August 2013 - Boost - lists.boost.org

[Interprocess] Named pipe interface proposal
by Geoff Shannon 18 Aug '13

18 Aug '13

I emailed the list a while ago that I was starting to work on a named pipe implementation for potential inclusion in the Boost.Interprocess library, and now I finally have some concrete evidence of progress. I've come up with a header file for my proposed interface and I would really appreciate any and all feedback on it. Particularly, I'm interested in ideas for an appropriate replacement for using char *'s as the data buffers for reading and writing. As a point of interest this interface is meant to be extremely simple. I don't intend to initially support ANYTHING except for basic creation and reading and writing. Thanks! -- Geoff Nothing is ever easy.

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about bessel function
by llwaeva＠gmail.com 17 Aug '13

17 Aug '13

Hi all, I am testing the bessel function boost::math::cyl_bessel_j in gnu compiler with boost 1.51.0, I am testing boost::math::cyl_bessel_j(2000, 0.9) boost::math::cyl_bessel_j(4000, 0.9) the first one give zero but the second one gives infinity while it should give zero also. I wonder why it doesn't work when the order is bigger than 4000?

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Re: [boost] [Interprocess] Named pipe interface proposal
by John Venarchick 15 Aug '13

15 Aug '13

> > > > I would URGE you to make this exclusively a Boost.ASIO implementation. > > I also agree, an ASIO implementation is the way to go with this. > > 3. There seemed to be some confusion regarding named pipes on POSIX. > > > The only difference between Windows and POSIX named pipes is that the > > > former use the NT kernel namespace, within which the filing systems > > > are mount points, whereas the latter use the filing system namespace > > > directly. In my own code, I use a magic directory in /tmp as the > > > namespace for all my named pipes in the system in an attempt to > > > replicate a similar behavior to Windows, but there are many other ways > > > of doing the same thing. > > > > > > > Hmmm, I see what you're saying and I agree with it, but I'm also not sure > that > > it's strictly true that this is the "only" difference. > also a +1 to using POSIX pipes instead of domain sockets. I don't think you'd need to copy Niall's /tmp/ magic directory or if so make that an option. > > Also, FYI, I'm doing this project as an independent study through my CS > program. > > I'm getting close to the end of the quarter and I need to have something > > concrete to show for my efforts. Since I've already started down the > path > of > > implementing this not inside of Boost.ASIO, for the purposes of my school > > project I'm going to continue with that. However, I plan to continue > working on > > it after the scholastic bit is finished, and then I would be interested > in > > implementing it as part of ASIO. > > That's pretty cool as a CS project. I hope you get a good grade. I've done far too much with Windows pipes and would definitely like to see an ASIO interface if not just to replace what I'm doing now. -John V

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Endian Library?
by Andrew Ho 15 Aug '13

15 Aug '13

Hi, I'm curious what the status for endian/byte order support in Boost is (namely, detecting system byte order and swapping between byte orders)? I did a quick search of the include dir and it seems that Spirit has some endian support, though I haven't found any documentation. There's also boost/detail/endian.hpp which has detection of the endian-ness, but doesn't provide any structure for switching between endians/byte-orders. I also found endian.h in predef, which appears to do something similar to boost/detail/endian.hpp. Searching through the list, there were at least 2 different proposals for Boost.Endian (a few years ago), though as far as I can tell neither of these implementations were formally adopted into Boost. I couldn't find any reason why they weren't included.

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server error on ci.boost.org?
by Anthony Foiani 15 Aug '13

15 Aug '13

[Sorry for sending this to the dev list, but I didn't see a server admin email address anywhere obvious. Or I just went right past it, one of the two...] I was searching for something on Google, and one of the hits was on ci.boost.org: http://ci.boost.org/websvn/filedetails.php?repname=repos+1&path=%2Ftrunk%2F… [shortened: http://preview.tinyurl.com/lkvqbo3 ] When I went there, I got the navigation elements, but the actual content was missing, and instead there was a yellow warning box with this message: Unable to cat file: svn: Can't write to stream: No space left on device Thought you all might like to know. Thanks, Anthony Foiani

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[Asio] Commit-rollback on asynchronous operations - cancel / close may fail
by Sorin Fetche 15 Aug '13

15 Aug '13

Hi, I noticed that functions for canceling asynchronous operations or closing objects on which they are executed are documented as being possible to fail. This is the case at least for the acceptor objects (basic_socket_acceptor or ip::tcp::acceptor), socket objects (basic_socket or ip::tcp::socket) and even timer objects (deadline_timer or steady_timer). In this case what are the options for implementing commit-rollback for asynchronous operations? By rollback I mean canceling a successfully started first operation in case a second operation in the batch of operations fails (as exemplified in the attached test code). As described in [1] a rollback operation absolutely relies on no-throw operations. What is supposed to happen with the handler associated with the asynchronous operation that failed to be canceled? Handlers, most often, at least for non-trivial programs are carrying shared resources with them and, if not called, may leave the application in a hanged state waiting for an event that will never come. I didn't find in the documentation any guarantees given regarding the handlers associated with the async-operations that they can or cannot be lost (that is never called). This of course, as long as io_service::run is running or the control returns to it after an exception. Also, as shown in [2] and as demonstrated by the attached test program, at least for async_write, invoking the destructor of an object on top of which asynchronous operations are being executed is not correct either and may lead to undefined behavior (crash). [1] Exception-Safety in Generic Components; section 6 http://www.boost.org/community/exception_safety.html [2] BoostCon 2011: Thinking Asynchronously; slide 47 https://github.com/boostcon/2011_presentations/raw/master/mon/thinking_asyn… Thank you, Sorin Fetche

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[serialization] How are floating point values handled?
by John Maddock 14 Aug '13

14 Aug '13

I can't find anything in the docs about how floating point types are handled by the serialization lib. It seems like text archives print however many digits are specified in the ostream's precision is that correct? If so I think this needs to be raised as a big red flag, because it means that floating point values, uniquely compared to other primitives, do not round trip by default. Except actually they do when using a binary archive. This actually raises a problem when using text archives with floating point data - if you want to be able to round trip the values, then how many digits precision should you set the stream to? Particularly if you're saving a complex structure containing different floating point types of differing precisions? I would have thought it would be better for the serialization lib to set the stream precision before outputting a primitive type - to std::numeric_limits<T>::max_digits10 (or std::numeric_limits<T>::digits10+2 if max_digits10 is not available). However, I recognize that this is a difficult issue! Cheers, John.

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Pre-build MSVC Boost binaries
by Fredrik Orderud 13 Aug '13

13 Aug '13

Over the last year, I've set up a small SourceForge "WinBin" project [1] for distributing Microsoft Windows binaries for Boost (and some other projects). The repository is sorted by Boost version, compiler version and shared vs. static linking. Each file archive contains pre-build boost in debug/release for both 32/64-bit, following a include/lib[64]/bin[64] folder structure. There also seems to be some other sources for pre-built boost around (e.g. https://sourceforge.net/projects/boost/files/boost-binaries/ and http://boost.teeks99.com/bin/) However, these do not seem to provide boost built for both static and shared linking. Also, they do not appear to adhere to the "quasi standard" include/lib[64]/bin[64] folder naming convention used by many libraries. Finally, they seem to lack information on which version of python (and possibly other 3rd party SW) they are compiled against. Therefore, I decided to set up my own boost-binaries webpage. Please let me know if you might be interested in either improving the "WinBin" project, or somehow joining forces to merge the various sources of Boost binaries into a single, more "authoritative" repository. I would be more than happy to shut WinBin down if "similar enough" binaries can be downloaded elsewhere. Thanks in advance, Fredrik Orderud [1] https://sourceforge.net/projects/winbin/files/boost/

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[utility] Fixes to value_init docs
by Robert Kawulak 13 Aug '13

13 Aug '13

I've made some small fixes to value_init docs (patch attached) that I want to commit. Any objections? Best regards, Robert

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Line endings fixes
by Vitaly Budovski 13 Aug '13

13 Aug '13

Hi, Please see the attached files. boost_endings1.patch just sets some of the cpp and other text files to have file endings consistent with the rest of the repository. boost_endings2.patch may be controversial as it does the same but for the svg files. Some of them are marked as text, others as binary. It's a real mess. Most of the svg files are generated from other sources so should probably be omitted from the repository and simply regenerated when docs are built. Came across these issues when checking out the modularised boost git repository. Regards, Vitaly

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unique_ptr for C++03
by Andrew Ho 13 Aug '13

13 Aug '13

Hi, I implemented std::unique_ptr using C++03 features plus a few other Boost Libraries. Incidentally, I also implemented default_delete (which binds to std::default_delete if available) because it's required for unique_ptr. https://github.com/helloworld922/unique_ptr The library binds to std::unique_ptr if standard library support is available. There are a few things I don't think I'll be able to emulate exactly. Namely: - I don't think the deleter can ever be forwarded correctly (limitation of C++03). Ideas/suggestions for how to best handle this are welcome (currently, I move the deleter if E == D and copy otherwise, I think) - There's no explicit conversion overloads in C++03. Currently I have operator bool() implemented non-explicitly if there's no compiler support, relying on the user to only use it "as-if explicit". An alternative solution is to remove the typecast operator and force users to use get() == NULL_VALUE. - functions relying on nullptr_t are only enabled if compiler support is available. Again, I don't think there's any possible work-around for C++03. There are also a few missing features (still working on the implementation): - make_unique (part of c++14) - nullptr_t comparison operators Current dependencies (assuming no C++11 std::unique_ptr): - Boost.Config - Boost.Move - Boost.TypeTraits Comments/Feedback is welcome.

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Location for library-specific utility files in Subversion trunk
by Jeremiah Willcock 12 Aug '13

12 Aug '13

I have a file containing the list of unmerged changes from BGL and some command lines to simplify merging changes from the trunk to the release branch and to help in writing release notes. They are not useful to have in a release, but I would like to have them stored somewhere other than just my home directory. Is there a path designated for that? Somewhere inside tools/release/? -- Jeremiah Willcock

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Inspection report: revision used?
by Joaquin M Lopez Munoz 11 Aug '13

11 Aug '13

Hi, The current inspection report, dated 15:30:32 UTC, Saturday 10 August 2013: http://boost.cowic.de/rc/docs-inspect-release.html fails to state the SVN revision being inspected The files checked were from unknown at revision unknown As it happens, whatever revision of the code is being used it has to be older than Aug 10, since the error reported at http://boost.cowic.de/rc/docs-inspect-release.html#flyweight has been fixed as of Aug 6, i.e. four days before: https://svn.boost.org/trac/boost/changeset/85227 Just a heads up in case there's something to fix on the inspection report running engine. Joaquín M López Muñoz Telefónica Digital

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[mixin] New library reminder
by Borislav Stanimirov 11 Aug '13

11 Aug '13

Hello, Some of you might remember the previous discussion on the subject (archived here: http://lists.boost.org/Archives/boost/2013/01/200598.php) Anyway, in short, I'm developing a library with the intention to formally submit it to Boost by the end of the year. You can find it here: https://github.com/iboB/boost.mixin The latest news about it is that I think that the library's features for the formal submission are done and all that's left are minor tweaks, bug fixes, tests, examples, and, most importantly, a complete documentation. In the meantime, I again invite you all to check it out. Any comments, suggestions, and questions will be greatly appreciated. Thanks, -- Borislav

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Fwd: Line endings fixes
by Vitaly Budovski 11 Aug '13

11 Aug '13

Hi, On 10 Aug 2013 18:55, "Paul A. Bristow" <pbristow(a)hetp.u-net.com> wrote: > > I'm confused, but does it help you to know that the many SVG files for Booth.Math are generated by a > C++ program that we run. > > This program writes html and end of line as std::endl;. > Regardless of the method, any text based formats should be checked into SVN with mime-type text/plain and native eol. > These SVG files are used to generate the PDF version of Boost.Math docs (because using PNG produces > very poor display). > No disagreement about SVG being the better choice where possible. > These SVG files are also converted to PNG for the html version. > <snip> > > HTH > > Paul Cheers, Vitaly

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Releasing Boost Dependency Analyzer 1.1
by Jens Weller 11 Aug '13

11 Aug '13

Hello boost community, a short notice that I just have released the version 1.1 of my dependency analyzing tool for boost. For now I have only managed to get a proper Windows Version, Linux Version will follow later. New Features: Configuration - the tool remembers the path to bcp now - select the source for libraries - maintainers.txt - libraries.xml - 2 filter options - filter libraries by name - filter edges by type, for now its header, source/lib, test and documentation. Export: - Export CSV File which has all libraries and the number of dependencies (sorted) libraries.xml - this is now a optional source for the library names Some feedback: libraries.xml as a lib name source is nice, but not quite perfect. I've seen different results from maintainers.txt and libraries.xml. As maintainers.txt also libraries.xml contains duplicates, some of its library names don't fit the expectation of bcp, so I applied some fixes for this in my program. The Dependency filter is yet not perfect, especially in detection. More details about this version and the download for it at my blog: http://www.meetingcpp.com/index.php/br/items/releasing-boost-dependency-ana… kind regards, Jens Weller

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Boost 1.54 build problem: --without-context not honoured?
by Steve M. Robbins 11 Aug '13

11 Aug '13

Hi, I'm digging into a build problem and noticed that even though I specify "./bjam --without-context", Boost.Context is still built! The bjam configuration output states that Context is not to be built: Component configuration: - atomic : building - chrono : building - context : not building - coroutine : building - date_time : building - exception : building But it is built nonetheless. This causes a build failure for architectures which are not supported; see build log [1]. Compare that to the build for 1.53 [2] which works fine. I've diffed the libs/context directory between 1.53 and 1.54 and nothing jumps out at me as the cause. Has anyone noticed and fixed this already? Thanks, -Steve [1] https://buildd.debian.org/status/fetch.php?pkg=boost1.54&arch=ia64&ver=1.54… [2] https://buildd.debian.org/status/fetch.php?pkg=boost1.53&arch=ia64&ver=1.53…

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[preprocessor] nested for_each not working like expected
by Eric Niebler 10 Aug '13

10 Aug '13

I can't figure out what I'm doing wrong. According to the docs, this should work: #define S0 (0)(1)(2)(3) #define S1 (5)(6)(7)(8) #define M4(R, DATA, ELEM) (DATA,ELEM) #define M2(R, DATA, ELEM) BOOST_PP_SEQ_FOR_EACH_R(R, M4, ELEM, S1); BOOST_PP_SEQ_FOR_EACH(M2, ~, S0) I expect to get a sequence like (0,1)(0,2)... for each combination. I get gibberish. (Please don't tell me to use FOR_EACH_PRODUCT. In my real use case, M2 and M4 are far more complicated, and a simple product won't do.) Can anybody please tell me what I'm doing wrong? TIA, -- Eric Niebler Boost.org

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[chrono] Outdated information in documentation
by Björn Pollex 10 Aug '13

10 Aug '13

In the getting started section [1] it refers to an issue with the BOOST_ERROR_CODE_HEADER_ONLY macro which seems to be fixed by now. Regards, Björn [1] http://www.boost.org/doc/libs/1_54_0/doc/html/chrono/users_guide.html#chron…

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[date time] std::out_of_range thrown on date 2012-5-29
by Matthijs Möhlmann 09 Aug '13

09 Aug '13

Hello all, Following piece of program gives a std::out_of_range exception: #include <boost/date_time/posix_time/posix_time.hpp> int main(int argc, char **argv) { boost::posix_time::ptime datetime; datetime = boost::posix_time::time_from_string("2012-5-29"); return 0; } Compiled with the following line: g++ -o main -lboost_date_time -g -std=c++11 main.cpp Output: matthijs@hammer % ./main terminate called after throwing an instance of 'std::out_of_range' what(): basic_string::at zsh: abort ./main Platform: x86_64 Boost version: 1.54 Compiler version: gcc 4.8 Where can I officially report bugs? Regards, Matthijs Möhlmann

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[move] forward with lvalue ref template param
by Andrew Ho 08 Aug '13

08 Aug '13

Hi during my implementation of unique_ptr I noticed that boost::forward doesn't play nicely with lvalue ref types. int a; int &b = a; int &c = std::forward<int&>(b); // compiles fine int &d = boost::forward<int&>(b); // compiler error I did a little playing around with the declarations of forward and I managed to get this to work: // if T is not a lvalue ref and movable template <class T> inline typename ::boost::move_detail::enable_if_c < enable_move_utility_emulation<T>::value && ::boost::move_detail::is_rv<T>::value && !::boost::move_detail::is_lvalue_reference<T>::value, const T &>::type forward(typename ::boost::move_detail::identity<T>::type &x) BOOST_NOEXCEPT { return const_cast<T&>(x); } // if T is not a lvalue ref and not movable template <class T> inline typename ::boost::move_detail::enable_if_c < enable_move_utility_emulation<T>::value && !::boost::move_detail::is_rv<T>::value && !::boost::move_detail::is_lvalue_reference<T>::value, const T &>::type forward(const typename ::boost::move_detail::identity<T>::type &x) BOOST_NOEXCEPT { return x; } // if T is a lvalue ref template <class T> inline typename ::boost::move_detail::enable_if_c < ::boost::move_detail::is_lvalue_reference<T>::value , T>::type forward(T x) BOOST_NOEXCEPT { return x; } Basically, this forces all calls to forward<A&> to simply return the lvalue ref (const-ness is maintained, I think), otherwise it does whatever boost::forward did before. As far as I can tell, this doesn't break boost::forward, and it enables it to properly handle taking lvalue refs. Am I right in my assumptions? Are there any cases where this would fail to produce standard-compliant/desired results?

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[git] eol issues and fetchRecurseSubmodules = on-demand
by Ahmed Charles 08 Aug '13

08 Aug '13

Two things: 1. tools\build\v2\engine\build.bat has LF instead of CRLF for line endings, which causes bootstrap.bat (which has the right endings) to not work properly. It seems like the top level .gitattributes doesn't apply to submodules. 2. After cloning and fetching modular boost each day for a while, I finally figured that waiting an hour or so to sync could probably be improved. So I read the docs and tested adding fetchRecurseSubmodules = on-demand for each submodule in .gitsubmodules and it seems to work much faster with the same result. (It would result in differences once the submodules can change without the super-project changing, but currently, I don't think that is the case.) Perhaps it's with considering?

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[boost/spirit] numeric policy
by Brian Schrom 07 Aug '13

07 Aug '13

I've had the case where I needed to retain formatting information for a number (general, fixed, scientific) and was nicely accomplished by extending the policy, but needed to have a begin_parse() and end_parse() for the policy to be complete. It seems that it makes some sense or is this accomplished another way? Maybe something to consider for policies in general? Index: qi/numeric/real_policies.hpp =================================================================== --- qi/numeric/real_policies.hpp (revision 85166) +++ qi/numeric/real_policies.hpp (working copy) @@ -28,6 +28,18 @@ static bool const allow_trailing_dot = true; static bool const expect_dot = false; + template <typename Attribute> + static void + begin_parse(Attribute& attr_) + { + } + + template <typename Attribute> + static void + end_parse(Attribute& attr_,bool /* result */) + { + } + template <typename Iterator> static bool parse_sign(Iterator& /*first*/, Iterator const& /*last*/) Index: qi/numeric/detail/real_impl.hpp =================================================================== --- qi/numeric/detail/real_impl.hpp (revision 85166) +++ qi/numeric/detail/real_impl.hpp (working copy) @@ -133,6 +133,7 @@ parse(Iterator& first, Iterator const& last, Attribute& attr, RealPolicies const& p) { + p.begin_parse(attr); if (first == last) return false; Iterator save = first; @@ -257,6 +258,7 @@ // If we got a negative sign, negate the number traits::assign_to(traits::negate(neg, n), attr); + p.end_parse(attr, true); // maybe this should return a bool and be the return value? // Success!!! return true; }

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[intrusive] Compilation problem with gcc 4.7
by Hartmut Kaiser 07 Aug '13

07 Aug '13

In code which compiled just fine I'm now seeing: In file included from /opt/boost/trunk-debug/boost/intrusive/slist_hook.hpp:24:0, from /opt/boost/trunk-debug/boost/intrusive/slist.hpp:21, from /opt/buildbot/slave/hpx_gcc47_x8664_boosttrunk_debug/build/hpx/lcos/local/mu tex.hpp:23, from /opt/buildbot/slave/hpx_gcc47_x8664_boosttrunk_debug/build/hpx/runtime/compo nents/server/wrapper_heap.hpp:20, from /opt/buildbot/slave/hpx_gcc47_x8664_boosttrunk_debug/build/hpx/runtime/compo nents/server/managed_component_base.hpp:13, from /opt/buildbot/slave/hpx_gcc47_x8664_boosttrunk_debug/build/hpx/lcos/base_lco .hpp:12, from /opt/buildbot/slave/hpx_gcc47_x8664_boosttrunk_debug/build/hpx/lcos/base_lco _with_value.hpp:11, from /opt/buildbot/slave/hpx_gcc47_x8664_boosttrunk_debug/build/hpx/performance_c ounters/counters.hpp:12, from /opt/buildbot/slave/hpx_gcc47_x8664_boosttrunk_debug/build/hpx/runtime/compo nents/server/runtime_support.hpp:32, from /opt/buildbot/slave/hpx_gcc47_x8664_boosttrunk_debug/build/hpx/runtime.hpp:1 2, from /opt/buildbot/slave/hpx_gcc47_x8664_boosttrunk_debug/build/src/hpx_main.cpp: 7: /opt/boost/trunk-debug/boost/intrusive/detail/generic_hook.hpp: At global scope: /opt/boost/trunk-debug/boost/intrusive/detail/generic_hook.hpp:134:55: error: declaration of typedef struct boost::intrusive::hooktags<typename GetNodeAlgorithms::type::node_traits, Tag, LinkMode, BaseHookType> boost::intrusive::generic_hook<GetNodeAlgorithms, Tag, LinkMode, BaseHookType>::hooktags [-fpermissive] /opt/boost/trunk-debug/boost/intrusive/detail/generic_hook.hpp:84:8: error: changes meaning of hooktags from struct boost::intrusive::hooktags<typename GetNodeAlgorithms::type::node_traits, Tag, LinkMode, BaseHookType> [-fpermissive] Ion, could you fix this, please? Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu

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MinGW test failures
by Andrey Semashev 07 Aug '13

07 Aug '13

Hi, I can see that almost all MinGW tests (jc-bell.com runner) for trunk are failing, at least for Boost.Log [1] and Boost.Atomic [2]. However, test logs don't show any errors, only compiler warnings. Does anyone know what is the problem? Also, this is not the first time when I see no errors in logs while the test is marked as failed. This is really unhelpful. Are some logs being lost by the test running suite? [1] http://www.boost.org/development/tests/trunk/developer/log.html [2] http://www.boost.org/development/tests/trunk/developer/atomic.html

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