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[Geometry] Packing algorithm for r-tree?
by Jeremy Murphy 27 Oct '14

27 Oct '14

I see that a fourth node splitting algorithm for bulk loading is documented in the Introduction to spatial indexes but not listed elsewhere (such as Creation and Modification). Is it hiding in the library somewhere or is the introduction just a tantalizing sneak preview? Thanks, cheers. Jeremy

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BGL, cut set
by Mads Jensen 27 Oct '14

27 Oct '14

Hi, I'm looking into how you can quickly find the cut set of a graph without having to loop over the colormap as a vector. I'm using the http://www.boost.org/doc/libs/1_56_0/libs/graph/doc/edmonds_karp_max_flow.h… (the example provided does mostly what I want, except that it uses a vector, and not a regular map). Boykov Kolmogorov also has the colormap parameter. It seems that associative_property_map could be used, but I don't really see how? Hints on how to do this will be appreciated. A lot of the examples of the Boost graph library use the preprocessor with a check similar to: #if defined(BOOST_MSVC) && BOOST_MSVC <= 1300 What's so special about this? Thank you, -- Med Venlig Hilsen / Kind regards, Mads Jensen

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[Serialization] Deserialization of base class fails
by Torsten Wylegala 25 Oct '14

25 Oct '14

Hi, I'm currently trying to serialize and deserialize a derived class using boost::archive::xml_iarchive/xml_oarchive Version 1.52. Everything works fine as long as I serialize and deserialize the same class (Example 1). The attributes of the derived class and the base class are both serialized and the deserialized correctly and requestPackageOut equals requestPackageIn (the base-class attributes are equal too). But if I serialize the derived class "RequestPackage" and try to deserialize it into the base-class "Package" (Example 2) I'm getting an "input stream error" exception while trying to deserialize with ia >> BOOST_SERIALIZATION_NVP(*package);. I'm quite new to this topic and found a lot of posting but none of them seems to match and solve my exact problem. It would by very nice if somebody could help me with that. Background information: I want to use xml-serialized objects for data exchange via network and want all the packages to inherit from Package-class which carries "packageId" and therefore give me the chance to identify the incoming xml-objects and handle every package based on this id. If some information is missing I will do my best to provide it later. Torsten Example 1: int main(int argc, char** argv){ std::cout << "Started!" << std::endl; std::string serializedObject; RequestPackage requestPackageOut; RequestPackage requestPackageIn; requestPackageOut.setPackageId(3); requestPackageIn.setPackageId(0); Serializer::serialize(&serializedObject,&requestPackageOut); Serializer::deserialize(&serializedObject,&requestPackageIn); return 0; } Example 2: int main(int argc, char** argv){ std::cout << "Started!" << std::endl; std::string serializedObject; Package package; RequestPackage requestPackageOut; RequestPackage requestPackageIn; requestPackageOut.setPackageId(3); requestPackageIn.setPackageId(0); Serializer::serialize(&serializedObject,&requestPackageOut); Serializer::deserialize(&serializedObject,&package); return 0; } The Rest: namespace Serializer{ template <typename T> int serialize(std::string *serializedObject, T *package){ int returnValue = 0; std::ostringstream objectOss; boost::archive::xml_oarchive oa(objectOss); try { oa << BOOST_SERIALIZATION_NVP(package); } catch (boost::archive::archive_exception const& ex) { returnValue = 1; } serializedObject->assign(objectOss.str()); return returnValue; }; template <typename T> int deserialize(std::string *serializedObject, T *package){ int returnValue = 0; std::istringstream objectIss(*serializedObject); boost::archive::xml_iarchive ia(objectIss); try { ia >> BOOST_SERIALIZATION_NVP(*package); } catch (boost::archive::archive_exception const& ex) { std::cerr << "Error: " << ex.what() << std::endl; std::cerr.flush(); returnValue = 1; } return returnValue; }; } class RequestPackage : public Package{ private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(Package); ar & BOOST_SERIALIZATION_NVP(requestId); } int requestId; public: int getRequestId() const; void setRequestId(int requestId); }; class Package{ private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & BOOST_SERIALIZATION_NVP(packageID); } int packageID; public: int getPackageId() const; void setPackageId(int packageId); };

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Boost Serialization
by Abraham, Marshel 25 Oct '14

25 Oct '14

I am trying to Serialize a class : StartPeerSessionRequest::StartPeerSessionRequest() { mProtocolVersion = 1*10000 + 14*100 + 4; mSessionFlags = 1; mMaxResponseLength = 0; mMake = "MyMake"; mModel = "MyModel"; mSerialNumber = "10000"; mTrackDelay = 0; mHeadUnitModel = "Headunit"; mCarModelYear = "2014"; mVin = "1234567980"; mVehicleMileage = 1000; mShoutFormat = 3; mNotificationInterval = 1; } template <class Archive> void StartPeerSessionRequest::serialize(Archive &ar, const unsigned int version) { ar & mProtocolVersion; ar & mSessionFlags; ar & mMaxResponseLength; ar & mMake; ar & mModel; ar & mSerialNumber; ar & mTrackDelay; ar & mHeadUnitModel; ar & mCarModelYear; ar & mVin; ar & mVehicleMileage; ar & mShoutFormat; ar & mNotificationInterval; } void StartPeerSessionRequest::save() { boost::archive::binary_oarchive oa(serlreq, boost::archive::no_header); oa << (*this); /*cout<<"\n binary_oarchive :"<<serlreq.size();*/ boost::archive::text_oarchive ota(serializedRequest, boost::archive::no_header); ota<<(*this); cout<<"\n text_oarchive :"<<serializedRequest.str()<<"size :"<<serializedRequest.str().size(); } serializedRequest.str.size() provides me a length of 87 actually it should provide me 65 bytes.( I ve counted u can figure that out from the constructor ) I suspect it is appending lengths in between. I have tried using text_archive also it doesnt work. What I need is to just plain serialize class members as it is. I guess i need to use some traits or wrappers, or boost::serialization::binary_object Please let me know Thanks Regards Marshel Abraham 3097146

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"event-driven" async-receive
by Alexander Carôt 25 Oct '14

25 Oct '14

Hello all, I have question regarding the async_receive_from – operation (using UDP): Right now I have a thread, which triggers the receive call in constant intervals. This works allright if the sender sends data in the same interval or larger intervals. However, if the send intervals are (much) smaller (or if multiple senders exist) the receive-operation is not triggered often enough. Eventually I’d like the receiving socket to behave in an „event-driven “ manner – so, whenever data is there the receive-handler should be invoked. I used to work with Qt, which works this way (via signals/slots) but since I moved to boost I wonder how I can reproduce this behavior. Can anyone tell how to approach this ? Thanks in advance, best Alex

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Applying Boost Phoenix to infinite sequence
by Aaron Levy 24 Oct '14

24 Oct '14

Is there a way to use Boost Phoenix to define an infinite sequence and evaluate specific terms of it, compute partial sums, etc? I am looking for pointers to specific libraries or examples. -- Aaron Levy aaron.levy(a)yandex.com

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cross compile for arm setup (solved)
by John Davis 24 Oct '14

24 Oct '14

Hello I appreciate the assistance. Below is the script and results for building boost with a cross compiler. It appears to work. -------------------------- #!/bin/bash # place this script in the $BOOST_ROOT directory and invoke it like so: # ./doit.sh # Clean up any stuff left over from a previous build rm -rf /opt/xxx/boost/include rm -rf /opt/xxx/boost/lib # edit /opt/xxx/yyy/boost/boost_1_51_0/tools/build/v2/user-config.jam to add the following line # using gcc : 4.3arm : arm-linux-gnueabi-g++ : <architecture>arm <target-os>linux ; # edit /opt/xxx/yyy/boost/boost_1_51_0/tools/build/v2/user-config.jam to remove the following line # using gcc ; # Ensure we are in host development environment and not using the cross compiler. # # Later we modify path and CROSS_COMPILE variables. # Here we are just ensuring we start properly, # make sure our path does not use the cross compiler at beginning export PATH=/usr/local/sbin:/usr/local/bin:/usr/bin:/opt/java6/bin:/opt/java6/db/bin:/opt/java6/jre/bin:/usr/bin/site_perl:/usr/bin/vendor_perl:/usr/bin/core_perl export CROSS_COMPILE= # In this stage, we are using the host compiler. # setup env variable for $BOOST_DIR # I'm not sure if this is being used, but set it just in case. export BOOST_ROOT=/opt/xxx/yyy/boost/boost_1_51_0 # Its important that the next step is run from $BOOST_DIR/tools/build/v2 aka /opt/xxx/yyy/boost/boost_1_51_0/tools/build/v2 cd $BOOST_ROOT/tools/build/v2 # NOTE: ask if we have removed gcc and replaced gcc with cross compiler in user-config.jam am I really # invoking gcc-arm below? Its not in my path at this point. ./bootstrap.sh --with-toolset=gcc echo current working directory is $PWD # checkpoint exit # At this point, /opt/xxx/boost is still empty. # # The ./bootstrap.sh script executed above in the tools/build/v2 directory # is complete and gives the following output: # #Bootstrapping the build engine with toolset gcc... engine/bin.linuxx86_64/bjam # #Bootstrapping is done. To build and install, run: # # ./b2 install --prefix=<DIR> # # !!! ERROR # We can't run b2 at this point, because we don't have the cross compiler in # our path yet. It dies looking for arm-linux-gnueabi-g++ # Furthermore, even though we were running in the tools/build/v2 directory # the explicit path of running ./b2 in the current directory is wrong. # Instead it should be run from the root directory. # This command failed at this point, try it again later with different CWD and # different options. #./b2 toolset=gcc install --prefix=/opt/xxx/boost #exit # At this point in the script, we have preconfigured the build of the libraries using # the cross compiler, the build tools which run on the host to build the libraries # are built (according to docs. where they are located is beyond me) , and our original project-config.jam file is still in place since # we issued bootstrap.sh in the v2 subdirectory. We need to change working # directories back to the root. # It builds b2 in the tools driectory. Maybe this is what the docs are referring to above? #cd $BOOST_ROOT #echo current working directory is $PWD #exit # We are switching to the cross compiler at this point, ensure it is in the # path first. # Setup path so that gcc from cross compiler is first in the path # also specify cross_compiler env variable in case its used. # # this will find the cross compiler for those who dont use the prefix, ie. gcc export PATH=/opt/arm/usr/local/arm-linux-gnueabi/bin:$PATH # this will find the cross compiler for those who use the prefix, ie. arm-linux-gnueabi-gcc export PATH=/opt/arm/usr/local/bin:$PATH # this will set the cross compiler prefix for those who use it. This export # is not used by Boost.Build but keep it here for our app which uses boost. export CROSS_COMPILE=arm-linux-gnueabi- # since we installed boost.build stuff to /opt/xxx/boost # in the step above, add that to the path for the next step as well. # Its currently empty but maybe it needs to be set during the next step. export PATH=/opt/xxx/boost/bin:$PATH # build boost.build so that we can build boost or are we building boost at this point? # # WARNING!!! # Specify an install directory so that it doesn't put the results in /usr/local/bin. # Even if you dont specify install as an option to ./b2 it will attempt to copy files to /usr/bin # in the following step! # # /opt/xxx/boost is where we want results. Our code will this dir in order to use boost. # /opt/xxx/yyy/boost/boost_1_51_0 is the top of the boost src. We are building beneath there. #./b2 --toolset=gcc-4.3arm --prefix=/opt/xxx/boost # hmm. I did not get any .a or .so after that last step. Try to add a install parameter. #./b2 toolset=gcc-4.3arm --prefix=/opt/xxx/boost --build-type=complete --layout=versioned # hmm. I did not get any .a or .so after that last step. Try to add a install parameter. # Above we use --with-toolset=, here we use just toolset= # It was suggested to use the additional options below (i'm not sure why, consider them later.) # --without-python # -sNO_BZIP2=1 ./b2 toolset=gcc-4.3arm --without-python --debug-configuration --prefix=/opt/xxx/boost --build-type=complete --layout=versioned install # running b2 using above syntax from the tools/v2/build directory, we have the following in the /opt/xxx/boost dir: # the version of b2 here is x86_64 # /opt/xxx/boost/bin/b2 # /opt/xxx/boost/bin/bjam # /opt/xxx/boost/share/boost-build/ whole subtree cd $BOOST_ROOT echo current working directory is $PWD /opt/xxx/boost/bin/b2 toolset=gcc-4.3arm --without-python --debug-configuration --prefix=/opt/xxx/boost --build-type=complete --layout=versioned install # At this point, we have the cross compiler in our path first. We are good to go for building our code using boost # with the cross compiler. ------------------------------------------------------------- -- John F. Davis 6 Kandes Court Durham, NC 27713 919-888-8358 独树一帜

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Map Binary archive problem May be a bug?
by Joshua Nocturne 24 Oct '14

24 Oct '14

On my phone, so I try my best to describe my problem. std::map<int,int> myMap; for(int i = 0; i != 30; i++) myMap.insert( make_pair(i,i+1) ); ofstream ofs("test"); binary_oarchive oa(ofs); oa<<myMap; ofs.close(); ofs.clear(); myMap.clear(); Ifstream ifs("test"); binary_iarchive ia(ifs); ia>>myMap; This code will throw an exception "input stream error". But if reducing the size of map like this for(int i = 0;i != 20; i++) It will run successful. Cause I can't figure it out so I seek your help. Look forward to your reply.

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Inserting in a boost::interprocess::map
by Hemanth Choudary M V (RBEI/ETA1) 24 Oct '14

24 Oct '14

Hi, I have the following boost::interprocess::map: std::shared_ptr<boost::interprocess::map<size_t,boost::interprocess::managed_shared_memory*> > memoryMap; I insert into the map in the following manner: memoryMap ->insert( std::make_pair (i, new boost::interprocess::managed_shared_memory(boost::interprocess::create_only, "MemoryMap", 128))); Compilation is successful. But there is the following run-time error during insert: "memory access violation occurred at address -----------, while attempting to read inaccessible data" Is there anything missing? Mit freundlichen Grüßen / Best regards Hemanth Choudary M V RBEI/ETA1 Tel. +49 7113423 2875 [cid:image001.gif@01CFEF7A.B28D3180] [cid:image002.gif@01CFEF7A.B28D3180]<https://www.facebook.com/BoschIndia> [cid:image003.gif@01CFEF7A.B28D3180] <https://twitter.com/boschindia> [cid:image004.gif@01CFEF7A.B28D3180] <http://www.linkedin.com/company/bosch-engineering-and-business-solutions?tr…>

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[Boost.TypeTraits] Which was the first Boost release that included make_signed?
by dariomt＠gmail.com 24 Oct '14

24 Oct '14

Looking at Boost.TypeTraits documentation it seems that boost/type_traits/ make_signed.hpp was added in version 1.35.0, but I can't find any reference to that change in the release notes. Which was the first Boost release that included make_signed?

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