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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