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Boost Based Proxy
by asim 29 Jul '14

29 Jul '14

In SSl case proxy will become a tunnel so whatever encrypted data i will get from client i have to forward it to server.But i am unable to read content as connection is keep alive (means no end of file exception) and due to encryption no header based reading i can do then how to read it. -- View this message in context: http://boost.2283326.n4.nabble.com/Boost-Based-Proxy-tp4665704.html Sent from the Boost - Users mailing list archive at Nabble.com.

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[Serialization] XML: Necessity of attribute class_id although class_name is given
by Frank Stähr 29 Jul '14

29 Jul '14

Hello everybody, I would like to know what the purpose of the xml attribute class_id is, how it works and in which cases it can be omitted. An example: “Base” is the (abstract) base class of _GMTF_ and _TTF_, and _Hist_ also has got a similar base class. If a pointer of Hist is a member of GMTF and you want to serialize a pointer of Base, you get something like: <filter class_id="0" class_name="GMTF"> <m_bufHalfMaxSize>4</m_bufHalfMaxSize> <m_cutDetector class_id="1" class_name="Hist"></m_cutDetector> </filter> Here, the macros • BOOST_CLASS_EXPORT_GUID(...), • BOOST_CLASS_IMPLEMENTATION(..., boost::serialization::object_serializable) and • BOOST_CLASS_TRACKING(..., boost::serialization::track_never) are used. The problem now is: Although the exact classes are given by human-readable class names (and used!), you cannot omit or change the class_id. If you edit the XML file by hand, it can become invalid (-> exception on reading). It seems that the class ids are just ascending non-negative numbers. What are the rules for choosing the class ids? Why are they necessary? Is there a trick to remove this attribute or at least to ignore it? Thanks, Frank -- Frank Stähr Technische Universität Berlin Communication Systems Group Sekr. EN1 Einsteinufer 17 10587 Berlin, Germany

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Pipe and Filters pattern with boost?
by Journeyer J. Joh 29 Jul '14

29 Jul '14

Hello list! I'd like to find a good approach to implement the Pipe and Filters pattern with boost. Could someone recommend me some useful boost library for this purpose? I only know asio. Is there any known example source code for this - Pipe and Filters pattern with boost. Thank you very much in advance! ---------------------------------------- Journeyer J. Joh o o s a p r o g r a m m e r a t g m a i l d o t c o m ----------------------------------------

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[Boost 1.56 Beta] [Serialization] Compilation problem with classes having special new operators
by Hijok Payne 28 Jul '14

28 Jul '14

I was trying out the new Boost 1.56 beta and some of my serialization code fails to compile (they work fine with previous versions of Boost e.g. Boost 1.55). I am trying to do serialization of Eigen (http://eigen.tuxfamily.org/) matrices with following code: #include <Eigen/Core> #include <fstream> #include <boost/serialization/vector.hpp> #include <boost/archive/binary_oarchive.hpp> #include <boost/archive/binary_iarchive.hpp> //Boost Serialization of Eigen Matrix namespace boost { template<class Archive, typename _Scalar, int _Rows, int _Cols, int _Options, int _MaxRows, int _MaxCols> inline void serialize(Archive & ar, Eigen::Matrix<_Scalar, _Rows, _Cols, _Options, _MaxRows, _MaxCols>& t, const unsigned int file_version) { size_t rows = t.rows(), cols = t.cols(); ar & rows; ar & cols; if (rows * cols != t.size()) t.resize(rows, cols); ar & boost::serialization::make_array(t.data(), t.size()); } } //Simple helper for serialization to a file template <typename T> bool serialize(const T& data, const std::string& filename) { std::ofstream ofs(filename.c_str(), std::ios::out | std::ios::binary); if (!ofs.is_open()) return false; { // use scope to ensure archive goes out of scope before stream boost::archive::binary_oarchive oa(ofs); oa << data; } ofs.close(); return true; } //Simple helper for de-serialization from a file template <typename T> bool deSerialize(T& data, const std::string& filename) { std::ifstream ifs(filename.c_str(), std::ios::in | std::ios::binary); if (!ifs.is_open()) return false; { // use scope to ensure archive goes out of scope before stream boost::archive::binary_iarchive ia(ifs); ia >> data; } ifs.close(); return true; } int main(int argc, char *argv[]) { typedef Eigen::Vector3d VectorType; VectorType* vec = new VectorType(1, 2, 3); serialize(vec, "v4d.dat"); std::cout << "v4d =\n" << *vec << std::endl; VectorType* vec_in; deSerialize(vec_in, "v4d.dat"); std::cout << "v4d_in =\n" << *vec_in << std::endl; return 0; } The error in Visual studio 2013 says: boost/archive/detail/iserializer.hpp(237): error C2665: 'Eigen::PlainObjectBase<Eigen::Matrix<double,3,1,0,3,1>>::operator delete' : none of the 3 overloads could convert all the argument types 2> c:\users\abhijit\codes\installs\eigen\eigen-install\include\eigen3\eigen\src/Core/PlainObjectBase.h(132): could be 'void Eigen::PlainObjectBase<Eigen::Matrix<double,3,1,0,3,1>>::operator delete(void *,const std::nothrow_t &) throw()' 2> c:\users\abhijit\codes\installs\eigen\eigen-install\include\eigen3\eigen\src/Core/PlainObjectBase.h(132): or 'void Eigen::PlainObjectBase<Eigen::Matrix<double,3,1,0,3,1>>::operator delete(void *,void *) throw()' 2> while trying to match the argument list '(VectorType *, size_t)' 2> C:\Boost\boost-1_56_0_b1\boost/archive/detail/iserializer.hpp(224) : while compiling class template member function 'void boost::archive::detail::heap_allocation<T>::has_new_operator::invoke_delete(T *)' There is also the following note, but I cannot seem to understand this. // if compilation fails here, the likely cause that the class // T has a class specific new operator but no class specific // delete operator which matches the following signature. Fix // your program to have this. Note that adding operator delete // with only one parameter doesn't seem correct to me since // the standard(3.7.4.2) says " // "If a class T has a member deallocation function named // 'operator delete' with exactly one parameter, then that function // is a usual (non-placement) deallocation function" which I take // to mean that it will call the destructor of type T which we don't // want to do here. I want to understand this issue because this breaks a lot of existing code.

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Geometry: modifiable?
by Jeremy Murphy 28 Jul '14

28 Jul '14

Is there a generic way to modify geometry structurally? Say if I have a ring and I want to insert a new point? Or would I need to reach into the underlying container to make that kind of change? Thanks, cheers. Jeremy

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[SmartPtr] enable_shared_from_raw
by Gavin Lambert 27 Jul '14

27 Jul '14

Hi all, Firstly, any chance this could get some documentation? Is the author still around? I'm thinking about using this at the moment for two separate reasons (and ways in which enable_shared_from_this seems to fall short): 1. shared_from_this can't be used from the constructor (requiring factory-method-init shenanigans); reportedly (https://groups.google.com/forum/#!topic/boost-list/8JWFZ56ry6k) shared_from_raw can, although I can't find specific details on the caveats mentioned. 2. What I *really* want to be able to do is to create a child object (most commonly a callback functor) that contains a weak_ptr, and it seems silly (and badly performant) to use the usual factory-init pattern to call shared_from_this just to degrade it back to a weak_ptr. And it should be possible to obtain that weak_ptr before any shared_ptr exists, and "fix" it later to point at the real shared_ptr, especially if it is known that the weak_ptr will never actually be used until that real shared_ptr exists. enable_shared_from_raw almost seems to fit the bill (according to http://stackoverflow.com/questions/22184772/why-is-boostenable-shared-from-…) but I encountered the same problem as in this post (http://lists.boost.org/boost-users/2013/05/78833.php) it works with shared_from_raw but not weak_from_raw. However this change: https://github.com/boostorg/smart_ptr/pull/8 fixes that. It looks like the two calls went down different code paths for some reason I can't fathom. Making this change (or the similar-but-better-style one mentioned in the PR discussion) makes the above scenario work as expected. I'm not sure if there was some specific reason to not do this before or if it was just an oversight. Any chance this can make it into 1.56? Or is it too late for that? Regards, Gavin Lambert

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[mpi] potentially blocking send - require blocking
by Dave Clarke 25 Jul '14

25 Jul '14

The boost::mpi documentation for send() is: "This routine executes a potentially blocking send" This differs from MPI_Send() "This routine will block until the message is sent to the destination." I am developing an application which requires the code not to progress until the communication is complete. In which situations does "potentially blocking" apply? And, is there a way of guaranteeing it is complete, the equivalent of MPI_Wait() for MPI_Isend()? Regards, Dave

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Compiling boost on Windows
by Freddy Martinez Garcia 24 Jul '14

24 Jul '14

Hi guys… I need compile the boost for windows but I’m not a windows user… I had made some compilation but the files generated by gcc (from MinGW) has .a extension and not .lib or .dll extension… how can I change that ?? best regard Freddy Martinez Garcia Lic. Ciencia de la Computacion C++ and Qt Senior Developer freddy311082(a)gmail.com

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unsubscribe
by Richard Greene 23 Jul '14

23 Jul '14

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[mpl] BOOST_MPL_ASSERT_MSG for static_assert
by Michael Powell 23 Jul '14

23 Jul '14

Hello, I would like to add some diagnostic messages during compile time, potentially enumerating one or more types as well. static_assert is great for simple messages but falls a bit short due to inability to list types and such. I wonder if BOOST_MPL_ASSERT_MSG is the right answer, however, I am getting the following errors: BOOST_MPL_ASSERT_MSG( std::is_base_of<xnode, Node>::value , "requested type is not a node" , (types<node_type>) ); 1>i:\source\kingdom software\cppxml\xml\domain\parts\xnode.h(111): warning C4002: too many actual parameters for macro 'BOOST_MPL_ASSERT_MSG' It's an error message, but not the one(s) I am expecting. Do I need to enable something, preprocessor definition, something like that? Best regards, Michael Powell

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