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Re: [Boost-users] Problem using serialization::xml_archive withpolymrphic classes
by przemyslaw.sliwa＠uk.bnpparibas.com 02 Sep '10

02 Sep '10

Thanks for reply, All classes a, b, c and d are actually defined within one dll (one module). I forgot to mention it. I can do this following thing: d* pD = mew d(); and then ar & boost::serialization::make_nvp("item", pD); but c* pD = new D(); ar & boost::serialization::make_nvp("item", pD); does not work at all! It throws this strange type of exceptions which I cannot handle at all. Another problem is that if I do the first version the member m_key variable of true_type in the call const boost::serialization::extended_type_info * true_type = i.get_derived_extended_type_info(t); is a null pointer which is not right. Do you have any idea what could be wrong? Thanks a lot for help ___________________________________________________________ This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and delete this e-mail. Any unauthorised copying, disclosure or distribution of the material in this e-mail is prohibited. Please refer to http://www.bnpparibas.co.uk/en/information/legal_information.asp?Code=ECAS-… for additional disclosures.

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Boost.Functional/Hash
by Andrej van der Zee 02 Sep '10

02 Sep '10

Hi, I have a question that I hope can be answered by using Boost. I have the following datastructure: struct ip_info { const u_int8_t _ifile_index; const unsigned long _src_ip; const unsigned long _dst_ip; const u_int16_t _id; const u_int16_t _length; const u_int16_t _src_port; const u_int16_t _dst_port; const u_int32_t _seq; const u_int32_t _ack_seq; }; The object is identified by all its members. Now I want to count duplicates. But I have MANY of these objects, I mean billions. I have to reduce the memory footprint of my program, because it soon grows over 4GB and boom! So I rather not keep all the objects in memory and why would I, because I do not need them. I just need to count duplicates. My idea was to hash such objects to a smaller values and use that hash value as key_type in a map. The value_type of the map would be an integer. This something like std::map<int32_t, u_int16_t> or something. Then I though maybe use Boost.Functional/Hash, but are there any guarantees that the hash value is unique? How unique are they? Are there better alternatives? Thank you, Andrej

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[BGL] Using pointers as indexes in graphs
by Bruno Barberi Gnecco 02 Sep '10

02 Sep '10

Hi, I want to store pointers in a graph. Can I somehow use their pointers as indexes? Here's the code I'm trying to execute. It does not work correctly, however; apparently graph add other nodes in the vector storage (to fill the holes?). I suppose I could use listS instead of vecS, but then I can't get the topological_sort code to work (I know I have to provide some form of indices, but I don't understand how to do that). Any suggestions to solve this? Thanks! #include <iostream> #include <boost/graph/graph_traits.hpp> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/topological_sort.hpp> class Plugin { public: // some data here int x; Plugin(int a) : x(a) {} }; typedef std::list< std::pair<Plugin *, Plugin *> > EdgeList; typedef boost::adjacency_list<boost::setS, boost::vecS, boost::directedS, Plugin *> PipelineGraph; typedef boost::graph_traits<PipelineGraph>::vertex_descriptor PipelineVertex; void graph(EdgeList edges) { PipelineGraph graph; for (EdgeList::iterator it(edges.begin()); it != edges.end(); it++) { PipelineVertex a(boost::vertex(reinterpret_cast<unsigned long> (it->first), graph)); PipelineVertex b(boost::vertex(reinterpret_cast<unsigned long> (it->second), graph)); boost::add_edge(a, b, graph); } // sort by topology, so we run the plugins in the correct order std::vector<PipelineVertex> sorted; boost::topological_sort(graph, std::back_inserter(sorted)); std::cout << sorted.size() << std::endl; // REVERSE topological order std::vector<PipelineVertex> vl(sorted.rbegin(), sorted.rend()); // loop for (std::vector<PipelineVertex>::iterator it(vl.begin()); it != vl.end(); it++) { Plugin *p = reinterpret_cast<Plugin *>(*it); std::cout << p->x << std::endl; } } int main() { EdgeList edges; Plugin *a = new Plugin(1); Plugin *b = new Plugin(2); Plugin *c = new Plugin(3); Plugin *d = new Plugin(4); edges.push_back(std::pair<Plugin*, Plugin*>(a, b)); edges.push_back(std::pair<Plugin*, Plugin*>(b, c)); edges.push_back(std::pair<Plugin*, Plugin*>(b, d)); graph(edges); return 0; }

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how to get std::min_element() working with boost::multi_array?
by Valmor de Almeida 02 Sep '10

02 Sep '10

Hello, Could someone help getting std::min_element() (or a variation of) to work with multi_array? boost::multi_array<int, 2> A; // code for dimensioning A and filling in; deleted cout << *min_element(A.begin(),A.end()) << endl; Thanks, -- Valmor

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Looking for Halfedge or other topologic representation library
by Lang Stefan 02 Sep '10

02 Sep '10

Hello everyone, While looking for an existing implementation of halfedge data structures or similar topological representations of 2-dimensional manifolds I found one article pointing to boost:graph. I've checked the documentation, but it seem that this library is way to generic/abstract for my purpose, and yet seems to miss a number of important functions that probably only make sense when working with a topological representation of a two-dimensional oriented manifold. Conceptually, Half-edge data structures would fit my needs very well, and I've found several sites with half-done or half-documented implemetations. But those that actually had code were either too specific to be useful for my purposes, or half of the site couldn't be retrieved, probably because the relevant pages are no longer hosted. So I was wondering, if there is, maybe, another library within boost that is dealing more with the topological aspect of graphs, whether or not based on boost::graph? What I am looking for is a topological framework for oriented surfaces that lets me retrieve adjacency information regarding faces, edges and vertices, disregardful of whether or not the set of surfaces represent the full surface of a 3D object or just a part of it. I also need to directly navigate between the objects defining the actual 3D points, curves, and surfaces, and the corresponding topological objects. But that, I hope, is just a minor detail. I suspect it won't be so hard to implement myself, but building on a well-designed library is so much less error prone... Cheers, Stefan

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Re: [Boost-users] does pool::release_memory() really require an ordered
by Lang Stefan 02 Sep '10

02 Sep '10

-----Ursprüngliche Nachricht----- Message: 5 Date: Wed, 1 Sep 2010 17:32:46 -0400 From: Mark Rajcok <mrajcok(a)gmail.com> To: boost-users(a)lists.boost.org Subject: [Boost-users] does pool::release_memory() really require an ordered pool? Message-ID: <AANLkTim0t9KTDJowTbn2viBu+RSTqnwfKA1c7qRbv_X2(a)mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 On page http://www.boost.org/doc/libs/1_44_0/libs/pool/doc/interfaces/pool.html there is this precondition for release_memory(): "t must be ordered". Does that mean that ordered_malloc() must always be used, if I want to use release_memory()? Looking at the implementation for release_memory(), it appears to be iterating through chunks in each block, which I wouldn't expect if ordered_malloc() were always used. What I'm really after: I want to use object_pool, but periodically I'd like to reclaim/release any memory blocks that are no longer in use. In my application, I may have traffic spikes, where I allocate a lot of memory, but then later (after spiking) I'd like to release it. (The object pools will persist for the life of the application, and there will probably always be some "active objects" -- i.e., allocated from the pool and not free()d yet.) (I'm hoping the documentation may be out of date, and release_memory() can be used on pools that don't use ordered_malloc() and on object_pools.) -- Mark ------------------------------ Mark, I cannot check the repository right now, but last time I did there were no changes to the version of boost::pool since I last tried to work with it, about three years ago. Back then I found that memory wasn't released at all due to a relevant part of the code being commented out. But even uncommenting it didn't help all that much: just like you, I found that the effort of releasing a single object was, essentially, proportional to the size of the pool, at best at an order of O(log(N)), maybe even worse. So just using standard new and delete operators would at some point outperform this pool implementation! I've done my own implementation in the meantime, with all operations at constant time, and using shared pointers to objects from the pool, which would make sure unused memory blocks can be released ASAP. Never got around to actually use it though, so I cannot say for sure if it has errors still. The tests and benchmarks I ran did look rather good, but I found that using malloc/free instead of new/delete got me about the same performance boost, which is why I ultimately discarded it. (malloc and free were already being used anyway, not that I was happy with it. But unfortunately I ran out of arguments to replace them...) Cheers, Stefan

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[BGL] Segmentation fault in clear_vertex
by Daniel Trebbien 02 Sep '10

02 Sep '10

I am attempting to modify my implementation of the Stoer–Wagner min-cut algorithm to modify the input graph. In the code sample below, t and s are vertex_descriptors that were calculated by a call to boost::detail::stoer_wagner_phase: boost::tie(s, t, w) = boost::detail::stoer_wagner_phase(g, assignments, weights, pq); assert(s != t); // ... std::multimap<vertex_descriptor, edge_descriptor> sOutEdges; BGL_FORALL_OUTEDGES_T(s, e, g, UndirectedGraph) { const vertex_descriptor u = target(e, g); if (t != u) { sOutEdges.insert(std::make_pair(u, e)); } } BGL_FORALL_OUTEDGES_T(t, e, g, UndirectedGraph) { const vertex_descriptor u = target(e, g); const weight_type eWeight = get(weights, e); typename std::multimap<vertex_descriptor, edge_descriptor>::iterator sOutEdgesIt, sOutEdgesEnd; boost::tie(sOutEdgesIt, sOutEdgesEnd) = sOutEdges.equal_range(u); if (sOutEdgesIt != sOutEdgesEnd) { for(; sOutEdgesIt != sOutEdgesEnd; ++sOutEdgesIt) { put(weights, sOutEdgesIt->second, get(weights, sOutEdgesIt->second) + eWeight); } } else if (t != u) { // need to update e to set the source to s edge_descriptor ePrime; boost::tie(ePrime, boost::tuples::ignore) = add_edge(s, u, g); put(weights, ePrime, eWeight); } } clear_vertex(t, g); The segmentation fault occurs in the call to clear_vertex, but does not occur if I comment out the line that adds an edge to the graph g. The type of g, by the way, is: boost::adjacency_list<boost::listS, boost::vecS, boost::undirectedS, boost::no_property, boost::property<boost::edge_weight_t, int> > Why does adding an edge between vertices s and target(e, g), both of which are not equal to t, cause a segmentation fault? For reference, gdb says that the fault occurs on line 999 of boost/graph/detail/adjacency_list.hpp: // O(E/V * E/V) template <class Config> inline void clear_vertex(typename Config::vertex_descriptor u, undirected_graph_helper<Config>& g_) { typedef typename Config::global_edgelist_selector EdgeListS; BOOST_STATIC_ASSERT((!is_same<EdgeListS, vecS>::value)); typedef typename Config::graph_type graph_type; typedef typename Config::edge_parallel_category Cat; graph_type& g = static_cast<graph_type&>(g_); typename Config::OutEdgeList& el = g.out_edge_list(u); typename Config::OutEdgeList::iterator ei = el.begin(), ei_end = el.end(); for (; ei != ei_end; ++ei) { detail::erase_from_incidence_list (g.out_edge_list((*ei).get_target()), u, Cat()); g.m_edges.erase((*ei).get_iter()); *// line 999* } g.out_edge_list(u).clear(); } Program received signal SIGSEGV, Segmentation fault. std::_List_node_base::unhook (this=0x3d7a38) at ../../../../gcc-4.4.0/libstdc++-v3/src/list.cc:134 134 ../../../../gcc-4.4.0/libstdc++-v3/src/list.cc: No such file or director y. in ../../../../gcc-4.4.0/libstdc++-v3/src/list.cc (gdb) bt #0 std::_List_node_base::unhook (this=0x3d7a38) at ../../../../gcc-4.4.0/libstdc++-v3/src/list.cc:134 #1 0x0045fa26 in std::list<boost::list_edge<unsigned int, boost::property<boost ::edge_weight_t, int, boost::no_property> >, std::allocator<boost::list_edge<uns igned int, boost::property<boost::edge_weight_t, int, boost::no_property> > > >: :_M_erase (this=0x22fa9c, __position=...) at c:/mingw/bin/../lib/gcc/mingw32/4.4.0/include/c++/bits/stl_list.h:1424 #2 0x0045fa0c in std::list<boost::list_edge<unsigned int, boost::property<boost ::edge_weight_t, int, boost::no_property> >, std::allocator<boost::list_edge<uns igned int, boost::property<boost::edge_weight_t, int, boost::no_property> > > >: :erase (this=0x22fa9c, __position=...) at c:/mingw/bin/../lib/gcc/mingw32/4.4.0/include/c++/bits/list.tcc:111 #3 0x00413ec9 in boost::clear_vertex<boost::detail::adj_list_gen<boost::adjacen cy_list<boost::listS, boost::vecS, boost::undirectedS, boost::no_property, boost ::property<boost::edge_weight_t, int, boost::no_property>, boost::no_property, b oost::listS>, boost::vecS, boost::listS, boost::undirectedS, boost::no_property, boost::property<boost::edge_weight_t, int, boost::no_property>, boost::no_prope rty, boost::listS>::config> (u=5, g_=...) at c:/mingw/bin/../lib/gcc/mingw32/4.4.0/../../../../include/boost/graph/det ail/adjacency_list.hpp:999 #4 0x0041b0cc in boost::detail::stoer_wagner_min_cut<boost::adjacency_list<boos t::listS, boost::vecS, boost::undirectedS, boost::no_property, boost::property<b oost::edge_weight_t, int, boost::no_property>, boost::no_property, boost::listS> , boost::adj_list_edge_property_map<boost::undirected_tag, int, int&, unsigned i nt, boost::property<boost::edge_weight_t, int, boost::no_property>, boost::edge_ weight_t>, boost::associative_property_map<std::map<int, bool, std::less<int>, s td::allocator<std::pair<int const, bool> > > >, boost::shared_array_property_map <unsigned int, boost::vec_adj_list_vertex_id_map<boost::no_property, unsigned in t> >, boost::d_ary_heap_indirect<unsigned int, 4u, boost::shared_array_property_ map<unsigned int, boost::vec_adj_list_vertex_id_map<boost::no_property, unsigned int> >, boost::shared_array_property_map<int, boost::vec_adj_list_vertex_id_map <boost::no_property, unsigned int> >, std::greater<int>, std::vector<unsigned in t, std::allocator<unsigned int> > > > (g=..., weights=..., parities=..., assignments=..., pq=...) ...

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does pool::release_memory() really require an ordered pool?
by Mark Rajcok 02 Sep '10

02 Sep '10

On page http://www.boost.org/doc/libs/1_44_0/libs/pool/doc/interfaces/pool.html there is this precondition for release_memory(): "t must be ordered". Does that mean that ordered_malloc() must always be used, if I want to use release_memory()? Looking at the implementation for release_memory(), it appears to be iterating through chunks in each block, which I wouldn't expect if ordered_malloc() were always used. What I'm really after: I want to use object_pool, but periodically I'd like to reclaim/release any memory blocks that are no longer in use. In my application, I may have traffic spikes, where I allocate a lot of memory, but then later (after spiking) I'd like to release it. (The object pools will persist for the life of the application, and there will probably always be some "active objects" -- i.e., allocated from the pool and not free()d yet.) (I'm hoping the documentation may be out of date, and release_memory() can be used on pools that don't use ordered_malloc() and on object_pools.) -- Mark

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Struggling to implement bzip2 on windows
by Jared James Thompson 02 Sep '10

02 Sep '10

Hi All, I'm a VS2008 user, trying to use the ESBTL library for a project, which implements Boost to do many operations. ESBTL #includes <boost/iostreams/filter/bzip2.hpp>, which has been disabled for the Boostpro installation of windows. Quite simply, I'm struggling to get bzip2 installed and set up so that boost runs with bzip2 enabled. Has anybody done this before? Can anyone offer me more information than "compile from source?" best, Jared -- Jared James Thompson Department of Medicinal Chemistry and Molecular Pharmacology Laboratory for Computational Drug Design and Biology RHPH 504C Heine Pharmacy Building 575 Stadium Mall Drive West Lafayette, IN 47907-2091

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lamba: QStringList <<
by Hicham Mouline 02 Sep '10

02 Sep '10

Hello, the following for_each call with _1 fails to compile #include <QStringList.h> #include <boost/lambda/lambda.hpp> using namespace boost::lambda; QStringList items_list; std::for_each(begin_items(),end_items(), items_list << _1 ); QStringList has these << operators defined: QStringList& operator<< ( const QString& str ); QStringList& operator<< ( const QStringList& other ); the type of item iterator returned by begin_items() is: const char* const* QString has a ctor: QString (const char * str) The compilation error is: error C2678: binary '<<' : no operator found which takes a left-hand operand of type 'const QStringList' (or there is no acceptable conversion) I don't see why it tries to find a << that takes a ***const*** QStringList left-hand operand? Regards,

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Boost.Random and Dieharder et al.
by Patricia Hawley 02 Sep '10

02 Sep '10

Hi, I am working with a team developing some utilities for a simulation, and one of our requirements is to test the quality of the random generators. We based the utility on Boost.Random, but now have to show that that was a good decision. Has anyone verified the generators (e.g. Mersenne Twister or Linear Congruential ) in Boost.Random pass the Dieharder, Ent, and/or TestU01 suites? Any comments or suggestions on this are appreciated, Pat

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Re: [Boost-users] Boost-users Digest, Vol 2466, Issue 3
by Clarke, Carus V 01 Sep '10

01 Sep '10

Steven Watanabe wrote: > AMDG > > Clarke, Carus V wrote: > >> It looks like stat is setting errno to ENOENT. > >> Do you get the same behavior if the file exists before > starting the > >> program? > > > > Yes, the behavior is the same whether the program writes > the file or if the file had been previously written. > > > > Okay. Try using stat directly, instead of using Boost.Filesystem. > If that works, then can you use a debugger to find exactly > what arguments Boost.Filesystem is passing to stat? > > In Christ, > Steven Watanabe > Actually, the Boost.Filesystem library for Boost 1.44 uses the Windows API GetFileAttributes functions for reading file status on Cygwin, and it was in calls to these functions that things were failing. Since my last post, the Cygwin developers have updated the base Cygwin system (to 1.7.7-1). Updating my Cygwin installation to the new version has fixed the problem. Apparently, the 1.7.6-1 version had some bugs that were inadvertently introduced in an attempt to improve Cygwin functionality. I do have a question that might be better asked in a new thread, but here it is. Why does the Boost.Filesystem library force the use of Windows-style paths for Cygwin? The Cygwin system prefers Posix or mixed paths with forward slashes as separators. The use of Win32 paths on Cygwin is now deprecated, and Cygwin actually issues a warning the first time it encounters a Windows-style path. See http://cygwin.com/cygwin-ug-net/using.html#using-pathnames for more information. The Cygwin GCC 4.3.4 compiler no longer supports the -mno-cygwin option that was supported under Cygwin 1.5 and earlier. This means that any application created with this compiler depends on the Cygwin dll. Also, Boost does not appear to have a Cygwin platform for regression testing. Would it help if I or someone else could set one up? Thanks for your help. Carus V. (Bud) Clarke carus.v.clarke(a)boeing.com

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Problem using serialization::xml_archive with polymrphic classes
by przemyslaw.sliwa＠uk.bnpparibas.com 01 Sep '10

01 Sep '10

HelloHello, I have written code below and it works fine when using text archives. However, when I try to run it with the xml archives it is throwing a strange error saying "Invalid XML tag name". I have no idea what that means and could not find it in the documentation of the serialization library. Could someone tell me what I am doing wrong in this code? Thanks a lot for help! #include <boost/smart_ptr/shared_ptr.hpp> #include <boost/archive/xml_oarchive.hpp> #include <boost/archive/xml_iarchive.hpp> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <boost/serialization/vector.hpp> #include <boost/serialization/string.hpp> #include <boost/serialization/shared_ptr.hpp> #include <boost/date_time/local_time/local_time.hpp> #include <boost/serialization/export.hpp> #include <iostream> using namespace boost; using namespace std; class Actor { public: Actor( void ) {} Actor( char gender ) : gender( gender ) {} virtual ~Actor() {} char Gender( void ) const { return gender; } private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & BOOST_SERIALIZATION_NVP(gender); } char gender; }; class Crit: public Actor { public: Crit( void ) {} Crit( int age ) : age( age ) { } int Age( void ) const { return age; } private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & BOOST_SERIALIZATION_NVP(boost::serialization::base_object< Actor >( *this )); ar & BOOST_SERIALIZATION_NVP(age); } int age; }; class Food: public Actor { public: Food( void ) {} Food( int energy ) : energy( energy ) { } int Energy( void ) const { return energy; } private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & BOOST_SERIALIZATION_NVP(boost::serialization::base_object< Actor >( *this )); ar & BOOST_SERIALIZATION_NVP(energy); } int energy; }; BOOST_CLASS_EXPORT_GUID( Actor, "Actor") BOOST_CLASS_EXPORT_GUID( Crit, "Crit") BOOST_CLASS_EXPORT_GUID( Food, "Food") template< typename T > void save( T& data, string filename ) { ofstream ofs( filename.c_str() ); boost::archive::xml_oarchive oa( ofs ); oa & BOOST_SERIALIZATION_NVP(data); } template< typename T > void load( T& data, string filename ) { ifstream ofs( filename.c_str() ); boost::archive::xml_iarchive ia( ofs ); ia & BOOST_SERIALIZATION_NVP(data); } void TestAlpha( void ) { shared_ptr< Crit > critAlpha( new Crit( 18 ) ); shared_ptr< Crit > critBravo( new Crit( 19 ) ); shared_ptr< Food > foodAlpha( new Food( 20 ) ); shared_ptr< Food > foodBravo( new Food( 21 ) ); vector< shared_ptr< Actor > > conAlpha; vector< shared_ptr< Actor > > conBravo; conAlpha.push_back( critAlpha ); conAlpha.push_back( foodAlpha ); // save string filename = "sav.sav"; save( conAlpha, filename ); // test assert( critBravo->Age() == 19 ); assert( foodBravo->Energy() == 21 ); // load load( conBravo, filename ); // test critBravo = dynamic_pointer_cast< Crit >( conBravo[ 0 ] ); assert( critBravo->Age() == 18 ); foodBravo = dynamic_pointer_cast< Food >( conBravo[ 1 ] ); assert( foodBravo->Energy() == 20 ); } int main() { try { TestAlpha(); } catch(boost::archive::archive_exception& e) { return -1; } return 0; } ___________________________________________________________ This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and delete this e-mail. Any unauthorised copying, disclosure or distribution of the material in this e-mail is prohibited. Please refer to http://www.bnpparibas.co.uk/en/information/legal_information.asp?Code=ECAS-… for additional disclosures.

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mpl::set and mpl::fold
by Paul Graphov 01 Sep '10

01 Sep '10

Hello Boost Users, I've encountered a problem while using mpl::fold with mpl::set I've defined a template to check if one sequence contains all elements of the other: namespace mpl = boost::mpl; template<class A, class B> struct subset : mpl::fold< A, mpl::true_, mpl::and_<mpl::_1, mpl::contains<B, mpl::_2> > > {}; It works fine with lists and vectors but when first template parameter (A) is set or set_c it fails to compile. Did I miss something? Why is it impossible to iterate through a set via fold? p.s. tested on gcc and clang under linux. p.p.s. compilation error is quite huge, the main message is /usr/local/include/boost/mpl/eval_if.hpp:38: error: no type named ‘type’ in ‘struct boost::mpl::next<boost::mpl::s_iter<boost::mpl::set_c<int, 1l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l, 9223372036854775807l>, boost::mpl::set0_c<int> > >’

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[gil] bit_aligned_pixel_iterator
by Christian Henning 01 Sep '10

01 Sep '10

Hi there, I have a problem with extracting the correct values out of a 3bit gray image. The test code below displays my problem. Here, there is a vector of unsigned chars which create a particular bit pattern though all pixels in the image should have the same values. The bit pattern is: 1011 0110 0110 1101 1101 1011 0000 0000. On my machine ( x86 ) this should be read out in values of 110b ( which is 6 ) for all pixels. Instead my code reads out: 6, 6, 2, 6, 6, 0, 6, 6, 0. Here is the code: #include <cassert> #include <vector> #include <boost/gil/gil_all.hpp> using namespace std; using namespace boost; using namespace gil; int main() { typedef bit_aligned_image1_type< 3, gray_layout_t >::type gray3_image_t; typedef gray3_image_t image_t; typedef image_t::view_t view_t; typedef view_t::reference ref_t; typedef view_t::value_type pixel_t; typedef bit_aligned_pixel_iterator< ref_t > iterator_t; vector< unsigned char > buf( 4 ); buf[0] = 182; buf[1] = 109; buf[2] = 219; buf[3] = 0; iterator_t it( &buf[0], 0 ); ref_t p1 = *it; it++; ref_t p2 = *it; it++; ref_t p3 = *it; it++; ref_t p4 = *it; it++; ref_t p5 = *it; it++; ref_t p6 = *it; it++; ref_t p7 = *it; it++; ref_t p8 = *it; it++; ref_t p9 = *it; it++; unsigned char v1 = get_color( p1, gray_color_t() ); unsigned char v2 = get_color( p2, gray_color_t() ); unsigned char v3 = get_color( p3, gray_color_t() ); unsigned char v4 = get_color( p4, gray_color_t() ); unsigned char v5 = get_color( p5, gray_color_t() ); unsigned char v6 = get_color( p6, gray_color_t() ); unsigned char v7 = get_color( p7, gray_color_t() ); unsigned char v8 = get_color( p8, gray_color_t() ); unsigned char v9 = get_color( p9, gray_color_t() ); return 0; } The first two values are correct since they covered by the first byte. The third value doesn't seem to take in account the first bit of the second byte. I think this is incorrect. The stepping of the bits of by the iterator seems correct. Each value that is covered by one byte completely is correct but when a value is stretched over two bytes there seems to be a problem. Regards, Christian

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[type_traits]: is_boost_optional?
by Roland Bock 01 Sep '10

01 Sep '10

Hi, is there something in Boost.TypeTraits (or somewhere else) that allows me to check if a type is a boost::optional? I'd like to do something like this: template<typename T> typename enable_if<is_boost_optional<T> >, T::value_type>::type foo(const T&); Thanks and regards, Roland

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Boost.Filesystem: question about code conversion for char16_t with version 3
by Yasuhiro Hara 01 Sep '10

01 Sep '10

Hello, I am studying Boost.Filesystem version 3, but I got a couple of questions. I am wondering if someone helps me to understand version 3. I saw the reference document and path.hpp header file, I am not sure how to specify a code conversion API for char16_t or char32_t. It looks like only code conversion API between wchar_t and char can be specified. Since version 3 tries to support char16_t and char32_t, I am a little puzzled. I would appreciate if someone helps me to understand how I can use char16_t with version 3. Best regrads, /yasu

1 0

compressed fusion::vector?
by Cory Nelson 01 Sep '10

01 Sep '10

Hello, Is there a compressed fusion::vector that minimizes the size if the types passed in are empty, like compressed_pair? Thanks! -- Cory Nelson http://int64.org

2 1

[iostreams] filtering_ostream does not flush std::cout.
by Duncan Smith 01 Sep '10

01 Sep '10

I'm using Boost 1.43.0, and I've found that filtering_ostream does not flush "std::cout". I found a relevant (and recent) ticket against Boost 1.44.0, but my issue is slightly different. https://svn.boost.org/trac/boost/ticket/4590 I'm using GCC 4.3.4 on Gentoo Linux. I'm hoping that I'm just doing something wrong, but if you think there's a bug, I'll add my testcase to the ticket. The basic recipe: filtering_ostream out; out.push(any_filter_at_all()); out.push(std::cout); out << "Hello World!" << std::flush; sleep(10); // Observe an empty console. std::cout << std::flush; sleep(10); // Observe printed text on console. This problem is quite bad for me when doing the following on the command-line (for a more complicated program): ./program 2>&1 | tee some-file.log Because stdout is not getting flushed, the stdout and stderr get intermingled strangely. However, disabling buffering on stdout works around the problem: stdbuf --output=0 ./program 2>&1 | tee some-file.log Please tell me if you think there's a bug in my code. If it's a bug in Boost.Iostreams (or I'm expecting the wrong behaviour), I would appreciate any ideas for workarounds (I tried cout.setf(unitbuf), and that doesn't seem to do the trick). Here's the full text of my code: ------------------ // Test case for flushing a filtering_ostream based on the // boost_iostreams_filtering_ostream.cpp attached to ticket #4950: // https://svn.boost.org/trac/boost/ticket/4590 // https://svn.boost.org/trac/boost/attachment/ticket/4590/boost_iostreams_fil… // changed to use "cout" as the sink. // // Flushing a filtering_ostream using the flush() global function does not work // in Boost 1.43. I suspect it also does not work in Boost 1.44. // // Using GCC-4.3.4 on Gentoo Linux. // #include <cassert> #include <string> #include <boost/iostreams/categories.hpp> #include <boost/iostreams/operations.hpp> #include <boost/iostreams/filtering_stream.hpp> #include <iostream> // Included for "sleep()" call below. #include <unistd.h> namespace io = boost::iostreams; // Simple output filter forwarding just forwarding the put chars to // the sink. struct transparent_output_filter { typedef char char_type; typedef io::output_filter_tag category; template <typename Sink> bool put(Sink& snk, char c) { return io::put(snk, c); } }; int main(int argc, char *argv[]) { using namespace std; io::filtering_stream<io::output> out; // Transparent filter just forward the characters to the sink. // // Note: I observe this behaviour with and without this line. out.push(transparent_output_filter()); // Sink appends characters to "cout". out.push(cout); // Write test string to filtering_ostream. out << "Hello World!"; // On my system, this will flush the buffer iff I'm on an // interactive console. "\n" and endl have the same effect. I believe // that my shell sets "stdout" to be line-buffered if it's interactive. // out << "\n"; bool wasFlushed = false; // The flush does *not* work in Boost 1.43. wasFlushed = io::flush(out); // This assertion does not go off, though. assert(wasFlushed); // This also doesn't work. wasFlushed = out.flush(); assert(wasFlushed); // This also doesn't work. out << std::flush; // Demonstrate that none of the above flush calls had any effect on "cout". sleep(10); // Now we finally get the characters on the console. cout << flush; // Demonstrate that the direct flush call works when called directly on // "cout". sleep(10); return 0; }

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Can I use both filesystem versions v2 and v3 in a program ?
by Timothy Madden 01 Sep '10

01 Sep '10

Hello Can I include <boost/filesystem.hpp> but use the BOOST_FILESYSTEM_V... macro to include one version in on of my cpps and another version in another cpp ? Do both versions get compiled when boost is built ? Thank you, Timothy Madden

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Re: [Boost-users] Boost.Serialization: Restoringobjectstate(preventcreation of a new object)?
by ray＠maya-studio.com 01 Sep '10

01 Sep '10

I've ended up with the following solution: #include <fstream> #include <iostream> #include <boost/archive/xml_iarchive.hpp> #include <boost/archive/xml_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <boost/archive/text_oarchive.hpp> #include <boost/serialization/export.hpp> #include <boost/foreach.hpp> #define _SERIALIZATION_FUNC(CLASS_NAME, ARCH_TYPE) \ public: \ virtual void Serialize(ARCH_TYPE& ar) \ { \ CLASS_NAME& x = *static_cast<CLASS_NAME*>(this); \ ar & BOOST_SERIALIZATION_NVP(x); \ } #define SERIALIZATION(CLASS_NAME) \ public: \ _SERIALIZATION_FUNC(CLASS_NAME, boost::archive::text_iarchive) \ _SERIALIZATION_FUNC(CLASS_NAME, boost::archive::text_oarchive) \ _SERIALIZATION_FUNC(CLASS_NAME, boost::archive::xml_iarchive) \ _SERIALIZATION_FUNC(CLASS_NAME, boost::archive::xml_oarchive) \ private: \ friend class boost::serialization::access; \ template<typename TArchive> \ void serialize(TArchive & ar, const unsigned int version /*file_version*/) class A { public: A() : m_a(0) {} protected: int m_a; private: SERIALIZATION(A) { ar & BOOST_SERIALIZATION_NVP(m_a); } }; class B : public A { public: B() : m_b(0) {} protected: int m_b; private: SERIALIZATION(B) { ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(A); ar & BOOST_SERIALIZATION_NVP(m_b); } }; BOOST_CLASS_EXPORT(B) int main(int argc, char* argv[]) { // ... A a; B b; std::list<A*> lst; // List of A* pointers lst.push_back(&a); // Base class lst.push_back(&b); // Derived //... // Save { std::ofstream ofs("c:/test.xml"); boost::archive::xml_oarchive oa(ofs); BOOST_FOREACH(A* pA, lst) { pA->Serialize(oa); } } //... // Restore { std::ifstream is("c:/test.xml"); boost::archive::xml_iarchive ia(is); BOOST_FOREACH(A* pA, lst ) { pA->Serialize(ia); } } //... } Everything works as expected (my classes can live with a few additional virtual functions :). And thank you for creating this excellent serialization library! Ray

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Using Boost.MPI with gather , data becomes overwritten after gather operation
by hgc-01134＠hkedcity.net wong 01 Sep '10

01 Sep '10

Hi, I am trying to use Boost.MPI to do a very simple program that 1. Processes from different ranks do a gather operation 2. The gather operation will gather the CoProcessInfo ( which is just a data structure of rank# and hostname) into a vector 3. After the gather operation, Rank 0 will print the CoProcessInfo one by one in the vector. ------------------------------------------------------------------------------------------------------------------------------------------------------ My testing environment consists of TWO virtual machine ( each of the machine has two cores ): Centos 5.5 mpich2 Boost.mpich2 Boost 1.41 mpiexec ------------------------------------------------------------------------------------------------------------------------------------------------------ The expected output of the program should be something like ( just an example order of ranks ): Host VM1, Rank 0 Host VM1, Rank 1 Host VM2, Rank 2 Host VM2, Rank 3 ---------------------------------------------------------------------------------------------------------------------------------------------------------- However, I got something like: ( just an example order of ranks ), the hostname is incorrect after gather operation ( three VM2 appears!) Host VM1, Rank 0 Host VM2, Rank 1 Host VM2, Rank 2 Host VM2, Rank 3 I found that each process CAN correctly found out the hostname and rank#, however, the data will become a bit like overwritten, after the gather operation. Thank you very much. ------------------------------------------- Source Code ------------------------------------------------------------------- #include <boost/asio/ip/host_name.hpp> #include <iostream> #include <vector> #include <string> #include <boost/mpi/environment.hpp> #include <boost/mpi/communicator.hpp> #include <boost/mpi.hpp> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <sstream> #include <fstream> using namespace std; namespace mpi = boost::mpi; class CoProcessInfo { private: string hostname; int rank; friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int /* version */) { ar & hostname & rank; } public: CoProcessInfo() { hostname = boost::asio::ip::host_name(); rank = 0; } void setRank(int _rank) { rank = _rank; } string getHostname() const { return hostname; } int getRank() const { return rank; } }; int main(int argc, char* argv[]) { int myrank; mpi::environment env(argc, argv); mpi::communicator world; myrank = world.rank(); CoProcessInfo localInfo; localInfo.setRank( myrank ); std::vector<CoProcessInfo> coProcInfo; mpi::gather(world, localInfo, coProcInfo, 0); if( myrank == 0 ){ for (std::vector<CoProcessInfo>::const_iterator it = coProcInfo.begin(); it !=coProcInfo.end(); ++it) { cout << endl << " Host : " << it->getHostname() << " , Rank : " << it->getRank() << endl; } } return 0; } ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- Regards, Joseph

2 1

boost::addressof
by Stanisław Findeisen 31 Aug '10

31 Aug '10

Hi! In the latest boost release (1.44) boost::addressof is defined as follows (boost/utility/addressof.hpp): namespace detail { template<class T> struct addr_impl_ref { T & v_; inline addr_impl_ref( T & v ): v_( v ) {} inline operator T& () const { return v_; } private: addr_impl_ref & operator=(const addr_impl_ref &); }; template<class T> struct addressof_impl { static inline T * f( T & v, long ) { return reinterpret_cast<T*>( &const_cast<char&>(reinterpret_cast<const volatile char &>(v))); } static inline T * f( T * v, int ) { return v; } }; } // namespace detail template<class T> T * addressof( T & v ) { #if defined( __BORLANDC__ ) && BOOST_WORKAROUND( __BORLANDC__, BOOST_TESTED_AT( 0x610 ) ) return boost::detail::addressof_impl<T>::f( v, 0 ); #else return boost::detail::addressof_impl<T>::f( boost::detail::addr_impl_ref<T>( v ), 0 ); #endif } Q1: What is volatile in the cast needed for? Q2: Could anyone please explain to me what are the 2nd parameters in each of the f functions in struct addressof_impl for? Q3: What is struct addr_impl_ref::operator T& () const ??! I understand it is there to get called when passing addr_impl_ref<T>(v) instead of v to addressof_impl<T>::f, but I've never seen such a thing before. I would understand T& struct addr_impl_ref::operator(), or something, but this one is different. Sorry if this is a newbie question. Q4: I can see that in 1.34.1 boost::addressof was much more simple: // VC7 strips const from nested classes unless we add indirection here # if BOOST_WORKAROUND(BOOST_MSVC, == 1300) template<class T> struct _addp { typedef T * type; }; template <typename T> typename _addp<T>::type # else template <typename T> T* # endif addressof(T& v) { return reinterpret_cast<T*>( &const_cast<char&>(reinterpret_cast<const volatile char &>(v))); } so I wonder what was the problem with this design?... -- http://eisenbits.homelinux.net/~stf/ OpenPGP: DFD9 0146 3794 9CF6 17EA D63F DBF5 8AA8 3B31 FE8A Like Hardship, Risk & Challenge? --- Follow Jesus!!

1 0

Creating a thread and blocking its execution
by Jean-Sebastien Stoezel 31 Aug '10

31 Aug '10

Hello, I use boost::thread as follow: mp_Thread = new boost::thread(boost::bind(CSubsystem::TaskWrapper, this)); to create a thread in an initialization method. I observe that this thread gets to run before my initialization method has completed its execution. I would like to create a thread from this initialization method, and wait for it to execute until the whole initialization process it done. Is it possible to create a thread in suspended mode, and then release it once the system is ready? Or do I need to use a synchronization mechanism like a semaphore to release it? Jean-Sebastien

3 3

Does BOOST ASIO HTTP support 1.1
by Manna Patri 31 Aug '10

31 Aug '10

Hi, Looking at the boost::asio:: http server I am very much interested to have it in my application server.However before proceeding further I would like to know does HTTP server implmentation supports HTTP 1.1 ? Looking at the example available under HTTP client it seems "HTTP 1.0" is sent across in header as part of HTTP message. And to my curoisity when I modifeid the client code to send "HTTP 1.1" that also worked. Reply in this regard is appreciated. Thanks. Manna

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Re: [Boost-users] Boost.Serialization: Restoring object state(preventcreation of a new object)?
by ray＠maya-studio.com 31 Aug '10

31 Aug '10

> That's likely something else entirely. We'd have to see more code. Forget my previous post, the exception was due to mixed up ofstream and ifstream... Just to resume - if I have a list of pointers to the objects (all derived from the same base class) and I'd like to serialize them through a reference, a code like this would be needed: // List of pointers A a; B b; // Derived from A C c; // Derived from C std::list<A*> list; list.push_back(&a); // Base list.push_back(&b); // Derived list.push_back(&c); // Derived ... // Save std::ofstream ofs("c:/test.xml"); boost::archive::xml_oarchive oa(ofs); BOOST_FOREACH(A* pA, list) { if (dynamic_cast<B*>(pA)) { B& b = *static_cast<B*>(pA); oa & BOOST_SERIALIZATION_NVP(b); } else if (dynamic_cast<C*>(pA)) { C& c = *pA; BOOST_SERIALIZATION_NVP(c); } else { A& a = *pA; BOOST_SERIALIZATION_NVP(a); } } Am I right?

2 2

multi_array: error: expected primary-expression before ‘)’
by Valmor de Almeida 31 Aug '10

31 Aug '10

Hello, I am trying from the multi_array web site doc: typedef boost::multi_array<double,3> array_type; array_type A(boost::extents[3][4][2],boost::fortran_storage_order); and getting the following compile-time error: g++ img2hermes2dmsh.cpp In function ‘int main()’: error: expected primary-expression before ‘)’ token Any insights? I am using boost-1.41 on gentoo linux. Thanks, -- Valmor

2 2

download question
by Stanisław Findeisen 31 Aug '10

31 Aug '10

Hi What are the file checksums? -- http://eisenbits.homelinux.net/~stf/ OpenPGP: DFD9 0146 3794 9CF6 17EA D63F DBF5 8AA8 3B31 FE8A Like Hardship, Risk & Challenge? --- Follow Jesus!!

1 0

Comparing boost bind object with a pointer to member function
by jej 31 Aug '10

31 Aug '10

Hello, Is is possible to compare a pointer to member function with a function object returned by boost bind? I have a class with several different functions; for each member function I use boost bind to bind the function object to several args. At the point where I want call the function object, I would like to check which member function it's been bound to, and decide whether or no it should be executed. For example, I would like the second comparison in the code snippet below to return "Bind match." For any other member function of foo it should return "Bind not match." Thanks. int main(int, char**) { Data d(1, 2); Foo fx, fy; //typedef void (Foo::*foofunctwo_t)(const Data&); //foofunctwo_t del1 = &Foo::FuncTwo; boost::function<void (Foo*, const Data&)> bf(&Foo::FuncTwo); if(bf == &Foo::FuncTwo) { cout << "match" <<endl; } else { cout << "no match" << endl; } boost::function<void (const Data&)> boundfunc = boost::bind(&Foo::FuncTwo, &fx, _1); if(boundfunc == &Foo::FuncTwo) { cout << "Bind match" << endl; } else { cout << "Bind not match" << endl; } return 0; }; -- View this message in context: http://old.nabble.com/Comparing-boost-bind-object-with-a-pointer-to-member-… Sent from the Boost - Users mailing list archive at Nabble.com.

2 2

Overloading boost::for_each()
by Jeremiah Willcock 31 Aug '10

31 Aug '10

There are several container types (such as typical deque implementations, if you have access to their internals) that can have for_each() implemented for them in a way that is faster than using iterators and a generic for_each() function. Is there a way to take advantage of that in Boost.Range, such as by overloading boost::for_each()? Is there some kind of Iterable concept that doesn't require actual iterators or allows them to be slow? Would it be worthwhile to add one? Are there any other techniques that would be useful instead, such as always calling for_each() unqualified in my code and using ADL to find custom versions (like is done for swap)? I am not interested in making Boost.Range algorithms use this new concept, but there are places in my own code that could use for_each() rather than explicit loops if that was faster. Thank you for any answers or advice. -- Jeremiah Willcock

7 17

asio HTTP client example always returns error 400
by G S 31 Aug '10

31 Aug '10

Hi all. I copied the boost::asio HTTP client example code: http://live.boost.org/doc/libs/1_39_0/doc/html/boost_asio/example/http/clie… and just replaced the argv stuff with a hard-coded domain name and "index.html". It appears to make the socket connection OK, but the response to the request is 400 ("bad request"). Is there something wrong with this request? boost::asio::streambuf request; std::ostream request_stream(&request); request_stream << "GET " << "index.html" << " HTTP/1.0\r\n"; request_stream << "Host: " << "musicobsession.com" << "\r\n"; request_stream << "Accept: */*\r\n"; request_stream << "Connection: close\r\n\r\n"; It doesn't matter what host I use (as long is it's real). Thanks for any insight!

2 3

[log] cost of record instantiation
by Matthias Vallentin 31 Aug '10

31 Aug '10

Hello, I am trying to understand the cost of log record instantiation. Say I have a global severity logger with several levels, of which the debug level produces a lot of output and record creation is expensive. Because the overhead should only incur when actually logging in debug mode, I would like to know how costly the level check is. That is, in the following code // The custom logger class here accommodates multiple severity // loggers for different facilities. #define LOG(level, facility) \ BOOST_LOG_SEV(global::logger->get(facility), level) LOG(debug, core) << ... some expensive construction would the stream expression be instantiated regardless of the logging level, yet simple be discarded when being in level lower than debug? (I am asking because I recall they are not streamed in a lazy fashion.) If this is the case, preventing the construction of the stream expression would need a different logging mechanism, e.g., /// Expensive logging when in Debug mode. #ifdef DEBUG #define LOGD(facility) \ LOG(log::debug, facility) #endif // Not being compiled. LOGD(core) << ... some expensive constrution However, this design does not have a uniform approach to logging, which makes it less attractive. Any thoughts? Matthias

2 1

[Boost.DateTime][Boost.Python] Year out of valid range error when streaming via Python module
by SamuelG 31 Aug '10

31 Aug '10

This problem occurs at a higher level but I've tried to strip it back. I've reproduced this problem GCC 4.3.4, Python 2.6.5 and Boost 1.41.0 32bit and 64bit Debians/Ubuntu. The problem does not seem to happen on Windows XP. I have embedded the Python interpreter in the attached http://old.nabble.com/file/p29579563/run_python.cpp run_python.cpp . When running this with the attached script http://old.nabble.com/file/p29579563/test.py test.py and which uses a test module http://old.nabble.com/file/p29579563/test_date_time.cpp test_date_time.cpp , the following Boost.DateTime error occurs: $ run_python test.py out() - entry out() - to_simple_string(): 2010-Aug-31 14:30:33.439172000 out() - manual format: 2010-Aug-31 14509:17:19.172000 out() - oss.str(): 2010-Aug-31 14509:17:19.172000 out() - now: Traceback (most recent call last): File "test.py", line 6, in <module> test_date_time.output() IndexError: Year is out of valid range: 1400..10000 However, when running the same script via python it is fine: $ python test.py out() - entry out() - to_simple_string(): 2010-Aug-31 14:30:31.208160000 out() - manual format: 2010-Aug-31 14:30:31.208160000 out() - oss.str(): 2010-Aug-31 14:30:31.208160000 out() - now: 2010-Aug-31 14:30:31.208160000 out() - exit Note that the time stamp in the first example is corrupt. Note also that the valid range error does not occur when using the date and time facets manually but when streaming the ptime object to std::cerr. The problem first arose for me when using Boost.Log with separate Python modules via *both* run_python and /usr/bin/python. See http://sourceforge.net/projects/boost-log/forums/forum/710022/topic/3748054 http://sourceforge.net/projects/boost-log/forums/forum/710022/topic/3748054 For this simple case, /usr/bin/python seems okay but the run_python error is identical to what happens in our proper application (where Boost.Log is used and multiple Python modules loaded). Has anyone witnessed similar behaviour? Or can they please test my example out? Thanks for any help, Sam -- View this message in context: http://old.nabble.com/-Boost.DateTime--Boost.Python--Year-out-of-valid-rang… Sent from the Boost - Users mailing list archive at Nabble.com.

1 0

Re: [Boost-users] boost::asio SSL connection thru proxy server
by Kumar, Akhilesh 31 Aug '10

31 Aug '10

Hi All, Considering that nobody replied my question I am wondering if anybody who has knowledge of this kind of problem has seen my previous message/question. I really need help on this issue if anybody has any thought on this pls. reply. Thanks, Akhilesh Kumar From: Kumar, Akhilesh Sent: Monday, August 23, 2010 5:10 PM To: 'boost-users(a)lists.boost.org' Subject: boost::asio SSL connection thru proxy server Hi, I am writing a boost socket client using boost::asio to do secure HTTP (HTTPS) communication. I Implemented my client based on the code sample based on (http://www.boost.org/doc/libs/1_39_0/doc/html/boost_asio/example/ssl/client…) with little changes as I am using sync socket. My client woks fine, when I am connecting to server directly, but I am not sure what changes I need to make when my communication going thru proxy. The unsecure connection(HTTP) work fine thru proxy, and here is what I do for unsecure connection, 1. Initialize boost socket(IO service and other stuff). 2. Resolve and Connect to Proxy server. 3. Start writing to actual server(HTTP send request). 4. Start uploading/downloading. 5. Close Socket. But I can't use this above procedure for (SSL) secure connection as I need to do handshaking with the server before I can write anything if my understanding is correct. Can somebody give me some pointer or code sample or step I need to do when I am doing secure connection thru proxy server. Just to clarify Microsoft WinInet does do (secure) HTTPS connection thru same proxy fine. If providing my code sample I am using for SSL might help understand the problem I can provide that. Thanks in advance for any help. Akhilesh Kumar

3 5

Re: [Boost-users] Boost.Serialization: Restoring object state (preventcreation of a new object)?
by ray＠maya-studio.com 30 Aug '10

30 Aug '10

>> Just avoid serialization through a pointer, serialize either the >> object or a reference to the object. Thanks, Robert. Serializing through a reference seems to be the only viable solution in my case. However, I'm not able to make it work (I didn't find any specific information about references in the library documentation - except for member variables) . For example: A a; ... A& aRef = a; ia & BOOST_SERIALIZATION_NVP(aRef);; // Throws an exception in load_override

2 1

[parameter] Using named parameter types in return type
by Jeremiah Willcock 30 Aug '10

30 Aug '10

In BOOST_PARAMETER_FUNCTION, one argument to specify is the return type of the function. How do I refer to the types deduced for the named parameters in the return type? I am creating a factory function for a class template (similar to std::make_pair) and would like to use named parameters for it. I did not see any obvious way to do this in the documentation. Is there a way? A documented name for the ArgPack? I am using C++0x so it would be OK to have a solution that requires that. -- Jeremiah Willcock

1 0

Re: [Boost-users] [filesystem] Using filesystem library from Boost version 1.44 on Cygwin 1.7
by Clarke, Carus V 30 Aug '10

30 Aug '10

> Date: Mon, 30 Aug 2010 08:36:49 -0700 > From: Steven Watanabe <watanabesj(a)gmail.com> > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] [filesystem] Using filesystem library from > Boost version 1.44 on Cygwin 1.7 > Message-ID: <4C7BD011.6010707(a)providere-consulting.com> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > AMDG > > Clarke, Carus V wrote: > > Steven Watanabe wrote: > >> Your code doesn't appear to print this last line. > > > > You are right. I added the last line after pasting in the > code. Here it is: > > > > boost_fs::file_status st = boost_fs::status(path, ec); > > <snip> > > std::cout << "Does file exist? " << boost_fs::exists(st) > << std::endl; > > return 0; > > } > > > > Is there anything I can do to make this work? > > > > It looks like stat is setting errno to ENOENT. > Do you get the same behavior if the file exists before > starting the program? > > In Christ, > Steven Watanabe > Yes, the behavior is the same whether the program writes the file or if the file had been previously written. Thanks, Carus V. (Bud) Clarke carus.v.clarke(a)boeing.com

2 1

Boost.Serialization: Restoring object state (prevent creation of a new object)?
by ray＠maya-studio.com 30 Aug '10

30 Aug '10

If an object is serialized (saved) from a pointer, the loading part automatically creates (instantiates) a new object. However, there are situations when the object is already created and all we need is to restore its state. The following code demonstrates one possible - although not elegant - solution using a temporary object:#include <fstream> #include <iostream> #include <boost/archive/xml_iarchive.hpp> #include <boost/archive/xml_oarchive.hpp> #include <boost/serialization/string.hpp> #include <boost/serialization/export.hpp> class A { public: A() : m_val(100) { } int m_val; private: friend class boost::serialization::access; template <typename Archive> void serialize(Archive &ar, const unsigned int version) { ar & BOOST_SERIALIZATION_NVP(m_val); } }; int main(int argc, char* argv[]) { A *a = new A(); // Save the object { std::ofstream os("d:/test.xml"); boost::archive::xml_oarchive oa(os); // Save from pointer oa & BOOST_SERIALIZATION_NVP(a); } // Change the object state a->m_val = 200; // Restore the state { std::ifstream is("d:/test.xml"); boost::archive::xml_iarchive ia(is); A* aTemp; ia & BOOST_SERIALIZATION_NVP(aTemp); a->m_val = aTemp->m_val; // Copy object state assert(a->m_val == 100); delete aTemp; } } Here is my question: Is there some more convenient way to restore the object state? In other words, is it possible to prevent creation of a new object and just 'populate' an existing object?

2 1

[filesystem] Using filesystem library from Boost version 1.44 on Cygwin 1.7
by Clarke, Carus V 30 Aug '10

30 Aug '10

Date: Fri, 27 Aug 2010 15:39:29 -0700 From: Steven Watanabe <watanabesj(a)gmail.com> To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] [filesystem] Using filesystem library from Boost version 1.44 on Cygwin 1.7 Message-ID: <4C783EA1.4070400(a)providere-consulting.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed AMDG Clarke, Carus V wrote: > I have been using the filesystem library from Boost version 1.43 on a Cygwin 1.7.6-1 platform without any problems. The library was built using the Cygwin version of GCC 4.3.4. The library from the 1.44 version of Boost compiles compiles o.k., but the functions that access files no longer work. This appears to be true for both versions 2 and 3 of the library. Below is a simple program that runs o.k. with the Boost version 1.43 version of the library. The program runs but can not read the file status using Boost version 1.44. This program also works fine when built using MSVC 9.0 and Boost version 1.44. > > //-------------------- > > <snip> > > int main() > { > <snip> > std::cout << "Error code message: " << ec.message() << std::endl; > return 0; > } > > //-------------------- > > This program's output on my system is shown below. The file 'foo' is written by the program and does actually exist. > > For version 2: > > boost::filesystem library version is v2 > Checking status of file foo... > Error code value: 0 > Error code message: The operation completed successfully > Does file exist? false > Your code doesn't appear to print this last line. In Christ, Steven Watanabe ------------------------------ You are right. I added the last line after pasting in the code. Here it is: boost_fs::file_status st = boost_fs::status(path, ec); <snip> std::cout << "Does file exist? " << boost_fs::exists(st) << std::endl; return 0; } Is there anything I can do to make this work? Thanks, Carus V. (Bud) Clarke carus.v.clarke(a)boeing.com ------------------------------

2 1

[parameter] Weird behavior with bools
by Ryan McConnehey 30 Aug '10

30 Aug '10

I'm new to the parameter library and started with a simple example to get my feet wet. The first problem I'm having is with type restriction. The "name" variable is being restricted to a boolean type. This doesn't seem to be enforced since I can pass this variable a value of 15 and get this same value out. Currently my output has "name = 15" and I expected the output to be "name = 1". Did I not correctly enforce the type? The second problem is with the default value of my variable. I thought if the variable wasn't used then the third parameter, in the declaration, is used for instantiation of that variable. I thought that meant I could do this "m_name(args[_name])". The compiler gives an error saying the operator[] can't deduce the arguments. What did I not do that would allow this behavior. Thank you for your time in helping me out. Ryan BOOST_PARAMETER_NAME(name) struct myclass_impl { template <class ArgumentPack> myclass_impl(ArgumentPack const& args) : m_name(args[_name | false]) //: m_name(args[_name]) //gives a compile error { std::cout << "name = " << m_name << std::endl; } private: int m_name; }; struct myclass : public myclass_impl { BOOST_PARAMETER_CONSTRUCTOR( myclass, (myclass_impl), tag , (optional (name, (bool), bool(false)))) // no semicolon }; int main(int argc, char* argv[]) { myclass x(_name = 15); return 0; }

4 7

Can I fstat or get the file date/time for a file stream ?
by Timothy Madden 30 Aug '10

30 Aug '10

Hello Is there a way to stat or to get file last accessed time from an opened std::fstream or boost::filesystem::fstream or a boost::iostreams::stream ? Or is there a way to get the underlaying file descriptor (or a FILE *) from a fstream so I can call POSIX fstat ? Thank you, Timothy Madden

1 0

Fwd: Some trouble using mutexes
by Ernest Galbrun 30 Aug '10

30 Aug '10

Ok, thank you for your reply, I have been away for a week and I am back to work, with this problem still preventing my program to work fine. To answer your question, I have only one Robot in my project (for now) and the io_service is a Robot member. I now get why the active_count goes negative when the count goes up, but now I can't figure how it can ever be incremented twice. When debugging, I see the active_count being either 0, -2147483648, OR -2147483647. In fact, even when the active_count is not ==0, the lock() call returns instantly. Any clue ? Ernest Galbrun. > > Ernest Galbrun wrote: > > I would be really grateful if someone could give me a hint about what I > am > > doing wrong with the mutex and thread class (I am using boost 1.43, on > > windows XP running visual c++ 2010, the library has been built using the > > bjam utility). > > > > I have a main thread that creates an object of class robot : > > > > class Robot > > { > > private: > > boost::mutex tcpLock; > > boost::thread continuousThread; > > ... > > } > > > > Robot k3; > > > > this thread launches a thread that makes continuous calls to a member > > function of the robot. Since this function uses network ressources, I > want > > it to be safe so i use a lock The function called is the only function in > my > > program that uses this lock : > > > > int Robot::sendMsg(string msg, int n, vector<string>* answer) > > { > > tcpLock.lock(); > > (do stuff with the tcp io service) > > tcpLock.unlock(); > > return 0; > > } > > > > Of course, I also call this function from the main thread. > > > > And I have disruptive behavior, which I don't understand. > > Do you have multiple Robots? Is the io_service shared between them? > > > When debugging, I > > see that the 'active_count' of the tcpLock object stays negative or ==0, > > which seem absolutely wrong to me, but I don't understand how it could > ever > > be anything other than 0 or 1. > > > > The implementation indicates that the mutex is locked with the > high-order bit, which means that a locked mutex will have > a negative active count. > > In Christ, > Steven Watanabe >

1 0

boost transfer pointers by serialize
by Jack Bryan 29 Aug '10

29 Aug '10

Dear All, I need to transfer some pointers from one process to another process on Open MPI cluster. These pointers are members of a class. They are like: class myClass{double *;int *;double**; } When I use serialize in boost , I got errors: /boost/serialization/access.hpp:118: error: request for member âserializeâ in âtâ, which is of non-class type âdoubleâ Any help is appreciated. JACK Aug. 29 2010

2 5

boost thread - bug pthread
by Kraus Philipp 29 Aug '10

29 Aug '10

Hi, I'm writing a multithread application and I test my program with valgrind. I create a thread group and valgrind shows this message: ==4608== Thread #1: Bug in libpthread: recursive write lock granted on mutex/wrlock which does not support recursion ==4608== at 0x503FC: pthread_cond_wait* (hg_intercepts.c:653) ==4608== by 0x19C3B7: boost::thread::join() (in libboost_thread.dylib) ==4608== by 0x15D8C: boost::thread_group::join_all() (in ./main) I use Boost 1.44 on OSX 10.5. How can I solve this "Bug"? Thanks Phil

1 0

string algo - documentation bug?
by mafeusek＠gmail.com 29 Aug '10

29 Aug '10

Hallo Group Members. in http://www.boost.org/doc/libs/1_44_0/doc/html/string_algo/concept.html I can read: * Function Finder. Finder can be any function object. That is, any ordinary function with the required signature can be used as well. However, such a function can be used only for a specific iterator type. boost::iterator_range<std::string> simple_finder( std::string::const_iterator Begin, std::string::const_iterator End ) { return boost::make_range( Begin, End ); } but following code does not compile: #include <iostream> #include <string> #include <boost/algorithm/string.hpp> #include <boost/range.hpp> int main(int argc, char *argv[]) { boost::iterator_range<std::string> dd; return 0; } As I understand, I need to put iterator as template parameter to iterator_range, thus: #include <iostream> #include <string> #include <boost/algorithm/string.hpp> #include <boost/range.hpp> /* boost::iterator_range<std::string> simple_finder( std::string::const_iterator Begin, std::string::const_iterator End ) { return boost::make_range( Begin, End ); } */ int main(int argc, char *argv[]) { boost::iterator_range<std::string::iterator> dd; return 0; } compiles ok. Is it documentation bug? best regards, Pawel

1 0

Any stream class for C standard FILE * streams ?
by Timothy Madden 29 Aug '10

29 Aug '10

Hello Is there a stream class in boost that would use a C standard FILE * stream as the buffer ? Thank you, Timothy Madden

2 1

Multiple link errors when using boost 1.44 boost::filesystem and gcc 4.1.2 on CentOS 5.5
by Potato Soup 29 Aug '10

29 Aug '10

I have installed gcc 4.1.2 (from Cent OS 5.5 repos), boost 1.44, and built all the libraries. I am able to link to all other libraries I try. As soon as I so much as add the include for boost::filesystem, and attempt to build my single .cpp file, I get the following errors: In function `__static_initialization_and_destruction_0(int, int)': testbuild.cpp:(.text+0xfa): undefined reference to `boost::system::generic_category()' testbuild.cpp:(.text+0x106): undefined reference to `boost::system::generic_category()' testbuild.cpp:(.text+0x112): undefined reference to `boost::system::system_category()' collect2: ld returned 1 exit status The linking stage fails and despite hours of googling I see no clear solution. I would be grateful for any advice on how to move past this, as it's the only thing holding me back from developing with boost. To be clear again, simply including <boost/filesystem.hpp> is enough to cause this when performing a link against libboost_filesystem.a.

2 1

boost serialize error
by Jack Bryan 29 Aug '10

29 Aug '10

Dear All: I am trying to use boost (1.43) serialize to transfer data. But I got errors: ---------------------------------------------------------------- path/boost_1_43_0/boost/config/stdlib/libstdcpp3.hpp:40:1: warning: "BOOST_HAS_THREADS" redefined<command line>:1:1: warning: this is the location of the previous definitionpath/boost_1_43_0/boost/serialization/access.hpp: In static member function âstatic void boost::serialization::access::serialize(Archive&, T&, unsigned int) [with Archive = boost::mpi::packed_iarchive, T = int*]â:path/boost_1_43_0/boost/serialization/serialization.hpp:74: instantiated from âvoid boost::serialization::serialize(Archive&, T&, unsigned int) [with Archive = boost::mpi::packed_iarchive, T = int*]âpath/boost_1_43_0/boost/serialization/serialization.hpp:133: instantiated from âvoid boost::serialization::serialize_adl(Archive&, T&, unsigned int) [with Archive = boost::mpi::packed_iarchive, T = int*]âpath/boost_1_43_0/boost/archive/detail/iserializer.hpp:182: instantiated from âvoid boost::archive::detail::iserializer<Archive, T>::load_object_data(boost::archive::detail::basic_iarchive&, void*, unsigned int) const [with Archive = boost::mpi::packed_iarchive, T = int*]â myProg.cpp:413: instantiated from herepath/boost_1_43_0/boost/serialization/access.hpp:118: error: request for member âserializeâ in âtâ, which is of non-class type âint*âpath/boost_1_43_0/boost/serialization/access.hpp: In static member function âstatic void boost::serialization::access::serialize(Archive&, T&, unsigned int) [with Archive = boost::mpi::packed_iarchive, T = double]â:path/boost_1_43_0/boost/serialization/serialization.hpp:74: instantiated from âvoid boost::serialization::serialize(Archive&, T&, unsigned int) [with Archive = boost::mpi::packed_iarchive, T = double]âpath/boost_1_43_0/boost/serialization/serialization.hpp:133: instantiated from âvoid boost::serialization::serialize_adl(Archive&, T&, unsigned int) [with Archive = boost::mpi::packed_iarchive, T = double]âpath/boost_1_43_0/boost/archive/detail/iserializer.hpp:182: instantiated from âvoid boost::archive::detail::iserializer<Archive, T>::load_object_data(boost::archive::detail::basic_iarchive&, void*, unsigned int) const [with Archive = boost::mpi::packed_iarchive, T = double]â myProg.cpp:413: instantiated from herepath/boost_1_43_0/boost/serialization/access.hpp:118: error: request for member âserializeâ in âtâ, which is of non-class type âdoubleâpath/boost_1_43_0/boost/serialization/access.hpp: In static member function âstatic void boost::serialization::access::serialize(Archive&, T&, unsigned int) [with Archive = boost::mpi::packed_oarchive, T = int*]â:path/boost_1_43_0/boost/serialization/serialization.hpp:74: instantiated from âvoid boost::serialization::serialize(Archive&, T&, unsigned int) [with Archive = boost::mpi::packed_oarchive, T = int*]âpath/boost_1_43_0/boost/serialization/serialization.hpp:133: instantiated from âvoid boost::serialization::serialize_adl(Archive&, T&, unsigned int) [with Archive = boost::mpi::packed_oarchive, T = int*]âpath/boost_1_43_0/boost/archive/detail/oserializer.hpp:148: instantiated from âvoid boost::archive::detail::oserializer<Archive, T>::save_object_data(boost::archive::detail::basic_oarchive&, const void*) const [with Archive = boost::mpi::packed_oarchive, T = int*]â ---------------------------------------------------------------- It does not indicate the line number of my program with errors. The 413 is the last line of myProg.cpp. What is the meaning of "request for member serialize in t, which is of non-class type double" ? Any help is appreciated. Jack Aug. 28 2010

1 0

Fwd: Bundled properties for GraphProperties
by Saeed Nari 29 Aug '10

29 Aug '10

Hi all, I wonder if I can use a user defined class (bundled property) as a GraphProperty. The documentation just says about vertex and edge properties. Actually I could compile the below line with no errors: typedef adjacency_list<listS, vecS, directedS, vClass, eClass, gClass> Graph; vClass, eClass and gClass are my own classes. I don't know how to access the members from gClass anyway. Graph g; Vertex v; Edge e; g[v].vMember and g[e].eMember work fine. But I get error for g.gMember. Thanks Saeed

4 3

Is Boost-CMake Dead or Alive?
by Michael Jackson 28 Aug '10

28 Aug '10

http://ryppl.org/news/ So the boost-svn tracking is now hosted at Github. Ok. If you read farther down the page then it looks like Boost-CMake really _is_ going to be resurrected in the future? Is there any current activity with respect to Boost and git and cmake? I am so confused. I was going to take over for Troy S. in getting Boost-CMake ready after each release but if there is "Official" work doing this then I am not going to waste me time. Clarifications would be wonderful at this point. Thanks Mike Jackson

5 5

Any class for a buffer or temporary file ?
by Timothy Madden 28 Aug '10

28 Aug '10

Hello Is there a class or stream class in boost to implement a buffer that will use memory storage fro small data sizes, and disk storage in temporary files for large data sizes ? Or is there a (random-access) file stream class to open some unnamed or temporary file that will automatically be deleted after closing ? Thank you, Timothy Madden

1 0

[filesystem] Using filesystem library from Boost version 1.44 on Cygwin 1.7
by Clarke, Carus V 27 Aug '10

27 Aug '10

I have been using the filesystem library from Boost version 1.43 on a Cygwin 1.7.6-1 platform without any problems. The library was built using the Cygwin version of GCC 4.3.4. The library from the 1.44 version of Boost compiles compiles o.k., but the functions that access files no longer work. This appears to be true for both versions 2 and 3 of the library. Below is a simple program that runs o.k. with the Boost version 1.43 version of the library. The program runs but can not read the file status using Boost version 1.44. This program also works fine when built using MSVC 9.0 and Boost version 1.44. Am I doing something wrong? Any help would be appreciated. Thanks, Carus V. (Bud) Clarke carus.v.clarke(a)boeing.com //-------------------- #include <fstream> #include <iostream> #include <string> #include <boost/version.hpp> #define BOOST_FILESYSTEM_NO_DEPRECATED # if !defined(BOOST_FILESYSTEM_VERSION) # define BOOST_FILESYSTEM_VERSION 3 // disabled: # define BOOST_FILESYSTEM_VERSION 2 # endif #include <boost/filesystem.hpp> #include <boost/system/error_code.hpp> int main() { namespace boost_fs = boost::filesystem; const std::string pathStr = "foo"; std::ofstream ostrm(pathStr.c_str()); if (ostrm) { ostrm << "abcde-12345" << std::endl; ostrm.close(); } boost_fs::path path(pathStr); boost::system::error_code ec; std::cout << std::boolalpha; std::cout << "Checking status of file " << pathStr << "..." << std::endl; boost_fs::file_status st = boost_fs::status(path, ec); std::cout << "Error code value: " << ec.value() << std::endl; std::cout << "Error code message: " << ec.message() << std::endl; return 0; } //-------------------- This program's output on my system is shown below. The file 'foo' is written by the program and does actually exist. For version 2: boost::filesystem library version is v2 Checking status of file foo... Error code value: 0 Error code message: The operation completed successfully Does file exist? false For version 3: boost::filesystem library version is v3 Checking status of file foo... Error code value: 2 Error code message: The system cannot find the file specified Does file exist? false //--------------------

2 1

Re: [Boost-users] [Boost.MPI] question about serializingcustomobject
by Elli Barasch 27 Aug '10

27 Aug '10

Robert Ramey <ramey(a)rrsd.com> wrote: >David Abrahams wrote: >>>> And since Boost.MPI and Boost.Serialization are so closely >>>> related, I think it's especially important that *you* underestand. >>> >>> I disagree. Boost MPI depends upon Boost.Serialization >>> but not the other way around. >> >> I didn't say they were interdependent, just that they were >> closely-related. But anyway, I think you're being shortsighted: The >> success of tools built on top of Boost.Serialization is an important >> indicator of the correctness and genericity of its design. > >> Boost.Serialization *is* dependent on Boost.MPI for a portion of its >> userbase, > ><off topic> what portion of the user base? (This is a rhetorical question >please don't spend any time answering it.) It's always bothered me >that we have no per library data/feedback on the interest/usage >on a library by library basis. I've spoken about this before and >I know you agree with me about it. But until this get's addressed >I think we just have to set these questions aside and recognize >that the answers are anyone's guess. > ><snip> > >> You can't be a generic serialization library without reference to real >> applications. Maybe you still haven't really decided whether serving >> Boost.MPI and its users is something you want to do. > > I think that >> might account for a good deal of the recurring friction we experience. >> It would be a good idea to settle on an answer to that question, along >> with the question of what other applications you're willing to >> support. > >I am acutely aware of this aspect of "generic library design". Every >post on this list reminds me of it. > >>> I only really have few observations/suggestions at this point. >>> >>> a) It would be helpful if there were a way to test the serialization >>> of the archive classes in boost MPI without having MPI installed. >>> If this is not possible, it would seem to me that the serialization >>> is intertwined with the data transport - rather than be separated >>> as it is in the stream/streambuf io/stream design. This would look >>> like a design flaw to me. >> >> Helpful to whom? I agree this is all a good idea, but I'm not sure >> how this relates to anything else we're discussing. > >It would permit me to use the MPI serialization as a use case >to verify that I hadn't broken anything. I know what your going >to say - concepts - but that is going to be a while before that >happens. > >>> b) user experience seems to show that archive >>> construction/destruction is a significant performance issue when a >>> new archive is made for each data transmission. On the other hand, >>> one has to do this since the current archive implemenation track >>> addresses of serialized obects so the same archive can't be use send >>> the same structure (maybe with changed data) multiple times. > >> I can't understand how you reach that conclusion. In my long >> explanation I thought I made it clear that Boost.MPI and its database >> get a great deal of its performance advantage from exactly that: >> sending the same structure multiple times with the same MPI type map. > >hmm - what about tracked objects? I suggested turning off tracking >and Matthias told me that it was needed to send pointers. But for this >to work an archive has to be reconstructed everytime to re-initialize >the tracking lists. I don't want to spend a lot of time on this as that >means I have to delve into the MPI serialization and I don't want >to do this. > >>> Given that MPI has a focus on performance, I wonder if this has been >>> considered. I looked a the documentation, code and examples and it >>> wasn't obvious to me how this is question was addressed - if at all. >> >> We've obviously misunderstood one another somewhere along the way. It >> would be good if we could get that cleared up. > >I think it would take too much time for me to understand. And if I did >come to understand it, I might have something to say about it. If I >said it, then it might start a thread which would cost even more time >which I don't have right now. > >Robert Ramey > > > > >_______________________________________________ >Boost-users mailing list >Boost-users(a)lists.boost.org >http://lists.boost.org/mailman/listinfo.cgi/boost-users

1 0

Re: [Boost-users] [Boost.MPI] question about serializingcustomobject
by Elli Barasch 27 Aug '10

27 Aug '10

Robert Ramey <ramey(a)rrsd.com> wrote: >David Abrahams wrote: >>>> And since Boost.MPI and Boost.Serialization are so closely >>>> related, I think it's especially important that *you* underestand. >>> >>> I disagree. Boost MPI depends upon Boost.Serialization >>> but not the other way around. >> >> I didn't say they were interdependent, just that they were >> closely-related. But anyway, I think you're being shortsighted: The >> success of tools built on top of Boost.Serialization is an important >> indicator of the correctness and genericity of its design. > >> Boost.Serialization *is* dependent on Boost.MPI for a portion of its >> userbase, > ><off topic> what portion of the user base? (This is a rhetorical question >please don't spend any time answering it.) It's always bothered me >that we have no per library data/feedback on the interest/usage >on a library by library basis. I've spoken about this before and >I know you agree with me about it. But until this get's addressed >I think we just have to set these questions aside and recognize >that the answers are anyone's guess. > ><snip> > >> You can't be a generic serialization library without reference to real >> applications. Maybe you still haven't really decided whether serving >> Boost.MPI and its users is something you want to do. > > I think that >> might account for a good deal of the recurring friction we experience. >> It would be a good idea to settle on an answer to that question, along >> with the question of what other applications you're willing to >> support. > >I am acutely aware of this aspect of "generic library design". Every >post on this list reminds me of it. > >>> I only really have few observations/suggestions at this point. >>> >>> a) It would be helpful if there were a way to test the serialization >>> of the archive classes in boost MPI without having MPI installed. >>> If this is not possible, it would seem to me that the serialization >>> is intertwined with the data transport - rather than be separated >>> as it is in the stream/streambuf io/stream design. This would look >>> like a design flaw to me. >> >> Helpful to whom? I agree this is all a good idea, but I'm not sure >> how this relates to anything else we're discussing. > >It would permit me to use the MPI serialization as a use case >to verify that I hadn't broken anything. I know what your going >to say - concepts - but that is going to be a while before that >happens. > >>> b) user experience seems to show that archive >>> construction/destruction is a significant performance issue when a >>> new archive is made for each data transmission. On the other hand, >>> one has to do this since the current archive implemenation track >>> addresses of serialized obects so the same archive can't be use send >>> the same structure (maybe with changed data) multiple times. > >> I can't understand how you reach that conclusion. In my long >> explanation I thought I made it clear that Boost.MPI and its database >> get a great deal of its performance advantage from exactly that: >> sending the same structure multiple times with the same MPI type map. > >hmm - what about tracked objects? I suggested turning off tracking >and Matthias told me that it was needed to send pointers. But for this >to work an archive has to be reconstructed everytime to re-initialize >the tracking lists. I don't want to spend a lot of time on this as that >means I have to delve into the MPI serialization and I don't want >to do this. > >>> Given that MPI has a focus on performance, I wonder if this has been >>> considered. I looked a the documentation, code and examples and it >>> wasn't obvious to me how this is question was addressed - if at all. >> >> We've obviously misunderstood one another somewhere along the way. It >> would be good if we could get that cleared up. > >I think it would take too much time for me to understand. And if I did >come to understand it, I might have something to say about it. If I >said it, then it might start a thread which would cost even more time >which I don't have right now. > >Robert Ramey > > > > >_______________________________________________ >Boost-users mailing list >Boost-users(a)lists.boost.org >http://lists.boost.org/mailman/listinfo.cgi/boost-users

1 0

Re: [Boost-users] [Boost.MPI] question about serializingcustomobject
by Elli Barasch 27 Aug '10

27 Aug '10

Robert Ramey <ramey(a)rrsd.com> wrote: >David Abrahams wrote: >>>> And since Boost.MPI and Boost.Serialization are so closely >>>> related, I think it's especially important that *you* underestand. >>> >>> I disagree. Boost MPI depends upon Boost.Serialization >>> but not the other way around. >> >> I didn't say they were interdependent, just that they were >> closely-related. But anyway, I think you're being shortsighted: The >> success of tools built on top of Boost.Serialization is an important >> indicator of the correctness and genericity of its design. > >> Boost.Serialization *is* dependent on Boost.MPI for a portion of its >> userbase, > ><off topic> what portion of the user base? (This is a rhetorical question >please don't spend any time answering it.) It's always bothered me >that we have no per library data/feedback on the interest/usage >on a library by library basis. I've spoken about this before and >I know you agree with me about it. But until this get's addressed >I think we just have to set these questions aside and recognize >that the answers are anyone's guess. > ><snip> > >> You can't be a generic serialization library without reference to real >> applications. Maybe you still haven't really decided whether serving >> Boost.MPI and its users is something you want to do. > > I think that >> might account for a good deal of the recurring friction we experience. >> It would be a good idea to settle on an answer to that question, along >> with the question of what other applications you're willing to >> support. > >I am acutely aware of this aspect of "generic library design". Every >post on this list reminds me of it. > >>> I only really have few observations/suggestions at this point. >>> >>> a) It would be helpful if there were a way to test the serialization >>> of the archive classes in boost MPI without having MPI installed. >>> If this is not possible, it would seem to me that the serialization >>> is intertwined with the data transport - rather than be separated >>> as it is in the stream/streambuf io/stream design. This would look >>> like a design flaw to me. >> >> Helpful to whom? I agree this is all a good idea, but I'm not sure >> how this relates to anything else we're discussing. > >It would permit me to use the MPI serialization as a use case >to verify that I hadn't broken anything. I know what your going >to say - concepts - but that is going to be a while before that >happens. > >>> b) user experience seems to show that archive >>> construction/destruction is a significant performance issue when a >>> new archive is made for each data transmission. On the other hand, >>> one has to do this since the current archive implemenation track >>> addresses of serialized obects so the same archive can't be use send >>> the same structure (maybe with changed data) multiple times. > >> I can't understand how you reach that conclusion. In my long >> explanation I thought I made it clear that Boost.MPI and its database >> get a great deal of its performance advantage from exactly that: >> sending the same structure multiple times with the same MPI type map. > >hmm - what about tracked objects? I suggested turning off tracking >and Matthias told me that it was needed to send pointers. But for this >to work an archive has to be reconstructed everytime to re-initialize >the tracking lists. I don't want to spend a lot of time on this as that >means I have to delve into the MPI serialization and I don't want >to do this. > >>> Given that MPI has a focus on performance, I wonder if this has been >>> considered. I looked a the documentation, code and examples and it >>> wasn't obvious to me how this is question was addressed - if at all. >> >> We've obviously misunderstood one another somewhere along the way. It >> would be good if we could get that cleared up. > >I think it would take too much time for me to understand. And if I did >come to understand it, I might have something to say about it. If I >said it, then it might start a thread which would cost even more time >which I don't have right now. > >Robert Ramey > > > > >_______________________________________________ >Boost-users mailing list >Boost-users(a)lists.boost.org >http://lists.boost.org/mailman/listinfo.cgi/boost-users

1 0

Re: [Boost-users] [Boost.MPI] question about serializingcustomobject
by Elli Barasch 27 Aug '10

27 Aug '10

Robert Ramey <ramey(a)rrsd.com> wrote: >David Abrahams wrote: >>>> And since Boost.MPI and Boost.Serialization are so closely >>>> related, I think it's especially important that *you* underestand. >>> >>> I disagree. Boost MPI depends upon Boost.Serialization >>> but not the other way around. >> >> I didn't say they were interdependent, just that they were >> closely-related. But anyway, I think you're being shortsighted: The >> success of tools built on top of Boost.Serialization is an important >> indicator of the correctness and genericity of its design. > >> Boost.Serialization *is* dependent on Boost.MPI for a portion of its >> userbase, > ><off topic> what portion of the user base? (This is a rhetorical question >please don't spend any time answering it.) It's always bothered me >that we have no per library data/feedback on the interest/usage >on a library by library basis. I've spoken about this before and >I know you agree with me about it. But until this get's addressed >I think we just have to set these questions aside and recognize >that the answers are anyone's guess. > ><snip> > >> You can't be a generic serialization library without reference to real >> applications. Maybe you still haven't really decided whether serving >> Boost.MPI and its users is something you want to do. > > I think that >> might account for a good deal of the recurring friction we experience. >> It would be a good idea to settle on an answer to that question, along >> with the question of what other applications you're willing to >> support. > >I am acutely aware of this aspect of "generic library design". Every >post on this list reminds me of it. > >>> I only really have few observations/suggestions at this point. >>> >>> a) It would be helpful if there were a way to test the serialization >>> of the archive classes in boost MPI without having MPI installed. >>> If this is not possible, it would seem to me that the serialization >>> is intertwined with the data transport - rather than be separated >>> as it is in the stream/streambuf io/stream design. This would look >>> like a design flaw to me. >> >> Helpful to whom? I agree this is all a good idea, but I'm not sure >> how this relates to anything else we're discussing. > >It would permit me to use the MPI serialization as a use case >to verify that I hadn't broken anything. I know what your going >to say - concepts - but that is going to be a while before that >happens. > >>> b) user experience seems to show that archive >>> construction/destruction is a significant performance issue when a >>> new archive is made for each data transmission. On the other hand, >>> one has to do this since the current archive implemenation track >>> addresses of serialized obects so the same archive can't be use send >>> the same structure (maybe with changed data) multiple times. > >> I can't understand how you reach that conclusion. In my long >> explanation I thought I made it clear that Boost.MPI and its database >> get a great deal of its performance advantage from exactly that: >> sending the same structure multiple times with the same MPI type map. > >hmm - what about tracked objects? I suggested turning off tracking >and Matthias told me that it was needed to send pointers. But for this >to work an archive has to be reconstructed everytime to re-initialize >the tracking lists. I don't want to spend a lot of time on this as that >means I have to delve into the MPI serialization and I don't want >to do this. > >>> Given that MPI has a focus on performance, I wonder if this has been >>> considered. I looked a the documentation, code and examples and it >>> wasn't obvious to me how this is question was addressed - if at all. >> >> We've obviously misunderstood one another somewhere along the way. It >> would be good if we could get that cleared up. > >I think it would take too much time for me to understand. And if I did >come to understand it, I might have something to say about it. If I >said it, then it might start a thread which would cost even more time >which I don't have right now. > >Robert Ramey > > > > >_______________________________________________ >Boost-users mailing list >Boost-users(a)lists.boost.org >http://lists.boost.org/mailman/listinfo.cgi/boost-users

1 0

Re: [Boost-users] BoostSerialization callinga customserialize method
by Elli Barasch 27 Aug '10

27 Aug '10

Robert Ramey <ramey(a)rrsd.com> wrote: >Pooyan Dadvand wrote: > >> Can you please explain me more the idea of extradata structure? >> Consider that my extradata can be a double, ublas::vector, or even >> std::vector<weak_ptr<Element> > or any new type of variables. I >> have: >> >> std::vector<std::pair<VariableData, extradata> > mData >> ... >> ar << mData; >> >> >> and each element of vector can have a different type of data with >> different size or even have pointers. (It's a heterogeneous >> container) > >The above will work as written. > >Maybe what you want is: > >template<class T> >class mytype : std::vector<std::pair<VariableData, T> > { > template<class Archive> > void serialize(Archive &ar, const unsigned int version){ > ar << boost::serialization::base_object(*this); > } >}; > >then you can > >mytype<double> m_t >... >ar << m_t > >The possibilities are endless. This really isn't about the serialization >library >but about C++ > >Robert Ramey > > > >_______________________________________________ >Boost-users mailing list >Boost-users(a)lists.boost.org >http://lists.boost.org/mailman/listinfo.cgi/boost-users

1 0

[boost::wave] Hooks not called for conditionals
by Alden King 27 Aug '10

27 Aug '10

I am currently working on a project that uses Wave to pre-process and tokenize C/C++ code, but I am not getting everything that I expect from the preprocessing hooks. We use the preprocessing hooks to extract data about false-branches, macro calls and macro expansions so this is a major roadblock for us. I am trying to extract information about the true and false branch of #if 1 int foo; #elif 0 float foo; #else struct { } foo; #endif The first #if is seen by 'found_directive'. If that returns false, then I get #ifint foo; #eliffloat foo; #else struct { } foo; #endif Note that it skips the newline after the #if and #elif and that it doesn't reveal their conditions. If it returns true, then 'evaluated_conditional_expression also gets called and I get #if 1 // [Taken] int foo; #elif0 float foo; struct { } foo; Without the #else directive, the #endif directive, and the whitespace between #elif and it's condition. My problem is that the false branch is not seen by either function (the endif also has trouble sometimes). I therefore expected all tokens in the false branch to be processed by 'may_skip_whitespace' or 'skipped_token', but that is not the case. Could you please help me to find our how to get the tokens from the false branch of the conditional expression using the preprocessing hooks? I've attached my wave test program and a sample input file. Thanks.

2 1

Boost Serialization calling a custom serialize method
by Pooyan Dadvand 27 Aug '10

27 Aug '10

Hi, Im trying to use the boost serialization in our project Kratos (a Multi-physics finite element code) in which I found the following problem, I have a class Variable which is derived from VariableData as follow: Class VariableData { std::size_t mKey; public: ..... }; template<class TDataType> class Variable : public VariableData { .... } Now I have a container which holds a pairs, consist of VariableData pointer to the Variable and a void* pointer to its value: std::vector<std::pair<const VariableData*, void*> > which I want to serialize but as it can be seen I dont have the pointer to data in my variable and I might need to implement a costumized version of Serialized with void* pValue as an additional parameter for VariableData and Variable classes: template<class TArchiveType> Variable::serialize(TArchiveType &rArchive, const unsigned int Version, void* pValue) { rArchive & static_cast<TDataType>(pVAlue); } The problem here is the template definition of this method which make it impossible to be virtual. I note that the library uses get_extended_type_info for this porposed. But I dont know how is its correct way of use. Can anybody give me a hint about how I can handle this problem? Just to add some restriction: - I dont want to add a hierarchy of handlers instead of pair because it adds another pointer jump to the container and reduce its performance in normal use of it - I dont want to add a version of non template members for each archive type while it makes a lot of duplications and makes extra dependency to the archive types in a layer of code which is not expected to have this dependency Thanks, Pooyan. ____________________________________________________________________________ ____________________________________________________________________________ _______________________ Dr. Pooyan Dadvand Member of Kratos team International Center for Numerical Methods in Engineering - CIMNE Campus Norte, Edificio C1 c/ Gran Capitán s/n 08034 Barcelona, España Tel: (+34) 93 401 56 96 Fax: (+34) 93.401.65 17 web: <http://www.cimne.com> www.cimne.com <http://www.cimne.com/kratos/> www.cimne.com/kratos/ ____________________________________________________________________________ ____________________________________________________________________________ _______________________ AVISO IMPORTANTE Los datos de carácter personal contenidos en el mensaje, se registrarán en un fichero para facilitar la gestión de las comunicaciones de CIMNE. Se pueden ejercitar los derechos de acceso, rectificación, cancelación y oposición por escrito, dirigiéndose a nuestras oficinas de CIMNE, Gran Capitán s/n, Edificio C1 - Campus Norte UPC, 08034 Barcelona, España. AVÍS IMPORTANT Les dades de caràcter personal contingudes en aquest missatge es registraran en un fitxer per facilitar la gestió de les comunicacions del CIMNE. Es poden exercir els drets d'accés, rectificació, cancel·lació i oposició, per escrit a les nostres oficines del CIMNE, Gran Capità s/n, Edifici C1, Campus Nord UPC, 08034 Barcelona, Espanya. IMPORTANT NOTICE All personal data contained in this mail will be processed confidentially and stored in a file property of CIMNE in order to manage corporate communications. You may exercise the right of access, rectification, deletion and objection by letter sent to CIMNE, Gran Capitán, Edificio C1 - Campus Norte UPC, 08034 Barcelona, Spain.

5 17

[Hash] Custom hash_value for Pointers
by Hossein Haeri 27 Aug '10

27 Aug '10

Dear all, Should not the program in the P.S. output "I got used!"? If not, how can I ensure that it's size_t hash_value(B*) which gets called upon use of bPtrHasher's operator()? TIA, --Hossein P.S. namespace Bs { struct B { virtual string id() const {return "This is a B!";} }; struct D: B { string id() const {return "And, this one is a D.";} }; size_t hash_value(B* bptr) { cout << "I got used!" << endl; boost::hash<string> hasher; return hasher(bptr->id()); } } int main() { Bs::B* bp1 = new Bs::B; Bs::B* bp2 = new Bs::D; boost::hash<Bs::B*> bPtrHasher; size_t h1 = bPtrHasher(bp1), h2 = bPtrHasher(bp2); }

2 1

NDEBUG causes a compilation error in Boost.Interprocess
by Sergey Kurenkov 27 Aug '10

27 Aug '10

I use Boost 1.42 and gcc 4.3.1 on HP-UX 11.31. So today I defined NDEBUG and BOOST_DISABLE_ASSERTS in my makefile, ran make and got this error: ../../../src/libs/src/external/boost/1.42.0/boost/interprocess/sync/posix/semaphore_wrapper.hpp: In function 'void boost::interprocess::detail::semaphore_close(sem_t*)': ../../../src/libs/src/external/boost/1.42.0/boost/interprocess/sync/posix/semaphore_wrapper.hpp:102: error: 'assert' was not declared in this scope ../../../src/libs/src/external/boost/1.42.0/boost/interprocess/sync/posix/semaphore_wrapper.hpp: In function 'void boost::interprocess::detail::semaphore_destroy(sem_t*)': ../../../src/libs/src/external/boost/1.42.0/boost/interprocess/sync/posix/semaphore_wrapper.hpp:137: error: 'assert' was not declared in this scope If I do not set NDEBUG and BOOST_DISABLE_ASSERTS everything is OK. Seems like the problem is that in semaphore_wrapper.hpp there is a call to assert() and if NDEBUG is set then correct headers are not included.

2 1

[Serialization] Combination of templates and polymorphism
by Michal Gregor 27 Aug '10

27 Aug '10

I am writing serialization for a template library I created. The problem is that I cannot figure out how to serialize templates of polymorphic classes (combination of polymorphism and templates). Polymorphic classes generally need to be exported using BOOST_CLASS_EXPORT, which however takes in a complete type so this would require me to register all possible instantiations of the templates, which is not possible - I don't know beforehand what instantiations might the library user make (I would have to rely on the user of the library to do the work and there is no way the user will even know which template classes may be instantiated behind the scenes somewhere). What I would like is a mechanism that would automagically register the class upon instantiation. Any ideas? -- View this message in context: http://old.nabble.com/-Serialization--Combination-of-templates-and-polymorp… Sent from the Boost - Users mailing list archive at Nabble.com.

1 0

How to disable warnings on gcc?
by Jean-Pierre Bergamin 27 Aug '10

27 Aug '10

Dear boost users On FreeBSD 8.1 with boost 1.43 and gcc 4.2.1 we have lots of warnings like: ... /usr/local/include/boost/type_traits/is_unsigned.hpp: In instantiation of 'boost::detail::is_ununsigned_helper<short int>': /usr/local/include/boost/type_traits/is_unsigned.hpp:73: instantiated from 'boost::detail::is_unsigned_imp<short int>' /usr/local/include/boost/type_traits/is_unsigned.hpp:123: instantiated from 'boost::is_unsigned<short int>' /usr/local/include/boost/type_traits/make_unsigned.hpp:110: instantiated from 'boost::detail::make_unsigned_imp<short int>' /usr/local/include/boost/type_traits/make_unsigned.hpp:130: instantiated from 'boost::make_unsigned<short int>' /usr/local/include/boost/lexical_cast.hpp:846: instantiated from here /usr/local/include/boost/type_traits/is_unsigned.hpp:40: warning: comparison between 'enum boost::detail::is_unsigned_values<short int>::<anonymous>' and 'enum boost::detail::is_unsigned_values<short int>::<anonymous>' ... Similar warnings about "comparison between ..." pop up in the serialization library as well. What is the easiest way to suppress these warnings? I tried using the switches "-Wno-sign-compare" and "-Wno-conversion", but the warnings don't go away. Thanks for your help James

2 4

[Serialization] Is there any documentation on make_nvp()?
by Robert Jones 27 Aug '10

27 Aug '10

If so, please point me to it. Thx - Rob.

2 2

Missing lib with Boost::Regex
by Emir D. 27 Aug '10

27 Aug '10

Hello everybody, I'm having some problems with using Boost's Regex in MS Visual Studio 2010. I've included the header file and downloaded the "bjam.exe" file, which I have run and it generated some lib and obj files. After including the newly generated files in VS2010, when I try to compile, I get the following: "fatal error LNK1104: cannot open file 'libboost_regex-vc100-mt-gd-1_43.lib' " I've inspected the bjam.exe generated files and it appears to have a lib file 'libboost_regex-vc100-mt-1_43.lib', but not 'libboost_regex-vc100-mt-gd-1_43.lib'. After doing some more googling, I have found a number of related questions, but failed to find an answer, although it seems to be a common problem. Can you please help me solve my problem? Thanks in advance, p.s. If i rename the lib file, it works, at least for now. However, it is a 'Release' version and therefore I can't using it in VS in debugging mode, meaning that I can only BatchBuild and create Release versions of my program, although I also need to create debug ones. p.s.s. My first Boost Mailing List post! p.s.s.s. I've just found out that VS10 has TR1 support, so I can TR1 Regex, which is Boost's Regex :) but I am still wondering how could of I solved the above stated problem? It's bound to happen with some other Boost library.

4 3

Boost test, segmentation fault.
by Matthijs Mohlmann 27 Aug '10

27 Aug '10

Hello all, First of all: I'm building an application and with that I use Boost test for unit testing. This helped me already to fix some obscure bugs. (I am very happy with boost test) I have the Master suite test setup in one file and the normal test suites each in one file. This worked very well. Now I have the following test suite which gives me a segmentation fault and I have no idea why: BOOST_AUTO_TEST_SUITE(ProgramOptions) BOOST_AUTO_TEST_CASE(ProgramOptions_Valid_Options) { // Output boost::test_tools::output_test_stream output("misc/ProgramOptions_01.output", true); // Save output buffer std::streambuf *strmbuffer; strmbuffer = std::cout.rdbuf(); // Redirect the output. std::cout.rdbuf(output.rdbuf()); // Redirect output stream so we can do some checks. printSomething(); BOOST_REQUIRE(output.match_pattern()); // Now lets process some arguments. printSomething(); BOOST_REQUIRE(output.match_pattern()); // Restore output buffer std::cout.rdbuf(strmbuffer); } BOOST_AUTO_TEST_SUITE_END() The function that gets tested: void printSomething() { std::cout << "Test output" << std::endl; } If I put the same content 'Test output' in the ProgramOptions_01.output file then everything is fine and executes ok. When putting different content in that file it goes wrong. I have also a gdb backtrace if that is interesting: (gdb) r Starting program: /home/matthijs/Projects/cppcms/trunk/cmsapp_test [Thread debugging using libthread_db enabled] Running 10 test cases... Program received signal SIGSEGV, Segmentation fault. 0xb7f6f9e8 in vtable for boost::unit_test::progress_monitor_t () from /usr/lib/libboost_unit_test_framework.so.1.42.0 (gdb) bt full #0 0xb7f6f9e8 in vtable for boost::unit_test::progress_monitor_t () from /usr/lib/libboost_unit_test_framework.so.1.42.0 No symbol table info available. #1 0xb7e5b77f in std::ostream::flush() () from /usr/lib/libstdc++.so.6 No symbol table info available. #2 0xb7f0a13d in boost::unit_test::output::compiler_log_formatter::log_finish(std::ostream&) () from /usr/lib/libboost_unit_test_framework.so.1.42.0 No symbol table info available. #3 0xb7f2e492 in boost::unit_test::unit_test_log_t::test_finish() () from /usr/lib/libboost_unit_test_framework.so.1.42.0 No symbol table info available. #4 0xb7f1a593 in boost::unit_test::framework::run(unsigned long, bool) () from /usr/lib/libboost_unit_test_framework.so.1.42.0 No symbol table info available. #5 0xb7f2f469 in boost::unit_test::unit_test_main(bool (*)(), int, char**) () from /usr/lib/libboost_unit_test_framework.so.1.42.0 No symbol table info available. #6 0x08062133 in main (argc=1, argv=0xbffff824) at /usr/include/boost/test/unit_test.hpp:59 No locals. Hopefully someone with some insight in boost.test can help me out here... Regards, Matthijs Möhlmann

2 2

[MPL] has_xxx always returns false!
by Eric 27 Aug '10

27 Aug '10

This code: BOOST_MPL_HAS_XXX_TRAIT_DEF(normal); template<class T, bool HasNormal> class getVertexHasNormal { public: static void getNormal(T &tv) {} }; template<class T> class getVertexHasNormal<T, true> // true case { public: static void getNormal(T &tv) { // do something } }; template<class VT> class A : public base { void doit(v) /* override */ { VT tv; getVertexHasNormal<VT, has_normal<VT>::value >::getNormal(tv); } } if I understand correctly, this code is suppose to do call a different "getNormal" method if the method "normal" exists (or not) in the template parameter class. Basically mimicking the infamous "__if_exists" macro on the Microsoft c++ compiler.... right? but, has_normal<VT> always return false (visual studio 2008) so we don't get the right expected behavior! Feel free to educate me.... thanks in advance. eric

5 6

[Serialization] Is this example legal usage of the serialization library
by Elizabeta 26 Aug '10

26 Aug '10

Hi, Is it ok to serialize/deserialize in the object I get when dereference a pointer ? void f() { B* bObj=new B(); /// save { std::ofstream ofs("C:\\hh.txt"); boost::archive::xml_oarchive oa(ofs); oa & make_nvp("bObj",*bObj); } //// Load { std::ifstream ifs("C:\\hh.txt"); boost::archive::xml_iarchive ia(ifs); ia & make_nvp("bObj",*bObj); } } My second question : Is it ok to serialize/deserialize in *this ? Thanks

3 3

[serialization] problem with custom archive type
by Kenneth Riddile 26 Aug '10

26 Aug '10

I have a custom input archive type that has worked fine when statically linked to the serialization library. I'm now must use serialization as a DLL and the code no longer compiles. This is under MSVC9 with BOOST_ALL_DYN_LINK defined. This code works fine on Linux/GCC with serialization built as a shared library...so the problem appears specific to Windows/MSVC. Here is a boiled down version of the code that exhibits the problem: // HEADER CONTENTS #include <boost/archive/xml_iarchive.hpp> class CustomArchive : public boost::archive::xml_iarchive_impl<CustomArchive> , public boost::archive::detail::shared_ptr_helper { public: CustomArchive( std::istream& is, int foo ) : boost::archive::xml_iarchive_impl<CustomArchive>( is, 0 ) , m_foo( foo ) { } int GetFoo() const { return m_foo; } template<class T> void load( T& t ) { boost::archive::xml_iarchive_impl<CustomArchive>::load( t ); } private: friend class boost::archive::xml_iarchive_impl<CustomArchive>; friend class boost::archive::basic_xml_iarchive<CustomArchive>; friend class boost::archive::load_access; int m_foo; }; // CPP CONTENTS #include <CustomArchive.hpp> #include <boost/archive/impl/basic_xml_iarchive.ipp> #include <boost/archive/impl/xml_iarchive_impl.ipp> #include <boost/archive/impl/archive_serializer_map.ipp> namespace boost { namespace archive { template class basic_xml_iarchive<CustomArchive>; template class xml_iarchive_impl<CustomArchive>; template class detail::archive_serializer_map<CustomArchive>; } } BOOST_SERIALIZATION_REGISTER_ARCHIVE( CustomArchive ) and here are the errors: 1>C:\Boost\include\boost/archive/impl/basic_xml_iarchive.ipp(41) : error C2491: 'boost::archive::basic_xml_iarchive<Archive>::load_start' : definition of dllimport function not allowed 1>C:\Boost\include\boost/archive/impl/basic_xml_iarchive.ipp(77) : error C2491: 'boost::archive::basic_xml_iarchive<Archive>::load_end' : definition of dllimport function not allowed 1>C:\Boost\include\boost/archive/impl/basic_xml_iarchive.ipp(83) : error C2491: 'boost::archive::basic_xml_iarchive<Archive>::load_override' : definition of dllimport function not allowed 1>C:\Boost\include\boost/archive/impl/basic_xml_iarchive.ipp(89) : error C2491: 'boost::archive::basic_xml_iarchive<Archive>::load_override' : definition of dllimport function not allowed 1>C:\Boost\include\boost/archive/impl/basic_xml_iarchive.ipp(95) : error C2491: 'boost::archive::basic_xml_iarchive<Archive>::load_override' : definition of dllimport function not allowed 1>C:\Boost\include\boost/archive/impl/basic_xml_iarchive.ipp(101) : error C2491: 'boost::archive::basic_xml_iarchive<Archive>::load_override' : definition of dllimport function not allowed 1>C:\Boost\include\boost/archive/impl/basic_xml_iarchive.ipp(108) : error C2491: 'boost::archive::basic_xml_iarchive<Archive>::basic_xml_iarchive' : definition of dllimport function not allowed 1>C:\Boost\include\boost/archive/impl/basic_xml_iarchive.ipp(111) : error C2491: 'boost::archive::basic_xml_iarchive<Archive>::~basic_xml_iarchive' : definition of dllimport function not allowed 1>Warning: This header is deprecated. Please use: boost/spirit/include/classic_rule.hpp 1>C:\Boost\include\boost/archive/impl/xml_iarchive_impl.ipp(83) : error C2491: 'boost::archive::xml_iarchive_impl<Archive>::load' : definition of dllimport function not allowed 1>C:\Boost\include\boost/archive/impl/xml_iarchive_impl.ipp(114) : error C2491: 'boost::archive::xml_iarchive_impl<Archive>::load' : definition of dllimport function not allowed 1>C:\Boost\include\boost/archive/impl/xml_iarchive_impl.ipp(127) : error C2491: 'boost::archive::xml_iarchive_impl<Archive>::load' : definition of dllimport function not allowed 1>C:\Boost\include\boost/archive/impl/xml_iarchive_impl.ipp(140) : error C2491: 'boost::archive::xml_iarchive_impl<Archive>::load' : definition of dllimport function not allowed 1>C:\Boost\include\boost/archive/impl/xml_iarchive_impl.ipp(153) : error C2491: 'boost::archive::xml_iarchive_impl<Archive>::load_override' : definition of dllimport function not allowed 1>C:\Boost\include\boost/archive/impl/xml_iarchive_impl.ipp(162) : error C2491: 'boost::archive::xml_iarchive_impl<Archive>::init' : definition of dllimport function not allowed 1>C:\Boost\include\boost/archive/impl/xml_iarchive_impl.ipp(189) : error C2491: 'boost::archive::xml_iarchive_impl<Archive>::xml_iarchive_impl' : definition of dllimport function not allowed 1>C:\Boost\include\boost/archive/impl/xml_iarchive_impl.ipp(202) : error C2491: 'boost::archive::xml_iarchive_impl<Archive>::~xml_iarchive_impl' : definition of dllimport function not allowed 1>C:\Boost\include\boost/archive/impl/archive_serializer_map.ipp(45) : error C2491: 'boost::archive::detail::archive_serializer_map<Archive>::insert' : definition of dllimport function not allowed 1>C:\Boost\include\boost/archive/impl/archive_serializer_map.ipp(57) : error C2491: 'boost::archive::detail::archive_serializer_map<Archive>::erase' : definition of dllimport function not allowed 1>C:\Boost\include\boost/archive/impl/archive_serializer_map.ipp(67) : error C2491: 'boost::archive::detail::archive_serializer_map<Archive>::find' : definition of dllimport function not allowed

2 4

[interprocess] Checking for existence Named Mutex
by Brian Davis 26 Aug '10

26 Aug '10

How do I check for the existence of a named resource in using boost interprocess without wrapping a open_only in a try catch block and waiting for the exception? Also are there calls for launching a process such as std::system that are nonblocking in Windows using the _spawnlp and friends calls?

3 5

Boost's additional test compilers - test results available?
by Jon Payne 26 Aug '10

26 Aug '10

Hi all, In the boost release notes (I was looked at 1.44) there is a section listing the "additional test compilers" - I use Borland/Codegear C++ 2010. Presumably this means the tests are run on those compilers? If so, are the results available anywhere? Thanks, Jon

1 0

Bost.thread: how to force Pthreads-w32 usage with MingW (x-compile)?
by Joost Kraaijeveld 26 Aug '10

26 Aug '10

Hi, I have x-compiled Boost using Pthreads-w32, using threading=multi,single threadapi=pthread. But when I x-compile my application Boost uses the win32 headers. I have looked at the thread sources but I cannot find out if it just should work or that I should use some macros. Can anyone help me with this? TIA -- Groeten, Joost Kraaijeveld Askesis B.V. Molukkenstraat 14 6524NB Nijmegen tel: 024-3888063 / 06-51855277 fax: 024-3608416 web: www.askesis.nl

1 0

X-compile: undefined reference to `boost::this_thread::interruptible_wait using Boost 1.42
by Joost Kraaijeveld 26 Aug '10

26 Aug '10

Hi, I am cross compiling an application from Linux to Windows using Boost 1.42. Doing that I get an undefined reference error when linking one of my own dll's to my own application: /bin/bash ../../libtool --tag=CXX --mode=link i586-mingw32msvc-g++ -pipe -Wall -Wextra -Wundef -Wshadow -Wconversion -I/home/jkr/mingw/boost/include -g -O2 -Wl,--enable-runtime-pseudo-reloc,--enable-auto-import -no-undefined -L/home/jkr/mingw/boost/lib -o ORBRegistration.exe ORBRegistration-Main.o ../../../library/DagdaORB/libdagdaorb.la ../../../library/DagdaCom/libdagdacom.la /home/jkr/Programming/C++/Danu/mingw/library/DanuBase/libdanubase.la /home/jkr/Programming/C++/Danu/mingw/library/DanuStream/libdanustream.la /home/jkr/Programming/C++/Danu/mingw/library/DanuDB/libdanudb.la -lboost_system-mt -lboost_serialization-mt -lboost_thread-mt -lboost_date_time-mt -lboost_filesystem-mt -lws2_32 -lmswsock libtool: link: i586-mingw32msvc-g++ -pipe -Wall -Wextra -Wundef -Wshadow -Wconversion -I/home/jkr/mingw/boost/include -g -O2 -Wl,--enable-runtime-pseudo-reloc -Wl,--enable-auto-import -o .libs/ORBRegistration.exe ORBRegistration-Main.o -L/home/jkr/mingw/boost/lib ../../../library/DagdaORB/.libs/libdagdaorb.a /home/jkr/Programming/C++/Dagda/mingw/library/DagdaCom/.libs/libdagdacom.a ../../../library/DagdaCom/.libs/libdagdacom.a /home/jkr/Programming/C++/Danu/mingw/library/DanuDB/.libs/libdanudb.a /home/jkr/Programming/C++/Danu/mingw/library/DanuStream/.libs/libdanustream.a /home/jkr/Programming/C++/Danu/mingw/library/DanuBase/.libs/libdanubase.a -lpthread -lodbc32 -lboost_system-mt -lboost_serialization-mt -lboost_thread-mt -lboost_date_time-mt -lboost_filesystem-mt -lws2_32 -lmswsock ../../../library/DagdaORB/.libs/libdagdaorb.a(libdagdaorb_la-IMRServer.o): In function `_ZN5boost6detail19basic_cv_list_entry4waitENS0_7timeoutE': /home/jkr/mingw/boost/include/boost/thread/win32/condition_variable.hpp:82: undefined reference to `boost::this_thread::interruptible_wait(void*, boost::detail::timeout)' collect2: ld returned 1 exit status I have no idea why I get this error, and hence no idea how to solve it. Does anyone have any idea? Additional info: - I cross-compiled Boost itself using the Debian's gcc-mingw32 4.4.4-0.1+b1 crosscompiler, - I used Pthreads-w32 release 2.8.0 (2006-12-22) - The full commandline I used was (the commandline is split for readability): PTW32_INCLUDE=/home/jkr/mingw/pthreads/include PTW32_LIB=/home/jkr/mingw/pthreads/lib bjam --prefix=/home/jkr/mingw/boost --layout=tagged link=shared variant=debug,release toolset=gcc target-os=windows threading=multi,single runtime-link=shared --without-python --without-mpi -sNO_BZIP2=1 -sNO_ZLIB=1 install TIA -- Groeten, Joost Kraaijeveld Askesis B.V. Molukkenstraat 14 6524NB Nijmegen tel: 024-3888063 / 06-51855277 fax: 024-3608416 web: www.askesis.nl

1 0

unresolved external when building Boost.Thread
by Kenneth Riddile 25 Aug '10

25 Aug '10

OS - Windows7 x64 compiler - MSVC9 Boost version - 1.44 Running the following command fails to build the thread library with the following error: bjam variant=release link=shared threading=multi runtime-link=shared --layout=tagged install thread.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) pu blic: __thiscall boost::gregorian::greg_month::greg_month(unsigned short)" (__im p_??0greg_month@gregorian@boost@@QAE@G@Z) referenced in function "public: __this call boost::gregorian::date::date(enum boost::date_time::special_values)" (??0da te@gregorian@boost@@QAE@W4special_values@date_time@2@@Z) bin.v2\libs\thread\build\msvc-9.0\release\threading-multi\boost_thread-vc90-mt-1 _44.dll : fatal error LNK1120: 1 unresolved externals Removing "--layout=tagged" from the command results in the thread library building successfully, but of course that isn't what I want :)

2 1

Running mcgregor_common_subgraphs on a graph with bundled properties
by Saeed Nari 25 Aug '10

25 Aug '10

Hi, Is it possible to run mcgregor_common_subgraphs algorithm on a graph with bundled properties? Thanks Saeed

2 2

[MultiArray, Thread] Setting the _ITERATOR_DEBUG_LEVEL
by lfrfly＠icqmail.com 24 Aug '10

24 Aug '10

It's probably well-known by now that multi_array has a problem with Visual Studio 2010: due to the way it identifies its iterators, you get errors unless you set the _ITERATOR_DEBUG_LEVEL preprocessor symbol to 0. First of all, when can we expect a fix for this (or is there one already)? Secondly, even if I manually set the _ITERATOR_DEBUG_LEVEL to 0 in Debug configuration (that's the default in Release), I am unable to build because when I try to link in the Boost Thread library, I get 2>libboost_thread-vc100-mt-gd-1_43.lib(thread.obj) : error LNK2038: mismatch detected for '_ITERATOR_DEBUG_LEVEL': value '2' doesn't match value '0' in test.obj This indicates that I need to build Boost Thread with that variable set to 0 as well, even in the debug mode; or else I need to somehow get the Release version of the library linked in instead. I'm not sure how to do either one of these options. Can anyone help me configure bjam to override the variable, or else override which lib is linked?

2 2

[boost-users][asio] Interaction problem with signals2?
by Germán Diago 24 Aug '10

24 Aug '10

Hello. I'm trying to call a signal after an async_read from inside a function called by boost::asio::io_service. The run function runs in a thread, and the observers are connected in a different thread. This is causing errors. It's my program or it's not possible to invoke a handler that is running in another thread from io_service::run? Thanks in advance.

1 0

using Regex and other Boost libraries that require a build
by Bhushan Inamdar 24 Aug '10

24 Aug '10

Hi all, I am relatively new to Boost but was wanting to install and do development on it for long now. Finally, I can now spare some time for that. I am using Visual Studio 2008 professional edition as a development IDE. I have installed Visual Assist X to assist me with the intellisense as well. I am having Windows 7 ultimate installed on my machine and I am trying to install latest i.e. BOOST 1.44.0 version. So far I have had partial success. I am able to build and compile the sample program on Boost site that needs only headers. But I am facing problems while building programs that reference other libraries. So here is what I did: - Tried unsuccessfully to install it using BoostPro; installation broke quite a few times. - So I gave up and downloaded the Boost compressed version and extracted it successfully in C: drive - The current location is C:\Program Files\Boost\Boost_1_44_0\....and the respective dir structure thereafter. - Then I downloaded the bjam utility and extracted it and then copied it to the Boost root dir - Following this, I double clicked bjam.exe and it ran the build. However, a lot of projects were skipped and virtually nothing was build. - Then I realized that it was Windows 7 we were dealing with and then immediately ran Bjam.exe as an administrator. - This time, it took a lot longer and I was seeing the compilation in progress and I think that it was satisfactory. - Then comes the part of linking the libraries through VC++ compiler to the code. - I then navigated to Tools->Options->Projects and Solutions->VC++Directories and selected Win32 on first combo on top left - There I selected Includes in the other combo on top right and added the C:\Program Files\Boost\Boost_1_44_0\Boost to the list - Then on the same page I changed the top right combo to Libraries and added C:\Program Files\Boost\Boost_1_44_0\libs to the list - Considering that I should not miss out on any other libraries, I added C:\Program Files\Boost\Boost_1_44_0\bin.V2 to the list as well; this directory was constructed as a result of build by Bjam.exe - Following that, I quickly followed the 2 tutorials on Boost site 1 for simple iostream (which worked after some adjustments) and the other for regex (which did not work). - Considering I might still have missed something, I went on to add the path C:\Program Files\Boost\Boost_1_44_0 to System variables and made changes to VC IDE accordingly. - Also, to mention, I did not find any simple way to build the libraries that need a separate build and neither did I found any simple tutorial on Boost site...where they have put the regex sample that extracts matched text from a paragraph So my questions: - I want to know if I have missed anything to build any of Boost libraries or link to VC IDE or else? - Is there a better way to make sure if all the variants of all the libraries are build and linked with VC? - Is there a way to do this with CMake? - I read that, some libraries have some dependencies like libz...etc. where can I get the list for all Boost libraries? - Although this Question is not related to Boost, on a lighter note, I would just want ask this. Please ignore this if it does not hold ground. I have installed Boost after I installed Visual Assist for Visual Studio. Hence, whereever I use Boost members and classes, it keeps on saying that refactoring data is not available. Hence, I presume that, if I uninstall and reinstall Visual Assist, it should help? Or in other words, is there a better way to refactor boost library code so that intellisense can pick that? I will continue searching for this and hope that there is an option in Visual Assist itself. Nonetheless, it is not as important as Boost build related questions. Hope to hear from you soon... Thanks and Regards, Bhushan.

4 3

preprocessing error
by Arnaud GELAS 24 Aug '10

24 Aug '10

Hi all, When compiling some code using boost, I get the following error: /usr/include/boost/type_traits/type_with_alignment.hpp:142: error: Not a valid preprocessing token ")BOOST_PP_LIST_FOLD_LEFT_CHECK_BOOST_PP_IIF" For more details, I posted the log here: http://gofigure2.sourceforge.net/temp/boost-error.txt Any idea what I could do wrong? My machine is a Fedora 13 (64 bits), the installed version of boost is 1.41.0, and I used gcc 4.4.4... Thanks in advance, Arnaud

1 0

Boost.Format
by John Dlugosz 24 Aug '10

24 Aug '10

I'm using Boost.Format as a simple way to create strings to pass to exception constructors and primitive logging output during debugging (Windows' OutputDebugString). I see that the format object can be inserted into a stream, easily. But, with arguments, it's awkward to convert it to a string -- you need extra parens around the whole thing. Is there some good reason why there is no implicit conversion to string? E.g. string message= boost.format("blah") % argument % errorcode; OutputDebugStringA (message.c_str()); throw std::runtime_error (message); Or, is there some simple way that I'm missing? Thanks, --John TradeStation Group, Inc. is a publicly-traded holding company (NASDAQ GS: TRAD) of three operating subsidiaries, TradeStation Securities, Inc. (Member NYSE, FINRA, SIPC and NFA), TradeStation Technologies, Inc., a trading software and subscription company, and TradeStation Europe Limited, a United Kingdom, FSA-authorized introducing brokerage firm. None of these companies provides trading or investment advice, recommendations or endorsements of any kind. The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer.

1 0

building all libs
by Kraus Philipp 24 Aug '10

24 Aug '10

Hi, I use boost with thread, iostreams and random. I compiled bjam first and uses them to compile all, but I must call every lib manual with ./bjam variant=release toolset=darwin threading=multi variant=release libs/iostreams/build How can I build the full boost with all libs in one run? Thanks Phil

4 4

cstdint.hpp causes warnings on VC10
by Michael Kaes 24 Aug '10

24 Aug '10

HI all, after switching to VC10 I recognized that including the cstdint.hpp header causes a warning. After looking into this header I saw that all defines like INT8_C are guarded to prevent multiple defines, except of the UINT8_C define (cstdint.hpp Line:400). Is this done on purpose because to me it looks as if the guard was just forgotten. Regards, Michael

2 1

[accumulators] chaining accumulator outputs
by Allen Chuang 24 Aug '10

24 Aug '10

Is there a way to chain the output of an accumulator and use it as the input of another accumulator? The sort of case I am thinking about is for example calculating the max of a rolling_mean. One obvious way to do this is to write a new rolling_mean_max accumulator and make it depend on rolling_mean, but the inner logic would be 99% duplicate of max. I was wondering if there was a way to do this without so much code duplication. -- GRATIS für alle GMX-Mitglieder: Die maxdome Movie-FLAT! Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome01

1 0

number cores / cpu
by Kraus Philipp 24 Aug '10

24 Aug '10

Hello, can I determine how many physical cpu and cores are installed in a system with the boost lib? Under *nix I would read /proc but I would like to do that with boost, because of "os-less". Thanks Phil

9 10

boost::asio SSL connection thru proxy server
by Kumar, Akhilesh 24 Aug '10

24 Aug '10

Hi, I am writing a boost socket client using boost::asio to do secure HTTP (HTTPS) communication. I Implemented my client based on the code sample based on (http://www.boost.org/doc/libs/1_39_0/doc/html/boost_asio/example/ssl/client…) with little changes as I am using sync socket. My client woks fine, when I am connecting to server directly, but I am not sure what changes I need to make when my communication going thru proxy. The unsecure connection(HTTP) work fine thru proxy, and here is what I do for unsecure connection, 1. Initialize boost socket(IO service and other stuff). 2. Resolve and Connect to Proxy server. 3. Start writing to actual server(HTTP send request). 4. Start uploading/downloading. 5. Close Socket. But I can't use this above procedure for (SSL) secure connection as I need to do handshaking with the server before I can write anything if my understanding is correct. Can somebody give me some pointer or code sample or step I need to do when I am doing secure connection thru proxy server. Just to clarify Microsoft WinInet does do (secure) HTTPS connection thru same proxy fine. If providing my code sample I am using for SSL might help understand the problem I can provide that. Thanks in advance for any help. Akhilesh Kumar

1 0

Using boost::bind with stl algorithms
by przemyslaw.sliwa＠uk.bnpparibas.com 24 Aug '10

24 Aug '10

Hello, I have the following question. I have two containers std::set<std::string> insertedEvents; std::vector<std::string> eventNames; How I would like to copy all those elements from eventNames which are not in insertedEvents. Can this can be done somehow using the boost::bind feature? I am doing it at the moment using a silly loop: for(size_t i=0; i<eventNames.size(); i++) { if (m_insertedEvents.find(eventNames[i])==m_insertedEvents.end()) eventNamesDegraded.push_back(eventNames[i]); } Thanks for any kind of help, Pshemek ___________________________________________________________ This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and delete this e-mail. Any unauthorised copying, disclosure or distribution of the material in this e-mail is prohibited. Please refer to http://www.bnpparibas.co.uk/en/information/legal_information.asp?Code=ECAS-… for additional disclosures.

4 4

bug in asio?
by Hei Chan 23 Aug '10

23 Aug '10

Hi, I am using a 3rd party library that uses boost::asio. The 3rd party library will call asyn_receive() with a callback handler, then when boost::asio::detail:: receive_op::do_complete() calls the callback handler, the handler consumes the message, calls asyn_receive() and then if there is no more message, it (the thread) waits for a condition -- the callback handler gets called again. The problem now is that once there is no more message, the thread enters the wait condition, and it never gets waken up again. Is it incorrect to enter the wait condition in the same thread that calls boost::asio::detail:: receive_op::do_complete()? Thanks in advance. Cheers, Hei

1 0

Getting started with Boost.Test
by Otto 23 Aug '10

23 Aug '10

Hi, I'm very new to C++ and Boost. I want to make a simple desktop application (a game editor, basically read/write a binary file) using QtCreator. Right now I'm only interested in Boost.Test for the unit tests. I tried to install using the instructions in "Getting started" but wasn't able to, probably because of bad english and lack of C++ knowledge. I unpacked Boost to /home/otto/boost_1_44_0/ >From there, I ran: $ mkdir dist $ ./bootstrap.sh --prefix=/home/otto/boost_1_44_0/dist --show-libraries --with-libraries=test $ ./bjam install It seems that config had no effect as it built everything (instead of just test) and to bin.v2/. A few "cp: cannot create regular file `/usr/local/lib/libboost_wave.a': Permission denied" errors too. What went wrong? Now I have bin.v2/libs/test/build/gcc-4.4.4/release with directories link-static and threading-multi. I also would like to configure it for usage with QtCreator. Thanks

3 5

Best method for making synchronous call from async handler
by David Daeschler 23 Aug '10

23 Aug '10

Good evening, Currently I have an application running on boost asio working very well. To simplify the heck out of it, it takes requests via tcp and passes back binary information stored on disk. However, I now need to add an extra step to processing. If the data is not available on the local disk, the server needs to contact one or more peer servers it knows about, send a query to each one via UDP asking if it has the data, and then use an existing TCP connection to that server to retrieve the asset. This step must be completed before any more processing can be done for the current client even though the client may be sending even more requests while we process. My question is, what is the best method for me to achieve the goal? Should I set up another io_service for the UDP query step along with retrieving the data from the other server? Is there a good wait to wait on that io_service to complete? Also in the case that one of the servers has gone away, can I use a deadline timer to cancel the UDP recvfrom if I don't get a response in time from one or more servers? I should also probably keep this second io_service alive throughout the lifetime of the application? Thank you in advance for advice on tackling this problem the right way with asio. -- David Daeschler

2 2

mpl::fold problems
by sergey kostanbaev 23 Aug '10

23 Aug '10

Hello everybody! I'm a newbie in boost and I've got some problems with boost::mpl #include <boost/mpl/vector.hpp> #include <boost/mpl/fold.hpp> #include <boost/mpl/arithmetic.hpp> template <class T, unsigned space=1> struct tr_field2 { static const unsigned count = space; } typedef boost::mpl::vector4< tr_field2<int, 4>, tr_field2<int, 7>, tr_field2<char, 1>, tr_field2<char, 1> > Test_description; I want to calculate a sum of all tr_field2::count I've read in the docs mpl::fold is for the case. I tried to compose typedef boost::mpl::fold<Test_description, boost::mpl::int_<0>, boost::mpl::plus<boost::mpl::_, boost::mpl::_::count > > >::type fcount; but it won't compile. It seems I misundestood something.

2 2

[BGL] Change order of edge iterator
by John Robertson 23 Aug '10

23 Aug '10

I want to be able to iterate through the edges in any given order, not just the order specified by tie(edge_iter, edges_end) = edges(g);. Is it possible to do something like the following. typename graph_traits<Graph>::edge_iterator edge_iter1, edges_end1, edge_iter2, edges_end2, edge_iter3, edges_end3; tie(edge_iter1, edges_end1) = edges(g); sort(edge_iter1, edges_end1, ordering_1()); tie(edge_iter2, edges_end2) = edges(g); sort(edge_iter2, edges_end2, ordering_2()); tie(edge_iter3, edges_end3) = edges(g); sort(edge_iter3, edges_end3, ordering_3()); (ordering_x() specified by some struct) Then I would have 3 different orderings of the edges available. Would this work or should I use an iterator adapter, or create a map and (if its possible) obtain an iterator from the mapping, or something else. Thanks

2 1

[DateTime] from time_t to ptime and back - or not
by Christoph Duelli 23 Aug '10

23 Aug '10

[I am using Boost 1.43.0 on linux, gcc 4.4.1] I am having trouble with date_time's ptime. I am passing it a time_t, and store that in a ptime object. When I retrieve the time_t, I am getting a different value than the one I passed to it originally. (the difference seems to be 2 hours - in all probability due to UTC vs local time issues). Code: time_t now = time(NULL); boost::posix_time::ptime pt = boost::posix_time::from_time_t(now); struct tm tm = to_tm(pt); time_t should_be_now = mktime(&tm); BOOST_CHECK_EQUAL(now, should_be_now); fails for me: now is by 7200 seconds (i.e. 2 hours) ahead of. Is this a bug in date_time or am I just failing to use it properly? Thank you, and best regards Christoph

3 3

[bind]Help! Can we modify parameters before pass them into bind (see the context below for details)
by jungleman 23 Aug '10

23 Aug '10

Hi, I have some problems on function template bind. the original usage of bind is : bind(func, _1, _2), and I wonder whether I can modify the parameters before pass them into bind, for example, functype function = bind(func, *_1, *_2). So that, when I use function(a, b), it will do like this: func(*a, *b). May it work, or some way else to do this? I just wanna do this in one line code. thanks in advance. -- Stay hungry, stay foolish !

3 2

Boost.Intrusive issues on IBM compiler
by Jeremiah Willcock 22 Aug '10

22 Aug '10

It appears that almost all of the Boost.Intrusive tests (at <URL:http://tinyurl.com/2bzhglh>, for example) fail on IBM's compiler. I get similar results, like the following from the test suite, from my own code: An expression of type "overloaded function: U::to_node_ptr" cannot be converted to type "boost::intrusive::list_node<void *> *(boost::intrusive::detail::base_hook_traits<boost::intrusive::testvalue<hooks<void *>,0>,boost::intrusive::list_node_traits<void *>,1,boost::intrusive::default_tag,1>::*)(testvalue<hooks<void *>,0> &)" Is there an easy workaround for this issue? Is there a plan to fix it? This has also been reported a couple of months ago as bug 4412 (<URL:https://svn.boost.org/trac/boost/ticket/4412>). Thank you. -- Jeremiah Willcock

2 1

axpy_prod Weirdness
by Jane Shevtsov 22 Aug '10

22 Aug '10

I have a little program that implements an ecological network analysis algorithm. (It looks at the importance of indirect energy or matter flows between species.) 01 //dea.cpp -- The fundamental DEA algorithm 02 03 #include <boost/numeric/ublas/matrix.hpp> 04 #include <boost/numeric/ublas/operation.hpp> 05 #include <boost/numeric/ublas/io.hpp> //for test 06 #include "storage_adaptors.hpp" //for test 07 08 using boost::numeric::ublas::matrix; 09 10 void dea(const matrix<double>[], int, int, matrix<double>[]); 11 matrix<double> indflow(const matrix<double> & Ndea, const matrix<double> & Gdea); 12 13 int main() { 14 using boost::numeric::ublas::make_matrix_from_pointer; 15 matrix<double> Garr[4]; 16 matrix<double> Narr[2]; 17 double G1[3][3] = {0, 0, 0, 0.33333, 0, 0, 0.66667, 1, 0}; 18 double G2[3][3] = {0, 0, 0, 0.6, 0, 0, 0.4, 1, 0}; 19 double G3[3][3] = {0, 0, 0, 0.55, 0, 0, 0.45, 1, 0}; 20 double G4[3][3] = {0, 0, 0, 0.5, 0, 0, 0.5, 1, 0}; 21 Garr[0] = make_matrix_from_pointer(G1); 22 Garr[1] = make_matrix_from_pointer(G2); 23 Garr[2] = make_matrix_from_pointer(G3); 24 Garr[3] = make_matrix_from_pointer(G4); 25 dea(Garr, 2, 4, Narr); 26 std::cout << Narr[0] << std::endl; 27 matrix<double> ratio = indflow(Narr[0], Garr[0]); 28 std::cout << ratio << std::endl; 29 return 0; 30 } 31 32 //The fundamental DEA algorithm 33 //Takes array of G matrices, window size, array length and empty array for N_DEA matrices as input 34 void dea(const matrix<double> Garr[], int win, int arrLen, matrix<double> Narr[]) { 35 using namespace boost::numeric::ublas; 36 int matSize = Garr[0].size1(); 37 for (int i = 0; i < arrLen - win; i++) { 38 matrix<double> Gprod = identity_matrix<double>(matSize); 39 Narr[i] = identity_matrix<double>(matSize); 40 //the core loop 41 for (int j = 0; j < win; j++) { 42 Gprod = prod(Gprod, Garr[i+j]); 43 Narr[i] += Gprod; 44 } 45 } 46 } 47 48 //computes indirect flow fraction 49 matrix<double> indflow(const matrix<double> & Ndea, const matrix<double> & Gdea) { 50 using namespace boost::numeric::ublas; 51 int matSize = Ndea.size1(); 52 matrix<double> iflow = Ndea - Gdea - identity_matrix<double>(matSize); //Ind = N-G-I 53 matrix<double> frac = zero_matrix<double>(matSize, matSize); //inialize indirect flow fraction matrix 54 //perform division for nonzero, off-diagonal elements 55 for (int i=0; i<matSize; i++) { 56 for (int j=0; j<matSize; j++) { 57 if (i != j && Ndea(i,j) != 0) //avoid division by zero 58 frac(i, j) = iflow(i, j) / Ndea(i, j); 59 } 60 } 61 return frac; 62 } The correct output is below. [3,3]((1,0,0),(0.33333,1,0),(1.26667,1,1)) [3,3]((0,0,0),(0,0,0),(0.473683,0,0)) The code given above works, but to speed it up, I tried replacing the first line of the core loop in dea() with axpy_prod(Gprod, Garr[i+j], Gprod, true);. This gives the following wrong output: [3,3]((1,0,0),(0,1,0),(0,0,1)) [3,3]((0,0,0),(0,0,0),(0,0,0)) And if I use axpy_prod(Gprod, Garr[i+j], Gprod, false);, I get: [3,3]((3,0,0),(1.26666,3,0),(2.33334,3,3)) [3,3]((0,0,0),(0.736843,0,0),(0.714285,0.666667,0)) What gives? When should I avoid using axpy_prod? -- ------------- Jane Shevtsov Ecology Ph.D. candidate, University of Georgia co-founder, <www.worldbeyondborders.org> Check out my blog, <http://perceivingwholes.blogspot.com>Perceiving Wholes "The whole person must have both the humility to nurture the Earth and the pride to go to Mars." --Wyn Wachhorst, The Dream of Spaceflight

1 0

[bind]Help! Can we modify parameters before pass them into bind (see the context below for details)
by jungleman 22 Aug '10

22 Aug '10

Hi, I have some problems on function template bind. when I uses stl algorithm adjacent_find(inputIterator begin, inputIterator) -- Stay hungry, stay foolish !

2 1

[asio] Feature request for serializable types.
by Germán Diago 22 Aug '10

22 Aug '10

Hello. I'm using boost.asio and trying to serialize a boost.variant, which is serializable because each of the fields I used in the variant have a serialize method required by boost.serialization library. I want to send my variant as binary data. This is not easy although I have a serialize method because this does not work: async_write(mysocket, boost::asio::buffer(myserializablevariant), when_done); I think all serializable types should be automatically usable as boost::asio::buffer, like std::vector, in this call. I think this shouldn't be too hard to implement, but I don't know how to serialize my data in binary format in a straight-forward way. Any ideas? Thanks in advance.

1 0

thread-safe initialization for singleton
by Kraus Philipp 22 Aug '10

22 Aug '10

Hi, I have written a class with static methods and properties. Now the class must be used in a multithreaded environment, so I get some race conditions error. I use boost::thread for implementating the threads. I have found boost_once but I don't know how to use it, so my class properties are initialized once. Thanks Phil

6 10

multiple serialized objects to same file
by Oscar Pernas 21 Aug '10

21 Aug '10

Hi! I know that this question is asked before but I cant see any answer about it. Is posible with boost serialization to write different objects to the same file? if is possible, is possible to access to each object with an iterator or with position like binary files? thanks -- Óscar Pernas Plaza.

2 1

[BGL] segFault
by John Robertson 21 Aug '10

21 Aug '10

I'm trying to obtain an iterator of edges with a different ordering than that given in egdes(g). The following compiles but segfaults at std::sort( VE.begin(), VE.end(), ordering< Graph, edd >() ); (runs ok if the above line is commented out) //////////////////////////////////////////////////////////////////////////////////////////////////////////////// typedef Traits::edge_descriptor edd; // Create ordering template < typename Graph, typename edd > struct ordering { Graph & g; bool operator ()(const edd & a, const edd & b) { return g[a].eName < g[b].eName; } }; template < typename Graph > int initialize_container( Graph & g ) { typename graph_traits<Graph>::edge_iterator edge_iter, edges_end; // create vector of edge descriptors. std::vector< Traits::edge_descriptor > VE(num_edges(g)+1); int i = 1; // (Sometimes I like to start at 1.) //insert edge descriptors into vector of edge descriptors. for (tie(edge_iter, edges_end) = edges(g); edge_iter != edges_end; ++edge_iter) { cout << " *edge_iter = " << *edge_iter << endl; VE[i++] = *edge_iter; } // segfaults here //sort vector of edge descriptors. std::sort( VE.begin(), VE.end(), ordering< Graph, edd >() ); //print sorted edge descriptors. for( int i = 1; i < num_edges(g)+1; ++i ) cout << " -Edge " << i << " = " << VE[i] << endl; } Thanks

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