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[Asio] read_some throws exception with IOCP disabled
by Collin Dauphinee 22 Jan '10

22 Jan '10

I have a piece of code that works completely fine with IOCP enabled, but when I disable it via the BOOST_ASIO_DISABLE_IOCP define, any attempts to call socket.read_some will throw an exception. This exception states that "An operation was attempted on something that is not a socket." However, I am able to write to this socket without problems; no exception is thrown and the data is received by the server. I've also tried reading and writing with the native Windows socket. Any calls to send() will succeed, but calls to recv() will return the error given above. This includes a write, read, write sequence; the first write will succeed, the read will fail, the second write will succeed even though the read told me that the handle isn't a socket. Only synchronous operations are being done on this socket. It's connected normally, no strange options are set on it, etc; the code is more or less the same as that found in the synchronous TCP client examples. Any solutions or workarounds to this problem would be greatly appreciated. I need to have IOCP disabled, so re-enabling it isn't a solution.

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[uBLAS] howto combine sparse AND symmetric?
by Tim Odenthal 22 Jan '10

22 Jan '10

Hi! I need to solve the classical linear equation A*x=b with x the unknown vector and A a very large, sparse and symmetrical matrix. I want to try the conjugate gradient iterative method to solve the problem (unless somebody knows a definitely much better one). Now I've seen that uBLAS provides the symmetric_adaptor class - should I use this one in combination with one of the sparse matrix classes? Does this reduce the memory usage as compared to only using a sparse matrix? Many thanks in advance Tim Odenthal

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[BGL] bundled GraphProperties
by Damien Maupu 22 Jan '10

22 Jan '10

Dear all, Are bundled properties available for GraphProperties (for adjacency list)? If no, why? Thank you Damien

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advance calculation statistical calculation
by eial＠cs.bgu.ac.il 22 Jan '10

22 Jan '10

hello. using boost::math::normal, mean and sd can I retrieve the value corresponding with percentage of the space of the created by the function which is bounded by the bell borders and a straight vertical line? e.g. the corresponding x value of the red line (by calculation of the space between the blue bell borders and the red vertical line in this picture http://img714.imageshack.us/img714/4789/normal2.png thanks

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[1.42.0] Beta 1 available on Sourceforge
by Beman Dawes 22 Jan '10

22 Jan '10

1.42.0 beta 1 is now available. This release contains one new library and numerous bug fixes for existing libraries. For details, including download links, see http://beta.boost.org/users/news/version_1_42_0 The release can also be downloaded directly from SourceForge. See http://sourceforge.net/projects/boost/files/ There are a few known problems in the beta: * An odd 'simplesectsep' tag that doxygen creates which has turned up in the generated documentation, such as at http://tinyurl.com/ygbgkge. * Doxygen isn't expanding some of the macros in Boost.Accumulators. * A nasty bug in Spirit affecting copy construction of rules (rev. 50156) has been tracked down and fixed, but the fix was too late for the beta. These will be fixed in the final release. Please report any other problems by responding to this message on either the users or the main developers mailing lists. Thanks, --The Boost release team

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How to create a Graph with BOOST Bib (e.g. adjacency_list)?
by Konstantin Silav 22 Jan '10

22 Jan '10

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[Boost] [Fusion] Help with tuple adapter
by Bill Nell 22 Jan '10

22 Jan '10

Hi all, I'm having some trouble getting the boost fusion tuple adapter working (the one that makes boost::tuples into conforming sequence types). I'm assuming that the adapted tuple should now be a legal MPL sequence but mpl::is_sequence yields false and consequently mpl::for_each doesn't work on the tuple type either. The following program is an illustration of what I am trying to do. I guess I must be missing something simple? Any help would be appreciated. Bill #include <iostream> #include <typeinfo> #include <boost/mpl/is_sequence.hpp> #include <boost/mpl/for_each.hpp> #include <boost/fusion/tuple.hpp> #include <boost/fusion/sequence.hpp> #include <boost/fusion/iterator.hpp> #include <boost/fusion/mpl.hpp> #include <boost/fusion/adapted/boost_tuple.hpp> struct helper { template <typename TT> void operator()(TT) { std::cout << typeid(TT).name() << std::endl; } }; int main() { typedef boost::fusion::tuple<int,char,double> FTUP; typedef boost::tuple<int,char,double> BTUP; // this works std::cout << boost::mpl::is_sequence<FTUP>::value << std::endl; std::cout << "fusion tuple\n"; boost::mpl::for_each<FTUP>(helper()); // this doesn't work std::cout << boost::mpl::is_sequence<BTUP>::value << std::endl; // the following lines won't compile because the BTUP is not a // sequence type. //std::cout << "boost tuple\n"; //mpl::for_each<BTUP>(helper()); return 0; }

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Problems with boost serialization/shared_ptr/container
by Guo, Yanchao 22 Jan '10

22 Jan '10

Hi I am using boost/1.41.0, and the following code give me compilation error when I try to deserialize a shared_ptr. The serialize part it compiled successfully. Can someone advise me if this is a bug in my code or a general issue for boost? Thanks. Yanchao #include <iomanip> #include <iostream> #include <cstddef> // NULL #include <fstream> #include <string> #include <list> #include <cstdio> // remove #include <boost/config.hpp> #if defined(BOOST_NO_STDC_NAMESPACE) namespace std{ using ::remove; } #endif #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <boost/archive/tmpdir.hpp> #include <boost/serialization/shared_ptr.hpp> #include <boost/serialization/list.hpp> #include <boost/serialization/map.hpp> #include <boost/shared_ptr.hpp> #include <list> #include <map> #include <string> #include <sstream> class A{ public: A(){} virtual ~A(){} private: friend class boost::serialization::access; template<class Archive> void serialize(Archive &ar, const unsigned int version) { ar & m_data; } int m_data; }; BOOST_SERIALIZATION_SHARED_PTR(A) typedef std::map<std::string, A > MyMap; BOOST_SERIALIZATION_SHARED_PTR(MyMap ) int main (){ boost::shared_ptr<std::map<std::string, A> > test_ptr; std::string data; std::stringstream buffer(data); boost::archive::text_iarchive ia(buffer); boost::archive::text_oarchive oa(buffer); ia >> test_ptr; //compile error oa << test_ptr; //this is ok return 1; } DISCLAIMER: This e-mail message and any attachments are intended solely for the use of the individual or entity to which it is addressed and may contain information that is confidential or legally privileged. If you are not the intended recipient, you are hereby notified that any dissemination, distribution, copying or other use of this message or its attachments is strictly prohibited. If you have received this message in error, please notify the sender immediately and permanently delete this message and any attachments.

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Q: N00b spinlock
by Moritz Moeller 21 Jan '10

21 Jan '10

I'm new to multi-threaded programming. So I apologize for aksing what is possibly a silly question. Will below code give me the behaviour of what is commonly called a "spinlock"? boost::unique_lock< boost::shared_mutex > guard( mutex, boost::try_to_lock ); if ( !guard.owns_lock() ) { while ( !guard.try_lock() ) { boost::thread::yield(); } } // access data Cheers, Moritz

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boost::thread object initialization. cannot understand.
by rabbitko＠tenbit.pl 21 Jan '10

21 Jan '10

hallo Group Members compilation of following simple program leads to an error: p1.cpp: In function "int main(int, char**)": p1.cpp:18: error: request for member "join" in "f", which is of non-class type "boost::thread(F (*)())" #include <boost/thread.hpp> #include <iostream> struct F { void operator()() { while (true) { std::cout << "hallo" << std::endl; } } }; int main(int argc, char *argv[]) { // boost::thread f = boost::thread(F()); // But with this line // instead, everything // is ok!! boost::thread f(F()); f.join(); return 0 ; } I am running fc12 with: prompt$ g++ --version g++ (GCC) 4.4.2 20091222 (Red Hat 4.4.2-20) Copyright (C) 2009 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. prompt$ rpm -qi boost Name : boost Relocations: (not relocatable) Version : 1.39.0 Vendor: Fedora Project Release : 8.fc12 Build Date: czw, 15 paĹş 2009, 15:15:15 Install Date: sob, 16 sty 2010, 13:38:26 Build Host: x86-3.fedora.phx.redhat.com Group : System Environment/Libraries Source RPM: boost-1.39.0-8.fc12.src.rpm Size : 0 License: Boost Signature : RSA/8, czw, 22 paĹş 2009, 10:57:44, Key ID 9d1cc34857bbccba Packager : Fedora Project URL : http://www.boost.org/ Summary : The Boost C++ Libraries Description : Boost provides free peer-reviewed portable C++ source libraries. The emphasis is on libraries which work well with the C++ Standard Library, in the hopes of establishing "existing practice" for extensions and providing reference implementations so that the Boost libraries are suitable for eventual standardization. (Some of the libraries have already been proposed for inclusion in the C++ Standards Committee's upcoming C++ Standard Library Technical Report.) have you got any explanation for this? Maybe I should learn C++ better? best regards, Michal

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