September 2010 - Boost-users - lists.preview.boost.org

[Proto] Default-constructing a proto::terminal
by Roland Bock 16 Sep '10

16 Sep '10

Hi, I have a class which has boost::proto::terminal members like this: struct _table { struct id { id(); // default constructible /*...*/ }; boost::proto::terminal<id> id_terminal; }; _table table; Will table.id_terminal be constructed correctly? I am asking because in Proto's documentation terminals are always instantiated with curly braces, e.g.: typedef proto::terminal<int>::type int_; int_ i = {42}, j = {24}; template<int I> struct placeholder {}; proto::terminal<placeholder<0> >::type const _1 = {{}}; proto::terminal<placeholder<1> >::type const _2 = {{}}; Thanks and regards, Roland

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OpenMP and Boost - can they be used together?
by Max S. Kaznady 16 Sep '10

16 Sep '10

Hello, I wrote a simple parallel program which computes the sum of elements across a matrix using Boost. When I use OpenMP, the program runs give different sums. When I use just simple arrays like double array[N][N], instead of boost::numeric::ublas::matrix<double>, the code work just fine and as expected. Does anyone know what is going on? It looks like the score function is not being modified properly, because Boost array returns just fine. The function compute_score() creates a matrix and computes the sum of its elements in parallel, copying the result to matrix temp and then printing temp, to make sure that the results can be copied in parallel too. The function is run infinitely many times, and if its return values differ then the program exits. [code] #include <iostream> #include <omp.h> #include <boost/numeric/ublas/io.hpp> #include <boost/numeric/ublas/matrix.hpp> #define ENABLE_OPENMP_SCORE 1 #define N 10 #define NUMTHREADS 2 using std::cout; using std::endl; using boost::numeric::ublas::matrix; double compute_score() { matrix<double> data1(N, N); for (unsigned i = 0; i < N; ++i) for (unsigned j = 0; j < N; ++j) data1(i, j) = i * N + j; double sc = 0.0; unsigned i, j; matrix<double> temp(N, N); #pragma omp parallel \ shared(sc,temp) \ private(i,j) \ if (ENABLE_OPENMP_SCORE) { omp_set_num_threads(NUMTHREADS); #pragma omp master sc = 0.0; #pragma omp for reduction(+:sc) schedule(static) collapse(2) nowait for (i = 0; i < N; ++i) { for (j = 0; j < N; ++j) { temp(i, j) = data1(i, j); sc += data1(i, j); } } } cout << temp << endl; return sc; } int main(void) { double oldval = compute_score(), newval; cout.precision(32); cout << "--" << endl; while (1) { newval = compute_score(); cout << "--" << endl; if (newval != oldval) { cout << " newval - oldval = diff, " << newval << " - " << oldval << " = " << newval - oldval << endl; exit(1); } oldval = newval; } return 0; } [/code] This problem is driving me insane... the code is really simple, but for some reason after using Boost it does not function as expected. Cheers, Max

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[Serialization] Encrypting an xml archive
by Sean Farrow 16 Sep '10

16 Sep '10

Hi: Has anyone had the need to encrypt an xml or binary archive? If so what is the best way of going about it? Do I need to create a totally new archive class, or can I just derive from another one of boosts archive classes, if yes which methods should be overridden? Thanks for any pointers Regards Sean.

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Editable XML Serialization
by Anne van Rossum 16 Sep '10

16 Sep '10

Dear list members, I guess it's one of the hardest search terms around but I would like to know if there is any editable XML serialization provided by Boost or other C++ libraries. And I don't mean the kind of thing that requires you to go jumping around through trees, with iterators etc. I don't want to see any iterator! I really iike the XML serialization method that boost::serialization provides: //! Give boost serialization libraries access to private fields friend class boost::serialization::access; //! Tell which private fields to serialize template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & boost::serialization::make_nvp("Phase", phase); ar & boost::serialization::make_nvp("Period", period); ar & boost::serialization::make_nvp("DutyCycle", dutycycle); } Just adding this to a file, and then: xml_out << boost::serialization::make_nvp("ApplicationConfig", config); Or: xml_in >> boost::serialization::make_nvp("ApplicationConfig", config); It's awesome! I don't need to care about descending trees, etc. However, the default serialization class does not allow for different orders of the XML tags, etc. It doesn't use the "ApplicationConfig" string, but just assumes that XML tag should be there if this read operation. If you change anything in the XML file, it is likely you will get a segfault, and you won't know what is causing the problem exactly. It would be so great if there is something like this in which the XML files can actually be edited! I am almost sure that there should be something like that, but I can't find it. Thanks in advance, Anne

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ASIO Win32 Thread not terminated
by Manuel Drews 16 Sep '10

16 Sep '10

Hi all, I have a question regarding boost::asio: if I run the example boost_asio/example/http/client/async_client.cpp on a Windows 7 or Vista and set a breakpoint on the very last line (return 0;), VisualStudio tells me that (apart from the Main Thread) two Threads named Win32 Thread are still running. Since the whole ASIO code is within the try block, everything connected to the sockets should be terminated when leaving the block, right? I get this behaviour also in a custom project, where I explicitly call close on the socket. My concern is, that a project which uses a lot of socket connections will end up with a dozen or more lingering threads. How can I avoid that? Thanx in advance Manuel -- GMX DSL SOMMER-SPECIAL: Surf & Phone Flat 16.000 für nur 19,99 Euro/mtl.!* http://portal.gmx.net/de/go/dsl

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Boost.math statistical distributions - testing inverse gamma and inverse chi squared and Bayesan examples - help wanted.
by Paul A. Bristow 16 Sep '10

16 Sep '10

I am working on adding (by popular request;-) a few more statistical distributions inverse gamma and inverse chi squared are close to being done. But I would be most grateful for help with 1 A few spot test values to check that I haven't made mistakes. Ideally I'd like some very accurate values from the ultimate reference Wolfram Mathematica, or perhaps an R add-on (not in main release?). If anyone can spare a moment to evaluate a few values for me please email me privately. 2 I have some suggestions for an example of using these distribution(s), but would like others. (We like to provide a real-life example of statistics in action in our documentation). Do any you followers of the Reverend Bayes have any suggestions for examples, preferably fully worked through from raw data? Thanks Paul PS If there are other distributions for which there are 'popular requests', now is the moment to ask ;-) --- Paul A. Bristow, Prizet Farmhouse, Kendal LA8 8AB UK +44 1539 561830 07714330204 pbristow(a)hetp.u-net.com

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[asio] An error occured in asio::win_mutex.hpp
by Yasuhiko Yoshimura (informax.co.jp) 16 Sep '10

16 Sep '10

Hi ALL, I have encountered this error, and would like to program a win32 FTP client with asio lib. In asio examples I reffenrenced at the 'Services(logger program)'. Could you help me ? I appriciate any suggestion. Thank all, Yasuhiko Yoshimura (Japan) An accsess violence occured at the below ===>> point. win_mutex.hpp:line 125: ------------------------------------------------------------------------ Then variable values are: &crit_section_ 0xcdcdcdcd this 0xcdcdcdcd (boost::noncopyable_::noncopyable) // Locking must be performed in a separate function to lock() since the // compiler does not support the use of structured exceptions and C++ // exceptions in the same function. int do_lock() { __try { ===>> ::EnterCriticalSection(&crit_section_); } __except(GetExceptionCode() == STATUS_INVALID_HANDLE || GetExceptionCode() == STATUS_NO_MEMORY ? EXCEPTION_EXECUTE_HANDLER : EXCEPTION_CONTINUE_SEARCH) { if (GetExceptionCode() == STATUS_NO_MEMORY) return ERROR_OUTOFMEMORY; return ERROR_INVALID_HANDLE; } return 0; } ------------------------------------------------------------------------ Here are my codes below. And error point was ===>> ------------------------------------------------------------------------ using boost::asio::ip::tcp; class ftp_client_dtp : public boost::enable_shared_from_this<ftp_client_dtp> { public: typedef boost::shared_ptr<ftp_client_dtp> pointer; static pointer create(boost::asio::io_service& io_service) { return pointer(new ftp_client_dtp(io_service)); } tcp::socket& socket() { return *work_socket_; } ... void start() { work_thread_.reset(new boost::thread( boost::bind(&boost::asio::io_service::run, &work_io_service_))); // Start an asynchronous resolve to translate the server and service names // into a list of endpoints. tcp::resolver::query query(sip_, sport_); work_resolver_->async_resolve(query, boost::bind(&ftp_client_dtp::handle_resolve, shared_from_this(), boost::asio::placeholders::error, boost::asio::placeholders::iterator)); } void close() { work_io_service_.post(boost::bind(&ftp_client_dtp::do_close, shared_from_this())); } ftp_client_dtp(boost::asio::io_service& io_service) : work_io_service_(), work_resolver_(new boost::asio::ip::tcp::resolver(work_io_service_)), work_socket_(new boost::asio::ip::tcp::socket(work_io_service_)) ===>> { } ~ftp_client_dtp() { work_.reset(); if (work_thread_) work_thread_->join(); } private: std::ofstream f; void handle_resolve(const boost::system::error_code& err, tcp::resolver::iterator endpoint_iterator) { ... } void handle_connect(const boost::system::error_code& err, tcp::resolver::iterator endpoint_iterator) { ... } void handle_read_content(const boost::system::error_code& err) { ... } void do_close() { work_socket_->close(); } std::string sip_, sport_, scurrentpath_, sfilename_; boost::asio::streambuf request_; boost::asio::streambuf response_; boost::scoped_ptr<boost::asio::ip::tcp::resolver> work_resolver_; boost::scoped_ptr<boost::asio::ip::tcp::socket> work_socket_; boost::asio::io_service work_io_service_; boost::scoped_ptr<boost::asio::io_service::work> work_; boost::scoped_ptr<boost::thread> work_thread_; }; ftp_client_dtp::pointer new_connection_; new_connection_ = ftp_client_dtp::create(io_service_); new_connection_->start(); ------------------------------------------------------------------------ Thank all, Yasuhiko Yoshimura (Japan)

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upgrade_to_unique_lock doesn't compile with vc2010
by Braden McDaniel 16 Sep '10

16 Sep '10

Using Boost 1.43, this program: # include <boost/thread.hpp> int main() { boost::shared_mutex mutex; boost::upgrade_lock<boost::shared_mutex> lock(mutex); boost::upgrade_to_unique_lock<boost::shared_mutex> write_lock(lock); } ... produces this error when compiled with Visual C++ 2010: C:\Users\braden>cl /I include/boost-1_43 /MD /EHsc upgrade_to_unique_lock_test.cpp Microsoft (R) C/C++ Optimizing Compiler Version 16.00.30319.01 for x64 Copyright (C) Microsoft Corporation. All rights reserved. upgrade_to_unique_lock_test.cpp include/boost-1_43\boost/thread/locks.hpp(823) : error C2679: binary '=' : no operator found which takes a right-hand operand of type 'boost::unique_lock<Mutex>' (or there is no acceptable conversion) with [ Mutex=boost::shared_mutex ] include/boost-1_43\boost/thread/locks.hpp(659): could be 'boost::upgrade_lock<Mutex> &boost::upgrade_lock<Mutex>::operator =(boost::upgrade_lock<Mutex>&)' with [ Mutex=boost::shared_mutex ] include/boost-1_43\boost/thread/locks.hpp(710): or 'boost::upgrade_lock<Mutex> &boost::upgrade_lock<Mutex>::operator =(boost::detail::thread_move_t<T>)' with [ Mutex=boost::shared_mutex, T=boost::upgrade_lock<boost::shared_mutex> ] include/boost-1_43\boost/thread/locks.hpp(717): or 'boost::upgrade_lock<Mutex> &boost::upgrade_lock<Mutex>::operator =(boost::detail::thread_move_t<T>)' with [ Mutex=boost::shared_mutex, T=boost::unique_lock<boost::shared_mutex> ] while trying to match the argument list '(boost::upgrade_lock<Mutex>, boost::unique_lock<Mutex>)' with [ Mutex=boost::shared_mutex ] include/boost-1_43\boost/thread/locks.hpp(820) : while compiling class template member function 'boost::upgrade_to_unique_lock<Mutex>::~upgrade_to_unique_lock(void)' with [ Mutex=boost::shared_mutex ] upgrade_to_unique_lock_test.cpp(7) : see reference to class template instantiation 'boost::upgrade_to_unique_lock<Mutex>' being compiled with [ Mutex=boost::shared_mutex ] I've searched a bit for previous reports of this sort of thing and I haven't found any. Hopefully that means I'm just doing something wrong. -- Braden McDaniel <braden(a)endoframe.com>

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selective enabling/disabling of BOOST_AUTO_TEST_CASE
by Suresh Kumar 16 Sep '10

16 Sep '10

Hi I have several tests in my unit test file each of them uniquely named using the function BOOST_AUTO_TEST_CASE. I may not need to run all of them always and as of now what I do is to comment out the tests which I dont want to run. Instead of commenting out code, is there any other way I can selectively enable or disable tests if i have created tests with BOOST_AUTO_TEST_CASE. thanks suresh -- R Suresh Kumar, http://www.ee.ucr.edu/~sramachandranna -- Dhyaana–moolam Guror murtih Puja-moolam Guroh padam Mantra – moolam Guror vakyam Moksha – moolam Guroh krpa.

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[Parameter] abstract base class
by Noah Roberts 15 Sep '10

15 Sep '10

I have a design in which I must inherit from a class with a whole lot of construction parameters. I need to have a pure virtual function in the class that inherits from this thing and is then provided by subclasses. Since the classes in question must all accept this huge list of construction parameters I would like to use named parameters. Unfortunately there's a problem caused by the attempt to create a function pointer declaration that takes the base class by value. I don't really understand why this is going on. Instead of just calling the base's constructor directly, the BOOST_PARAMETER_CONSTRUCTOR macro creates a type resolution instantiation with this: boost::parameter::aux::unaryfunptr_arg_type< void(*)(B) >::type 'B' being the base class. This explodes if B is an abstract class. Both g++ 3.4.5 (mingw) and VS2010 hate this line. Before I go about attempting to devise a workaround, what is the purpose of this strange bit of code? Why not just use 'B' directly?? The type resolution metafunction simply returns the 'B' place argument as its type anyway... I note some weird workaround code for ancient versions of MSVC but they seem to be created to make this type resolution thing work, not because 'B' is not known or something. However, I figure the people who wrote this library are smarter and more knowlegeable than I so the fact that I see no need for this code is probably my problem and not a reflection of it being unnecessary. -- http://crazyeddiecpp.blogspot.com/

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Read from serial devices on USB
by Alejandro Martínez 15 Sep '10

15 Sep '10

Hi, I'm trying to communicate with a usb serial device plugged to a USB port. I've seen some examples with boost::asio and connecting to ie: /dev/ttyUSB0 for linux, or COM1 for windows etc. But i need something more robust and multiplatform. Like listing all the available devices and choosing by looking at the vendor id, or device id or something like that. How can i do that? Can this same approach be used later for say... bluetooth serial devices? How? Thank you all in advance. Alejandro

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M68K-Coldfire: Boost 1.44 seems to have a problem with low level locking
by Andreas Wehrmann 15 Sep '10

15 Sep '10

Hello, I recently upgraded boost on my embedded linux platform (m68k coldfire architecture) from version 1.41 (cmake release) to 1.44. Boost itself compiles flawlessly but when I tried to link my application (which makes use of the thread, regex, system libraries) it fails with (note the last line): squ_loopback_timer.o: In function `boost::asio::detail::wait_handler<boost::_bi::bind_t<void, boost::_mfi::mf1<void, rapp::squ_loopback_timer_t, boost::system::error_code const&>, boost::_bi::list2<boost::_bi::value<rapp::squ_loopback_timer_t*>, boost::arg<1> > > >::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code, unsigned int)': squ_loopback_timer.cpp:(.text._ZN5boost4asio6detail12wait_handlerINS_3_bi6bind_tIvNS_4_mfi3mf1IvN4rapp20squ_loopback_timer_tERKNS_6system10error_codeEEENS3_5list2INS3_5valueIPS8_EENS_3argILi1EEEEEEEE11do_completeEPNS1_15task_io_serviceEPNS1_25task_io_service_operationESA_j[boost::asio::detail::wait_handler<boost::_bi::bind_t<void, boost::_mfi::mf1<void, rapp::squ_loopback_timer_t, boost::system::error_code const&>, boost::_bi::list2<boost::_bi::value<rapp::squ_loopback_timer_t*>, boost::arg<1> > > >::do_complete(boost::asio::detail::task_io_service*, boost::asio::detail::task_io_service_operation*, boost::system::error_code, unsigned int)]+0x72): undefined reference to `__sync_lock_test_and_set_4' What changed about the locking mechanism? Btw. I'm also using boost version 1.38 in another project (but on the same platform). My compiler is g++ version 4.2.0 20070318 (prerelease) (Sourcery G++ Lite 4.2-35). Any hints or help is appreciated! Best regards -- Dipl.-Ing. (FH) Andreas Wehrmann Software Development -------------------------------------------------------------- Center Communication Systems GmbH A-1210 Wien, Ignaz-Köck-Straße 19 Sitz in Wien FN 796 88p, Firmenbuchgericht Wien www.centersystems.com Tel.: +43 (0) 190 199 - 3616 Mobile: +43 (0) 664 884 75916 Fax: +43 (0) 190 199 - 2110 E-Mail: a.wehrmann(a)centersystems.com ---------------------------------------------------------------- This message was sent using IMP, the Internet Messaging Program.

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[asio] io_service::work and cpu load
by Daniele Barzotti 15 Sep '10

15 Sep '10

Hi, in my DLL I create an endless io_service::work object to assign to a serial_port. I noted that, when I load the application that uses this DLL my CPU load raise up to 50% only when the io_service is created. Any suggestions? regards, Daniele.

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Building PBGL
by David Doria 15 Sep '10

15 Sep '10

I downloaded PBGL from here: http://osl.iu.edu/research/pbgl/ <http://osl.iu.edu/research/pbgl/>When running CMake, it said that it couldn't find boost_mpi. I read that I need to do ./bjam --with-mpi I did that and it seemed to be successful (though very very quick): -------------------- Component configuration: ... - mpi : building ... ...found 1 target... The Boost C++ Libraries were successfully built! -------------------- So my questions are: 1) Does PBGL not come with the normal boost package from sourceforge ( http://sourceforge.net/projects/boost/files/boost/1.44.0/)? 2) How can I tell if boost_mpi built properly? Thanks, David

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Re: [Boost-users] Why doesn't boost::function use get_pointer() ?
by Peter Soetens 15 Sep '10

15 Sep '10

On Tuesday 14 September 2010 23:47:41 Steven Watanabe wrote: > AMDG > > Peter Soetens wrote: > > When using boost::bind, I can write this: > > > > struct X > > { > > void foo(int) {} > > }; > > > > shared_ptr<X> x( new X ); > > // bind takes shared_ptr: > > bind(&X::foo, x, 3)(); > > > > But I can't write this: > > > > function<void(X*,int)> foo = &X::foo; > > // function refuses shared_ptr: > > foo(x,1); > > > > Why doesn't boost::function have the same get_pointer() trick ? > > Overload resolution for calling a boost::function is exactly the > same as for calling a function with that signature. shared_ptr<X> > is not convertible to X*, so the call fails. So this is by design I presume. > > > Or how can I > > rewrite the function signature such that it does work with shared > > pointers ? > > function<void(const shared_ptr<X>&, int)> foo; Thank you. The problem was that I didn't know if the first argument was a regular pointer or a shared pointer (generic code!). I have also found another solution, that is, by 'always' writing the call like this: foo(get_pointer(x),1); Which will work for all cases of x, and the signature of foo can remain void(X*,int). Peter

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[BGL] changes in graph => changes in filtered_graph?
by Adam Spargo 15 Sep '10

15 Sep '10

Hi, Just a simple question - if I have a filtered_graph fg, based on adjacency_list g, do changes to g automagically turn up in fg? Or do I need to make a new fg, once I have finished changing g? I know I could write a simple test to find out, which I am doing, but I'd be grateful if someone with more experience of BGL could let me know of any exceptions or potential pitfalls. Thanks in advance, Adam. -- Dr Adam Spargo High Performance Assembly Group email: aws(a)sanger.ac.uk Wellcome Trust Sanger Institute Tel: +44 (0)1223 834244 x7728 Hinxton, Cambridge CB10 1SA Fax: +44 (0)1223 494919 -- The Wellcome Trust Sanger Institute is operated by Genome Research Limited, a charity registered in England with number 1021457 and a company registered in England with number 2742969, whose registered office is 215 Euston Road, London, NW1 2BE.

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[Filesystem] v3: preferred() vs. make_preferred()
by PB 15 Sep '10

15 Sep '10

Hello, I have built up a path in which the underlying string has a mixture of slashes and backslashes. I'm passing my_path.string().c_str() to a Windows API function which is getting confused because the string is being provided verbatim. I'm therefore looking to convert the string. According to the Filesystem tutorial (http://www.boost.org/doc/libs/1_44_0/libs/filesystem/v3/doc/tutorial.html) I can use the preferred() observer method to get the string that is suitable for the current (Windows) platform. This sounds like quite a nice design. However, it seems the preferred() method doesn't exist (i.e. the tutorial is wrong). There is a make_preferred() method which is non-const because it *changes the underlying representation* to the format preferred by the operating system. >From my application developer point of view, the preferred() observer is neater/better. I don't care and don't need to know what the underlying path format is. I have no desire to change it. All I am bothered about is that I can store it to a string (perhaps in an external file), and reconstruct the path from the same string. There are a few points in the application however where I need to present the path in a particular way, and it'd be nice to just throw a call to preferred() there. e.g. listBox_.AddString(my_path.preferred().c_str()); I've now got to do: bfs::path pref = my_path; pref.make_preferred(); listBox_.AddString(pref.string().c_str()); because the function that does the rendering of the string to the list box accepts the path as a const boost::filesystem::path& and therefore cannot change it. Wanted to point out the mismatch between the tutorial and the source code, and am wondering on the rationale behind make_preferred() over preferred()? Always possible I'm missing something! Thanks, Pete

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boost::bind correct way
by Kraus Philipp 15 Sep '10

15 Sep '10

Hi, I'm using boost::bind for creating a thread group. My code shows this way: boost::thread_group l_threadgroup; for(std::size_t i=0; i < boost::thread::hardware_concurrency(); ++i) l_threadgroup .create_thread( boost::bind( &ncd<T>::multithread_deflate_symmetric, this, i ) ); The code runs within the class method "symmetric" and should be called from the self object the multithread_deflate_symmetric. My class "ncd" is a template class. I debug the code on a amd64 Gentoo Linux with valgrind 3.5 and get a "data race condition". Valgrind shows this message: ==6914== Possible data race during read of size 8 at 0x7fefff6d0 by thread #1 ==6914== at 0x4C2B138: ??? (in /usr/lib64/valgrind/ vgpreload_helgrind-amd64-linux.so) ==6914== by 0x6152B10: boost::thread::start_thread() (in /opt/ library/Boost/1.44/lib/libboost_thread.so.1.44.0) ==6914== by 0x414B50: boost::thread::thread<boost::_bi::bind_t<void, boost::_mfi::mf1<void, ncd<double>, unsigned long const&>, boost::_bi::list2<boost::_bi::value<ncd<double>*>, boost::_bi::value<unsigned long> > > >(boost::_bi::bind_t<void, boost::_mfi::mf1<void, ncd<double>, unsigned long const&>, boost::_bi::list2<boost::_bi::value<ncd<double>*>, boost::_bi::value<unsigned long> > >, boost::disable_if<boost::is_convertible<boost::_bi::bind_t<void, boost::_mfi::mf1<void, ncd<double>, unsigned long const&>, boost::_bi::list2<boost::_bi::value<ncd<double>*>, boost::_bi::value<unsigned long> > >&, boost::detail::thread_move_t<boost::_bi::bind_t<void, boost::_mfi::mf1<void, ncd<double>, unsigned long const&>, boost::_bi::list2<boost::_bi::value<ncd<double>*>, boost::_bi::value<unsigned long> > > > >, boost::thread::dummy*>::type) (in main) ==6914== by 0x419F4D: ncd<double>::symmetric(std::vector<std::string, std::allocator<std::string> > const&, bool const&) (in main) ==6914== by 0x40B10F: main (in main) ==6914== This conflicts with a previous write of size 8 by thread #2 ==6914== at 0x4C2B263: ??? (in /usr/lib64/valgrind/ vgpreload_helgrind-amd64-linux.so) Do I use boost::bind in the correct way? Thanks Phil

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Property Tree problem with equal range.
by Andrew Maclean 14 Sep '10

14 Sep '10

I am using Boost 1.43 and last line in the following code causes this error: /usr/local/include/boost/property_tree/detail/ptree_implementation.hpp:471: error: ‘class boost::multi_index::detail::bidir_node_iterator<boost::multi_index::detail::ordered_index_node<boost::multi_index::detail::index_node_base<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::property_tree::basic_ptree<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, std::allocator<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, boost::property_tree::basic_ptree<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > > > > >’ has no member named ‘base’ Here is the code fragment. pt is the property tree. std::string key = "program.query"; std::size_t num = pt->count(key); std::cout << "Number = " << num << std::endl; typedef boost::property_tree::ptree::assoc_iterator assocIt; typedef std::pair< assocIt, assocIt > TRangeItPair; TRangeItPair er = pt->equal_range(key); The only fix I could see was here: http://lists.boost.org/boost-users/2010/02/55806.php But I cannot see how to apply it to the above code fragment. Any help is appreciated. Regards Andrew -- ___________________________________________ Andrew J. P. Maclean Centre for Autonomous Systems The Rose Street Building J04 The University of Sydney 2006 NSW AUSTRALIA Ph: +61 2 9351 3283 Fax: +61 2 9351 7474 URL: http://www.acfr.usyd.edu.au/ ___________________________________________

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Why doesn't boost::function use get_pointer() ?
by Peter Soetens 14 Sep '10

14 Sep '10

When using boost::bind, I can write this: struct X { void foo(int) {} }; shared_ptr<X> x( new X ); // bind takes shared_ptr: bind(&X::foo, x, 3)(); But I can't write this: function<void(X*,int)> foo = &X::foo; // function refuses shared_ptr: foo(x,1); Why doesn't boost::function have the same get_pointer() trick ? Or how can I rewrite the function signature such that it does work with shared pointers ? Any chance it gets into C++0x ;-) ? Thanks, Peter

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[Filesystem] query
by Sean Farrow 14 Sep '10

14 Sep '10

Hi: I have a path of the form: Drive\directory1\directory2, how would I go about retrieving the second directory only i.e in this example directory2? Is this the same code in filesystem 2 and 3? Regards Sean.

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Building FileSystem Version 3 static libraries
by Bibbo, Joe 14 Sep '10

14 Sep '10

I have downloaded the boost v1.44 and would like to see if our usage of the FileSystem library is compatible with Version 3 of library. I am having trouble building the library. Using the command bjam toolset=msvc-9.0 variant=debug threading=multi link=static define=_BIND_TO_CURRENT_VCLIBS_VERSION define=BOOST_FILESYSTEM_VERSION=3 --with-filesystem I am seeing following error message " .. compile-c-c++ bin.v2\libs\system\build\msvc-9.0\debug\link-static\threading-multi\error_code.obj error_code.cpp msvc.archive bin.v2\libs\system\build\msvc-9.0\debug\link-static\threading-multi\libboost_system-vc90-mt-gd-1_44.lib common.copy stage\lib\libboost_system-vc90-mt-gd-1_44.lib bin.v2\libs\system\build\msvc-9.0\debug\link-static\threading-multi\libboost_system-vc90-mt-gd-1_44.lib 1 file(s) copied. compile-c-c++ bin.v2\libs\filesystem\build\msvc-9.0\debug\link-static\threading-multi\v2\src\v2_operations.obj v2_operations.cpp S:\sony4\boost\boost_1_44_0\boost/filesystem/v2/config.hpp(16) : fatal error C1189: #error : Compiling Filesystem version 2 file with BOOST_FILESYSTEM_VERSION defined != 2 call "G:\Program Files\Microsoft Visual Studio 9.0\VC\vcvarsall.bat" x86 >nul cl /Zm800 -nologo @"bin.v2\libs\filesystem\build\msvc-9.0\debug\link-static\threading-multi\v2\src\v2_operations.obj.rsp" ...failed compile-c-c++ bin.v2\libs\filesystem\build\msvc-9.0\debug\link-static\threading-multi\v2\src\v2_operations.obj... compile-c-c++ bin.v2\libs\filesystem\build\msvc-9.0\debug\link-static\threading-multi\v2\src\v2_path.obj v2_path.cpp S:\sony4\boost\boost_1_44_0\boost/filesystem/v2/config.hpp(16) : fatal error C1189: #error : Compiling Filesystem version 2 file with BOOST_FILESYSTEM_VERSION defined != 2 call "G:\Program Files\Microsoft Visual Studio 9.0\VC\vcvarsall.bat" x86 >nul cl /Zm800 -nologo @"bin.v2\libs\filesystem\build\msvc-9.0\debug\link-static\threading-multi\v2\src\v2_path.obj.rsp" ...failed compile-c-c++ bin.v2\libs\filesystem\build\msvc-9.0\debug\link-static\threading-multi\v2\src\v2_path.obj... compile-c-c++ bin.v2\libs\filesystem\build\msvc-9.0\debug\link-static\threading-multi\v2\src\v2_portability.obj v2_portability.cpp S:\sony4\boost\boost_1_44_0\boost/filesystem/v2/config.hpp(16) : fatal error C1189: #error : Compiling Filesystem version 2 file with BOOST_FILESYSTEM_VERSION defined != 2 call "G:\Program Files\Microsoft Visual Studio 9.0\VC\vcvarsall.bat" x86 >nul cl /Zm800 -nologo @"bin.v2\libs\filesystem\build\msvc-9.0\debug\link-static\threading-multi\v2\src\v2_portability.obj.rsp" ... " Is there something else I need to configure to build this version of the library? Regards, Joe

4 4

[Unordered] size() != distance(begin(), end())
by Hossein Haeri 14 Sep '10

14 Sep '10

Dear all, I have an instance of boost::unordered_map<> somewhere in my codebase (GCC 4.5.1, MinGW, WinXP) with the following funny piece of test code: container_[id].insert(v); cout << "container insertion succesful" << endl; cout << "The container now contains " << container_.size() << " ids in it." << endl; cout << "distance from begin to end = " << distance(container_.begin(), container_.end()) << endl; Strangely enough, it happens sometimes that the output I get is: container insertion succesful The container now contains 2 ids in it. distance from begin to end = 1 I.e., size() != distance(begin(), end()) which is against the documentation: http://www.boost.org/doc/libs/1_44_0/doc/html/boost/unordered_map.html#id13… Am I missing anything? Or, is this a bug in the implementation of boost::unordered_map<>? TIA, --Hossein

2 2

Is there still a way to explicitly compose functors ?
by Timothy Madden 14 Sep '10

14 Sep '10

Hello I just do not like the ugly syntax with using the _1 placeholder (or _2, or whatever) used in bind and lambda; is there still some other way to compose functors ? Like with compose ? Thank you, Timothy Madden

2 3

How to use %e for the format of time_input_facet?
by xiada74＠sina.com 14 Sep '10

14 Sep '10

Hello,   I tried the below code: #include <boost/date_time.hpp> #include <boost/date_time/posix_time/ptime.hpp> #include <iostream> using namespace boost::posix_time; int main() { std::string _format1 = "%Y-%m-%d %H:%M:%S"; std::string _format2 = "%Y-%m-%e %H:%M:%S"; std::string teststring = "2010-09-10 10:01:01"; ptime time1, time2; time_input_facet facet1(_format1, 1); time_input_facet facet2(_format2, 1); std::stringstream ss1(teststring); std::stringstream ss2(teststring); ss1.imbue(std::locale(ss1.getloc(), &facet1)); ss1 >> time1; ss2.imbue(std::locale(ss2.getloc(), &facet2)); ss2 >> time2; std::cout << "Time1: " << time1 << std::endl; std::cout << "Time2: " << time2 << std::endl; return 0; } The output is: Time1: 2010-Sep-10 10:01:01 Time2: not-a-date-time   Howto fix the issue for the format using "%e"?   Thanks!

1 0