November 2008 - Boost-users

new using Boost (Problem at the asynchronous TCP Server example)
by Daniel França 09 Nov '08

09 Nov '08

BOOST: Duvida link em um asynchronous TCP serverHi everyone, I'm new at this list and new using the boost library. I'm little by little learning about boost. Now I was trying to do this example: http://www.boost.org/doc/libs/1_36_0/doc/html/boost_asio/tutorial/tutdaytim… The source is here: http://www.boost.org/doc/libs/1_36_0/doc/html/boost_asio/tutorial/tutdaytim… But when I try to link I get this errors: /usr/include/boost/system/error_code.hpp undefined reference to `boost::system::get_posix_category()' The program is linking with the follows boost librarys: boost_filesystem-gcc42-mt boost_system-gcc42-mt boost_unit_test_framework-gcc42-mt Maybe I forgot something when I did compile boost? My version of boost is 1.36. I use Linux (Slackware 12.1 + KDE 4.1), gcc 4.2.3 and Eclipse+CDT Best Regards -- Daniel C. França Tecnosapiens: http://tecnosapiens.wordpress.com 24Quadros: http://24quadros.wordpress.com

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1.37 build problems/error on linux/gcc
by Olaf Peter 09 Nov '08

09 Nov '08

I've got the following compiler error: olaf@tux:/var/tmp/boost_1_37_0$ ./configure --prefix=/usr/local/boost_1_37_0 Building Boost.Jam with toolset gcc... tools/jam/src/bin.linuxx86/bjam Detecting Python version... 2.5 Detecting Python root... /usr Unicode/ICU support for Boost.Regex?... /usr Generating Boost.Build configuration in user-config.jam... Generating Makefile... olaf@tux:/var/tmp/boost_1_37_0$ make ./tools/jam/src/bin.linuxx86/bjam -sICU_PATH=/usr --user-config=user-config.jam error: at /var/tmp/boost_1_37_0/tools/build/v2/build/project.jam:846 error: duplicate initialization of gcc with the following parameters: error: version = 4.3.2 error: previous initialization at /var/tmp/boost_1_37_0/tools/build/v2/build/project.jam:846 Not all Boost libraries built properly. on: olaf@tux:/var/tmp/boost_1_37_0$ LANG=en gcc -v Using built-in specs. Target: i486-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu 4.3.2-1ubuntu11' --with-bugurl=file:///usr/share/doc/gcc-4.3/README.Bugs --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --enable-shared --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --enable-nls --with-gxx-include-dir=/usr/include/c++/4.3 --program-suffix=-4.3 --enable-clocale=gnu --enable-libstdcxx-debug --enable-objc-gc --enable-mpfr --enable-targets=all --enable-checking=release --build=i486-linux-gnu --host=i486-linux-gnu --target=i486-linux-gnu Thread model: posix gcc version 4.3.2 (Ubuntu 4.3.2-1ubuntu11) what gone wrong here? Thanks Olaf

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Boostcon 2009 call for sessions
by dan marsden 09 Nov '08

09 Nov '08

3rd annual Boost Conference 2009 Aspen CO, USA, May 3-9, 2009, www.boostcon.com ---------------------------------------------------------------------------- Call for participation ---------------------- Promising to be the main face-to-face event for all things Boost (www.boost.org) BoostCon'09 opens the door to your C++ future. From using the Boost libraries to writing and maintaining them, from evangelizing to deploying Boost within your organization, from infrastructure and process to vision and mission, and from TR1 to TR2 and the new C++0x Standard, BoostCon brings together the sessions, the colleagues, and the inspiration to support your work with C++ and Boost in particular for the next year. To reflect the breadth of the Boost community, the conference includes sessions aimed at two constituencies: Boost end-users and hard-core Boost library and tool developers. The program fosters interaction and engagement within and across those two groups, with an emphasis on hands-on, participatory sessions. Session topics -------------- * Topics of interest include, but are not restricted to, the following: * General tutorial sessions introducing one or more Boost libraries * In-depth sessions on using specific libraries * Case studies on using Boost * Experts panels * Advanced sessions on implementation techniques used within Boost libraries * C++0x and how it will change life for users and library writers * TR1 and TR2 * 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 * Other topics likely to be of great interest to Boost users and Developers. Interactive and collaborative sessions are encouraged, as this is the nature of both the on-line Boost community and 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 Boost and Boost users. Panels ...... Panels feature three or four people presenting their ideas and experiences relating to 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 Boost-relevant skills. 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 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 90 minute, 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 lightning-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 have to be done through the EasyChair conference management system: http://www.easychair.org/conferences/?conf=boostcon09. 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 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 papers 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 BoostCon CD handed out to attendees. For general information on the BoostCon 2009 paper submission or the scope of technical papers solicited, please refer to the conference website at www.boostcon.com. For any other questions about the submission process or paper format, please contact the Program Committee at boostcon09(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 BoostCon. Important dates --------------- Proposals for submissions due: January 10th 2009. Proposals acceptances sent (tentative program available): February 10th, 2009 Fully scheduled program available: March 1st, 2009 Session materials due: April 1st 2009. Hartmut Kaiser, email: hartmut.kaiser(a)gmail.com (Program Committee Chair) David Abrahams, email: dave(a)boostpro.com (Conference Chair) On behalf of the conference organizers

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boost::signals - missing static runtime builds for VC8.0
by Dimitri Kaparis 09 Nov '08

09 Nov '08

Hello, I'm using the boostpro installer and noticed the static runtime multithread builds for VC8.0 of the Boost Signals (and several other) libraries are missing. All builds are available for both VC7.1 and VC9.0. I have also tried building the current boost version (although I haven't gone deep into the details of the build process) and at a glance it seems the multithread static runtime library variants are not built here either (I'm missing libboost_signals-vc80-mt-sgd-1_36.lib and libboost_signals-vc80-mt-s-1_36.lib). Any ideas why is that? Regards, Dimitri

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[type_traits] is_convertible bug with gcc 4.3.0
by Terry G 09 Nov '08

09 Nov '08

I'm playing with move semantics (still/again). The following program compiles and runs fine with msvc8 but does not compile with gcc 4.3.0 when ENABLE_IS_CONVERTIBLE_CHECK is defined. Should it? The problem has something to do with U's copy constructor being private. I've inluded the compiler output below too. terry ============================================ #include <boost/type_traits.hpp> #include <boost/utility/enable_if.hpp> #include <cassert> template <typename T> class move_from { private: T* _source; public: explicit move_from(T& x) : _source(&x) { } T& get() const { return *_source; } }; // move_from #define ENABLE_IS_CONVERTIBLE_CHECK template <typename T> inline move_from<T> move(T& x #ifdef ENABLE_IS_CONVERTIBLE_CHECK , typename boost::enable_if< boost::is_convertible<move_from<T>, T> >::type* = 0 #endif ) { return move_from<T>(x); } template <typename T> class U { T* _ptr; public: void reset(T* p=0) { delete _ptr; _ptr = p; } T* release() { T* rval = _ptr; _ptr = 0; return rval; } U() : _ptr(0) { } U(T* x) : _ptr(x) { } U(move_from<U> x) : _ptr(x.get().release()) { } U& operator=(move_from<U> x) { reset(x.get().release()); } T* get() const { return _ptr; } T* operator->() const { return get(); } T& operator*() const { return *get(); } private: explicit U(const U&); U& operator=(const U&); }; // U int main() { U<int> x(new int(1234)); U<int> z(move(x)); // Seems to convert ok here. assert(*z == 1234); assert(!x.get()); return 0; } // main ============================================ In file included from c:/boost/boost/type_traits.hpp:38, from bug.cpp:1: c:/boost/boost/type_traits/is_convertible.hpp: In instantiation of ' const bool boost::detail::is_convertible_basic_impl< move_from<U<int> >&, U<int> >::value' : c:/boost/boost/type_traits/is_convertible.hpp:295: instantiated from ' const bool boost::detail::is_convertible_impl< move_from<U<int> >, U<int> >::value' c:/boost/boost/type_traits/is_convertible.hpp:418: instantiated from 'boost::is_convertible<move_from<U<int> >, U<int> >' c:/boost/boost/utility/enable_if.hpp:36: instantiated from 'boost::enable_if< boost::is_convertible<move_from<U<int> >, U<int> >, void >' bug.cpp:46: instantiated from here c:/boost/boost/type_traits/is_convertible.hpp:136: error: no matching function for call to 'U<int>::U(U<int>)' bug.cpp:34: note: candidates are: U<T>::U(move_from<U<T> >) [with T = int] bug.cpp:33: note: U<T>::U(T*) [with T = int] c:/boost/boost/type_traits/is_convertible.hpp:136: error: initializing argument 1 of ' static boost::type_traits::yes_type boost::detail::checker<T>::_m_check(T, int) [with T = U<int>]' from result of 'U<T>::U(move_from<U<T> >) [with T = int]'

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A lot of warnings with Boost.Filesystem
by ancode tran 08 Nov '08

08 Nov '08

Dear boosters, I got 25 warnings in total from "boost/filesystem/path.hpp" and "boost/filesystem/operations.hpp" about "comparison between signed and unsigned integer expressions". This is because the type of dot<Path>::value (and the likes, e.g slash<Path>::value) is char regardless of the type of Path::value_type, which is an unsigned integral type in case of wchar_t. Obviously, they are not errors but for me, these 25 warnings are too much and unfriendly. I hope this will be fixed in future version of Boost. Thank you for reading this. Best regards, An P.S: I use gcc(winxpsp2/linux) + boost 1.36.0 + stlport 5.1.6 --------------------------------- Đặt ngay địa chỉ email mới! Lấy ngay địa chỉ email bạn từng muốn có trước khi có người khác nhanh tay hơn!

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asio 10022 error
by Amit Sonawane 08 Nov '08

08 Nov '08

Hi, I am using boost 1.36.0 asio. I have to connect to several ip/ports within my application, asio successfully connects to some ips/ports while it throws an error with code 10022, "An invalid argument was supplied". In my case the ip/ports supplied are on the same ip i.e. same server. Any ideas what I could be doing wrong? Esta mensagem pode conter informação confidencial e/ou privilegiada. Se você não for o destinatário ou a pessoa autorizada a receber esta mensagem, não deverá utilizar, copiar, alterar, divulgar a informação nela contida ou tomar qualquer ação baseada nessas informações. Se você recebeu esta mensagem por engano, por favor avise imediatamente o remetente, respondendo o e-mail e em seguida apague-o. Agradecemos sua cooperação. This message may contain confidential and/or privileged information. If you are not the addressee or authorized to receive this for the addressee, you must not use, copy, disclose, change, take any action based on this message or any information herein. If you have received this message in error, please advise the sender immediately by reply e-mail and delete this message. Thank you for your cooperation.

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Concurrency and session termination in boost::asio
by Scott Gifford 08 Nov '08

08 Nov '08

Hello, I'm experimenting with boost::asio as the basis for communications and event handling for a network server. The server will support many clients, and should scale well to machines with multiple processors/cores, so I'd like to use thread pools to execute requests. I've done this by calling io_service.run() from multiple threads, which seems to be the normal way to do it. Each client session always has an asynchronous read operation waiting for new commands. If the server has a notification for a thread, it will send it by starting an asynchronous write on that session. Notifications can come at any time, not just in response to a request, so it is common for a session to simultaneously have oustanding asynchronous read and write requests. Sessions are terminated when the socket is closed or when the client sends a quit command. I'm trying to make sure that my handling of session termination is threadsafe. It seems that the normal way to handle this is to detect an error or end-of-file in an asynchronous event handler, then delete the object to end the session. Because my server is using a threadpool and waiting for both read and write events, it is possible for a read and write callback to be running concurrently on different CPUs. In that case, if one of those callbacks detects an error and deletes the object, the other will continue running using an invalid object. In a simple echo server I wrote to learn about boost::asio, I can see these invalid accesses when running under valgrind with a large number of clients, so unless I have made an error in my server, this appears to be a real problem. I rewrote it to have write errors handled by closing the session, which causes the read callback to run, notice the session has been closed, and delete the object. This seemed to solve the problem, but it still seems there is a potential problem if the read callback finishes deleting the object while the write callback is running. Is there a better way to handle session termination? Can I use io_service::strand to prevent this by having the readers and writers for the same session running in the same strand? Thanks for any thoughts! ----Scott.

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[trunk] Support for Intel-linux 11.0?
by Mikko Vainio 08 Nov '08

08 Nov '08

Dear boosters, Is someone out there working on fixes required for boost to work with the brand-new Intel Compiler v11.0 for linux? Should we users wait for a few days before start making tickets for the observed errors? Anyway, here's one to start with: /usr/local/include/boost/type_traits/is_class.hpp(129): error: namespace "boost" has no member "remove_cv" BOOST_TT_AUX_BOOL_TRAIT_DEF1( ^ Cheers, Mikko

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[signals2][review] The review of the signals2 library is scheduled to end on Monday, November 10th
by Stjepan Rajko 08 Nov '08

08 Nov '08

Hello, The review of the signals2 library is scheduled to end on Monday, November 10th. We have had some good discussion so far and a couple of reviews. I hope the remaining few days will provide enough time to others that were planning on submitting a review. If anyone needs any more discussion time or time to write the review, please let me know (so we can see about extending the review period, or so that I know to wait for your review longer). Kind regards, Stjepan

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