March 2011 - Boost-users - lists.preview.boost.org

[Review] Boost.Type Traits Extension by Frederic Bron
by Joel Falcou 18 Mar '11

18 Mar '11

Dear All, This is the first day of the fast track review of Frédéric Bron's extensions to the Type Traits Library.This reviews will last until March 18th, 2011 under my management. All comments and reviews are very welcome. =========== What is it? =========== This extension adds 37 new traits corresponding to the following 37 operators: - binary: ==, !=,<,<=,>,>=, , +, -, *, /, %, +=, -=, *=, /=, %=, , &&, ||, ,&, |, ^,<<,>>,&=, |=, ^=,<<=,>>= - prefix: ++, --, +, -, !, ~, * - postfix: ++, -- Each trait can detect if the operator can be used with particular types and if needed, if the return type is convertible to some type. =================== Getting the library =================== The latest version can be downloaded by different ways: - from the vault with unix line ending: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=type_t… - from the vault with dos line ending: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=type_t… - from the sandbox:http://svn.boost.org/svn/boost/sandbox/type_traits/ The entry point of the documentation is type_traits/libs/type_traits/doc/html/boost_typetraits/category/value_traits/operators.html The library has been tested with: - MSVC 8, 9, 10 on Windows, - g++ 4.4.5 on Linux, - intel 10.0 and 11.1 on Linux. To test the library, the simplest is to untar the headers in your boost include directory. For this, you can download the header part of the extension: - from the vault with unix line ending: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=type_t… - from the vault with dos line ending: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=type_t…

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Specifying a NVP wrapper
by simone pilozzi 18 Mar '11

18 Mar '11

Hi All, I am working with the serialization library and I made an example class like this. class Contact{ public: Contact(){} Contact(string& name, int phonenumber,long contactdate):name_(name), pnumber_(phonenumber),contactdate_(contactdate){} const string getName() const{return name_;} const long getPhone() const{return pnumber_;} const long getDate() const{return contactdate_;} private: string name_; long pnumber_,contactdate_; friend class boost::serialization::access; template<typename Archive> void serialize(Archive& ar, const unsigned int version){ ar & boost::serialization::make_nvp("name", name_); ar & boost::serialization::make_nvp("phone", pnumber_); ar & boost::serialization::make_nvp("contactdate", contactdate_); } }; Now I would like to allocate the xml file created with the use of this class in a vector, and this is the function: void getFromFile(std::vector<Contact>& contacts,const char* file){ std::ifstream ifile(file); boost::archive::xml_iarchive ia(ifile); ia >> contacts; ifile.close(); } The compiler complains because it misses a NVP wrapper for the class. I could not find an example for that in boost. Could you help me ? Thanks in advance Simone

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Invitation à se connecter sur LinkedIn
by Germain Barret via LinkedIn 18 Mar '11

18 Mar '11

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[regexp] Replace a substring with a regexp
by Olivier Tournaire 18 Mar '11

18 Mar '11

Hi all, I am not really familiar with regexp, an I am facing a problem. I have some strings containing unicode sequences (like "\u****"), and I would like to replace them with html sequences (such that "\u****" becomes "&#x****;"). I think I can do that with boost regexp, but I really do not know how. The major problem is that I do not now in advance what are the characters for "****". I however know that they are always 4 and alphanumeric. So, I have to detect them and also append after a ";". Do you have any hint on how to do that? Best regards, Olivier

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Boost conflict with OpenCV, Eigen?
by Prva Ponta 18 Mar '11

18 Mar '11

Hi there, I have a program that uses Filesystem, which compiles and runs without problem, but only if used by itself. If I use Filesystem within a program that also needs OpenCV and Eigen libraries, there seems to be a conflict: ... In file included from C:\boost_1_45_0/boost/filesystem/v3/path_traits.hpp:22:0, from C:\boost_1_45_0/boost/filesystem/v3/path.hpp:25, from C:\boost_1_45_0/boost/filesystem.hpp:32, from ..\src\ComputeNatScaleFunction.cpp:18: C:\boost_1_45_0/boost/type_traits/decay.hpp: In instantiation of 'boost::decay<cv::<anonymous enum> >': C:\cmake_binaries\include/opencv2/core/operations.hpp:766:23: instantiated from here C:\boost_1_45_0/boost/type_traits/decay.hpp:28:66: error: 'cv::' is/uses anonymous type C:\boost_1_45_0/boost/type_traits/decay.hpp:28:66: error: trying to instantiate 'template struct boost::remove_reference' C:\boost_1_45_0/boost/type_traits/decay.hpp:38:17: error: 'cv::' is/uses anonymous type C:\boost_1_45_0/boost/type_traits/decay.hpp:38:17: error: trying to instantiate 'template struct boost::remove_reference' C:\boost_1_45_0/boost/type_traits/decay.hpp: In instantiation of 'boost::decay<cv::<anonymous enum> >': C:\cmake_binaries\include/opencv2/core/operations.hpp:917:21: instantiated from here C:\boost_1_45_0/boost/type_traits/decay.hpp:28:66: error: 'cv::' is/uses anonymous type C:\boost_1_45_0/boost/type_traits/decay.hpp:28:66: error: trying to instantiate 'template struct boost::remove_reference' C:\boost_1_45_0/boost/type_traits/decay.hpp:38:17: error: 'cv::' is/uses anonymous type C:\boost_1_45_0/boost/type_traits/decay.hpp:38:17: error: trying to instantiate 'template struct boost::remove_reference' C:\boost_1_45_0/boost/type_traits/decay.hpp: In instantiation of 'boost::decay<Eigen::<anonymous enum> >': C:\Eigen2/Eigen/src/Core/GenericPacketMath.h:116:18: instantiated from here C:\boost_1_45_0/boost/type_traits/decay.hpp:28:66: error: 'Eigen::' is/uses anonymous type C:\boost_1_45_0/boost/type_traits/decay.hpp:28:66: error: trying to instantiate 'template struct boost::remove_reference' C:\boost_1_45_0/boost/type_traits/decay.hpp:38:17: error: 'Eigen::' is/uses anonymous type C:\boost_1_45_0/boost/type_traits/decay.hpp:38:17: error: trying to instantiate 'template struct boost::remove_reference' etc. Are there known conflicts between Boost (1.45) and OpenCV 2.2/Eigen2/other libraries? I am using Eclipse CDT and MinGW toolchain. After going through problems described in http://boost.2283326.n4.nabble.com/How-to-built-boost-td3053130.html, my Filesystem library is of version 3, whereas other ones are of version 2. Cheers, PP

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[Graph] Switching from depth_first_search to depth_first_visit
by Marcus Riemer 17 Mar '11

17 Mar '11

Hello there! I just stumbled over a little bug that is simply due to the wrong visiting pattern used. From what I understand it should simply print a graph with children being indented. The visitor defined for the task itself is just fine. Problem is that currently a depth first *search* is used, which prints each vertex only once. So from my understanding the only thing I need to do is to replace that search with a visit. Sadly replacing the call to depth_first_visit with a call to depth_first_visit is not as easy as I thought ... For the record: The search call itself looks like this: boost::depth_first_search(mGraph, boost::visitor(printer).root_vertex(start)); Looking at the documentation [0] it seems that there is no version with named parameters for the depth first visit. So I need to pass the graph itself, the starting vertex, the visitor and a color map. And its the color map that troubles me ... I have tried around a little to construct such a thing, but so far without success. My try can be found at [1]. This results in a massive compilation error [2]. I am not really experienced with the extent templates are used in the BGL and have no idea what the compiler tries to tell me. Could anyone give me a hint what I am doing wrong? If more sourcecode is required thats not a problem at all. Simply tell me if anything is missing. Access to the source is also not a problem, compilation is quite easy using cmake. Thanks in advance Marcus Riemer [0] http://www.boost.org/doc/libs/1_44_0/libs/graph/doc/depth_first_visit.html [1] http://pastebin.com/ALvnTdj9 [2] http://pastebin.com/bh6d4NpH

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[BGL] clear_out_edges and MutableIncidenceGraph
by Shaun Jackman 17 Mar '11

17 Mar '11

Hi, adjacency_list implements clear_out_edges, but it's not required by any of the graph concepts: http://www.boost.org/doc/libs/1_46_1/libs/graph/doc/graph_concepts.html Could it be added to MutableIncidenceGraph? Actually, now that I check, I don't see MutableIncidenceGraph on that page either, although it is in graph_concepts.hpp. MutableIncidenceGraph requires remove_edge and remove_out_edge_if. clear_out_edges would fit nicely in here, and clear_in_edges in MutableBidirectionalGraph. Cheers, Shaun

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shared_lock( ) causes Segmentation Fault in CentOS 5.5 x64?
by DesertFish 17 Mar '11

17 Mar '11

Dear Pals, I wrote a server program, and there is a class called "apInfoMutex", which can store client's file descriptor info and what messages they sent; the class code is as below: --- class apInfoTable{ public: apInfoTable(); boost::shared_mutex rwMutex; void addFD(int apfd, char *srvceType, vector<string> *codeList); void delFD(int apfd); bool getFD(list<int> *des, char *srvceType, char *srvceCode); private: boost::unordered_map<int, boost::unordered_set<pair<string, string> > > tableFD; boost::unordered_map<pair<string, string>, boost::unordered_set<int> > tablePush; }; --- there is just one apInfoTable as global declaration in my program, but there would be two or more threads to calling these public method at the same time, and there is a method called "getFD()" in this class, the code is as below: --- bool apInfoTable::getFD(list<int> *des, char *type, char *code){ bool flag=false; boost::shared_lock<boost::shared_mutex> lock(rwMutex); for(boost::unordered_set<int>::iterator it=tablePush[pair<string, string> (type, code)].begin();it!=tablePush[pair<string, string>(type, code)].end ();it++){ flag=true; des->push_back(*it); } return flag; } --- I found if I calling getFD() method like this: char type[12]; char code[32]; list<int> fdList; memset(type, 0x00, sizeof(type)); memset(code, 0x00, sizeof(code)); memcpy(type, "My Type", sizeof("My Type")); memcpy(code, "My Code", sizeof("My Code")); fdList.clear(); bool rc=getFD(&fdList, type, code); I will got "Segmentation Fault" problem, but if I put different parameter like this: bool rc=getFD(&fdList, "My Type", "My Code"); or using boost::mutex instead of shared_lock() and shared_mutex in getFD(), there wouldn't be any problem when running program. is there any problem with my code? or did I use shared_lock() and shared_mutex incorrectly? P.S--I tried using unique_lock or scoped_lock instead of shared_lock(), but there is just no any problem when I using normal boost::mutex sincerely thanks to you Zap

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[Review] Type Traits Extension ending tomorrow
by Joel Falcou 17 Mar '11

17 Mar '11

Dear All, The fast track review of Frédéric Bron's extensions to the Type Traits Library is ending tomorrow. If you plan to submit a review, please do so as soon as possible. Thanks in advance to all participants of the review. =========== What is it? =========== This extension adds 37 new traits corresponding to the following 37 operators: - binary: ==, !=,<,<=,>,>=, , +, -, *, /, %, +=, -=, *=, /=, %=, , &&, ||, ,&, |, ^,<<,>>,&=, |=, ^=,<<=,>>= - prefix: ++, --, +, -, !, ~, * - postfix: ++, -- Each trait can detect if the operator can be used with particular types and if needed, if the return type is convertible to some type. =================== Getting the library =================== The latest version can be downloaded by different ways: - from the vault with unix line ending: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=type_t… - from the vault with dos line ending: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=type_t… - from the sandbox:http://svn.boost.org/svn/boost/sandbox/type_traits/ The entry point of the documentation is type_traits/libs/type_traits/doc/html/boost_typetraits/category/value_traits/operators.html The library has been tested with: - MSVC 8, 9, 10 on Windows, - g++ 4.4.5 on Linux, - intel 10.0 and 11.1 on Linux. To test the library, the simplest is to untar the headers in your boost include directory. For this, you can download the header part of the extension: - from the vault with unix line ending: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=type_t… - from the vault with dos line ending: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=type_t…

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Boost profile for ODB
by Boris Kolpackov 17 Mar '11

17 Mar '11

Hi, I would like to briefly mention that we have released the Boost profile for ODB, an open-source object-relational mapping (ORM) system for C++. The Boost profile provides glue code that seamlessly integrates various Boost components, such as smart pointers, containers, and value types, with ODB. This initial release of the profile covers the most commonly used types from the smart_ptr, unordered, and date_time Boost libraries. For example, now we can easily persist a class like this: #pragma db object class employee { ... boost::gregorian::date born_; boost::unordered_set<std::string> emails_; boost::shared_ptr<employer> employer_; }; For a more detailed discussion of the Boost profile, see the following blog post: http://www.codesynthesis.com/~boris/blog/2011/03/16/odb-1-2-0-released/ Or refer directly to Part III, "Profiles" in the ODB Manual: http://www.codesynthesis.com/products/odb/doc/manual.xhtml#III Boris

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