May 2010 - Boost - lists.preview.boost.org

[svn] https://svn.boost.org SSL negotiation failed, ssl_error_ssl2_disabled
by Niels Dekker - address until 2010-10-10 29 May '10

29 May '10

TortoiseSVN tells me, when I try to update: > > Command: Update > Error: OPTIONS of 'https://svn.boost.org/svn/boost': SSL negotiation failed: SSL > Error: error: unknown protocol (https://svn.boost.org) > Finished!: And when I try to open https://svn.boost.org in Firefox (running on Windows XP), it tells me: > > Secure Connection Failed > An error occurred during a connection to svn.boost.org. > > Can't connect securely because the site uses an older, insecure version of the SSL protocol. > > (Error code: ssl_error_ssl2_disabled) Is the server down? Thanks in advance, Niels -- Niels Dekker http://www.xs4all.nl/~nd/dekkerware Scientific programmer at LKEB, Leiden University Medical Center

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[log] Condition variable has not been initialized
by Jorge Moraleda 29 May '10

29 May '10

When testing boost.log for race conditions using valgrind drd, some non initialized condition variables are reported at initialization time. I am using Valgrind-3.6.0.SVN and gcc version 4.4.4 (Debian 4.4.4-1). These are the valgrind error messages: ==27651== condition variable has not been initialized: cond 0x6174420 ==27651== at 0x4C267B9: pthread_cond_broadcast@* (drd_pthread_intercepts.c:756) ==27651== by 0x66DBCD2: ??? (in /usr/local/lib/libboost_log.so.1.42.0) ==27651== by 0x6719E85: ??? (in /usr/local/lib/libboost_log.so.1.42.0) ==27651== by 0x66C4BD2: ??? (in /usr/local/lib/libboost_log.so.1.42.0) ==27651== by 0x7FF000561: ??? ==27651== by 0x722F63762F656771: ??? ==27651== by 0x2F6E69622F657068: ??? ==27651== by 0x722F726576726572: ??? ==27651== by 0x767265732D657068: ??? ==27651== by 0x2D2D00772D007264: ??? ==27651== by 0x72635F776F6C6C60: ??? ==27651== by 0x62645F65746164: ??? ==27651== ==27651== condition variable has not been initialized: cond 0x6174420 ==27651== at 0x4C267B9: pthread_cond_broadcast@* (drd_pthread_intercepts.c:756) ==27651== by 0x66D7F1A: boost::log_mt_posix::basic_core<char>::get() (in /usr/local/lib/libboost_log.so.1.42.0) ==27651== by 0xB5087C: boost::log_mt_posix::sources::basic_logger<char, boost::log_mt_posix::sources::severity_logger_mt<util::logging::severity_level>, boost::log_mt_posix::sources::multi_thread_model<boost::log_mt_posix::aux::light_rw_mutex> >::basic_logger() (basic_logger.hpp:122) ==27651== by 0xB4F166: boost::log_mt_posix::sources::basic_severity_logger<boost::log_mt_posix::sources::basic_logger<char, boost::log_mt_posix::sources::severity_logger_mt<util::logging::severity_level>, boost::log_mt_posix::sources::multi_thread_model<boost::log_mt_posix::aux::light_rw_mutex> >, util::logging::severity_level>::basic_severity_logger() (severity_feature.hpp:169) ==27651== by 0xB4DA3D: boost::log_mt_posix::sources::basic_composite_logger<char, boost::log_mt_posix::sources::severity_logger_mt<util::logging::severity_level>, boost::log_mt_posix::sources::multi_thread_model<boost::log_mt_posix::aux::light_rw_mutex>, boost::mpl::vector1<boost::log_mt_posix::sources::severity<util::logging::severity_level> > >::basic_composite_logger() (basic_logger.hpp:391) ==27651== by 0xB4C771: boost::log_mt_posix::sources::severity_logger_mt<util::logging::severity_level>::severity_logger_mt() (severity_logger.hpp:77) ==27651== by 0xB4BA3C: __static_initialization_and_destruction_0(int, int) (Logging.cpp:35) ==27651== by 0xB4BAC6: global constructors keyed to _ZN4util7logging3aux9theLoggerE (Logging.cpp:215) ==27651== by 0xB58095: ??? (in /home/jorge/vc/ripe/bin/server/ripe-server) ==27651== by 0x9D3732: ??? (in /home/jorge/vc/ripe/bin/server/ripe-server) ==27651== ==27651== condition variable has not been initialized: cond 0x6174420 ==27651== at 0x4C267B9: pthread_cond_broadcast@* (drd_pthread_intercepts.c:756) ==27651== by 0x5F6AD14: ??? (in /usr/local/lib/libboost_thread.so.1.42.0) ==27651== by 0x5F6AD48: boost::detail::get_current_thread_data() (in /usr/local/lib/libboost_thread.so.1.42.0) ==27651== by 0x5F6AD68: boost::detail::find_tss_data(void const*) (in /usr/local/lib/libboost_thread.so.1.42.0) ==27651== by 0x5F6ADD8: boost::detail::get_tss_data(void const*) (in /usr/local/lib/libboost_thread.so.1.42.0) ==27651== by 0x66D6FAB: boost::log_mt_posix::basic_core<char>::implementation::init_thread_data() (in /usr/local/lib/libboost_log.so.1.42.0) ==27651== by 0x66D7619: boost::log_mt_posix::basic_core<char>::open_record(boost::log_mt_posix::basic_attribute_set<char> const&) (in /usr/local/lib/libboost_log.so.1.42.0) ==27651== by 0x9F5432: boost::log_mt_posix::basic_record<char> boost::log_mt_posix::sources::basic_logger<char, boost::log_mt_posix::sources::severity_logger_mt<util::logging::severity_level>, boost::log_mt_posix::sources::multi_thread_model<boost::log_mt_posix::aux::light_rw_mutex> >::open_record_unlocked<boost::parameter::aux::tagged_argument<boost::log_mt_posix::keywords::tag::severity, util::logging::severity_level const> >(boost::parameter::aux::tagged_argument<boost::log_mt_posix::keywords::tag::severity, util::logging::severity_level const> const&) (basic_logger.hpp:269) ==27651== by 0x9F3EDE: boost::log_mt_posix::basic_record<char> boost::log_mt_posix::sources::basic_severity_logger<boost::log_mt_posix::sources::basic_logger<char, boost::log_mt_posix::sources::severity_logger_mt<util::logging::severity_level>, boost::log_mt_posix::sources::multi_thread_model<boost::log_mt_posix::aux::light_rw_mutex> >, util::logging::severity_level>::open_record_unlocked<boost::parameter::aux::tagged_argument<boost::log_mt_posix::keywords::tag::severity, util::logging::severity_level const> >(boost::parameter::aux::tagged_argument<boost::log_mt_posix::keywords::tag::severity, util::logging::severity_level const> const&) (severity_feature.hpp:226) ==27651== by 0x9F2511: boost::log_mt_posix::basic_record<char> boost::log_mt_posix::sources::basic_composite_logger<char, boost::log_mt_posix::sources::severity_logger_mt<util::logging::severity_level>, boost::log_mt_posix::sources::multi_thread_model<boost::log_mt_posix::aux::light_rw_mutex>, boost::mpl::vector1<boost::log_mt_posix::sources::severity<util::logging::severity_level> > >::open_record<boost::parameter::aux::tagged_argument<boost::log_mt_posix::keywords::tag::severity, util::logging::severity_level const> >(boost::parameter::aux::tagged_argument<boost::log_mt_posix::keywords::tag::severity, util::logging::severity_level const> const&) (basic_logger.hpp:509) ==27651== by 0xB4B5DF: util::logging::init(util::logging::severity_level, std::string const&) (Logging.cpp:190) ==27651== by 0xB49DA0: util::logging::init(std::string const&, std::string const&) (Logging.cpp:96) ==27651== ==27651== condition variable has not been initialized: cond 0x6174420 ==27651== at 0x4C267B9: pthread_cond_broadcast@* (drd_pthread_intercepts.c:756) ==27651== by 0x66D8D1A: ??? (in /usr/local/lib/libboost_log.so.1.42.0) ==27651== by 0x66D9F43: boost::log_mt_posix::aux::stream_provider<char>::allocate_compound(boost::log_mt_posix::basic_record<char> const&) (in /usr/local/lib/libboost_log.so.1.42.0) ==27651== by 0x9F3F72: boost::log_mt_posix::aux::record_pump<boost::log_mt_posix::sources::severity_logger_mt<util::logging::severity_level> >::record_pump(boost::log_mt_posix::sources::severity_logger_mt<util::logging::severity_level>&, boost::log_mt_posix::basic_record<char> const&) (record_ostream.hpp:293) ==27651== by 0xB4B5FC: util::logging::init(util::logging::severity_level, std::string const&) (record_ostream.hpp:330) ==27651== by 0xB49DA0: util::logging::init(std::string const&, std::string const&) (Logging.cpp:96) ==27651== by 0x9DB05C: util::Configuration::parseCommandLine(int, char**) (Configuration.hpp:176) ==27651== by 0x9D6C5C: ripe_server::Configuration::Configuration(int, char**) (Configuration.cpp:70) ==27651== by 0xA48A86: main (posix_main.cpp:94) ==27651==

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[proposal] The boost.org Maintenance Effort
by Dean Michael Berris 28 May '10

28 May '10

Hi Everyone, [First of all, this is a warning -- this is a long post, and I would really appreciate it if you read through the whole thing first before posting a comment on any specific thing I say. What follows is more supposed to be read as a document, so please bear with me. :D] A couple of days ago I posted a question about who is managing the boost.org website and the current process by which the website is being generated/hosted. That discussion led to a few realizations for me that I am including in this proposal to address the relative "pain" required to maintain the current site and move forward. This post is a proposal is designed to address three key areas of the boost.org maintenance effort: * The toolchain requirements for building/generating the boost.org site. * Addressing the non-interactivity of the boost.org website and the related pages. * Per-library community/documentation management. First, a preamble: The boost.org website is meant to be the face of the Boost C++ Libraries. It should be the facade that communicates the quality and the high standard the the Boost development community hold dear as the differentiating factors that make Boost what it is. As the face of the community, the website should encourage: participation, collaboration, community building, and open communication. The website shall host all community-developed and enforced policies, all official communications from the Boost community to the world, and serve as an umbrella that shelters the libraries and communities that do become part of the Boost C++ Library effort. Next, let me outline a few broad things with specific points: Communication * We should make it easy for the whole boost community (boost.org) and individual library maintainers/community to communicate messages to the world at large in an easy, unobtrusive manner. * We should make communication a two-way process by encouraging participation (see Participation below). * We should strive to communicate more, instead of communicating less -- to do this we should make it part of the goal of those in the Boost community (not necessarily developers) to promote the libraries and the website itself. Participation * Let's encourage participation in the form of comments to blog posts, feedback on documentation pages, and discussions on specific topics/threads. * Let's make it easier for non-developers to contribute to the effort in the form of community building, providing support, and advocate the library. * We should use the boost.org website as a means of reaching out to and being one of the ways the open source community and industry at large can get in touch with: individual developers, library maintainers, or the Boost community (including users) at large. Collaboration * Let's add the boost.org website as an additional channel through which collaboration can occur as a complement to the boost-developers and boost-users mailing lists. * Let's foster a more community-driven way of solving problems without having to require everyone to be part of a central list. * Let's allow communities around Boost libraries to grow and get things done on the boost.org website. After all the "marketing" stuff above, I'll outline below the concrete steps I propose people allow me to do. Ultimately though there should be a means of measuring whether the steps I take would lead to an agreeable measure of success, so I point out some measures by which you may hold me accountable to getting done. I invite everyone to please comment on and discuss whether the steps/proposal makes sense and whether there is a better way you think I can achieve this in case you agree to my above statements. Step 1: Move static and not-so-static content over to Wordpress MU [0] The current boost.org website is composed of mostly static content that says things about the submission-review process, the guidelines for libraries, what the goal of the project is, and the like. These pages can be ported to Wordpress MU manually either by copy-pasting the content into the WYSIWYG editor or typing the content in (and editing it in the process). This step will include the establishment of who would be the administrators and the eventual maintainers of the boost.org facade. All the information regarding the Boost Community and the maintaining of the content that's specific to the boost.org website would be written, article submissions curated, and copy-edited by the administrators. I have personally volunteered to be one of these administrators who would basically act as an editor for the site. I would take on the responsibility of achieving the following (measurable) goals: 1. Establishing a "Feedback" button that allows anybody visiting the site to post feedback on whatever they think. I would prefer to use a service called Get Satisfaction [1] to gather and manage the feedback, as well as responding to feedback posted through that service. 2. Incorporating a DisQus [2] discussion system to manage comments on pages. There is already a Wordpress plugin for this and comment moderation would mostly be handled initially by me and other administrators interested in helping out in this effort. 3. Integrating and publishing regularly the Google Analytics and Wordpress MU stats on the whole site. Regularly can mean either monthly or weekly depending on who often the community wants information about the site. [0] http://mu.wordpress.org/ [1] http://getsatisfaction.com/ [2] http://disqus.com/ Step 2: Make it easy to jump from Wordpress MU to Trac for the Wiki, Tickets, and Source Viewer This would mean adding links to the appropriate pages in Trac, and in these pages a way to jump back to the boost.org website. This will require some changes in the Trac site which should be easy to pull off. The measurable outcome for this would be to see the actual integration done in a satisfactory manner. Satisfactory of course means, that it works. ;) Step 3: Set up blogs for individual libraries (who want it, or at least for library maintainers/volunteers who want to manage it) Ideally this should be done for all the libraries. Each sub-site would include (at the minimum): * A blog -- where only the maintainers and those nominated by the maintainers to have blog posting access can communicate what's happening, what's coming, whether they need help, or whether there are any nasty bugs that need attention (as well as just some general updates or cool findings regarding the library). * Static Pages -- typically there would be pages like "About", "History", "Examples", and "FAQs" which generally are mostly static. These can be edited by the maintainers and those nominated by the maintainers who would have access to these pages. * Support Information -- this would be a special static page which would point to Trac, or other places where the development and support system of the library is hosted. I am not excluding the possibility of having libraries developed in github/gitorious/sourceforge. Links to things like the mailing list on which the discussion happens, whether there's a web-based forum, or whether there's a number/company to call for support would generally go here too. * Online documentation -- as an absolute minimum there should be a page on documentation for each library in Boost accessible from the boost.org website. It would be a good thing to integrate the generated library documentation into the wordpress system itself, but at the minimum links to the generated library docs that are statically served (just like now) would be acceptable. My personal vision for boost.org would be to become the hub over which the Boost C++ community and the surrounding ecosystem of companies can join in on the action. I would even go so far as say that we should encourage and allow industry players that offer support for Boost libraries or who use Boost libraries to place advertising on the site to help with shouldering the cost of BoostCon, or other things that the Free Software Conservancy would deem necessary to spend money on. I also would like to see it be the face of the Boost community, and really a means to get users to start using boost, get excited about it, and eventually contribute back to the cause. Users who are already passionate about providing support for a wider audience of Boost users could also contribute to the cause not as library developers but people who publicize and liberally put links to the boost.org site on their blogs, on their email correspondence, and in stackoverflow.com answers. Ultimately I would personally want to see boost.org be able to handle the growth of the Boost C++ Library, and allow for more communities (not just one community) to through the site. I don't want it to replace the mailing list for Internet old timers like me who like this feel of email conversation, but for things like announcements and communicating to the wider audience I think the website should do that job superbly. Thanks for reading this far, comments, suggestions, reactions, and pledges to help would be greatly appreciated. Have a great day everyone and I hope to hear from you soon! -- Dean Michael Berris deanberris.com

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BoostCon 2011 Dates and Hotel Discount (this week only!)
by David Abrahams 28 May '10

28 May '10

Hi All, BoostCon #4 was a resounding success, with 95 registrants—attendance holding steady in the face of a poor economy—and nothing but smiles all ’round. One participant was heard to say “after last year, I thought about not coming because I was sure nothing could possibly be cooler that experience, but this is even better.” I'll have more to say about the event soon, but for now a couple important details about next year: 1. Next year, BoostCon is scheduled a week later: May 15-20, 2011 which avoids a conflict with Mother's Day, a perennial issue for some attendees… and is a bit less likely to bring us snow ;-) 2. Because BoostCon has been an excellent regular customer, the Aspen Meadows is offering a $20/night discount for any Boost participant who books on or before **this Friday**, May 21 2010. After taxes, etc., that's more than a $100 savings. Use the following link to make your reservation: https://resweb.passkey.com/Resweb.do?mode=welcome_ei_new&eventID=2547965&fr… Lastly, the Meadows wants you to know that your companies or universities are welcome back for other meetings, and requests that, if you had a good hotel experience this year, you please post positive feedback on http://tripadvisor.com. See you next year, if not before! Cheers, -- Dave Abrahams Meet me at BoostCon: http://www.boostcon.com BoostPro Computing http://www.boostpro.com

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[concept] "not" and "or" concept constraints (N2081)
by Lorenzo Caminiti 28 May '10

28 May '10

Hello all, How can I use Boost.ConceptCheck to implement "not" and "or" concept constraints as they are defined in N2081? (If this is obvious from the documentation, please just point me to the link.) For example, how can I program the following code from N2081 using Boost.ConceptCheck: // "not" `!` concept constraint for some concept C (not C++ code). template<Regular T> where !C<T> void f(T x) { ... } // "or" `||` concept constraint (not C++ code). template<Regular T> where Integral<T> || Floating<T> T cos(T x) { ... } If I understand it right, I can program the "and" concept constraints in Boost.ConceptCheck just by specifying multiple concepts as in: // "and" `&&` concept constraint. template<typename T> BOOST_CONCEPT_REQUIRES( ((boost::Integral<T>)) ((boost:: Arithmetic<T>)), T) f(T x) { ... } But how do I use BOOST_CONCEPT_REQUIRES(), etc to program "not" and "or" concept constraints? Thank you very much. -- Lorenzo

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Re: [boost] [boost::endian] Request for comments/interest
by Dave Handley 28 May '10

28 May '10

"Scott McMurray" wrote: > On 28 May 2010 13:44, Cliff Green <cliffg(a)codewrangler.net<mailto:cliffg@codewrangler.net>> wrote: > > > > Studies have been performed comparing "receiver makes right" designs (where > > swapping is only performed by the receiver, if needed) with others. The > > costs of swapping on modern processors is pretty minimal compared with the > > design overhead and complexity, so "receiver makes right" many times is not > > justified. > > > > I understood it more as "we use little-endian for our network format, > since most of our machines are little-endian, but still want to allow > things to work on the couple of big-endian machines", not as "receiver > makes right". I need to reiterate that I was not talking about a "receiver makes right" design. I don't like these at all for complexity reasons. But in this day and age when a significant percentage of computers being sold are little-endian, deciding to make an internal protocol little-endian and almost completely eliminating endian swaps can make a lot of sense. If you are processing data off multiple 10Gb Ethernet feeds simultaneously, removing a single copy can make all the difference. Especially when you consider memory bandwidth constraints on a multi-threaded process. If you consider the hoops that C++0x has tried to jump through to make move semantics work, removing unnecessary copies, especially in a low level process, seems to be important to a lot of people. Dave

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Re: [boost] [boost::endian] Request for comments/interest
by Dave Handley 28 May '10

28 May '10

"Cliff Green" wrote: > In most general marshalling / serialization designs where portable binary > values are required, the transform step (from "wire" to "object / memory" > model) requires a copy anyway. The low-level endian facilities should not > require an extra copy, but trying to minimize all copying and constraining > the endian library design might be misguided. In the sort of code I write, an endian swapper that had copies that weren't necessarily required, especially in the "do nothing" case where network and machine have the same endianness would not be fit for purpose. " " wrote: > This is not completly true, as your implementation will at least visit the instance. I disagree. If you look in more detail at the code that Tom has submitted, the "do nothing" case does exactly that - nothing. Specifically line 147-154 has the template specialisations that get invoked when a no-op is required, and they have no code in them. Only in the case where an endian swap is required does the implementation walk through the whole data structure. Dave

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Review of a safer memory management approach for C++?
by Bartlett, Roscoe A 28 May '10

28 May '10

Hello Boost developers, I am interested in finding one or more individuals who are knowledgeable about memory management in C++ (and especially of the reference-counting approach taken by boost::shared_ptr and boost::weak_ptr) to review an idea for a comprehensive approach to safer memory management in C++ that encapsulates all raw C++ pointers in high-level code. The technical report for the approach is: Teuchos C++ Memory Management Classes, Idioms, and Related Topics The Complete Reference A Comprehensive Strategy for Safe and Efficient Memory Management in C++ for High Performance Computing and can be found at: http://www.cs.sandia.gov/~rabartl/TeuchosMemoryManagementSAND.pdf If someone would be willing to at least go through the abbreviated table of contents laid out in the Preface and provide some feedback, I would be greatly appreciative. If there is a better mail list to send this too, please let me know. Thanks, - Ross P.S. Please make sure and respond to me personally (rabartl(a)sandia.gov<mailto:rabartl@sandia.gov>) or a spam filter will likely kill it. ----------------------------------------------------------------------- Dr. Roscoe A. Bartlett Sandia National Laboratories Department of Optimization and Uncertainty Estimation Trilinos Software Engineering Technologies and Integration Lead (505) 844-5097

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[concept] concept-based overloading (N2081)
by Lorenzo Caminiti 28 May '10

28 May '10

Hello all, How do I use Boost.ConceptCheck and/or Bosot.EnableIf to implement concept-based overloading (as discussed in N2081)? For example, from N2081, the following functions are selected based on `Iter` matching one of the two specified concepts: template<InputIterator Iter> // proposed concept syntax (not C++) void advance(Iter& x, Iter::distance_type n) { while (n > 0) { ++x; --n; } } template<BidirectionalIterator Iter> // proposed concept syntax (not C++) void advance(Iter& x, Iter::distance_type n) { if (n > 0) while (n > 0) { ++x; --n; } else while (n < 0) { --x; ++n; } } How do I program this in C++ using Boost libraries? N2081 briefly mentions this can be done in C++ using SFINAE, etc. I think I could use `enable_if` if I had some sort of `is_input_iterator` metafunction... Please just point me to the documentation if this has already been addressed there. Thank you very much. -- Lorenzo

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[iterator] issues with Boost.Iterator and Boost.MultiArray
by Thomas Klimpel 28 May '10

28 May '10

Hi, The issues reporteted in <http://lists.boost.org/Archives/boost/2010/05/165798.php> are still open. Even so I wrote: > But from my point of view, the only responsibility I may > have with respect to these issues is to notify the authors > of the affected libraries, which I have done now. it seems that I wasn't yet successful in my attemps to notify the authors. The only one that has answered so far was Thomas Witt <http://lists.boost.org/Archives/boost/2010/05/165837.php>, claiming that the bug is in Boost.MultiArray. However, my personal belief is that the bug is in <http://svn.boost.org/svn/boost/trunk/boost/iterator/detail/facade_iterator_…>. But there is definitively a "quasi unrelated" bug in Boost.MultiArray on trunk (and Thomas Witt might refer to this bug), as the "resize" regression test fails on nearly all compilers on trunk but passes on release <http://lists.boost.org/Archives/boost/2010/05/165810.php> (the link contains a patch that fixes the failures). I would be most happy, if 1) Ron (or somebody else that is allowed to apply patches to Boost.MultiArray) would simply fix the failure of the "resize" regression test on trunk (either by applying the provided patch or by fixing it in some other way). 2) Dave (or somebody else that has deep knowledge about Boost.Iterator) would confirm that the failures of Boost.MultiArray on MSVC-10 are caused by an issue in Boost.Iterator (and are probably related to Jeremy Siek's patch <https://svn.boost.org/trac/boost/changeset/21683>). I guess the result if somebody will answer at all is that I will be asked to enter a track ticket for Boost.Iterator. So if this mail should stay without useful feedback, I will enter two track tickets for Boost.MultiArray and one track ticket for Boost.Iterator, in anticipation that the feedback would probably have suggested that I should do that. Regards, Thomas

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