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Platform Champions needed
by Beman Dawes 28 May '08

28 May '08

Awhile back, there was discussion of setting up a list of platform champions. Platform champions are experts that Boost developers can turn to when they have a problem with a particular compiler or operating system. Whether it is a question about configurations, features, or submitting a bug report to the compiler supplier, these folks know the ropes for the platform. If you are knowledgeable about at platform, and would like to be a platform champion, please add yourself to the list! The list is found at http://svn.boost.org/trac/boost/wiki/PlatformChampions --Beman

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thread_group
by David Abrahams 28 May '08

28 May '08

I don't know if thread_group is supposed to stay around now that we have movable threads, but if we're going to keep it I would like to propose a few changes. 1. add_thread should take an auto_ptr<thread> (and eventually unique_ptr<thread>) so the signature indicates the ownership transfer. 2. remove_thread should be called release_thread. "Release" is at least not ambiguous about whether the thing is being destroyed. -- Dave Abrahams BoostPro Computing http://www.boostpro.com

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iterator_facade, decoupling of access and traversal?
by Roland Schwarz 28 May '08

28 May '08

After having read http://www.boost.org/doc/libs/1_35_0/libs/iterator/doc/index.html I have been left, believing that the new iterator concepts will allow me to create an iterator that may return a proxy instead of a reference. I tried to do this by using the iterator_facade template, and for the "Reference" parameter I specified a proxy class that has a conversion operator to the "Value" type. This almost works, but fails for expressions of Val v = it[n]; expressions, because iterator facade does not return "Reference" objects in that case, but operator_brackets_proxy objects that are convertible to "Reference". So I am wondering if I understand something wrong? Isn't the decoupling of access and traversal meant to allow "Reference" be a proxy object? Any hints appreciated! -- _________________________________________ _ _ | Roland Schwarz |_)(_ | aka. speedsnail | \__) | mailto:roland.schwarz@chello.at ________| http://www.blackspace.at

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movable threads, locks, and boost::array
by David Abrahams 27 May '08

27 May '08

I just discovered that while none of my standard containers are "move-aware" in the way needed by boost::thread, I can use boost::array to store threads by simply move-assigning new threads into the elements it contains: boost::array<boost::thread, 100> thread_q; for (int i = 0; i < 100; ++i) thread_q[i] = boost::thread( some_function ); it ain't perfect, but given that the number of cores on any real machine is limited these days, you can do a lot with a fixed-size array of thread. Pretty cool; it sure beats using shared_ptr. -- Dave Abrahams BoostPro Computing http://www.boostpro.com

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[exception] enable_error_info.hpp compile errors
by Beman Dawes 27 May '08

27 May '08

Boost.Filesystem's wide_test is failing on trunk due to enable_error_info.hpp compile errors. It's happening with many (or maybe all) compilers. See below for typical error messages. --Beman ..\boost/exception/enable_error_info.hpp(23): error: not a class or struct name public T, ^ detected during: instantiation of class "boost::exception_detail::error_info_injector<T> [with T=char [29]]" at line 90 instantiation of "boost::exception_detail::enable_error_info_return_type<T>::type boost::enable_error_info(const T &) [with T=char [29]]" at line 58 of "..\boost/throw_exception.hpp" instantiation of "void boost::throw_exception(const E &) [with E=char [29]]" at line 114 of "..\libs\filesystem\test\wide_test.cpp" ..\boost/exception/enable_error_info.hpp(28): error: "T" is not a nonstatic data member or base class of class "boost::exception_detail::error_info_injector<char [29]>" T(x) ^ detected during: instantiation of "boost::exception_detail::error_info_injector<T>::error_info_injector(const T &) [with T=char [29]]" at line 95 instantiation of "boost::exception_detail::enable_error_info_return_type<T>::type boost::enable_error_info(const T &) [with T=char [29]]" at line 58 of "..\boost/throw_exception.hpp" instantiation of "void boost::throw_exception(const E &) [with E=char [29]]" at line 114 of "..\libs\filesystem\test\wide_test.cpp"

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Re: [boost] Question regarding logging, persistence, threadcommunication, network messaging and async frameworks
by brass goowy 27 May '08

27 May '08

Scott Woods writes: >Hi, >Is there a place in Boost for a library that tackles all of the above? I >believe the realistic >answer is no but I would be happy to be proven wrong. >Work in the different areas mentioned in the subject line recently collapsed >into a single >underlying technique. Given the example UDT below; >struct person >{ >std::string name; >std::vector<unsigned> score; >std::set<string> team; >}; >persistence is achieved using; >person new_member; >codec_object<person> configuration( "profile" ) >configuration << new_member; // Save in a disk file name >"profile" >configuration >> new_member; // Load from the same disk file >transmitting the same object between threads looks like; >send( new_member, other_thread ); >while receiving that transmission occurs in code that looks like; >my_thread::received( person &new_member ) >{ >.. >} >Transmission of messages across networks looks like; >send( new_member, socket_proxy ); >Yes, its the same as for inter-thread communications. The "socket_proxy" >just >happens to be a variation on "my_thread" that forwards materials it receives >onto a socket connection. >Logging looks like; >WINSOCK( socket, AF_INET << SOCK_STREAM << 0 ); >COMMENTARY( "connection to " << address_entered << " failed (" << >failure << ")" ); >Logging messages can be routed anywhere based on the type and unique >identity of >the originating party. >The fragments of code provided above hide a lot. While that's technically >desirable >I can appreciate that it might not flesh out my question at all (i.e. >...room in Boost). But >actually this is precisely the most compelling thing about the library - it >reduces code >that traditionally can be quite difficult into fragments such as those >shown. Shalom From what you've shown it looks like the duplication of data members in serialization methods is not needed. Some have been struggling to eliminate the need for that duplication -- http://preview.tinyurl.com/6kpx8t . Maybe more details about codec_object<> would be helpful. Brian Wood Ebenezer Enterprises www.webEbenezer.net

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promote "unwrap" to ref.hpp
by Ronald Garcia 27 May '08

27 May '08

Hi all, boost::reference_wrapper exists at the top-level of boost (in boost/ ref.hpp), but that header provides no way to unwrap a reference_wrapper. There are two implementations floating around of "unwrap", one in boost.bind's implementation details, and one in boost.mpl's implementation details. Is there any problem with providing a version of unwrap in ref.hpp? ron

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[test] Documentation confusion
by Maik Beckmann 27 May '08

27 May '08

Hello, I am confused about the boost.test documentation. There are docs in trunk and after some hours of digging via gmane if found this one http://www.patmedia.net/~rogeeff/html/index.html index.html in trunk : ... Revised: 28 February, 2006 index.html external link: Copyright © 2001-2007 Gennadiy Rozental ... My impression is that the 2007 version is much more comprehensive. Why isn't the most recent one in trunk? Do the trunk docs got a link the the external docs? -- Maik

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[Parameter] template return type
by brook＠biology.nmsu.edu 27 May '08

27 May '08

I am trying to use Boost.Parameter to construct some objects, much like make_tuple(A,B) does except with some of the arguments being optional and replaced by defaults (which may depend on the other arguments). The return type, however, must be a template class with the template arguments dependent on the arguments supplied. Is this possible? How can the return type for a Boost.Parameter frunction be specified as a template type? Thanks for your help. Cheers, Brook

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[MPI] Compile problem while building Boost 1.35.0
by Adam Stephens 27 May '08

27 May '08

Hi, all, I'm trying to build Boost on linux using bjam. Everything seems to compile smoothly except one file in Boost.MPI. The error is lengthy, but the first part reads: intel-linux.compile.c++ bin.v2/libs/mpi/build/intel-linux/release/threading-multi/datatypes.o ./boost/mpi/python/serialize.hpp(321): error: no operator "<<" matches these operands operand types are: boost::mpi::packed_oarchive << boost::mpl::if_<boost::is_fundamental<long>, long, long &>::type ar << extract<Type>(obj)(); ^ detected during: instantiation of "void boost::python::detail::direct_serialization_table<IArchiver, OArchiver>::default_saver<T>::operator()(OArchiver &, const boost::python::api::object &, unsigned int) [with IArchiver=boost::mpi::packed_iarchive, OArchiver=boost::mpi::packed_oarchive, T=long]" at line 158 of "./boost/function/function_template.hpp" My compiler is Intel/9.1 and the implementation of MPI is openmpi 1.2.4. I've also tried to build using intel/10.1, and I got the same error. My user-config.jam, the first several lines of output from bjam --debug-configuration, and the section of the bjam output with all the errors is posted at http://utilitybase.com/paste/6780 Thanks

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