May 2008 - Boost-users - lists.preview.boost.org

Exposing C++ Functions with Container Arguments in Boost.Python
by Bilokon, Paul 11 May '08

11 May '08

[This question is about Boost.Python. If there is a more approprate mailing list to send it to, please do let me know.] Hi all, This is probably a trivial question, but after some research I was unable to find a "best practice" answer, so my sincere apologies. I am trying to expose a C++ function which takes an std::vector<double> as its argument, some void A::foo(std::vector<double> v); And perhaps void A::bar(std::vector<double> & v); Whether it is a good practice to have such arguments is, of course, open to debate (shouldn't they be iterators?), but this is what I have to work with. The question remains, what is the best way to expose these to python? I cannot pass a Python list -- it's a type mismatch. Many thanks! Regards, Paul - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - This message is intended only for the personal and confidential use of the designated recipient(s) named above. If you are not the intended recipient of this message you are hereby notified that any review, dissemination, distribution or copying of this message is strictly prohibited. This communication is for information purposes only and should not be regarded as an offer to sell or as a solicitation of an offer to buy any financial product, an official confirmation of any transaction, or as an official statement of Lehman Brothers. Email transmission cannot be guaranteed to be secure or error-free. Therefore, we do not represent that this information is complete or accurate and it should not be relied upon as such. All information is subject to change without notice.

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read/write lock for concurrent access
by Selçuk Giray Özdamar 11 May '08

11 May '08

Hi everyone, Does boost supports for CREW(concurrent read/exclusive write) model for preventing race conditions? Also in another words does it support read/write lock ? Tnx... ---Sgo--- Selçuk Giray ÖZDAMAR - Araştırmacı TÜBİTAK Marmara Araştırma Merkezi - Bilişim Teknolojileri Enst. *selcuk.ozdamar(a)bte.mam.gov.tr |( +90 262 677 (2518)

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[bgl] graphML support and non PIC expat library
by come raczy 11 May '08

11 May '08

Hello, Is there any way to build the bgl with graphml support, using an expat static lib which has been compiled without the '--with-pic' configure option? I am asking because the expat static library provided by ubuntu 8.04 is compiled for non PIC object. Therefore, I was wondering if there were better solutions than either recompiling expat or linking the bgl to the shared expat library. Cheers Come

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Asio & inter-thread events
by TD 11 May '08

11 May '08

Hello, I encounter many scenarios where a thread needs to sleep on both an IO event and a logical event. Here's a common case. Thread A is an IO thread. It gets data from a socket, puts it in a buffer pool, and notifies thread B. Thread B is a worker thread. It calculates stuff, then returns buffers to the pool. It follows then that thread A sometimes sleeps on IO (when waiting for socket data), and sometimes sleeps waiting for the pool to become non-empty. It would be nice if there were a uniform way for the thread to sleep on stuff. For example, using Windows API, a completion port can be used to sleep on both a socket and an event object. In UNIX, thread A could select both a socket (for data) and a pipe. I don't, however, understand how to do so cleanly using asio. Anything that I can think up doubles up the size/complexity of the code, and seems to use more system calls. I'd appreciate any suggestions. Thanks, TD

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using std::wstring in serialization
by Dennis Yurichev 10 May '08

10 May '08

Hello, I'm looking on possibility to use std::wstring in serialization. Here is a simple example which I try to compile: #define UNICODE #include <windows.h> #include <assert.h> #include <stdio.h> #include <string> #include <map> #include <iostream> #include <fstream> #include <boost/config.hpp> #include <boost/archive/binary_oarchive.hpp> #include <boost/archive/binary_iarchive.hpp> #include <boost/serialization/map.hpp> #include <boost/serialization/string.hpp> int main() { std::map<std::wstring, std::wstring> t; std::ofstream ofs ("test.dat", std::ios::trunc | std::ios::binary ); boost::archive::binary_oarchive oa(ofs); assert (ofs.good()); t[L"asd"]=L"test"; oa << t; ofs.close(); }; I use latest downloaded boost and mingw 3.4.5. I got such error: c:/boost/boost/serialization/access.hpp: In static member function `static voidboost::serialization::access::serialize(Archive&, T&, unsigned int) [with Archive = boost::archive::binary_oarchive, T = std::basic_string<wchar_t, std::char_tr aits<wchar_t>, std::allocator<wchar_t> >]': c:/boost/boost/serialization/serialization.hpp:81: instantiated from `void boost::serialization::serialize(Archive&, T&, unsigned int) [with Archive = boost::archive::binary_oarchive, T = std::basic_string<wchar_t, std::char_traits<wchar_ t>, std::allocator<wchar_t> >]' c:/boost/boost/serialization/serialization.hpp:140: instantiated from `void boost::serialization::serialize_adl(Archive&, T&, unsigned int) [with Archive = boost::archive::binary_oarchive, T = std::basic_string<wchar_t, std::char_traits<w char_t>, std::allocator<wchar_t> >]' c:/boost/boost/archive/detail/oserializer.hpp:151: instantiated from `void boost::archive::detail::oserializer<Archive, T>::save_object_data(boost::archive::detail::basic_oarchive&, const void*) const [with Archive = boost::archive::binar y_oarchive, T = std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >]' test.cpp:96: instantiated from here c:/boost/boost/serialization/access.hpp:109: error: 'struct std::basic_string<wchar_t, std::char_traits<wchar_t>, std::allocator<wchar_t> >' has no member named 'serialize' So, what the right way to use wstring here? -- My PGP public key: http://yurichev.com/dennis.yurichev.asc

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Boost Bimap Question
by Surya Kiran Gullapalli 10 May '08

10 May '08

Hello, I've started using boost bimap recently and i encountered a problem. With the standard c++ containers, I can always use forward declaration of my classes in the interface files (header files) and then include the appropriate header files in the implementation files (source files). With boost bimap this seems to be not possible. Lets say I've MyClass and I do like this. ---------------------------- class MyClass boost::bimap<string, MyClass> my_bimap ; -------------------------- The compiler spits out a lot of error messages. But If i avoid forward declaration and include MyClass header file before declaring boost::bimap, every thing is normal. Is there any way I can avoid this header file inclusion just use forward declaration ? Thanks in advance, Surya

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testing for multi_index equality
by Ted Pederson 09 May '08

09 May '08

Is there an easy way to test two multi_index containers for equality, c1 == c2?

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Re: [Boost-users] asio: handshaking crashes
by gfsdjkgf＠Safe-mail.net 09 May '08

09 May '08

ok, i use a this instead of a shared_from_this(). Now it works. I still need an answer for question 1 though...

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Re: [Boost-users] asio: handshaking crashes
by gfsdjkgf＠Safe-mail.net 09 May '08

09 May '08

Ok, I know where the server crashes now. int SSL_accept(SSL *s) { if (s->handshake_func == 0) /* Not properly initialized yet */ SSL_set_accept_state(s); return(s->method->ssl_accept(s)); } the application cannot access ssl_accept. Apparently s->method is "invalid".

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asio: handshaking crashes
by gfsdjkgf＠Safe-mail.net 09 May '08

09 May '08

Hello, i want to etablish a secure communication between my client and my server. To do so, I use boost.asio with openssl. First question: Do I have to build and include the openssl library libraries on my own (I do so now and it is working fine...)? Second question: The ssl-context for server and client is: ssl::context Context(IOService, ssl::context::sslv23); Context.set_options(ssl::context::default_workarounds); Context.set_verify_mode(ssl::context::verify_none); the client simply connects to the (listening) server pSSLSocket->lowest_layer().connect(ip::tcp::endpoint(ip::address_v4(acIP),999)); pSSLSocket->handshake(ssl::stream_base::client); the server executes an async_handshake if it accepts a new connection m_SSLSocket.async_handshake(ssl::stream_base::server, bind(&CConnection::OnHandshake, this, placeholders::error)); Unfortunately the async_handshake call (or the corresponding run call) fails. I am not sure why as I am not able to attach a debugger to my application, but the application definitely crashes. What's wrong?

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