu Suzuki

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[testing] How do you interpret the SHA1 revision (outdated results)?
by John Maddock 24 Jan '14

24 Jan '14

So... I'm looking into Boost.Regex and I'm seeing some failures which appear to refer to outdated sources (line numbers are all wrong for current source), for example: http://www.boost.org/development/tests/develop/developer/output/marshall-ma… But how on earth do I check this? Reported run date is yesterday, but this was fixed/changed on Dec 20th: almost a month ago. And the revision listed on the page is a SHA1 which I can't seem to relate to anything useful? Thanks, John.

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Compile time reflection for IPC using
by Oleg Labutin 24 Jan '14

24 Jan '14

Do you now about one approach (for two compilers (gcc 3.7, and MSVC (last)) emulate compile time reflection with difference scope? Like struct some { META_STRUCT(some); FLD(int, a); FLD(int, b); METH(int, call_0, (int, a)); METH(int, call_1, (int, b)); }; void in() { typedef hl::reflection_extract<some>::field_accessors acc; some s; s.*hl::at<acc, a_accessor>::get() = 5; } We can see here https://github.com/ol72/hl/tree/ And you can try to compile this attached demo Use __J_ACTIVE define to see as reflection worked in json oriented part of project. For which you should install json. Without this you can see ability take meta information by query. But global goal I think we understanding Our backend can be something else. Like client server , data base oriented structures in which we can use by SQL like C++ syntax We can make (and I made it ) database like structures struct human_tables { TABLE(names) { fields((int) index, (std::string) name, .... ); }; TABLE(country) { fields((names_table::index) name, ... ); }; TABLE(human) { indexes(names_table::index_field); fields((names_table::index_field) name, (country_table::index) country...); }; };

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C++03 and C++11 ABI compatibility for compiled libraries
by Andrey Semashev 24 Jan '14

24 Jan '14

Hi, I would like to raise the issue of binary compatibility of compiled Boost libraries between C++03 and C++11. I faced this problem with gcc on Linux, but other compilers and platforms may be affected as well. To summarize the problem: * Most, if not all Linux distributions build packages in C++03 mode. This is also the default in gcc. * Some Boost libraries conditionally use C++11 features in their binary interfaces (see [1] as an example). This makes C++03 and C++11 versions of the library binary incompatible. * Given that, users are unable to use C++11 in their code that uses Boost because of linker failures. I don't have the complete list of the offending C++11 features that break ABI, but it would seem that at least scoped enums and rvalue references are among them. Are there any more? I would like to hear opinions on the possible course of action to tackle this problem. Currently, I see 2 choices: 1. Avoid using C++11 features in binary interfaces. This may also mean avoiding STL types in binary interfaces, if they differ between C++03 and C++11 (I didn't verify that). This is my suggested hotfix solution for Boost.Filesystem [1] and the approach I took in Boost.Log. Obviously, this cripples code and error prone, but it keeps a single binary that can be used from any flavor of C++ on the user's side. 2. Compile different versions of Boost libraries, for each supported C++ version. The C++ version should be encoded into the library file names, so that different versions can coexist. This would require changes in Boost.Build and autolinking support code, but I think this would be a better long-term solution. Opinions? [1] https://svn.boost.org/trac/boost/ticket/6779

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Boost.Fiber review January 6-15
by Nat Goodspeed 23 Jan '14

23 Jan '14

Hi all, The review of Boost.Fiber by Oliver Kowalke begins today, Monday January 6th, and closes Wednesday January 15th. ----------------------------------------------------- About the library: Boost.Fiber provides a framework for micro-/userland-threads (fibers) scheduled cooperatively. The API contains classes and functions to manage and synchronize fibers similar to Boost.Thread. Each fiber has its own stack. A fiber can save the current execution state, including all registers and CPU flags, the instruction pointer, and the stack pointer and later restore this state. The idea is to have multiple execution paths running on a single thread using a sort of cooperative scheduling (versus threads, which are preemptively scheduled). The running fiber decides explicitly when it should yield to allow another fiber to run (context switching). Boost.Fiber internally uses coroutines from Boost.Coroutine; the classes in this library manage, schedule and, when needed, synchronize those coroutines. A context switch between threads usually costs thousands of CPU cycles on x86, compared to a fiber switch with a few hundred cycles. A fiber can only run on a single thread at any point in time. docs: http://olk.github.io/libs/fiber/doc/html/ git: https://github.com/olk/boost-fiber src: http://ok73.ok.funpic.de/boost.fiber.zip The documentation has been moved to another site; see the link above. If you have already downloaded the source, please refresh it; Oliver has added some new material. --------------------------------------------------- Please always state in your review whether you think the library should be accepted as a Boost library! Additionally please consider giving feedback on the following general topics: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? Nat Goodspeed Boost.Fiber Review Manager ________________________________

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Volunteers needed to run regression test reporting
by Beman Dawes 23 Jan '14

23 Jan '14

We have had a long term problem with regression test reporting going offline unexpectedly. The process used XSLT processing was hard to configure, horribly slow, and very fragile, and those factors made it a pain to run. Last year, Steven Watanabe rewrote the report generation in C++, and those issues have pretty much disappeared, so the process is now far easier to run. It runs in five minutes or less. Hooray C++! Hooray Steven! And Hooray Tom Kent who runs the reports! The remaining reliability factors are local ones like system crashes. Since the reports run as cron jobs, it can be quite a while before anyone is inconvenienced enough to report it to the Boost list, and Murphy's Law ensures that it is always the day after the person running the reports left for a week-long back country hike. We can mitigate that by having several people running the reports. I've written some docs, so it shouldn't be too hard, although right now it does require a *nix-like system. I've been running them on a Windows host using a VirtualBox virtual Ubuntu system, and have found it to be easy. One possibility would be for Tom to continue to run the reports on the hour, a second person to run them twenty minutes after the hour, and a third to run forty minutes after the hour. Please volunteer to help make regression reporting more timely and reliable! --Beman

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[phoenix] 7181
by Fletcher, John P 23 Jan '14

23 Jan '14

________________________________________ From: Boost [boost-bounces(a)lists.boost.org] on behalf of Mathieu Champlon [m.champlon(a)free.fr] Sent: 23 January 2014 12:11 To: boost(a)lists.boost.org Subject: Re: [boost] [phoenix] 9111 and 9113 > Hi John, >There is https://svn.boost.org/trac/boost/ticket/7181 which is also >about a warning albeit a different one. >Thanks for doing this ! >MAT. I have pushed to phoenix develop using the patch in 7181 John _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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[phoenix] 9111 and 9113
by Fletcher, John P 23 Jan '14

23 Jan '14

________________________________________ From: Boost [boost-bounces(a)lists.boost.org] on behalf of Mathias Gaunard [mathias.gaunard(a)ens-lyon.org] Sent: 21 January 2014 16:44 To: boost(a)lists.boost.org Subject: Re: [boost] [phoenix] New maintainer On 20/01/14 13:40, Fletcher, John P wrote: >> If you have any information on your problems with Phoenix, in particular any not already on the bug system, please let me know. >> > I filed bugs about warnings a while ago. (9111, 9113) > It shouldn't take much work to fix those and it would be great if I > could finally make my code compile without warnings. I have now pushed a fix for 9111 and some fixes for 9113 to the develop branch. The report on 9113 says there are others, so any other reports would be helpful. John _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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raw.github.com access from behind firewall
by Belcourt, Kenneth 22 Jan '14

22 Jan '14

Hi, When I try to run github hosted regression tests with run.py, access to raw.github.com times out even though it seems to be using the specified our proxy server. # Running regressions in /scratch/modular-boost... # Creating regression scripts at /scratch/modular-boost/tools_regression_src... # Dowloading regression scripts from https://raw.github.com/boostorg/boost/develop/tools/regression/src... --- http://wwwproxy.sandia.gov:80 What's interesting is that I'm able to clone from github.com just fine, as you can see here. -bash-4.1$ git clone https://github.com/boostorg/boost Initialized empty Git repository in /scratch/modular-boost/boost/.git/ remote: Counting objects: 180556, done. remote: Compressing objects: 100% (68339/68339), done. remote: Total 180556 (delta 111934), reused 180501 (delta 111879) Receiving objects: 100% (180556/180556), 68.21 MiB | 10.23 MiB/s, done. Resolving deltas: 100% (111934/111934), done. But we're not able to clone from raw. -bash-4.1$ git clone https://raw.github.com/boostorg/boost Initialized empty Git repository in /scratch/modular-boost/boost/.git/ error: The requested URL returned error: 403 while accessing https://raw.github.com/boostorg/boost/info/refs fatal: HTTP request failed which means this clone (https://raw.github.com/boostorg/boost/develop/tools/regression/src) will fail. Is this a known issue and / or is there a workaround for this? This is on RHE Linux with git 1.8.5.1. -- Noel Belcourt

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[phoenix] bug 9111
by Fletcher, John P 22 Jan '14

22 Jan '14

From: Boost [boost-bounces(a)lists.boost.org] on behalf of Mathias Gaunard [mathias.gaunard(a)ens-lyon.org] Sent: 21 January 2014 16:44 To: boost(a)lists.boost.org Subject: (was Re: [boost] [phoenix] New maintainer > I filed bugs about warnings a while ago. (9111, 9113) > It shouldn't take much work to fix those and it would be great if I > could finally make my code compile without warnings. I have looked at the code for no 9111 and it looks like this: template <int M, typename RhsRT, typename RhsFP> bool operator==(function_ptr<M, RhsRT, RhsFP> const & rhs) const { return false; } For some reason that specialized case is always returning false, which is why rhs is unused. I need to look into why that is the case, or else do some dummy operation on rhs which will suppress the warning. John

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[config] BOOST_NOINLINE on nvcc
by Mathias Gaunard 22 Jan '14

22 Jan '14

Hi, I noticed that I had some problems with some nvcc (NVIDIA CUDA) versions and BOOST_NOINLINE. The logic for defining BOOST_NOINLINE seems to be the same as that of BOOST_FORCEINLINE, which does work correctly, so it seems to be a nvcc bug that's not fully compatible with GCC despite claiming to be. What would be the correct way to fix that?

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[git] boost + git flow
by Oliver Kowalke 22 Jan '14

22 Jan '14

does boost follows the git-flow schema, e.g. merging the changes from branch develop into master is not required by the library developer (this is done by the release manager)?! Oliver

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[testing] Reports that lead nowhere?
by John Maddock 22 Jan '14

22 Jan '14

While we're updating and fixing testing issues, I notice the report generator is still creating content-free failures, for example this one: http://www.boost.org/development/tests/develop/developer/marshall-mac-regex… Ultimately leads nowhere :-( Thanks, John.

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[regex] Need some help with msvc-11/12
by John Maddock 22 Jan '14

22 Jan '14

Can anyone with access to msvc-11 or 12 tell me what's causing this failure: http://www.boost.org/development/tests/develop/developer/output/DrWeb_vc12_… You will probably need to build and run under the debugger to find out I suspect... Many thanks in advance, John.

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Support for Android
by Vicente J. Botet Escriba 22 Jan '14

22 Jan '14

Hi, I see that there are some trouble with Boost and Android: https://svn.boost.org/trac/boost/ticket/9082 http://www.boost.org/development/tests/develop/developer/output/apolukhin-A… Could someone state what is the Boost approach to support Android? Should the user build with NDK r8e? Does bjam supports a specific android platform? Best, Vicente

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[wave] preprocessor directives in output
by Eric Niebler 22 Jan '14

22 Jan '14

I'm looking at automating the regeneration of Fusion's preprocess headers with the wave tool. Currently, it's impossible because of stuff like this (from container\vector\vector.hpp): #if !defined(BOOST_NO_CXX11_RVALUE_REFERENCES) vector(vector&& rhs) : vec(std::forward<vector_n>(rhs.vec)) {} #endif When the wave driver is run, either BOOST_NO_CXX11_RVALUE_REFERENCES is defined, in which case the block of code gets left out, or else it isn't, in which case the block of code is left in. Both are wrong. What should happen is that the #if and #else directives should be present in wave's output. I can keep wave from expanding certain named macros with the -N switch, but there doesn't seem to be a way to selectively keep wave from evaluating #if/#else directives. Or is there? Any help appreciated. Eric

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