December 2012 - Boost - lists.preview.boost.org

Interest in serialization library
by iwg molw5 28 Dec '12

28 Dec '12

I recently wrote a small C++11 template library to unify the specification and construction of a serializable object. The library introduces a simple template markup language used to specify the layout of data on the wire, using that specification to construct the type in question much like a named tuple. A sample of the syntax used by the library is provided below: struct Object : serializable <Object, value <NAME("Field 1"), little_endian <uint32_t>>, value <NAME("Field 2"), big_endian <uint32_t>>> { }; The library is available under the MIT license at: http://www.github.com/molw5/framework with associated documentation located at: http://molw5.github.com/framework Is there any interest in including this library in Boost?

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boost-commit list down?
by Marshall Clow 28 Dec '12

28 Dec '12

The last message I got from boost-commits was: Author: apolukhin Date: 2012-12-27 13:54:28 EST (Thu, 27 Dec 2012) New Revision: 82224 URL: http://svn.boost.org/trac/boost/changeset/82224 The archives at http://lists.boost.org/boost-commit/2012/12/date.php only go through revision 82223. -- Marshall

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[odeint] Typo in Boost.Odeint
by Michel Morin 28 Dec '12

28 Dec '12

Boost.Odeint contains nearly 200 typos! Patch attached in #7835 https://svn.boost.org/trac/boost/ticket/7835 (I don't know why but the owner of odeint is empty in the ticket.) Regards, Michel

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Re: [boost] [GitHelp] Sandbox library to GitHub
by Brian Wood 28 Dec '12

28 Dec '12

Edward Diener: > >On 12/26/2012 5:10 AM, Daniel Pfeifer wrote: >> 2012/12/26 Andrey Semashev <andrey.semashev(a)gmail.com>: >>> >>> Perhaps you didn't set up a ssh public key? >>> >>> https://help.github.com/articles/generating-ssh-keys#platform-windows >>> >>> You will also have to add the key to TortoiseGit/PuTTY. >> >> If you push over HTTPS, you don't need an ssh key. > > That sounds like what I want to do. The whole low-level business of > generating public/private keys, when I already have signed up for GitHub > with a username/password, seems silly to me. I know the Linux gurus all > love this kind of intricate stuff, but I do not. It's one command: ssh-keygen -t rsa -C "username(a)email.net" If you have Cygwin installed on Windows you can use the same command there. -- Brian Ebenezer Enterprises -- in G-d we trust. http://webEbenezer.net (651) 251-9384

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[thread] to std:: or not to std::
by Michael Caisse 27 Dec '12

27 Dec '12

There seems to be a trend to migrate boost::thread to std::thread. Has there been consideration that perhaps the user community may not want this? There are differing opinions on threads (obviously) and recent breaking changes concern me. For example, the thread destructor now calling terminate instead of detach has made the upgrade to 1.52 more troublesome than it should have been. Will the next move be to remove interruption points? We have purposely selected Boost.Thread on a few projects that are also using C++11 because we prefer the Boost.Thread behaviour and feature set. The purpose of this email isn't to debate the merit of the Boost.Thread feature set but instead to understand the future direction of the library. Can Vicente or someone provide the intended road map or general plan for the library? Thanks! michael -- Michael Caisse ciere consulting ciere.com

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Patch for functional/hash
by Thomas Heller 27 Dec '12

27 Dec '12

Hi, Attached is a patch for functional/hash. The first chunk essentially gets rid of some UB (the same technique was already applied for the remainder so this looks like an oversight). I don't remember why exactly i added the second chunk, it helps on some compilers though (I think gcc on Android). Save to apply that patch? Regards, Thomas

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[proposal] safe_ref<T>
by Fernando Pelliccioni 27 Dec '12

27 Dec '12

Hi all, The motivation is to avoid code like the following... //---------------------------------------------------------------------------- #include <iostream> #include <string> struct A { void do_something( std::string s ) const { std::cout << "do something with " << s << " and " << i_ << "\n"; } int i_ = 99; }; // unsafe traditional code struct Unsafe { void set_ref( A& a ) { a_ptr_ = std::addressof(a); } void use_ref( std::string s ) const { if (a_ptr_ != nullptr) { a_ptr_->do_something(s); } } void use_ref_2( std::string s ) const { //forgot to check for nullptr a_ptr_->do_something(s); } A* a_ptr_ = nullptr; //I can't use A& nor reference_wrapper<A>, need to be nullable. }; void f() { A a; Unsafe unsafe; unsafe.use_ref( "hello" ); //null reference, do nothing, hope! unsafe.set_ref(a); unsafe.use_ref( "hello world!" ); //not-null reference, Ok! Unsafe unsafe2; unsafe2.use_ref( "hello" ); //null reference, do nothing, hope! unsafe2.use_ref_2( "hello" ); //null reference, Ops! } //---------------------------------------------------------------------------- The proposed solution: //---------------------------------------------------------------------------- // Proposed (draft) //---------------------------------------------------------------------------- template <typename T> class safe_ref { public: typedef T type; explicit safe_ref() : t_( nullptr ) {} explicit safe_ref(T& t) : t_( std::addressof(t) ) {} template <typename Func> void use ( Func f ) const { if ( is_initialized() ) { f( *t_ ); } } private: bool is_initialized() const { return t_ != nullptr; } T* t_; }; template <typename T> inline safe_ref<T> const ref(T& t) { return safe_ref<T>(t); } template <typename T> inline safe_ref<T const> const cref(T const& t) { return safe_ref<T const>(t); } //---------------------------------------------------------------------------- // Usage //---------------------------------------------------------------------------- #include <iostream> #include <string> struct A { void do_something( std::string s ) const { std::cout << "A::do_something with " << s << " and " << i_ << "\n"; } int i_ = 99; }; struct Safe { void set_ref( A& a ) { a_ref_ = ref(a); } void use_ref( std::string s ) const { a_ref_.use( [&s] ( A& a ) { a.do_something(s); }); } safe_ref<A> a_ref_; }; void usage1() { A a; Safe safe; safe.use_ref( "hello" ); //null reference, do nothing safe.set_ref(a); safe.use_ref( "hello world!" ); //safe reference, Ok! } void usage2() { safe_ref<int> si; si.use( [] (int& i ) { std::cout << i << std::endl; }); int temp = 15; safe_ref<int> si2(temp); si2.use( [] (int& i ) { std::cout << i << std::endl; }); si = ref(temp); si.use( [] (int& i ) { std::cout << i << std::endl; }); } //---------------------------------------------------------------------------- It is similar to optional<T>, but in this case the idea is to not allow access to internal data if the pointer is null, only allowing a safe usage There is interest to add something like this to Boost? Any comments or remarks? Thanks and regards, Fernando Pelliccioni.

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[GitHelp] Sandbox library to GitHub
by Edward Diener 27 Dec '12

27 Dec '12

Under Windows following the instructions at https://svn.boost.org/trac/boost/wiki/ExtractSandbox for moving an SVN sandbox library to GitHub I am successful in the first step of cloning SVN sandbox library to a temporary local directory. But when I go to that local directory and try: git push --mirror git@github.com:eldiener/variadic_macro_data.git I receive a PuTTY message of: "Disconnected: No supported authentication methods available (server sent: publickey)" I have no idea how PuTTY gets into this. I am using TortoiseGit and Git for Windows and evidently getting Git to work under Windows is difficult in some way. Anybody have any idea how to straighten this out ?

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[git] What about unmaintained libraries?
by Andrey Semashev 26 Dec '12

26 Dec '12

Hi, I have little experience with git and none with GitHub, so apologies if my questions sound silly. We have a number of unmaintained libraries in Boost. With svn anyone with commit rights can apply fixes and even take over these libs. In the end of the day, I think, this is a good thing - community support is better than no support. Even with maintained libs, it is sometimes simpler to just apply the fix instead of filing a ticket and waiting for the maintainer to get to it. Also, remember the bug fixing weeks we had a while ago - anyone could choose a library and resolve tickets against it. I'm not sure how this will work after transition to git. IIUC, every lib will be extracted into a separate git repository, and presumably only the library maintainer will have the commit rights to that repo. Essentially this means that unmaintained libs will become immutable after the transition. Also, every minor fix will have to go through the library maintainer, however busy he may be. I suppose the problem with unmaintained libs could be solved by forking but what if noone is ready to become the official maintainer but occasionally people commit fixes and improvements to the lib? I believe, at least Boost.DateTime is currently in such situation. Also, forking does not solve the problem for minor fixes to maintained libs. I would really like it if there was some kind of a user group (of all Boost maintainers) that could be used to grant commit rights to the libraries. Whatever the git term is, by "commit" here I mean the ability to publish the changes to the repository on GitHub, so that they are visible to other developers, including monolithic Boost release scripts. Is this possible? If yes, I think all repositories produced as a result of the transition to git should grant commit rights to this group by default, so that the access rights are the same as with svn now.

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[move] uninitialized_move
by Adam Wulkiewicz 26 Dec '12

26 Dec '12

Hi, I recently saw how boost::uninitialized_move is implemented, it doesn't check for exceptions thrown by move ctor and don't delete already constructed objects. Is this intentional? Regards, Adam

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Boost SIMD beta release
by joel falcou 25 Dec '12

25 Dec '12

We're rolling a beta release of Boost.SIMD along with a beta release of NT2. This version comes very late because we were busy with other things but hopefully we'll now do rolling releases frequently. Documentation is quite lacking but code is relatively stable and works. * Release Files can be found here: http://nt2.metascale.org/downloads/ * Additional material about the library can be found here : - Boost.SIMD PACT paper : http://www.lri.fr/~falcou/pub/pact-2012.pdf - Boost.SIMD MeetingC++ slides : http://meetingcpp.com/tl_files/mcpp/slides/12/simd.pdf * We welcome comments, questions and random requests/rants/bug reports as to polish the library before actual submission to the boost review. Such comments can be sent there, on our nt2-dev Google groups or in the nt2 issue tracker. Regards

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automatic SVN mirror down?
by Robin Eckert 24 Dec '12

24 Dec '12

Hello, The latest commit on the live boost SVN mirror (git://github.com/ryppl/boost-svn.git) is 11 days old. Is the automatic mirror jammed right now or is the mirror probably shut down due to the modularization effort? Regards, Robin

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[GitHelp] Help desk ready to assist
by Beman Dawes 24 Dec '12

24 Dec '12

See https://svn.boost.org/trac/boost/wiki/GitHelp for details. --Beman

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[Git] ** Attention All Boost Committers **
by Dave Abrahams 24 Dec '12

24 Dec '12

If you have *ever* checked *anything* (e.g. code or documentation) into the Boost Subversion repository, this message applies to you. Git uses email addresses to identify authors and committers. In order to accurately convert Subversion history to Git, we need to map all (or as many as possible) Subversion user IDs to working email addresses. I have posted a provisional UserID mapping table at https://github.com/boost-lib/boost/wiki/AuthorMapping (with a simple mangling of '@'=>'<>' and '.'=>'~'). If your email address is already in the table, you've been Bcc'd on this message, which may explain the appearance of multiple copies in your mailbox. I request that you make corrections to this table. To edit the table directly, you'll need to be logged into GitHub. Direct correction is by far the preferable approach, but if you don't have---and don't want to acquire---a free GitHub account, you can send edits directly to me. Important notes (these also appear on the page with the table) * You may have several userids (e.g. I appear to have "dave," "abrahams," and "david_abrahams" --- probably left over from the transition from SourceForge CVS to our own SVN). Please look carefully to be sure that you have accounted for all your userids, and please use the same name and email address for each of them. Please *make sure that all non-duplicate userids stay in the table*. For example, all three of my userids are still there. * A given userid may appear several times in the table. If that userid belongs to you, please delete all but one line. If you don't, we will just use the first entry with that userid. * If you have a GitHub account, please make sure the email address you use in the table is associated with that account at https://github.com/settings/emails Thanks for your cooperation. -- Dave Abrahams BoostPro Computing Software Development Training http://www.boostpro.com Clang/LLVM/EDG Compilers C++ Boost

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[TypeErasure] Similar simple class.
by Arman Hunanyan 23 Dec '12

23 Dec '12

Hi All, I have implemented xany class https://sourceforge.net/projects/extendableany/?source=directory. Then I noticed that there is a Boost.TypeErasure library which allows to do same as xany does and something more. Implementation of class xany has 1005 lines and it is implemented and tested in a week. Of course xany isn't comparable with Boost.TypeErasure, but it may be interesting to look. Below is a definition of same method for Boost.TypeErasure and for xany. // definition of push_back for Boost.TypeErasure template<class C, class T> struct push_back { static void apply(C& cont, const T& arg) { cont.push_back(arg); } }; namespace boost { namespace type_erasure { template<class C, class T, class Base> struct concept_interface< ::push_back<C, T>, Base, C> : Base { void push_back(typename rebind_any<Base, const T&>::type arg) { call(::push_back<C, T>(), *this, arg); } }; } } any<push_back<_self, int>, _self&> c; // definition of push_back for xany template <typename Xany, typename T> struct push_back_method { typedef void (Xany::* signature) (const T&); template <typename B> struct wrapper : public B { void push_back(const T& e) { this->call(push_back_method(), e); } }; struct implementation { template <typename Container> void operator() (Container& c, const T& e) { c.push_back(e); } }; }; xany<boost::mpl::vector<push_back_method<boost::mpl::_1, int> > > c; xany requires additional signature type to be specified. This allows to use dispatching in implementation. struct implementation { void operator() (OtherCodingStyleContainer& c, const T& e) { c.PushBack(e); } template <typename Container> void operator() (Container& c, const T& e) { c.push_back(e); } }; Documentation contains more examples.

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[Inspect] hadn't run since... August
by Artyom Beilis 23 Dec '12

23 Dec '12

Boost.Inspect hadn't run on trunk or release sinse august: From: http://beta.boost.org/development/testing.html trunk - http://boost.cowic.de/rc/inspect-trunk.html release - http://boost.cowic.de/rc/inspect-snapshot.html Artyom Beilis -------------- CppCMS - C++ Web Framework: http://cppcms.com/ CppDB - C++ SQL Connectivity: http://cppcms.com/sql/cppdb/

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[atomic, x86] need another pair of eyes
by Tim Blechmann 23 Dec '12

23 Dec '12

hi all, i need another pair of eyes regarding boost.atomic on x86: the implementation of memory barrier is merely a compiler barrier, but not a CPU barrier, as it is using code like: __asm__ __volatile__ ("" ::: "memory"); afaict, one should use a `real' CPU barrier like "mfence" or "lock; addl $0,0(%%esp)". is this correct? apart from that, i've seen that compare_exchange is using explicit memory barriers before/after "cmpxchg" instructions. i somehow though that cmpxchg and the 8b/16b variants implicitly issue a memory barrier, so the resulting code would generate multiple memory barriers. can someone with some insights in the x86 architecture confirm this? thanks, tim

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Re: [boost] Boost SIMD beta release
by Brian Wood 23 Dec '12

23 Dec '12

From: Mathias Gaunard: On 20/12/2012 20:34, Dave Abrahams wrote: >> Yes; there's a runtime test. > > Let's put a runtime test at every step of our critical loop, sounds like > a good idea. > I actually somewhat looked into this, and in this case segmented > iterators don't allow any optimization compared to normal iterators. I think less sarcasm would be helpful. >> I'm afraid you have not been specific enough about the >> problem you claim to see for me to be able to evaluate >> whether it exists or not. > > I'm afraid you're the one trying to make everything fit into this > model you've somehow taken a liking to. I'd prefer to focus on results rather than motives. Shalom Brian Ebenezer Enterprises http://webEbenezer.net (651) 251-9384

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[BTREE] Get BTREE library into boost - Market Research
by Joel Young 22 Dec '12

22 Dec '12

My organization is investigating contracting for enhancements to the boost::btree library developed by Beman Dawes with all enhancements to remain under the boost license and author(s) retaining all copyright. No travel is expected to be required as part of this project. We are considering the following enhancements: 1. Develop detailed developer and tutorial documentation in customary boost formats 2. Enhancing the interface to provide more explicit preload and caching control to include the amount of RAM to reserve, perhaps with the ability to specify posix alignment to maximize benefit of linux anonymous huge page support. 3. Make the library C++ 11 ready 4. Finalize data layout and support for variable length payloads 5. Provide convenient interface for storing std::string (or the contents thereof) in payloads 6. Prepare the library for submission for formal review Any comments and suggestions on this are greatly appreciated. Of particular interest are discussions of technical approaches and estimates of hours required. Please do not send formal proposals. In addition to replying on this list (preferred) I can be reached at the telephone numbers and email below. Comments sent by 21 December will be most valuable. Discussion after that is still very welcome! Please don’t include any proprietary data. Also note that I am not authorized to commit the government in any way--this is simply market research. Thanks! Joel Dr. JOEL D. YOUNG Assistant Professor Computer Science Department Naval Postgraduate School Glasgow East Rm 338 jdyoung(a)nps.edu (831) 656-3518

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Security bugs policy
by Artyom Beilis 22 Dec '12

22 Dec '12

Hello, I would like to know if there is any policy about security bug fixes, updates or releases. What I'm talking about. Consider a security related bug discovered in boost library. For example: For example recently reported bug in Boost.Locale that will be fixed in 1.53 https://svn.boost.org/trac/boost/ticket/7743 I consider it security bug as an application that validates the input (checks if it is UTF-8) may accept an invalid sequence. Or very critical bug in UUID (fixed in 1.43): https://svn.boost.org/trac/boost/ticket/3971 That any application that used them may be target to UUID guessing. These kind of bugs in general should be considered critical and somehow published, it may be also important to backport the fixes to stable releases, because not everybody can move forward and they may need to stick with older releases (as Boost is neither ABI nor API backward compatible even between minor releases). Annoucements of such bugs may be critical for example for stable Linux distributions that ship some older Boost versions and likely need to backport such bug fixes to their own boost tree because Boost doesn't do it. Questions: - Do we have any policy about it? - If not we probably need one including backporting of security bug fixes to stable releases. What brings me to other issues... Should Boost support older releases with critical bug fixes/security bug fixes? For how long time? Artyom Beilis -------------- CppCMS - C++ Web Framework: http://cppcms.com/ CppDB - C++ SQL Connectivity: http://cppcms.com/sql/cppdb/

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Question about test failures
by Andrey Semashev 22 Dec '12

22 Dec '12

Hi, I've been looking through Boost.Atomic test results [1] and saw that all tests on IBM_Canada_Ltd are marked as failed. The test result [2] refer to Boost.Thread build results [3] which I think is supposed to mean that the test failed because the dependent library failed to build. However, the Boost.Thread build report is marked as succeeded. I'm not sure how to interpret these results. Can someone clarify this? Thank you. [1] http://www.boost.org/development/tests/trunk/developer/atomic.html [2] http://www.boost.org/development/tests/trunk/developer/output/IBM_Canada_Lt… [3] http://www.boost.org/development/tests/trunk/output/IBM_Canada_Ltd-boost-bi…

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[release] add comments/changes
by Oliver Kowalke 21 Dec '12

21 Dec '12

Which files do I've to use in order to add notes about changes and new features of the next release? thx, Oliver

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[Git] Extracting libraries from the svn sandbox
by Beman Dawes 20 Dec '12

20 Dec '12

One of the issues that came up in the documentation discussion was the desire to extract still useful sub-trees from the old svn sandbox, and to move them to GitHub. I've been able to extract my proposed endian library from the sandbox, history and all. Here was the process: 1) Created a empty repository named "endian" in my GitHub account via the usual web interface. 2) From the command line, in a temporary directory: git svn clone https://svn.boost.org/svn/boost/sandbox/endian (Got a "Error validating server certificate...", and gave "p" as a response to the "(R)eject, accept (t)emporarily or accept (p)ermanently?" query. The process ran for perhaps 10 minutes, but that was fine because it was successful at recovering history. And it is a one-time process.) cd endian git branch -d git-svn git push --mirror git@github.com:Beman/endian.git That's it! The git branch command deletes the git-svn branch, which is an artifact of the conversion process. Finish off by cloning the library in its permanent local location: cd permanent-local-location git clone git@github.com:Beman/endian.git Comments? Is there a better way to do this? Once comments have come in, I'll create a doc page for doing this, with a link from the FAQ. --Beman

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[intrusive] boost/intrusive/detail/has_member_function_callable_with.hpp: inheriting from a const class
by Krzysztof Czainski 20 Dec '12

20 Dec '12

Hello, I tried to use a boost::container::vector with a Texas Instruments compiler, and I got an error pointing to line 88 of <boost/intrusive/detail/has_member_function_callable_with.hpp> "Invalid base class", with Type=const std::allocator<something>" Here's the context: template <typename Type> class BOOST_PP_CAT(has_member_function_named_, BOOST_INTRUSIVE_HAS_MEMBER_FUNCTION_CALLABLE_WITH_FUNCNAME) { struct BaseMixin { void BOOST_INTRUSIVE_HAS_MEMBER_FUNCTION_CALLABLE_WITH_FUNCNAME(); }; struct Base : public Type, public BaseMixin { Base(); }; // <-- line 88 The problem seems to be the constness of Type. Here's a simplified example: struct X {}; template < class T > struct Y : T { Y() {} }; int main() { Y<const X> y; } The above example compiles fine with Linux gcc version 4.5.4, and MinGW 4.5.0, but fails with my TI compiler. My question is: is this a bug of the TI compiler, or is that compiler actually right about this, and should we fix this in Boost? For now, my workaround is: struct Base : public ::boost::remove_cv<Type>::type, public BaseMixin { Base(); }; // <-- line 88 Regards, Kris

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[GIT] What happens to the Trac?
by John Maddock 20 Dec '12

20 Dec '12

Currently the issue tracker is somewhat nicely integrated with SVN, what are we doing for issue tracking short/medium/long term? Apologies if this has been covered already, John.

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[release][thread] Permission to merge.
by Vicente J. Botet Escriba 19 Dec '12

19 Dec '12

Hi, I would like to merge this change [1][82094] It is related to this feature request [2](#7422 Provide a condition variable with zero-overhead performance penality), but we can consider it as a bug, as the performance were degraded since boost.1.45. After the change the performances have been improved consequently as showed in [3] trunk-ni-7422 in green respect to trunk-ni in orange. [1] https://svn.boost.org/trac/boost/changeset/82094 [2] https://svn.boost.org/trac/boost/ticket/7422 [3] https://docs.google.com/spreadsheet/ccc?key=0Ai_v0rSH1AXrdHl2RDN4UkFYNHZ2aX… Please, could I merge it after the regression test cycle? Best, Vicente

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Should I use std::get or boost::get (or both) in Boost.Array
by Marshall Clow 19 Dec '12

19 Dec '12

I've got a feature request for Boost.Array to provide compile-time checked access to the members of an array. In C++11, this is done using std::get<Idx> (std::array). Fine, I can specialize this in Boost.Array - well, for C++11. I can't specialize a nonexistent template in namespace std for C++03 (well, I _can_ but the standard says I must not). But Boost.Tuple has a get<> template. I believe I can specialize that for Boost.Array, w/o stepping on Boost.Tuples code. What do people think? boost::get? std::get? Both? -- 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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Re: [boost] Heads up - string_ref landing
by Yanchenko Maxim 19 Dec '12

19 Dec '12

Marshall. low <mclow.lists. at> gmail.com> writes: > Please let me know what you think! As probably everyone, we have our own device for this. Here are some points and experience we gathered. 1. This class is essentially just an iterator_ range<char*> (modulo template for const/wchar_t), so it should either inherit from it or have corresponding converting ctors/operators. In this sense Olaf/Gennadiy's remarks are pretty valid. OTOH size is needed very frequently and having it precomputed is a good thing, so conversion approach seems to be better (but then we lose passing by reference as iterator_range, type_traits etc). I'm not sure what's more important. 2. Given the above, the name is misleading as it's not a reference to std::string. We use name char_range. 3. It's worth having a static constructor 'literal' (templated with size) to construct char_ranges from literals - as the compiler knows their size in compile time (minus zero terminator). It can be a constexpr too. Same manner - static function 'from_array', embrasing an array of chars in whole, assuming there is no zero terminator - useful for working with structures representing messages in char-based protocols with fixed-width fields. 4. (hack) We had to add a member function 'assign' (this is just operator=) to make boost::tokenizer return char_ranges. I don't like this part at all as it contradicts the meaning of say std::vector::assign, so I'd prefer another solution, probably in form of a customization point in boost::tokenizer. Thanks, Maxim

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[Git] Boost website changes?
by Beman Dawes 18 Dec '12

18 Dec '12

The www.boost.org web site content needs to be reviewed, and all the Subversion references and instructions changed to Git and modular Boost. What is the best way to handle that? Create a branch similar to beta.boost.org? Who is willing to take on the management of updating web site content and monitor progress? --Beman

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[Container] 'to_pointer' problem since 1.52
by Rich E 18 Dec '12

18 Dec '12

Just wanted to point out that there's an outstanding bug report due to some changes in Boost.Container that seem to have occured somewhere in the 1.52 dev cycle, reported here <https://svn.boost.org/trac/boost/ticket/7650>. In a nutshell, there is a compile time error caused by boost::container::list::const_iterator is trying to use a method called 'to_pointer' that doesn't exist (there is a 'pointer_to' method defined). We're using a modified version of boost/container/list.hpp at the moment, but it would be nice to ditch that come 1.53. The patch is so trivial that I thought it best to leave it up to the maintainer, as I really have no idea how to work with the current svn setup. cheers, Rich

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Another set of macros to deprecate (and then remove)?
by Marshall Clow 18 Dec '12

18 Dec '12

There are a set of macros in Boost.config that describe "features that are not required by the C++ standard" Some of these features have been incorporated into C++11. I propose that we retire these macros, and have people use the shiny C++11 versions. In particular: BOOST_HAS_STATIC_ASSERT should be ! BOOST_NO_CXX11_ASSERT BOOST_HAS_VARIADIC_TMPL should be ! BOOST_NO_CXX11_VARIADIC_TEMPLATES BOOST_HAS_RVALUE_REFS should be ! BOOST_NO_CXX11_RVALUE_REFERENCES BOOST_HAS_CHAR_16_T should be ! BOOST_NO_CXX11_CHAR_16_T BOOST_HAS_CHAR_32_T should be ! BOOST_NO_CXX11_CHAR_32_T I'm using "!" here generically; in code you would replace #ifdef OLD_MACRO with #ifndef NEW_MACRO etc. I don't think this will be very disruptive; very few boost libraries use these macros. Opinions? Other macros that fit into this group? -- 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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compilation warning on HEAD
by Gaetano Mendola 18 Dec '12

18 Dec '12

The HEAD in trunk have some compilation warnings using gcc 4.7.2 the following will fix some of those. Another warning about unused result is in here: libs/serialization/src/basic_iarchive.cpp line 576, the value is used in a BOOST_ASSERT, I don't know how you manage those cases. Regards Gaetano Mendola Index: libs/serialization/src/basic_serializer_map.cpp =================================================================== --- libs/serialization/src/basic_serializer_map.cpp (revision 81900) +++ libs/serialization/src/basic_serializer_map.cpp (working copy) @@ -43,8 +43,7 @@ BOOST_ARCHIVE_DECL(bool) basic_serializer_map::insert(const basic_serializer * bs){ // attempt to insert serializer into it's map - const std::pair<map_type::iterator, bool> result = - m_map.insert(bs); + m_map.insert(bs); // the following is commented out - rather than being just // deleted as a reminder not to try this. Index: boost/archive/iterators/transform_width.hpp =================================================================== --- boost/archive/iterators/transform_width.hpp (revision 81900) +++ boost/archive/iterators/transform_width.hpp (working copy) @@ -112,6 +112,7 @@ transform_width(BOOST_PFTO_WRAPPER(T) start) : super_t(Base(BOOST_MAKE_PFTO_WRAPPER(static_cast< T >(start)))), m_buffer_out_full(false), + m_buffer_in(), m_remaining_bits(0), m_end_of_sequence(false) {} @@ -119,8 +120,8 @@ transform_width(const transform_width & rhs) : super_t(rhs.base_reference()), m_buffer_out_full(rhs.m_buffer_out_full), + m_buffer_in(rhs.m_buffer_in), m_remaining_bits(rhs.m_remaining_bits), - m_buffer_in(rhs.m_buffer_in), m_end_of_sequence(false) {} }; -- cpp-today.blogspot.it

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[Git] Documentation for Git and Modular Boost conversion
by Beman Dawes 18 Dec '12

18 Dec '12

We are starting to pull together documentation for the Git and Modular Boost conversion. https://svn.boost.org/trac/boost/wiki/WikiStart#GitandModularBoost Comments and corrections welcome! I'm particularly interested in unanswered questions you have after reading these initial docs. --Beman

20 98

static_vector using aligned_storage
by Adam Wulkiewicz 18 Dec '12

18 Dec '12

Hi, I'm developing R-tree container for Boost.Geometry. To keep it short, there are containers of Values in leaf nodes. Those containers must have push_back() functionality. For static-size nodes I'm using a container based on boost::array. Unfortunately this means that default constructors of stored Values are called when the container is created. I'd like not to expect that Values have their default ctor implemented. I've implemented an alternative container using boost::aligned_storage. This is just a proof of concept. The code is available here: https://svn.boost.org/svn/boost/sandbox-branches/geometry/index/tests/stati… I've searched for this kind of container in Boost since I remember that someone proposed it some time ago but didn't find it anywhere. Is it released somewhere? Maby as a part of some library? If not, would you be so kind and see if my solution should work for any/most popular compiler/platform? I've tested it only on clang. To be specific, won't there be any problems with the memory aligmnent if I use this code for storage: boost::aligned_storage<sizeof(Value) * Capacity> m_storage; this for access: *(reinterpret_cast<Value*>(m_storage.address()) + i); and this for construction new (reinterpret_cast<Value*>(m_storage.address()) + i) Value(value); Regards, Adam

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[range] Adapter to select class member
by Mark Snelling 17 Dec '12

17 Dec '12

Hi, I'm not sure if this has already been done but I have created a new Boost.Range adapter that will return a specified member variable of the class in the range, similar to the existing map_keys and map_values adapters. Would there be interest in this? For example consider the following code: #include <boost/range/adaptor/member.hpp> #include <boost/range/algorithm/copy.hpp> #include <boost/lexical_cast.hpp> #include <iostream> #include <vector> #include <string> struct A { int foo; std::string bar; }; int main(int argc, char* argv[]) { std::vector< A > input; for ( int i = 0; i < 10; ++i ) { A a; a.foo = i; a.bar = boost::lexical_cast< std::string >( i * 10 ); input.push_back( a ); } boost::copy( input | boost::adaptors::selected_member( &A::foo ), std::ostream_iterator< int >( std::cout, "," ) ); std::cout << std::endl; boost::copy( input | boost::adaptors::selected_member( &A::bar ), std::ostream_iterator< std::string >( std::cout, "," ) ); return 0; } Cheers, Mark

2 1

[crypto]not in https://github.com/boost-vault
by Jeff Flinn 16 Dec '12

16 Dec '12

It appears the crypto library that was in: http://www.boost-consulting.com/vault/index.php?action=downloadfile&filenam… Didn't get moved to https://github.com/boost-vault. Does anyone have access to the last vault incarnation? Thanks, Jeff

2 2

[release] permission to merge atomic and lockfree
by Tim Blechmann 16 Dec '12

16 Dec '12

hi all, apparently boost.atomic has been abandoned. i must admit, i'm very disappointed that the original author did hardly reacted neither on-list nor off-list. furthermore, it is blocking the release of boost.lockfree, so i'm volunteering to maintain this library. i'd rather see helge bahmann coming back and taking over responsibility for his code, but frankly, i lost all hopes that this is going to happen. iac, i'd like to get permission from the release managers to merge both atomic and lockfree to the release branch. thanks, tim

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[GitHelp] Help desk support for developers moving to Git and modular Boost
by Beman Dawes 15 Dec '12

15 Dec '12

Documentation will aid developers moving to Git and modular Boost. See https://svn.boost.org/trac/boost/wiki/WikiStart#GitandModularBoost Beyond documentation, simply asking questions via a search engine works particularly well for Git. There is a vast amount of Git material available on the web, including some excellent YouTube videos. But documentation, web searches, and YouTube videos are not enough. Learning Git can be daunting - Git has more surface area than Subversion and it isn't obvious at first why some operations need to be done in a certain sequence or in a certain way or why they even need to be done at all. Two or three developers at C++Now mentioned that they became discouraged when they inadvertently got painted into a Git corner and couldn't find a way out. And even experienced git uses occasionally run into something they need human help with. This post proposes a virtual "Help Desk" to provide Boost specific answers to the inevitable questions that will come up during the transition to Git and modular Boost. The idea is that postings with at [GitHelp] subject tag will signal a request for help wrt Git or modular Boost. Anyone who can help should jump right in with a response. Comments? Suggestions? --Beman

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[graph] A* search applied to knight's tour
by Dave Abrahams 15 Dec '12

15 Dec '12

Hi, I was just trying to work up an example for a class I'm teaching, to illustrate implicit graphs. The following shows how far I've gotten: https://gist.github.com/4153918 This is attempting to apply Warnsdorff's heuristic (choose the next move with the least out-degree) using A* search. I'm running into several problems having to do with the requirements of astar_search_no_init. In particular, the requirement that we can assign an index to every vertex is quite painful, since enumerating all the possible vertices in the search space is difficult. Any advice here? I suppose I could keep a real map and simply assign indices in the order vertices are encountered, but that seems pretty ugly to me. Any hints? -- Dave Abrahams BoostPro Computing Software Development Training http://www.boostpro.com Clang/LLVM/EDG Compilers C++ Boost

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Deadline extension: C++ Now 2013, Call for Submissions
by Hartmut Kaiser 15 Dec '12

15 Dec '12

Please see below for the extended deadline. ---------------------------------------------------------------------------- C++ NOW CONFERENCE 2013 - Aspen CO, USA, May 13-17, 2013, www.cppnow.org ---------------------------------------------------------------------------- CALL FOR SUBMISSIONS -------------------- We invite you to submit session proposals to the 2nd annual C++ Now Conference (Aspen CO, USA, May 13-17, 2013). Building upon the resounding success of C++ Now 2012 and five years of BoostCon, C++ Now 2013 will present leading speakers from the whole C++ community. The C++ Now Conference is dedicated to discussion and education about C++, an open and free language and standard. Our Conference will focus on discussion and education about open source software usage and developments in the C++ developer and user community. To reflect the breadth of the C++ and Boost communities, the conference includes sessions aimed at three constituencies: C++ and Boost end-users, hard-core Boost library and tool developers, and researchers pushing the boundaries of computation. The program fosters interaction and engagement within and across those groups, with an emphasis on hands-on, participatory sessions. As a multi-paradigm language, C++ is a melting pot where the most compelling ideas from other programming communities are blended in powerful ways. Historically, some of the most popular sessions at C++ Now have highlighted these concepts, from DSLs to functional programming to transactional memory and more. Bring your C#, Python, Ruby or Haskell influences to bear in an environment that will broaden their exposure. At C++ Now 2013 we would like to focus on parallel and distributed computing with C++. However, by no means this is intended to restrict the topics of proposals we hope to see. Any other topic related to C++ as outlined below is perfectly fine for submission. IMPORTANT DATES --------------- New proposal submissions due: January 5th, 2013. Proposals decisions sent (tentative program available): January 30th, 2013. Fully scheduled program available: February 24th, 2013. BEST PRESENTATION AWARDS ------------------------ We know how much effort it takes to prepare talks for our conference. For this reason we will award the best presentations in the following categories: Best Presentation, Best Short Presentation, Best Tutorial, and Best Workshop. The awards will be given based on the audience's voting. Each award will include the author's name listed on the cover of the C++ Now website for that year and a plaque containing all the C++ Now conference information. SESSION TOPICS -------------- Topics of interest include, but are not restricted to, the following: * Parallelism in the new C++11 standard * Parallel, distributed and GPGPU topics relating to C++ * C++11 and how it changes life for users and library writers * General tutorial sessions on C++11, the C++11 Standards library, and one or more Boost libraries * In-depth sessions on using specific Boost libraries * Case studies on using Boost * Experts panels * Advanced sessions on implementation techniques used within Boost libraries * Development workshops to extend or enhance existing Boost libraries * Workshops on design process * Infrastructure workshops such as Build tools, Website, Testing * Concepts and Generic Programming * Hardware and infrastructure presentations focused on how libraries can make better use of the technology * Software development tools and their application to C++ and or Boost * Other topics likely to be of great interest to C++ users and developers Interactive and collaborative sessions are encouraged, as this is the style of learning and participation that has proven most successful at such events. Sessions can be tutorial based, with an emphasis on interaction and participant involvement, or workshop based, whether hands-on programming or paper-based, discussion-driven collaborative work. SESSION FORMATS --------------- Presentations Presentations focus on a practitioner's ideas and experience with anything relevant to C++11, Boost and users. Panels Panels feature three or four people presenting their ideas and experiences relating to C++11 and Boost's relevant, controversial, emerging, or unresolved issues. Panels may be conducted in several ways, such as comparative, analytic, or historic. Tutorials Tutorials are sessions at which instructors teach conference participants specific skills relevant to C++11 and Boost. Workshops Workshops provide an active arena for advancements in Boost-relevant topics. Workshops provide the opportunity for experienced practitioners to develop new ideas about a topic of common interest and experience. Author's Corner Presentations These were introduced at BoostCon 2008, and were a great success. They are short (30 minute) sessions, focusing on tips on usage and design. In addition, we're looking to uncover the hidden design gems in Boost libraries. Tool Vendors Presentations We actively encourage tool vendors and ISP's to submit proposals for a special Tool Vendors Session Track aimed at products related to Boost and C++ (compilers, libraries, tools, etc.). Other formats may also be of interest. Don't hold back a proposal just because it doesn't fit into a pigeonhole. SUBMITTING A PROPOSAL --------------------- Standard Sessions are 90 minutes. You may submit a proposal for fractions Or multiples of 90-minutes. Fractional proposals will be grouped into 90 Minute sessions covering related topics. Longer sessions, such as tutorials and classes, will be assigned three hour (i.e. half day), or six hour (i.e. full day) time slots. Please include: * The working title. * Type of session: presentation, panel, tutorial, workshop, authors corner, vendor track, other. * A paragraph or two describing the topic covered, suitable for the conference web site. * Proposed length: 10-20 minute short talks, 45 minutes, 90 minutes, half day, full day. * Alternate lengths, if you are willing to make adjustments: 10-20 minute short-talks, 45 minutes, 90 minutes, half-day, full day. * Audience: users, developers, both. * Level: basic, intermediate, advanced. * A biography, suitable for the conference web site. * Your contact information (will not be made public). SUBMISSION DETAILS ------------------ All submissions should be made through the EasyChair conference management system: http://www.easychair.org/conferences/?conf=cppnow2013. If you have not already registered at EasyChair, you will need to do so in order to submit your proposal. All submissions will go through a peer review process. Authors are invited (but are not required) to submit PDF versions of full papers of up to 10 pages in ACM conference proceedings format (see http://www.acm.org/sigs/publications/proceedings-templates) The full papers are not required unless you want them published in the proceedings. All accepted proposals will be made available in the Association for Computing Machinery (ACM) Digital Library (approval pending). Best papers, after further reviews, will be considered to be book chapters or journal articles in a renowned journal. The session materials go on the C++ Now website and will be available to attendees. For general information on the C++ Now 2013 paper submission or the scope of technical papers solicited; please refer to the conference website at www.cppnow.org. For any other questions about the submission process or paper format, please contact the Program Committee at cppnow2013(a)easychair.com. If you have any technical problems with EasyChair, please contact EasyChair for help. Note: Presenters must agree to grant a non-exclusive perpetual license to publish submitted materials, either electronically or in print, in any media related to C++ Now. Hartmut Kaiser, email: hartmut.kaiser(a)gmail.com (Program Committee Chair) Dave Abrahams, email: dave(a)boostpro.com (Conference Chair) On behalf of the conference organizers

1 0

[system] Add noexcept to conform with C++11
by Vicente J. Botet Escriba 14 Dec '12

14 Dec '12

Hi, any news on https://svn.boost.org/trac/boost/ticket/7278. I could add them if you don't have the time now. Best, Vicente

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[test] Getting an execution monitor to ignore a failed child processes
by Daniel James 14 Dec '12

14 Dec '12

Hi, A couple of days ago the inspect report was failing on the release branch and not the trunk branch (not currently, because I reverted the change which caused it). It turns out that this happened because inspect uses the program execution monitor. Inspect runs subversion to get the version information, but I wasn't running it in a subversion checkout, so the child process fails, which causes a signal which the execution monitor detects, throwing an exception. I guess it's thrown from the top level, so I can't catch it. I've got a patch ready which fixes this by running subversion from inside a nested execution monitor so that the exception is thrown at a more appropriate location. But this is a bit verbose, is there a better way to handle this? Perhaps temporarily stop the program execution monitor from handling failed process signals? I don't want to disable it for the rest of the program. Secondly, this doesn't happen on trunk. It looks like the program execution monitor isn't detecting the failure. This might be a bug in the new version. thanks, Daniel

1 0

[Proposal] Adding CPUID Library in Boost
by Shakti Misra 14 Dec '12

14 Dec '12

Hi All, Any interest in a cross platform CPU ID library? For a application I wanted to get the CPUID mostly to check the SSE2 status. So I missed it in Boost. So any interest for it? I am currently evaluating the library http://libcpuid.sourceforge.net/ This has a permissive license that I think can go with the Boost license. I mailed the author also, although he does not use boost, he told he can give any fixes or support needed. ~Thanks smisra

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[odeint] Regression tests fail for unknown reason
by Karsten Ahnert 14 Dec '12

14 Dec '12

On some machines all of odeints regression tests in the release branch fail for an unknown reason (http://www.boost.org/development/tests/release/developer/numeric-odeint.html) Does anyone know what happens here?

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Re: [boost] [Boost-testing] [odeint] Regression tests fail for unknown reason
by Vicente J. Botet Escriba 14 Dec '12

14 Dec '12

Le 13/12/12 21:40, Vicente J. Botet Escriba a écrit : > Le 13/12/12 21:28, Daniel James a écrit : >> On 13 December 2012 20:21, Vicente J. Botet Escriba >> <vicente.botet(a)wanadoo.fr> wrote: >>> Maybe, but I don't think so. All the Boost.Thread test are failling, and >>> most of them don't use Boost.Test. >>> The problem is that here is no information. What is happening with the >>> regression test results? >> I tried it on my machine: >> >> darwin.compile.c++ >> ../../../bin.v2/libs/thread/build/darwin-4.7x/debug/link-static/threading-multi/pthread/thread.o >> ../../../libs/thread/src/pthread/thread.cpp: In member function 'bool >> boost::thread::joinable() const': >> ../../../libs/thread/src/pthread/thread.cpp:398:34: error: cannot >> convert 'boost::detail::thread_data_ptr {aka >> boost::shared_ptr<boost::detail::thread_data_base>}' to 'bool' in >> return >> ../../../libs/thread/src/pthread/thread.cpp:399:5: warning: control >> reaches end of non-void function [-Wreturn-type] >> >> So it's shared_ptr's explicit bool? >> > Yes. I need to merge from trunk. I believed that I did it already :( > 06:01 Changeset /[81788]/ by viboes > <https://svn.boost.org/trac/boost/changeset/81788> > > Thread: fix shared_ptr implicit conversion to bool introduced in > [81780] <https://svn.boost.org/trac/boost/changeset/81780> > > I will take care also of the merge of Boost.Test > > 06:43 Changeset /[81791]/ by viboes > <https://svn.boost.org/trac/boost/changeset/81791> > Test: fix shared_ptr implicit conversion to bool introduced in > [81780] <https://svn.boost.org/trac/boost/changeset/81780> > why we are not able to see the comile errors on the regression test results? Vicente

2 2

Boost.Process: Formal review request
by Boris Schaeling 14 Dec '12

14 Dec '12

I'd like to ask for a formal review of the library which is known as Boost.Process 0.5: - Docs: http://www.highscore.de/boost/process0.5/ - Code: http://www.highscore.de/boost/process0.5/process.zip Since 2006 a lot of people spent a tremendous amount of work on a process management library for Boost. Since then Boost.Process went through two GSoC projects, had a formal review in 2011 where it got rejected, was discussed at BoostCon, went through a complete overhaul afterwards, spun off boost::asio::windows::object_handle and got a sponsorship. In fact the library is around for so long and has attracted so much interest that it could be called a de facto Boost library. People call it Boost.Process, and there are some who use the library in their projects. The main reason why Boost.Process is under construction for six years: Differences between the supported platforms Windows and POSIX. There are other libraries like Boost.Asio or Boost.Interprocess which have to deal with platform differences, too. But in their case no core functionality is affected. Classes like boost::asio::posix::stream_descriptor or boost::interprocess::windows_shared_memory are nice to have, and no one is worried that they only work on one platform. Boost.Process has to deal with platform differences in core functions. For example, resource leaking is unacceptable (zombie processes on POSIX and open HANDLEs on Windows when child processes exit). Given that platforms are very different two extreme solutions are possible: Abstract away differences at all costs. Or tell the library user to call platform-specific system functions. As none is satisfactory, a balance between these extremes has to be found. But where this balance should be exactly can be discussed with no end. Someone has to make a decision at some point, and that will be another important role for the review manager. :) Looking back at what has been accomplished since the first review, I think Boost.Process 0.5 is a huge step forward: * The library is now fully customizable. While previous versions had a function called launch() which was immutable, the current version is based on things called executors and initializers. An executor is basically a struct with member variables which will be passed as arguments to a system function to spawn a child. Initializers set those member variables. Library users pick initializers provided by Boost.Process or define their own to setup executors. * Boost.Process 0.5 is cleaner and more focused as it makes better use of other Boost libraries. For example, previous versions had their own stream classes. They were removed in the current version - Boost.Iostreams is used instead. Now Boost.Process doesn't reinvent concepts or reimplement functions anymore which belong in other libraries. All of that makes me believe it's time for a new review. Boris

5 9

[Interprocess] Experimental Win32 Mutexes
by Brink, Robert (GE Aviation, US) 13 Dec '12

13 Dec '12

I'm running Boost 1.52 on Windows 7, Visual Studio 2010. I noticed in sync\interprocess_mutex.hpp there is a windows mutex implementation that is hidden behind the BOOST_INTERPROCESS_FORCE_GENERIC_EMULATION macro. The comment indicates that it is "Experimental". Could someone shed some light on what is Experimental about it and what the general plans for this feature are? I was having a problem with many processes all spin-locking when allocating shared memory that I traced down to the old mutex implementation for shared memory. I enabled the experimental feature in my local build ( by commenting out the above macro in the detail\workaround.hpp file) and it seems to fix my problems. My performance is much improved. But what are my risks for using this implementation? I'm a little nervous to depend on something marked as "Experimental". Thanks Rob Brink

3 5

[Interprocess] Managed mapped file questions
by Jorge Lodos Vigil 13 Dec '12

13 Dec '12

Hi First of all, thank you for boost interprocess :-) I have a couple of questions: 1. When you grow a managed mapped file, the current implementation fills all the new space with zeroes. This is less efficient than just resizing the file. The comments in the code implies there is a reason, so what is it? 2. When the size to map is too small, take 1 or 2 bytes for instance, the library fails in a non elegant way. This is a corner case, but I could not find this documented. Is this a bug? I'm asking this before sending any sample code or creating tickets, but of course I could do that as well if there is the need. Thanks again. Cheers Jorge

2 4

[Container][Move] #if defined(BOOST_MOVE_USE_STANDARD_LIBRARY_MOVE): boost::move_backward is undefined
by Hartmut Kaiser 13 Dec '12

13 Dec '12

Hey, If BOOST_MOVE_USE_STANDARD_LIBRARY_MOVE is defined, then compiling Boost.Container fails because its missing boost::move_backward. Patch is attached. Ok to commit? Regards Hartmut --------------- http://boost-spirit.com http://stellar.cct.lsu.edu

2 3

Boost.Process 0.5: And another minor update
by Boris Schaeling 13 Dec '12

13 Dec '12

I've uploaded a new version of Boost.Process 0.5 to <http://www.highscore.de/boost/process0.5/>: - First command line argument passed to set_args is used as a path to the executable to start - No escaping of command line arguments anymore with set_args (see <http://article.gmane.org/gmane.comp.lib.boost.devel/236137>) - Updated documentation Boris

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