January 2009 - Boost-users - lists.preview.boost.org

Re: [Boost-users] behavior conditional on template argument
by Hicham Mouline 21 Jan '09

21 Jan '09

That is a beautiful trick. The sizeof trick basically. "C++ template metaprogramming" p212 As Joel says in that post, it should definitely be included in standard boost. Perhaps in the type traits library? thank you, > ----- Original Message ----- > From: "Igor R" <boost.lists(a)gmail.com> > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] behavior conditional on template argument > Date: Wed, 21 Jan 2009 13:17:56 +0200 > > > > > > You can use enable_if to let the compiler decide which one it should > > instantiate. And the argument will be a custom defined type trait. I > > think there are facilities to automatically define it on the presence > > of a type, there may be soemthing for fucntions as well, but I don't > > remember where they live (MPL ?) > > > Here it is: > http://www.nabble.com/compile-time-check-that-a-member-function-exists-td18… > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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Making Boost Portable with Our Code
by Gundala Viswanath 21 Jan '09

21 Jan '09

Dear all, I have a set of codes that use a lot of Boost tool. I then want to release the source code for public. Is there a way I can make port Boost in my code so that when people want to build/compile my code they don't need to have Boost install in there computer? - Gundala Viswanath Jakarta - Indonesia

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Problem serializing a std::vector of a user-defined class containing a std::string
by Ivan Gonzalez 21 Jan '09

21 Jan '09

Dear all, I'm having problems to serialize a std::vector of a small class I use in my code. The class contains 3 members: a std::string, a size_t, and an another class passed as a template parameter (see the code below.) The class passed as a template is basically a std::map<int, blitz::Array<double, 2> >(see this post http://lists.boost.org/boost-users/2008/05/36282.php). I'm using the serialization library with the last class elsewhere in my code and works with no problems, so I guess the error must be in the code below. My program compiles and finishes OK, but the results I'm getting are slightly different from what I should get: it seems that somewhere in the serialization process the numbers stored in the third class get corrupted. I'm using boost 1.35, I need the binary file (I'm taking advantage of the serialization stuff for arrays contiguous in memory), and everything happens in the same machine in a single run of my code (so it is not a problem of different binary archives for different machines.) Thanks in advance, Ivan //-------------------------------------------------------------------------------------------- #include <iostream> #include <sstream> // for std::istringstream #include<boost/serialization/string.hpp> #include<boost/serialization/vector.hpp> #include<boost/archive/binary_oarchive.hpp> #include<boost/archive/binary_iarchive.hpp> template<class DataType> class ThingToStore{ public: typedef DataType data_type; ThingToStore() : site_(), name_(), data_() {} ThingToStore(const data_type& data, const std::string& name, int site) : site_(site), name_(name), data_(data) {} const std::string & name() const { return name_; } size_t site() const { return site_; } const data_type& map() const { return data_; } private: friend class boost::serialization::access; template<class Archive> inline void serialize(Archive& ar, const unsigned int file_version) { ar & BOOST_SERIALIZATION_NVP(site_); ar & BOOST_SERIALIZATION_NVP(name_); ar & data_; } size_t site_; std::string name_; data_type data_; }; template<class DataType> class StoredThingList { private: typedef std::vector<ThingToStore<DataType> > this_type; public: StoredThingList() {} template<class Index> void save(const Index& i, const std::string& name="blockOps_") const { // make a string for the name file std::ostringstream oss; oss<<i<<"_"<<".aux"; std::string s=name+oss.str(); // make a output stream to the file above and open it std::ofstream ofile(s, std::ios::binary); if ( ofile.is_open() ) { boost::archive::binary_oarchive oa(ofile); oa & (*this); } } template<class Index> void load(const Index& i, const std::string& name="blockOps_") { // make a string for the name file std::ostringstream oss; oss<<i<<"_"<<".aux"; std::string s=name+oss.str(); // make a input stream to the file above and open it std::ifstream ifile(s, std::ios::binary); if ( ifile.is_open() ) { vec_.clear(); boost::archive::binary_iarchive ia(ifile); ia & (*this); } } private: friend class boost::serialization::access; template<class Archive> inline void serialize(Archive& ar, const unsigned int version) { ar & vec_; } this_type vec_; }; //--------------------------------------------------------------------------------------------

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boost geometry lib
by Andruit＠gmx.de 21 Jan '09

21 Jan '09

Hello, I am a newbie to boost and I have a question concerning the installation of additional libs. I am really interested in the geometry library (http://geometrylibrary.geodan.nl/ ) , but I don't know how to install it and compile my programs using that library. Has anybody done this before. Thanks in advance. Andreas -- Sensationsangebot verlängert: GMX FreeDSL - Telefonanschluss + DSL für nur 16,37 Euro/mtl.!* http://dsl.gmx.de/?ac=OM.AD.PD003K1308T4569a

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Older boost releases
by Birju Prajapati 21 Jan '09

21 Jan '09

Hi, Is the only way to get an older boost release, i.e. 1.36, via subversion? I can't see any direct links on the site. If svn is the way, then is this the right directory to checkout v1.36? http://svn.boost.org/svn/boost/tags/release/Boost_1_36_0/ TIA, Birju Schneider Trading 4th Floor, 25 Copthall Avenue London EC2R 7BP -------------------------------------------------------- Message from: Birju.Prajapati(a)schneidertrading.com Message to: boost-users(a)lists.boost.org Attached files: 0 This e-mail and any files transmitted with it are confidential, may be legally privileged, and are for the sole use of the intended recipient. Copyright in this e-mail and any accompanying document created by us is owned by us. If you are not the intended recipient of this e-mail or any part of it please telephone our IT Department at the number shown above or by e-mail at info(a)schneidertrading.com. You should not use or disclose to any other person the contents of this e-mail or its attachments (if any), nor take copies. This e-mail is not a representation or warranty and is not intended nor should it be taken to create any legal relations, contractual or otherwise. Schneider Trading Associates Ltd (Registration No. 3692131) is incorporated in England and Wales and the registered office is at 25 Copthall Avenue, London EC2R 7BP. The company is authorised and regulated by the Financial Services Authority

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behavior conditional on template argument
by Hicham Mouline 21 Jan '09

21 Jan '09

Hello, I have a template function template <typename M> void f(const M&) { // call M.f1() // call M.f2() // some Ms have a function f1Andf2() which does f1()+ f2() work faster // how can I write code that runs f1Andf2() if it's there // otherwise runs f1() then f2() } regards,

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up gradation problem on boost 1.37
by Bijay Panda 21 Jan '09

21 Jan '09

Hi All, I tried to upgrade boost 1.34 to 1.37 in ubuntu 7.10 through package manager. At the end of installation it shown an error like Internal Error, Could not perform immediate configuration (2) on libc6 I already removed 1.34 version from /usr/lib and /var/cache/apt/archives. I unable to find where the problem lies. Can any one please help me out. -- Thanks & Regards Bijay

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Adding constness to an iterator
by er 21 Jan '09

21 Jan '09

Hello, I'm looking to define AddConst to be used as below: template<typename BaseIter> class my_iter : public iterator_adaptor< my_iter<AddConst<BaseIter>::type>, AddConst<BaseIter>::type>{ //... }; I guess add_const<range_iterator<X>::type> is not the same as range_iterator<add_const<X>::type>::type, otherwise I could just take AddConst = add_const.

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about CVE-2008-5077(vulnerability of OpenSSL)
by Shinya TAKEBAYASHI 21 Jan '09

21 Jan '09

Hello, I'm making the HTTP proxy server that uses boost::asio. Now, I'm anxious about the impacts by CVE-2008-5077(vulnerability of OpenSSL). http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2008-5077 Does anyone have information on the impacts given to boost::asio? Regards, ---------------------------------------------------------------- Shinya TAKEBAYASHI E-mail : makoto(a)kanon-net.jp GPG ID : FFD20D1F GPG FP : 7B5B E0FC B785 7457 683C 47D6 5564 DDDD FFD2 0D1F CC FP : 7456 70EE 0A68 BC95 B1FC F78F C6A9 3E0E F798 A218 ----------------------------------------------------------------

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Re: [Boost-users] Generating a large number of class member variables: PP vs mpl
by Hicham Mouline 20 Jan '09

20 Jan '09

I just realized you can instantiate fusion vector objects (forgot fusion is about runtime too) So I have this example: struct A { explicit A(int) {} }; struct B { explicit B(int) {} }; struct C { explicit C(int) {} }; class Derived1 { public: Derived1 () : members( A(5), B(5), C(5) ) {} private: const boost::fusion::vector< A, B, C > members; }; All members are constructed with the same argument(s) : 5 Now: 1. I may have 20 members in vector.... Is there a way not to explicitly construct them in the Derived1 ctor 2. Derived3 and Derived7 have the same vector of members. Is there a way, inside Derived3 and 7, to take the vector from Derived1? > ----- Original Message ----- > From: "Joel Falcou" <joel.falcou(a)u-psud.fr> > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Generating a large number of class member variables: PP vs mpl > Date: Tue, 20 Jan 2009 11:25:30 +0100 > > > Hicham Mouline a écrit : > > But once I have my mpl::vector or fusion::vector, > > how do i apply a meta function like for_each > > to generate the class members automatically. > > > > fusion::vector does generate the members for you.

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