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[Proto] terminal class acting as Pod
by Joel Falcou 11 Nov '08

11 Nov '08

I remember seeing a example code where terminal where treated as POD thanks to some macro. basically, if i have a foo_expr in a foo_domain, how can I build a special terminal class which acts as a POD if foo_expr is generated using pod_generator so I can write stuff like : foo x = { ... soem value }; where foo is a terminal extending foo_expr -- ___________________________________________ Joel Falcou - Assistant Professor PARALL Team - LRI - Universite Paris Sud XI Tel : (+33)1 69 15 66 35

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Fwd: [signals2][review] little REVIEW
by Stjepan Rajko 11 Nov '08

11 Nov '08

I am forwarding the review below: ---------- Forwarded message ---------- From: <Jean-Christophe.BENOIST(a)fr.thalesgroup.com> Date: Tue, Nov 4, 2008 at 8:43 AM Subject: [signals2][review] The review of the signals2 library (formerly t hread_safe_signals) begins today, Nov 1st : little REVIEW To: stjepan.rajko(a)gmail.com (first of all please excuse my weak english, I am not a native english speaker) I am a regular user of boost::signals, so I am very interested by signals2. I'll review from a user standpoint. * On the documentation : - I am surprised to find very little information or rationale about multi-threading in documentation. We know the library is now "thread safe" but we don't know exactly what it means. There is only one MT use case (just) detailed in "tutorial" : what happens when a thread disconnect a slot from a signal, while another thread calls it. But there are another interesting MT use cases : - what if 2 threads simultaneously calls the same signal ? How to mutex slots in this case ? Are slots automatically excluded by an hidden mutex ? - What if a thread adds a slot to a signal while another calls it ? Is the slot added after signal call ? There should be tutorials and explanations for these cases, IMO. - About rationale : why is there special signals2::mutex ? May we use boost::thread::mutex for mutex template ? What are advantages/drawbacks of choosing signals2::mutex or boost::thread::mutex ? - Use of "postconstructible" or "predestructible" classes is rather obscure, and should be tutorialized / better documented. * On interface : - Very close from original signals interface : no particular comment. * On test suite / test cases : - I cannot see any MT test case (from the documentation, in "acceptance tests" section at least). It's rather surprising. I cannot imagine there is no test case for MT (calling a signal while disconnecting slot etc..). In particular, I'd whish to see if this library is robust in a multi-core environment and run test cases in this environment (I know cases where a library is perfectly thread safe on mono-core, even hyperthreading, but fails on multi-core). At least, there should be a rationale explaining why this library should be robust in a multi-core environment (especially with a proprietary signals2::mutex). * Final statement : All in all, I think this library is very close to be accepted as a Boost library, but without MT test cases and MT documentation, I can't give a total agreement for now. I have little doubt this library is MT tested and robust, even in a multi-core environment, but I have no real clue to assert it. Feel free to ask me further details. Best regards Jean-Christophe BENOIST Software Engineer THALES Communications France

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ICC and _syn_lock bug again
by Joel Falcou 11 Nov '08

11 Nov '08

As shown here : http://lists.boost.org/Archives/boost/2008/06/138322.php There *was* a bug with intel Compiler and shared_ptr using the __sync_lock intrinsic. It has been fixed on ICC 9.x but today I tried to sue this with latest ICC 10.1.018 on ubuntu linux and got the very same error than in the original topic. Is there something I miss ? -- ___________________________________________ Joel Falcou - Assistant Professor PARALL Team - LRI - Universite Paris Sud XI Tel : (+33)1 69 15 66 35

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boost 1.37, tr1 and gcc 4.x
by Acsoft Acsoft 11 Nov '08

11 Nov '08

Hello, I am using boost 1.37 and gcc 4.3.2. I am getting a very nasty error when I mix up boost headers and tr1 headers in one compilation unit. Here is my code: #include <functional> using namespace std; using namespace tr1; #include <boost/program_options.hpp> using namespace boost; void blub() { } function<void()> i1(blub); //error: expected constructor, destructor, or type conversion before '<' token std::function<void()> i2(blub); //Compiles fine tr1::function<void()> i3(blub); //Compiles fine boost::function<void()> i4(blub); //Compiles fine I did add the 'boost/tr1/tr1/' folder to the very beginning of global include list. What is wrong?

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Asio acceptor : Multiple client connections on single port
by Amit Sonawane 11 Nov '08

11 Nov '08

I have a acceptor server which listens to various connections from clients. It creates one server object per client connection. I need the clients to connect to only one IP port of the server. Following the examples in boost I do this: (sample code) boost::asio::ip::tcp::acceptor m_acceptor; boost::asio::ip::tcp::resolver resolver(iosvr); boost::asio::ip::tcp::resolver::query query(host.c_str(),boost::lexical_cast<std::string>(port)); boost::asio::ip::tcp::endpoint endpoint = *resolver.resolve(query); m_acceptor.open(endpoint.protocol()); m_acceptor.set_option(boost::asio::socket_base::reuse_address(true)); if( bNoDelay ) m_acceptor.set_option(boost::asio::ip::tcp::no_delay(true)); else m_acceptor.set_option(boost::asio::ip::tcp::no_delay(false)); m_acceptor.bind(endpoint); m_acceptor.listen(); At runtime the server listens to one and only one client connection, the others are not connected at all. What is wrong in the implementation? OR How do I make acceptor to accept multiple connections on the same server port? Any help is highly appreciated. 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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boost::unordered_map thread safety
by Kenny Riddile 11 Nov '08

11 Nov '08

This is a simple question, but a quick search didn't turn up any answers. Is it safe for multiple readers to access a boost::unordered_map concurrently? -Kenny Riddile

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[format] How to trigger compile-time error for mismatched arguments
by Jeffrey Chang 11 Nov '08

11 Nov '08

Hi, I'm using boost::format library, and this may be obvious to those experienced users: is there any way to detect the mismatch of number of expected arguments in a boost::format object? Both of the following statements throw out runtime exceptions (which is correct): std::cout << boost::format ("%s %s") % "Hello"; std::cout << boost::format ("%s") % "Hello" % "world"; It'd be great if this type of parameter-mismatch error can be caught at compile-time, instead of run-time. We use boost::format library extensively for logging, and inevitably there're human errors like this mismatched number of arguments. IMHO, this kind of error should have been detected by compiler at build time, s.t. the developer won't be embarrassed by QA or customers at run-time. Actually, what's even worse is the following that doesn't generate error at all: std::cout << boost::format ("%s %s") % "Hello" % 12345; There's a type-mismatch ('char*' versus 'int') for the second argument, but there's neither compile-time nor run-time error. The output is "Hello 12345", which may be correct, but it may not be what the programmer intended to do. Any way of turning those typo into compile-time error? --- Jeffrey

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Boost MPI + Serialization
by Raymond Wan 11 Nov '08

11 Nov '08

Hi all, I am using Boost MPI and would like to send user-defined objects between processes. As the Boost MPI tutorial / documentation suggests (http://www.boost.org/doc/libs/1_37_0/doc/html/mpi/tutorial.html) I should use serialization and in this document, they show an example class gps_position which is a friend with boost::serialization::access. So far, I understand what's going on, but I don't know what is the next step. The example in the documentation stops there and says that the example continues in the Serialization document. It also just mentions that one could store it in many forms, such as XML on disk, in addition to sending it to processes. If all I want to do is send it between processes, which one of the formats listed in boost/archive/*.hpp should I use? In the Serialization document, it continues by creating a boost::archive::text_oarchive object. But, if I am sending things like vectors of unsigned integers and strings, a binary format should be more compact? Or does this not matter and sticking with the Serialization example is fine? Thank you in advance! Ray

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[signals2][review] The review period of the signals2 library is over
by Stjepan Rajko 11 Nov '08

11 Nov '08

Hello all, The review period of the signals2 library finishes today, November 10th. I would like to thank the author, Frank Mori Hess, for preparing the library for review and for diligently answering questions, and all those that have participated in the review for their thoughtful comments and reviews. A few more reviews will be coming late - if anyone that hasn't contacted me yet would like to submit a review in the following few days please let me know so I know to wait for your review. I will start working on summarizing the content of the reviews and comments submitted so far, and will post a report within a week. Kind regards, Stjepan

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[boost.python] Hello world example of is not working with msvc
by Sandeep Gupta 11 Nov '08

11 Nov '08

Hi, I am reasonably sure that this is due to omission in the configuration file. I checkout from the trunk and all compilation went without problem. But the hello world example within the boost.python is failing with error: LINK : fatal error LNK1104: cannot open file 'boost_python-vc80-mt-gd-1_38.lib' call "f:\Program Files\Microsoft Visual Studio 8\VC\vcvarsall.bat" x86 >nul link /NOLOGO /INCREMENTAL:NO /DLL /DEBUG /subsystem:console /out:"bin\msvc-8.0\debug\hello_ext.pyd" /IMPLIB:"bin\msvc-8.0\debug\hello_ext.lib" /LIBPATH:"F:\CodeBase\Libs\Python-2.5.2\PCbuild8\win32release" @"bin\msvc-8.0\debug\hello_ext.pyd.rsp" .... .... >From what I can make that LIBPATH doesn't have path to boost_python-vc80-mt-gd-1_38.lib. The lib in question is build at its requisite place. Appreciate any help. Thanks sandeep

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