April 2013 - Boost-users - lists.preview.boost.org

PBGL Dijkstra's Single Source Shortest Path
by claire eisner 15 Apr '13

15 Apr '13

Is there a way to access the shortest path from source to target? The issue I am having is that only the local portions of the predecessor maps are written. Claire

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MSM: Initialize inner state machine from outer state machine
by Dan Schatzberg 15 Apr '13

15 Apr '13

Hi, I have shared data between states which are state machines themselves. I've stored the shared data in the outer state machine and wish to initialize each of the inner state machines with a reference to the shared data. Is this the "right way" to do this? How would I do this? Here's an example of what I'm doing: struct Outer_ : state_machine_def<Outer_> { int foo; struct Inner_ : state_machine_def<Inner_> { int& foo; Inner_(int& f) : foo(f) {} ... } ... } How do I get the inner state machines constructor called with data from the outer state machine? Or is this just the wrong way to do things? Thanks

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[serialization] EOF marker?
by Ramey, Larry 15 Apr '13

15 Apr '13

Is there a way to serialize an unknown number of items and then read them back? In essence, I'd like to do this: Ignore the variables being serialized, these are pointers to base classes, they go in and out just fine. try { ofstream ofs(fileName.c_str(),ios::binary); portable_binary_oarchive oa(ofs); //boost::archive::text_oarchive oa(ofs); oa<<qdc <<qdf <<qdenv <<qdmsg <<qsd <<qdfc <<qdce; } catch(boost::archive::archive_exception& ae) { cout<<ae.what(); } try { ifstream ifs(fileName.c_str(),ios::binary); portable_binary_iarchive ia(ifs); //boost::archive::text_iarchive ia(ifs); while( true ) { ia>>qdc2; cout<<qdc2->GetElementDebugType()<<endl; delete qdc2; qdc2=NULL; } } catch(boost::archive::archive_exception& ae) { cout<<ae.what(); } catch( std::exception& e) { cout<<e.what(); } What happens is that an exception gets tossed with this message: 5 2 14 1 3 18 Access violation - no RTTI data! The numbers are correct, those are the elements that got serialized. I'd like to do something like: while( ia ) { Ia>>qdc2; } But there is no () operator on an portable_binary_iarchive . I tried to do the test on the input stream, but that didn't work either. I don't know how many elements there are because I'm writing them as I go, I don't want to catch that exception as the EOF marker, because it really isn't the correct exception for that. I tried walking through the serialization code to see where it actually reads a byte stream form the file... but I'm apparently not smart enough to unravel that much templated Macro awesomeness. :) Larry E. Ramey

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Compile error in boost atomic on iOS
by Olivier Tristan 15 Apr '13

15 Apr '13

Hi Guys, I'm trying to use boost lockfree and a fixed size queue on iOS and I got some compile issue. The target is an armV7 compiled with clang in c++11 mode from Xcode 4.6 Does this ring a bell to someone ? Thanks, In file included from /usr/local/include/boost/lockfree/queue.hpp:22: In file included from /usr/local/include/boost/lockfree/detail/atomic.hpp:39: In file included from /usr/local/include/boost/atomic.hpp:12: In file included from /usr/local/include/boost/atomic/atomic.hpp:16: In file included from /usr/local/include/boost/atomic/detail/platform.hpp:37: In file included from /usr/local/include/boost/atomic/detail/gcc-armv6plus.hpp:245: /usr/local/include/boost/atomic/detail/cas32weak.hpp:892:21: error: invalid operands to binary expression ('value_type' (aka 'boost::lockfree::detail::tagged_index') and 'value_type') if (tmp != expected) { ~~~ ^ ~~~~~~~~ /usr/local/include/boost/atomic/detail/cas32weak.hpp:905:5: note: in instantiation of member function 'boost::atomics::detail::base_atomic<boost::lockfree::detail::tagged_index, void, 4, false>::compare_exchange_strong' requested here BOOST_ATOMIC_DECLARE_BASE_OPERATORS ^ /usr/local/include/boost/atomic/detail/base.hpp:44:16: note: expanded from macro 'BOOST_ATOMIC_DECLARE_BASE_OPERATORS' return compare_exchange_strong(expected, desired, order, calculate_failure_order(order)); \ ^ /usr/local/include/boost/lockfree/queue.hpp:290:31: note: in instantiation of member function 'boost::atomics::detail::base_atomic<boost::lockfree::detail::tagged_index, void, 4, false>::compare_exchange_strong' requested here tail_.compare_exchange_strong(tail, new_tail); ^ /usr/local/include/boost/lockfree/queue.hpp:261:16: note: in instantiation of function template specialization 'boost::lockfree::queue<StreamingCommand, boost::lockfree::fixed_sized<true>, boost::lockfree::capacity<1024>, boost::parameter::void_>::do_push<true>' requested here return do_push<true>(t); -- Olivier Tristan

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[preprocessor] Is there an equivalent of "delayed expansion"?
by Mostafa 15 Apr '13

15 Apr '13

Is there an equivalent in boost for delaying the expansion of a macro? For example, I want EAT to act on TSEQ2, so I have to use trick on line 4. #define TSEQ2 (w)(x)(y)(z)(a)(b)(c)(d 2) #define IDENTITY(x) x #define EAT(x) IDENTITY(IDENTITY(EAT)TSEQ2) Thanks, Mostafa

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[Graph] dijkstra_shortest_paths: weird distance to vertex (1.79769e+308)
by The Maschine 15 Apr '13

15 Apr '13

Hi all, Might be something really stupid but I cant think of a problem. (maybe its my limited experience with BGL common pitfalls) for (boost::tie(vi, vi_end) = boost::vertices(m_ugraph); vi != vi_end; ++vi) { depth += distances[*vi]; ..... path to:51886 distance to that node: 16.2 current total: 437998 path to:51887 distance to that node: 16.3 current total: 438014 path to:51888 distance to that node: 16.2 current total: 438031 path to:51889 distance to that node: 16.2 current total: 438047 path to:51890 distance to that node: 16.1 current total: 438063 path to:51891 distance to that node: 16.2 current total: 438079 path to:51892 distance to that node: 1.79769e+308 current total: 1.79769e+308 path to:51893 distance to that node: 16.3 current total: 1.79769e+308 path to:51894 distance to that node: 13.8 current total: 1.79769e+308 path to:51895 distance to that node: 13.9 current total: 1.79769e+308 I have checked my weights: if(edge_w<=0.0) edge_w = 0.1; if(edge_w >2.0) edge_w = 2.0; if( !(std::isnan(edge_w)) ) edge_w = 0.1; if( !(std::isfinite(edge_w)) ) edge_w = 0.1; boost::dijkstra_shortest_paths(m_ugraph, *vertex_iterator_begin, boost::distance_map(distanceMap)); typedef double Weight; typedef boost::property<boost::edge_weight_t, double> EdgeWeightProperty; typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, VertexProperties, EdgeWeightProperty> unGraph; Any ideas? Thanks a lot Tasos

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Re: [Boost-users] [Graph] dijkstra_shortest_paths: weird distance to vertex (1.79769e+308)
by The Maschine 15 Apr '13

15 Apr '13

This is not in my actual code! and not risponsible for my problem. Its incorrect from the copy/paste. !(std::isnan(edge_w)) its: std::isnan() Tasos

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Accessing members from a shared pointer passed as argument to a function gives incorrect results without typecast
by Deepak Gunjal 15 Apr '13

15 Apr '13

Hi, class A; class B; typedef boost::shared_ptr<A> pSharedPtrA; typedef boost::shared_ptr<B> pSharedPtrB; class B { public: int memberB; }; Class A { public: pSharedPtrB pMember; }; Suppose i have one shared pointer of type pSharedPtrA pointing to an object of class A and the member variable pMember pinging to a valid object of class B. Now if i pass the shared pointer of type pSharedPtrA to a function suppose Test_Func(pSharedPtrA): void Test_Func(pSharedPtrA pLocalA) { pSharedPtrA ptrA = boost::static_pointer_cast<A> (pLocalA) pSharedPtrB tmpB = boost::static_pointer_cast<B>(ptrA->pMember) Another_Func(tmpB) } Another_Func(pSharedPtrB pLocalB) { int x = pLocalB->memberB; //Gives WRONG value pSharedPtrB ptmp = boost::static_pointer_cast<B> (pLocalB) x = ptmp ->memberB; //Gives CORRECT Value } The problem is when typecast is not used then in function Another_Func(pSharedPtrB pLocalB), pLocalB->memberB is not giving the correct result but after typecast it is giving the correct results. The inference is that in function Another_Func() data is preserved in the pLocalB but without typecast i am not able to access it. Though i have not declared any virtual functions in above code but where we are having problem does contain the vritual functions. I dont know if it has any bearing on behavior observed. I want to know why typecasting is required to get the correct result and why cant i access the members without typecasting. Thanks and Regards Deepak

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unit test on vc++ 64 bit application
by young 15 Apr '13

15 Apr '13

I try to use boost 1.51 for my vc++ 64 bit application on windows 7 enterprise. In short, if I set config to 32 bit, everything is OK. I mean build successfully. But if I changed to 64 bit, I get build error. I am sure I include the 64 bit header and the lib path is 64 bit lib. My test application is win32 console application. The error I got: Error 1 error LNK2019: unresolved external symbol main referenced in function __tmainCRTStartup D:\Temp\test\test\MSVCRTD.lib(crtexe.obj) test My test.cpp: #define BOOST_TEST_MAIN #include <boost/test/unit_test.hpp> Why 32 bit build and 64 bit would not? The library I used is from www.boostpro.com. -- View this message in context: http://boost.2283326.n4.nabble.com/unit-test-on-vc-64-bit-application-tp464… Sent from the Boost - Users mailing list archive at Nabble.com.

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Unit Test for vc++ exe project possible?
by young 15 Apr '13

15 Apr '13

I see a good tutorial for Boost Test using Visual Studio. (http://legalizeadulthood.wordpress.com/2009/07/04/c-unit-tests-with-boost-t…) But it looks like only forstatic or dynamic library. Is that possible to unit test the exe production project using Boost Test? If yes, how? Any link for tutorial, etc? -- View this message in context: http://boost.2283326.n4.nabble.com/Unit-Test-for-vc-exe-project-possible-tp… Sent from the Boost - Users mailing list archive at Nabble.com.

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