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[MPL] meta-function returning the arity of lambda expression
by Joel Falcou 22 Jan '09

22 Jan '09

Is there any meta-function that returns the arity of a MPL meta-function as an integral constant ? -- ___________________________________________ Joel Falcou - Assistant Professor PARALL Team - LRI - Universite Paris Sud XI Tel : (+33)1 69 15 66 35

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Transferring files across a network.
by Andrew Maclean 22 Jan '09

22 Jan '09

We have a situation where there are several computers that have a folder where files are periodically deposited. Currently, in each computer, this folder is scanned periodically and the files are parsed by a program that then sends the SQL data to a central machine where there is postgresql server running. The files are generally small because they are compressed. But the uncompressing and subsequent parsing into SQL strings dramatically inflates the amount of data that is sent across the network. What I am thinking of doing is sending the all the files to a directory on the central machine then parsing them there for subsequent inclusion into the database. So I need a program to periodically scan the folder on the computer and send these files to the central machine. On the central machine I need a similar program to listen for incoming files and put them into a directory for subsequent processing. The listner on the central machine will need to process files arriving simultaneously from several machine. There is no issue with file name conflicts as the names are unique. Can anyone give me any pointers? I think I should use boost asio but I don't know where to start with it. The tutorial and examples, while good haven't provided me with an insight yet! The main requirement I have is that it should be cross-platform. I looked at cURL/cURLpp but there are immense difficulties building this in a windows environment. I would like to stick with boost if possible. Thanks Andrew -- ___________________________________________ Andrew J. P. Maclean Centre for Autonomous Systems The Rose Street Building J04 The University of Sydney 2006 NSW AUSTRALIA Ph: +61 2 9351 3283 Fax: +61 2 9351 7474 URL: http://www.acfr.usyd.edu.au/ ___________________________________________

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[Program Options] Streaming of actual option values.
by Rodolfo Federico Gamarra 22 Jan '09

22 Jan '09

Hi all!! I'm using <boost/program_options.hpp> to allow options in my program to be configured using 3 flavors: - Command line values - Config-file values ( parse_config_file). - Default values ( value<double>(&myDouble)->default_value(3.3) ) prioritized in the given order and put all together in the same variables_map. Upon finalization I'd like to generate a config-file (as required by the 2nd flavor) with the actual values used in the run. So far I've come with a solution that involves iterating over the map, and performing the outstreaming by myself. Something in the line of for(variables_map::const_iterator i = vm.begin(); i != vm.end();++i) { std::cout << i->first << " " << i->second.as<std::string>() << std::endl; } What is cumbersome of this approach is that, actually, not all my args are "std::string", so in reality the call to as<>() ends with bad_any_cast in some cases: it seems that there's no operator << defined for i->second or its underlying "boost::any". So I'd have to switch-case over all the types I'm using for the values. Second, I have to format the output in accordance to parse_config_file by myself. Is there any better solution to this? Thanks a lot in advance. -- Rodolfo Federico Gamarra

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[BGL] - filtered_graph EdgePredicate performance
by Michael Fawcett 22 Jan '09

22 Jan '09

filtered_graph documentation says: [1] The reason for requiring Default Constructible in the EdgePredicate and VertexPredicate types is that these predicates are stored by-value (for performance reasons) in the filter iterator adaptor, and iterators are required to be Default Constructible by the C++ Standard. http://www.boost.org/doc/libs/1_37_0/libs/graph/doc/filtered_graph.html I only noticed this after scouring the documentation for hints as to why dijkstra_shortest_paths was taking 2 hours with a filtered_graph compared to 2 seconds with my adjacency_list. The reason for this huge difference was my filter's EdgePredicate had a boost::unordered_set member that returned true if the edge was in it. Changing that member to a pointer to an unordered_set reduced running time back down to the 2 second range. As I now understand it, every time a filtered graph iterator adaptor is incremented, it actually incrememts in a loop while the EdgePredicate returns false (or end is reached). This implies that the EdgePredicate should be extremely lightweight, since it is stored by-value in the iterator. What is the general recommendation when writing filter_graph predicates? My use case is filtering out all edges that reside inside a polygonal region. To do this, I do the intersection, then store the edges that are inside that region in an unordered_set. This requires that my EdgePredicate store a pointer to the graph and a pointer to the unordered_set since I can't hash an edge_descriptor without a reference to the graph (to get the target and source). That still seems big to me, given that it will be copied per iterator increment. On top of that, to ensure proper release of the unordered_set, I need to use shared_ptr or something similar, instead of just having the predicate own the unordered_set like it logically should, introducing yet more overhead in reference counting. The footnote states that it is stored by value for performance reasons. What types of predicate implementations were in mind when that was decided? I can't see a realistic filtering predicate that could say true/false with no member variables - at the very least it must store a pointer to the graph so that it can use the edge_descriptor. Is there a different, preferred way of writing EdgePredicates? Is there a way to get target/source from an edge_descriptor without the graph instance? Thanks, --Michael Fawcett

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[GIL] Raw C pointer from any_image
by Olivier Tournaire 21 Jan '09

21 Jan '09

Hi all, I am wondering if it is posible to get a raw C pointer from an any_image / any_image_view. I tried this (taken from the tutorial): typedef boost::mpl::vector<gray8_image_t, rgb8_image_t> my_img_types; any_image<my_img_types> runtime_image; jpeg_read_image(filename.toStdString().c_str(), runtime_image); unsigned char* data = interleaved_view_get_raw_data( any_image_view<my_img_types>(runtime_image) ); And got the following errors: /usr/include/boost/gil/extension/io/../dynamic_image/../../image_view_factory.hpp:95: error: 'value' is not a member of 'boost::gil::view_is_mutable< .................. > error: no matching function for call to 'interleaved_view_get_raw_data(boost::gil::any_image_view< .................. > As I am really not familiar with the MPL, I am certainly doing something bad. Hope you could help. Regards, Olivier -- Olivier Tournaire MATIS - Institut Géographique National 73, Ave de Paris 94165 St Mandé cedex, France tel: (+33) 1 43 98 80 00 - 71 25 fax: (+33) 1 43 98 85 81

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Pointer serialization
by niranjan bangera 21 Jan '09

21 Jan '09

hi am facing isssue in pointer serialization: version:1.36.0 linux : g++ 4.1.1 Where in sample ex shows; header file my.h contains: ------------------------- class second { int var1; float var2; template<class Archive> void serialize(Archive & ar, const unsigned int file_version) { ar & var1; ar & var2; } }; class first { second so; template<class Archive> void serialize(Archive & ar, const unsigned int file_version) { ar & so; } }; mymain.cpp ---------- #include "my.h" first *ptr; { std::ofstream ofs("filename"); boost::archive::text_oarchive oa(ofs); oa << ptr: } here in while compiling this(my.cpp) i am getting these errors -------------------------------------------------------------- /project_new/boost_1_36_0/include/boost-1_36/boost/archive/detail/oserializer.hpp:154: undefined reference to `boost::archive::detail::archive_pointer_oserializer<boost::archive::text_oarchive>::~archive_pointer_oserializer()' /project_new/boost_1_36_0/include/boost-1_36/boost/archive/detail/oserializer.hpp:154: undefined reference to `boost::archive::detail::archive_pointer_oserializer<boost::archive::text_oarchive>::~archive_pointer_oserializer()' /project_new/boost_1_36_0/include/boost-1_36/boost/serialization/extended_type_info_typeid.hpp:76: undefined reference to `boost::serialization::detail::extended_type_info_typeid_0::extended_type_info_typeid_0()' /project_new/boost_1_36_0/include/boost-1_36/boost/serialization/extended_type_info_typeid.hpp:78: undefined reference to `boost::serialization::detail::extended_type_info_typeid_0::type_register(std::type_info const&)' /project_new/boost_1_36_0/include/boost-1_36/boost/serialization/extended_type_info_typeid.hpp:78: undefined reference to `boost::serialization::detail::extended_type_info_typeid_0::type_register(std::type_info const&)' /project_new/boost_1_36_0/include/boost-1_36/boost/serialization/extended_type_info_typeid.hpp:78: undefined reference to `boost::serialization::detail::extended_type_info_typeid_0::type_register(std::type_info const&)' /project_new/boost_1_36_0/include/boost-1_36/boost/serialization/extended_type_info_typeid.hpp:78: undefined reference to `boost::serialization::detail::extended_type_info_typeid_0::type_register(std::type_info const&)' /project_new/boost_1_36_0/include/boost-1_36/boost/serialization/extended_type_info_typeid.hpp:78: undefined reference to `boost::serialization::detail::extended_type_info_typeid_0::type_register(std::type_info const&)' ...................... /project_new/boost_1_36_0/include/boost-1_36/boost/archive/detail/oserializer.hpp:94: undefined reference to `boost::archive::detail::basic_oarchive::end_preamble()' /project_new/boost_1_36_0/include/boost-1_36/boost/archive/detail/oserializer.hpp:94: undefined reference to `boost::archive::detail::basic_oarchive::end_preamble()' /project_new/boost_1_36_0/include/boost-1_36/boost/archive/detail/oserializer.hpp:94: undefined reference to `boost::archive::detail::basic_oarchive::end_preamble()' Any suggestions will be accepted. Regards Niranjan

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[Units] Can't assign equation
by Daniel Dilts 21 Jan '09

21 Jan '09

I'm using Boost.Units in a program for school to make certain that my equations are consistent (and that I didn't screw them up entering them). In the next Velocity equation, first get assigned with no problems, second causes a compiler error that I believe is saying that the constructor for quantity<velocity> is explicit. Why does first work without a conversion and second doesn't? Also, how do I get second to work? I assume this will require some type of explicit conversion, but wrapping the right-hand side with quantity<velocity>(...) doesn't work. const quantity<dimensionless> pi = 3.14159265358979323846264338327950288419716939937510582097494459230781640628620899862803482534211706798; const quantity<time> deltaTime = .1 * second; const quantity<length> particleDiameter = .001 * meter; const quantity<dimensionless> dragCoefficient = 0.5; const quantity<dimensionless> specificGravityGold = 19.32; const quantity<acceleration> gravity = 9.80665 * meters_per_second_squared; const quantity<length> initialHeight = 0 * meters; const quantity<time> initialTime = 0 * seconds; const quantity<velocity> initialVelocity = root<2>(4.0/3 * specificGravityGold * gravity * particleDiameter / dragCoefficient); const quantity<mass_density> densityWater = 1000 * kilograms_per_cubic_meter; const quantity<mass_density> densityGold = 19300 * kilograms_per_cubic_meter; const quantity<mass> particleMass = 4.0 / 3.0 * pi * pow<3>(particleDiameter / 2.0) * densityGold; quantity<velocity> nextVelocity(quantity<velocity> old) { quantity<velocity> first = (pi / 6.0 * pow<3>(particleDiameter) * gravity * (densityWater - densityGold)) * deltaTime / particleMass; quantity<velocity> second = (pi / 8.0 * densityWater * dragCoefficient * old * root<2>(pow<2>(old))) * deltaTime / particleMass; ... }

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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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Re: [Boost-users] Annoying coding
by Alan M. Carroll 20 Jan '09

20 Jan '09

Why not use Boost.Bind? It will bind to data members, returning a functor that accesses that member. E.g. boost::bind(&A::a, _1); will create a functor that takes an instance of A and returns a reference to the a member. You can then pass that to whatever other functor is being used. Something like (not tested!) std::accumulate(m.begin(), m.end(), bind(std::add, _1, bind(&std::map<std::string, int>::value_type::first, _1)); Boost.Lambda can do this as well, but I am not familiar enough with it to provide an example. At 07:22 AM 1/20/2009, you wrote: >Hi again, > >I have a problem. Not really big one but annoying. >Often we need to write code like this: > >struct A{ > int a; > std::string b; >}; > >int a_sum(int i, const A &v){ return v.a + i; }; > >std::vector<A> v; >//fill this vector somewhere > >std::accumulate( v.begin(), v.end(), 0, a_sum ); > >or something like > >int m_sum(int i, const std::pair<int, std::string> p) { return p.first + i; }; > >std::map <std::string, int> m; > >std::accumlate( m.begin(), m.end(), 0, m_sum); > >Or in common words we need to write some kind functor which just get >member from element and apply it to another functor. > >Of course I can write something like: > >template<typename T_, typename V_, V_ T_::*Ptr_> >struct get_mem{ > const V_ &operator()(const T_ &elem){ > return elem->*Ptr_; > }; >}; > >but may be there is library way to do this? >_______________________________________________ >Boost-users mailing list >Boost-users(a)lists.boost.org >http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Annoying coding
by Maxim Koshelev 20 Jan '09

20 Jan '09

Hi again, I have a problem. Not really big one but annoying. Often we need to write code like this: struct A{ int a; std::string b; }; int a_sum(int i, const A &v){ return v.a + i; }; std::vector<A> v; //fill this vector somewhere std::accumulate( v.begin(), v.end(), 0, a_sum ); or something like int m_sum(int i, const std::pair<int, std::string> p) { return p.first + i; }; std::map <std::string, int> m; std::accumlate( m.begin(), m.end(), 0, m_sum); Or in common words we need to write some kind functor which just get member from element and apply it to another functor. Of course I can write something like: template<typename T_, typename V_, V_ T_::*Ptr_> struct get_mem{ const V_ &operator()(const T_ &elem){ return elem->*Ptr_; }; }; but may be there is library way to do this?

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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

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. for e.g., I define the vector<> with 15 elements, I should be able to have 15 member types in the class, without manually writing at_c<0> .... at_c<1>? I'm now looking again at mpl::inherit_linearly rds, > ----- Original Message ----- > From: "Juraj IvanÄiÄ" <juraj.ivancic(a)gmail.com> > 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 11:03:56 +0100 > > > Hicham Mouline wrote: > > > Is it possible to generate the members from the mpl::vector<> ? > > It is certainly possible and is already done in Boost.Fusion. > > See > http://www.boost.org/doc/libs/1_37_0/libs/fusion/doc/html/index.html > and especially > http://www.boost.org/doc/libs/1_37_0/libs/fusion/doc/html/fusion/container.… > > HTH, > Juraj

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Generating a large number of class member variables: PP vs mpl
by Hicham Mouline 20 Jan '09

20 Jan '09

Hello, I have a base class with a number of derived classes. Derived classes might have large number of private member variables, each with a different type. Some of these derived classes may have identical lists of member names and types. I seem to have 2 possibilities to generate the list of member variables: class Derived1 { ... typedef mpl::vector< Type1, Type2, Type3, Type4, Type5, Type6 > memberTypes; // then try to generate automatically from memberTypes, as: // const Type1& mType1; // const Type2& mType2;... // const Type6& mType6; // with some meta function }; or // use only PP class Derived1 { ... #define MYNAMESPACE_MEMBER_TYPES (Type1)(Type2)(Type3)(Type4)(Type5)(Type6) // use PP macros to generate the members }; Is it possible to generate the members from the mpl::vector<> ? in particular, willing to use the mpl::size meta function will forbid me from using PP... The advantage I think is a cleaner definition of types, and other derived classes may use the same type memberTypes. The code generating the member types could isolated in some user meta function. regards,

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create type inside boost::variant without calling copy constructor
by Maxim Koshelev 20 Jan '09

20 Jan '09

Hi, all! At first small example which introduce problem and solutions. Let's write class that hold some object and give us access to it (it's not for real usage, only for demonstration): class Holder{ struct Impl{}; template<typename T_> struct Impl{ T_ val; Impl(const T_ &v):val(v){} }; Impl *v_; public template<typename T_> Holder(const T_&val):v_(new Impl<T_>(val)){}; template<T_> T_ get(){ dynamic_cast<T_>(*v_); }; }; now we have a constructor which create Holder with some type inside by copying it. If we want to create Holder with some type without copying, just created by default constructor, we can use "traits" technics: template<typename T_> class Trait{ typedef T_ type; } template<typename T_> Holder(const Trait<T_>):v_(new Impl<T_>){}; and when we want to create Holder with some type inside we use: Holder v( Trait<SomeType>() ); And now problem: is there any way to create boost::variant with a type inside without calling copy constructor? Currently I see only one way: boost::variant< std::string, std::pair<std::string, std::string> > p; p=std::string(); in this code we create "empty" variant variable "p", then copy empty string inside it. But I need just create p with std::string inside, without copying! Any solution? Thanks in advance, and additional thanks if you have read till this sentence :-) P.S. Sorry for my ugly English :-)

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[filesystem] running afoul of _HAS_ITERATOR_DEBUGGING - VC 9.0
by Raman 19 Jan '09

19 Jan '09

Hello, I'm a boost newbie, so please bear with me if this sounds trivial. I'm rebuilding our code that uses boost heavily with VC 9.0 on Windows 2008, 32-bit. All of our code is compiled with _SECURE_SCL=0 & _HAS_ITERATOR_DEBUGGING=0. And I rebuild boost with the same flags. Our code links with boost as static libraries. However, at runtime - I'm seeing access violations occuring in the Microsoft secure STL code that should have been disabled with _HAS_ITERATOR_DEBUGGING=0. A specific example, when we call filesystem::basic_path::normalize(), this calls: // path.hpp template<class String, class Traits> void basic_path<String, Traits>::m_append_separator_if_needed() { if ( # ifdef BOOST_WINDOWS_PATH *(m_path.end()-1) != colon<path_type>::value && # endif // >>>>>> following is the offending line *(m_path.end()-1) != slash<path_type>::value ) { m_path += slash<path_type>::value; } } which leads me to: //xtring reference __CLR_OR_THIS_CALL operator*() const { // return designated object #if _HAS_ITERATOR_DEBUGGING if (this->_Mycont == 0 || _Myptr == 0 // >>>>>> following is the offending line - _MyCont contains garbage || _Myptr < ((_Mystring *)this->_Mycont)->_Myptr() || ((_Mystring *)this->_Mycont)->_Myptr() + ((_Mystring *)this->_Mycont)->_Mysize <= _Myptr) { _DEBUG_ERROR("string iterator not dereferencable"); SCL_SECURE_OUT_OF_RANGE; } __analysis_assume(_Myptr != 0); #else if (this->_Mycont != _IGNORE_MYCONT) { _SCL_SECURE_VALIDATE(this->_Has_container()); _SCL_SECURE_VALIDATE_RANGE(_Myptr < (((_Mystring *)this->_Mycont)->_Myptr() + ((_Mystring *)(this->_Mycont))->_Mysize)); } #endif /* _HAS_ITERATOR_DEBUGGING */ return (*_Myptr); } I'm stumped as to why its even in that piece of code when I've disabled HAS_ITERATOR_DEBUGGING. Any help/guidance is appreciated. Thanks Raman

3 5

[range, iterator?] compiler error going from 1.34 to 1.37
by Martin Livesey 19 Jan '09

19 Jan '09

We are upgrading our legacy code to use boost 1.37 from version 1.34 and have hit a slight hitch. The following (massively simplified) code no longer compiles. I tried it on more than one compiler and the error messages aren't too useful in helping to determine the issue. (The target compiler will be VS 2k8). Any assistance would be appreciated. Thanks in advance. #include "tchar.h" #include <boost/iterator/filter_iterator.hpp> #include <boost/range/iterator_range.hpp> #include <list> class A{}; class B { public: typedef std::list<A>::iterator iterator; iterator begin() { return bs.begin(); } iterator end() { return bs.end(); } private: typedef std::list<A> List; List bs; }; template <class Predicate> struct FilteredRange { typedef boost::filter_iterator<Predicate, B::iterator> iterator_type; typedef boost::iterator_range<iterator_type> range_type; }; template <typename Predicate> typename FilteredRange<Predicate>::range_type getFilteredRange(B *list) { return boost::make_iterator_range(boost::make_filter_iterator<Predicate>(list->begin(), list->end()), boost::make_filter_iterator<Predicate>(list->end(), list->end())); } class C { public: bool operator()(const A &a) const {return true;} }; int _tmain(int argc, _TCHAR* argv[]) { getFilteredRange<C>(new B).size(); return 0; }

2 1

[boost-users][function] how to
by Igor R 19 Jan '09

19 Jan '09

Hello, function<void(Base *)> funcB; function <void(Derived *)> funcD; Is it possible to convert somehow funcD --> funcB ? Thanks.

2 3

Boost::interprocess sharing string
by Federico Golfrè Andreasi 19 Jan '09

19 Jan '09

Hi ! I have a problem sharing a string within a shared memory segment using named objects. (Boost.interporcess 1.36.0) I attach here the code of the two programs: one writes the string and the other read it. In the reader a segmentation fault is throw. Where am I wrong? Thank you very much Federico

2 1

[proto] applying proto to real problems
by Michael Marcin 19 Jan '09

19 Jan '09

I haven't used proto before and as I read the documentation everything makes sense but I can't figure out how to apply the information there to solve my problems. I think if I can figure out how to solve a simplified example from my actual problem I can figure out the rest. // typical 3d vector template< typename T > struct vec3 { T x,y,z; }; // typical 3d dot product template< typename T > T dot_product( const vec3<T>& a, const vec3<T>& b ) { return a.x*b.x + a.y*b.y + a.z*b.z; } // typical 16.16 fixed point number struct fixed { boost::int32_t data; }; // typical multiplication for this fixed point number fixed operator*( fixed lhs, fixed rhs ) { fixed result = { static_cast<boost::int32_t> ( ( boost::int64_t(lhs.data)*rhs.data ) >> 16 ) }; return result; } // however using the typical dot product with // fixed numbers is too lossy and inefficient // so we have to specialize dot_product for // these fixed point numbers to do this template<> fixed dot_product( const vec3<fixed>& a, const vec3<fixed>& b ) { fixed result = { static_cast<boost::int32_t> ( ( boost::int64_t(a.x.data) * b.x.data + boost::int64_t(a.y.data) * b.y.data + boost::int64_t(a.z.data) * b.z.data ) >> 16 ) }; return result; } What I want to be able to do is to make the typical dot product generate code that is equivalent to the specialized dot product when instantiated with T = fixed. This seems like something proto should handle easily from the description of the library but I just don't get proto yet. Thanks, -- Michael Marcin

3 2

Comparing is_pointer with true_
by jean-louis.a.leroy＠fortis.com 19 Jan '09

19 Jan '09

Hello. I need to compare is_const<T> with true_ or false_. I don't find an easy way to do it. I have tried: void foo(mpl::true_) { cout << "true" << endl; } void foo(mpl::false_) { cout << "false" << endl; } int _tmain(int argc, _TCHAR* argv[]) { foo(is_same< mpl::true_, is_pointer<void*>() >()); foo(is_same< mpl::true_, is_pointer<void*>::type() >()); foo(is_convertible< is_pointer<void*>(), mpl::true_ >()); foo(is_base_of< mpl::true_, is_pointer<void*>() >()); return 0; } (in case you wonder why I don't simply pass is_pointer to foo(), here's why: I have a function object that is called twice with a bool_ template argument; the first time it handles all non-pointer types and in a second pass it handles the pointer types; in fact I'm trying to implement the equivalent of b1 == b2, where b1 and b2 are bools). I understand that is_pointer<T> derives either from true_type or false_type. Thus it's normal that is_same fails. But what of the others? Jean-Louis = = = = = = = = = = = = = = = = = = = = = = = = = Fortis disclaimer : http://www.fortis.be/legal/disclaimer.htm Privacy policy related to banking activities of Fortis: http://www.fortis.be/legal/privacy_policy.htm = = = = = = = = = = = = = = = = = = = = = = = = =

2 3

Re: [Boost-users] problems installing boost -- explorer.exe
by Marks, Joseph 19 Jan '09

19 Jan '09

For what it's worth, I have had a similar problem with the "7z" or 7-zip program. I had to re-install this program this morning, as it was "acting" up. I don't know what you're using for zips -- WinZip, 7-zip, j-zip, or some other program, but the problem *could* be with that software; then again, it might not. ADMG Joseph

1 0

problems installing boost -- explorer.exe Application error
by Paul Epstein 19 Jan '09

19 Jan '09

I have been trying to install the latest version of Boost from sourceforge.net. I have a Windows Vista operating system. I downloaded the boost.zip file and the boost-jam.zip file. I was able to extract the boost-jam file without problems. However, whenever I try and extract the boost.zip file to a folder I created I get the message: explorer.exe - Application Error The exception unknown software exception (0xc000000d) occurred in the application at 0x75afc02c. I tried ending the process explorer.exe, but when I kill that process, I am unable to do the extracting. I know this is a basic problem. I doubt that the issue is specifically Boost-related but since the problem arose in a boost-context, I'm hopefully on topic. Many thanks for your help. Paul Epstein

2 1

Building iostreams with zlib support on Windows XP in mingw-msys
by e m 19 Jan '09

19 Jan '09

I use bjam like so: bjam toolset=gcc link=static runtime-link=static threading=single \ --with-iostreams --with-filesystem \ -sNO_COMPRESSION=0 -sNO_ZLIB=0 -sZLIB_SOURCE=C:/zlib123 \ --build-type=release install -------------------------------------------------- But, I do not believe that zlib is being built or linked in to iostreams. The only libs I get in C:/Boost/lib after bjam are these: libboost_filesystem-mgw34-s.lib libboost_system-mgw34-s.lib libboost_iostreams-mgw34-s.lib However, the output from bjam does not indicate any errors with iostreams or zlib. -------------------------------------------------- When I try to compile the zlib example from here: http://www.boost.org/doc/libs/1_37_0/libs/iostreams/doc/classes/zlib.html#e… I get these errors: C:/Users/e4m/AppData/Local/Temp/ccSscQ9O.o:zlib_test.cpp:(.text$_ZN5boost9iostreams6detail22zlib_decompressor_implISaIcEED2Ev[boost::iostreams::detail::zlib_decompressor_impl<std::allocator<char> >::~zlib_decompressor_impl()]+0x58): undefined reference to `boost::iostreams::detail::zlib_base::reset(bool, bool)' C:/Users/e4mAppData/Local/Temp/ccSscQ9O.o:zlib_test.cpp:(.text$_ZN5boost9iostreams6detail22zlib_decompressor_implISaIcEED2Ev[boost::iostreams::detail::zlib_decompressor_impl<std::allocator<char> >::~zlib_decompressor_impl()]+0x6a): undefined reference to `boost::iostreams::detail::zlib_base::~zlib_base()' ... ... ... -------------------------------------------------- I am trying to compile the example like this: g++ -static -O3 zlib_test.cpp -o zlib_test.exe -Ic://Boost/include/boost-1_37/ c://Boost/lib/libboost_iostreams-mgw34-s.lib -------------------------------------------------- Here is the example source code as I have modified it slightly while experimenting: #include <fstream> #include <iostream> #include <boost/iostreams/filtering_streambuf.hpp> #include <boost/iostreams/copy.hpp> #include <boost/iostreams/filter/zlib.hpp> //#include "C:/boost_1_37_0/boost_1_37_0/libs/iostreams/src/zlib.cpp" #define BOOST_IOSTREAMS_NO_LIB int main() { using namespace std; using namespace boost::iostreams; ifstream file("hello.z", ios_base::in | ios_base::binary); filtering_streambuf<input> in; in.push(zlib_decompressor()); in.push(file); boost::iostreams::copy(in, cout); return 0; } -------------------------------------------------- I've googled a lot for the last week trying to figure out what I'm doing wrong, to no avail... Can someone help me? Thanks, e

3 3

[fusion - I think!] Multiple nested range traversal.
by Robert Jones 19 Jan '09

19 Jan '09

I recently asked a question on here about traversal of multiple indices, which produced a luke-warm reaction, mainly because I wasn't really asking the right question! So here's another try. Consider a bit of code like this for ( unsigned i=0; i!=3; ++i ) for ( unsigned j=2; j!=5;++j ) for ( unsigned k=4;k!=10;++k ) f( i, j, k ); I'd guess this comes up pretty often, and by generalising it to * an arbitrary number of ranges, of arbitrary types * f() implemented as a lambda or bind function would have quite wide applicability. I've considered writing an implemetation, which has dragged me into examining fusion and mpl in some detail, but doing so does not seem to me be trivial at all. Is there already something in Boost which does this? Thanks, Rob.

2 2

[boost-users][serialization]
by Igor R 19 Jan '09

19 Jan '09

Hello, I've just started to use serialization in my project. When I try to save some struct into archive: boost::archive::xml_oarchive archive = ....; archive << BOOST_SERIALIZATION_NVP(descriptor_); ...the following error occures (boost 1.36.0, MSVC9.0SP): boost/serialization/level.hpp(54) : error C2039: 'basic_traits' : is not a member of 'boost::serialization::boost::serialization' What does it mean in terms of my code, i.e. where should I look for an error? Thank you.

1 1

[Variant] Odd linker errors that somehow involve boost::variant
by James Madison 19 Jan '09

19 Jan '09

[NOTE : this is using boost v1.32. I am forced to use this version] In the code I am trying to compile I have a boost variant defined as: boost::variant<int, char, double, std::string, ACE_Time_Value> and it is used in several different ways. This project compiles and links fine using debug settings, essentially the -g flag in gcc, however whenever I try to compile without that flag I get the following error, repeated hundreds of times: `.gnu.linkonce.t._ZNSt3mapIiN5boost7variantIicdSs14ACE_Time_ValueNS0_6detail7variant5void_ES5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_EESt4lessIiESaISt4pairIKiS6_EEEixERSA_' referenced in section `.gnu.linkonce.r._ZNSt3mapIiN5boost7variantIicdSs14ACE_Time_ValueNS0_6detail7variant5void_ES5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_EESt4lessIiESaISt4pairIKiS6_EEEixERSA_' of ./src/geneva/infra/messaging/ResponseMsg.o: defined in discarded section `.gnu.linkonce.t._ZNSt3mapIiN5boost7variantIicdSs14ACE_Time_ValueNS0_6detail7variant5void_ES5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_S5_EESt4lessIiESaISt4pairIKiS6_EEEixERSA_' of ./src/geneva/infra/messaging/ResponseMsg.o Google is not helping diagnose the problem at all. I am wondering if anyone here can point me in the right direction.

4 3

Problem with shared_ptr
by Germán Diago 18 Jan '09

18 Jan '09

What's wrong with this code? When I push_back ptr to the vector, it pushes 0 instead of the value contained in ptr (which I checked and is non-zero). std::vector<boost::shared_ptr<BaseClass> > baseobjects = get_base_objects(path); std::vector<boost::shared_ptr<DerivedClass> > result(get_base_objects.size()); BOOST_FOREACH (boost::shared_ptr<BaseClass> en, baseobjects) { boost::shared_ptr<DerivedClass> ptr = boost::dynamic_pointer_cast<DerivedClass>(en); //Error when push_back. Instead of ptr, I get 0 result.push_back(ptr); } Thanks.

6 7

combining asio::serial_port with iostreams::stream
by Christoph Gysin 18 Jan '09

18 Jan '09

Hi boost users I'm a newbie to boost trying to use a serial port as an iostream. While searching the archives I found a post by Rob Desbois (2008-01-18 13:02) trying to achive the same. Unfortunately the solution wasn't posted. This is what I got so far: #include <boost/asio.hpp> #include <boost/iostreams/stream.hpp> class serial_device { public: typedef char char_type; typedef boost::iostreams::bidirectional_device_tag category; serial_device(boost::asio::io_service& io_service, const std::string& port, int baudrate = 9600) : serial_port(io_service, port) { typedef boost::asio::serial_port_base spb; serial_port.set_option(spb::baud_rate(baudrate)); }; std::streamsize read(char* buf, std::streamsize n) { boost::asio::read(serial_port, boost::asio::buffer(buf, n)); } std::streamsize write(const char* buf, std::streamsize n) { boost::asio::write(serial_port, boost::asio::buffer(buf, n)); } private: boost::asio::serial_port serial_port; }; int main(void) { boost::asio::io_service io_service; serial_device serial(io_service, "/dev/ttyS0", 115200); //boost::iostreams::stream<serial_device> s(serial); } If I uncomment the last line it fails to compile: g++ -lboost_iostreams-mt -lboost_system-mt -lboost_thread-mt iostream.cpp -o iostream /usr/include/boost/noncopyable.hpp: In copy constructor 'boost::asio::basic_io_object<boost::asio::serial_port_service>::basic_io_object(const boost::asio::basic_io_object<boost::asio::serial_port_service>&)': /usr/include/boost/asio/basic_io_object.hpp:30: instantiated from 'boost::iostreams::stream<Device, Tr, Alloc>::stream(Device&, int, int) [with Device = serial_device, Tr = std::char_traits<char>, Alloc = std::allocator<char>]' iostream.cpp:36: instantiated from here /usr/include/boost/noncopyable.hpp:27: error: 'boost::noncopyable_::noncopyable::noncopyable(const boost::noncopyable_::noncopyable&)' is private /usr/include/boost/asio/basic_io_object.hpp:30: error: within this context /usr/include/boost/noncopyable.hpp: In copy constructor 'boost::asio::detail::reactive_descriptor_service<boost::asio::detail::epoll_reactor<false> >::implementation_type::implementation_type(const boost::asio::detail::reactive_descriptor_service<boost::asio::detail::epoll_reactor<false> >::implementation_type&)': /usr/include/boost/noncopyable.hpp:27: error: 'boost::noncopyable_::noncopyable::noncopyable(const boost::noncopyable_::noncopyable&)' is private /usr/include/boost/asio/detail/reactive_descriptor_service.hpp:47: error: within this context /usr/include/boost/asio/basic_io_object.hpp: In copy constructor 'boost::asio::basic_io_object<boost::asio::serial_port_service>::basic_io_object(const boost::asio::basic_io_object<boost::asio::serial_port_service>&)': /usr/include/boost/asio/basic_io_object.hpp:30: note: synthesized method 'boost::asio::detail::reactive_descriptor_service<boost::asio::detail::epoll_reactor<false> >::implementation_type::implementation_type(const boost::asio::detail::reactive_descriptor_service<boost::asio::detail::epoll_reactor<false> >::implementation_type&)' first required here /usr/include/boost/asio/basic_serial_port.hpp: In copy constructor 'boost::asio::basic_serial_port<boost::asio::serial_port_service>::basic_serial_port(const boost::asio::basic_serial_port<boost::asio::serial_port_service>&)': /usr/include/boost/asio/basic_serial_port.hpp:51: note: synthesized method 'boost::asio::basic_io_object<boost::asio::serial_port_service>::basic_io_object(const boost::asio::basic_io_object<boost::asio::serial_port_service>&)' first required here iostream.cpp: In copy constructor 'serial_device::serial_device(const serial_device&)': iostream.cpp:5: note: synthesized method 'boost::asio::basic_serial_port<boost::asio::serial_port_service>::basic_serial_port(const boost::asio::basic_serial_port<boost::asio::serial_port_service>&)' first required here /usr/include/boost/iostreams/stream.hpp: In constructor 'boost::iostreams::stream<Device, Tr, Alloc>::stream(Device&, int, int) [with Device = serial_device, Tr = std::char_traits<char>, Alloc = std::allocator<char>]': /usr/include/boost/iostreams/stream.hpp:129: note: synthesized method 'serial_device::serial_device(const serial_device&)' first required here make: *** [iostream] Error 1 Could anyone please explain what I'm doing wrong? Thanks, Chris -- echo mailto: NOSPAM !#$.'<*>'|sed 's. ..'|tr "<*> !#:2" org@fr33z3

1 0

[program_options] Can you use position-sensitive parameters?
by Adam Nielsen 18 Jan '09

18 Jan '09

Hi all, I can't find anything in the docs that tells me whether this is possible without writing custom parsers etc. so if anyone knows whether this can be done please let me know. I'd like to be able to use position-sensitive parameters. For example, a program to work with .zip files: zip --rename=one.bin:alpha.bin --add=one.bin --rename=one.bin:beta.bin Using this example, the initial --rename would need to be acted upon first, before -add (otherwise one.bin would get overwritten) and likewise the last --rename must be acted upon after -add, otherwise the wrong file (or no file) would be renamed. If I use normal string vectors the order of the parameters will be lost so this won't work. Is this sort of parsing possible with program_options? Thanks, Adam.

1 0

shared_ptr custom deleter implementation
by Zachary Turner 18 Jan '09

18 Jan '09

I'm trying to write a class lazy<T>, the skeleton of which is as follows: template<class T> class lazy { public: template<class F> lazy(F fetcher) //Store fetcher somehow { } T get() { if (!cache) cache = fetch(); //Access fetcher from constructor in a type-safe way return cache.get(); } private: optional<T> cache; }; My problem is how to store / access the fetch function in a type safe way. The reason I titled this message how I did is because I see that shared_ptr does almost exactly the same thing with its deleter. But I'm still kind of new to the whole metaprogramming thing and having a little difficulty really getting my head around how it works. I guess there is some general "pattern" that applies in both of these cases as well as any other case where you want to store some value, the type of which is deduced by the constructor, and then later accessing that value in a type safe way. This message could probably have been equally well fitting in a general C++ forum, but since this is a problem that seems to arise really frequently in boost and other code using heavy templates, I guess I'm in pretty good company here as well. The following seems close to a solution: template<class T> class lazy_impl_base { virtual T fetch() = 0; }; template<class T, class F> class lazy_impl : public lazy_impl_base<T> { // etc }; and then storing a lazy_impl_base<T>* in lazy<T>. But there are strange compiler warnings, and I fear I will encounter subtle errors when I attempt to use it with functors, binders, and other non trivial "functions". Can anyone offer some guidance here? Maybe a quick high level overview of how shared_ptr and other boost libraries solve this problem, or even an implementation of lazy that works :P

2 1

Optionally enforce const correctness in argument dependent lookup
by er 18 Jan '09

18 Jan '09

Hi All, The example below illustrates my intent, but obviously it's not the right approach... so I'm hoping someone has a suggestion. template<typename X> struct enforce_constness{ typedef add_reference<const X> type; }; template<template<typename> class T = enforce_constness> struct A{ template<typename X> void operator()(typename T<X>::type x)const{ // Under default I'd like const X& }; } X x; A<> a; a(x); no match for call to (A<T>)(X&)

2 2

problem with boost::is_same
by Zachary Turner 18 Jan '09

18 Jan '09

I have a question about the following code: typedef void(intArrayParamFunc)(int[]); typedef void(intPtrParamFunc)(int*); BOOST_STATIC_ASSERT((boost::is_same<intArrayParamFunc,intPtrParamFunc>::value)); BOOST_STATIC_ASSERT((boost::is_same<int*,int[]>::value)); cout << typeid(intArrayParamFunc).name() << endl; cout << typeid(intPtrParamFunc).name() << endl; cout << typeid(int*).name() << endl; cout << typeid(int[]).name() << endl; The first assert compiles but the second fails, which means that boost::is_same<> thinks that int* and int[] are different, but void(int[]) and void(int*) are the same. Why is this? The typeids print out the following: void __cdecl(int * const) void __cdecl(int *) int * int [0] I'm using Visual Studio 2008. I notice that typeid tells me that intArrayParamFunc is void(int* const). So why does boost::is_same<> compare them equal? Surely void(int* const) should not be the same type as void(int*). Unless this is just some obscure language subtlety I'm not aware of. So is this a bug in boost::is_same<>, a bug in my compiler, or no bugs at all and everything is working perfectly?

2 1

[date_time] Error compiling greg_month with Intel C++ 11.0
by Remko Tronçon 17 Jan '09

17 Jan '09

Hi, I'm having a problem compiling greg_month.cpp with Intel C++ 11.0. I used bcp to create a local version of boost 1.37.0. When I run icc -I. -c libs/date_time/src/gregorian/greg_month.cpp I get: (0) internal error: backend signals (and nothing more). Is this a known problem? It works fine with other compilers, and the rest of boost compiles fine for me with ICC as well. thanks, Remko

1 0

Serialization on Mac Followup
by Brandon Aubie 17 Jan '09

17 Jan '09

I have gotten everything working correctly now. The first time when I installed boost, I downloaded the source, did the regular configure, make, install into /usr/local. I then tried using MacPorts to install Boost 1.37 and this time, using the MacPorts installation, everything is working fine!

1 0

[boost][iostreams] Crash when using bzip2 codec
by Marc Viala 17 Jan '09

17 Jan '09

Hi, During our migration from Boost 1.34.1 to Boost 1.37.0 we are facing a bug in bzip2 codec (boost::iostreams::bzip2_compressor & boost::iostreams::bzip2_compressor). To demonstrate it, you will find hereafter a code snippet: #include <fstream> #include <boost/iostreams/filtering_stream.hpp> #include <boost/iostreams/combine.hpp> #include <boost/iostreams/filter/bzip2.hpp> #include <boost/iostreams/filter/gzip.hpp> #include <boost/iostreams/filter/zlib.hpp> void main() { using namespace boost::iostreams ; // Run smoothly { filtering_stream<bidirectional> chain ; chain.push(combine(gzip_decompressor(), gzip_compressor())) ; chain.push(std::fstream("test.gz", std::ios::binary|std::ios::out)) ; chain << "test" ; } // Run smoothly { filtering_stream<bidirectional> chain ; chain.push(combine(zlib_decompressor(), zlib_compressor())) ; chain.push(std::fstream("test.zip", std::ios::binary|std::ios::out)) ; chain << "test" ; } // Crash in bzip2_decompressor_impl::close { filtering_stream<bidirectional> chain ; chain.push(combine(bzip2_decompressor(), bzip2_compressor())) ; chain.push(std::fstream("test.bz2", std::ios::binary|std::ios::out)) ; chain << "test" ; } } The crash in bzip2_decompressor_impl::close is due to an access violation @ line 359 in boost/iostreams/filter/bzip2.hpp. For the other codec, zlib & gzip, everything runs smoothly. Set-up: Boost 1.37.0 Windows XP SP3 Visual C++ 7.1 Bzip2 Library 1.0.5 With Boost 1.34.1 the bzip2 codec seems to run smoothly. Is there any work around for this codec w/ Boost 1.37.0? Thanks in advance. Best regards, Marc Viala

2 1

Boost::Serialize on OS X 10.5.6 with g++ 4.3.1 -- Fails to initialize
by Brandon Aubie 17 Jan '09

17 Jan '09

Hello all, I have an application that works fine in Linux that I'm trying to port to OS X. Since it mostly relies on Boost, I was hoping this would be easy, but Boost::Serialization is causing me grief. I have tried this with both binary_oarchive and text_oarchive to the same results (I am using Boost 1.37). Everything compiles fine, but I get an "Abort trap" program crash at this line: ofstream ofs("output"); boost::archive::text_oarchive oa(ofs); // <--- HERE I know it's that line since I put a cout << "Above" << endl; above it and a cout << "Below" << endl; below it and the only thing that gets printed in "Above". I'm using g++ 4.3.1 from MacPorts and I compiled Boost 1.37 with that compiler. Like I said, everything compiles fine, but the program crashes at this point. It works fine in Linux. Any ideas? Thanks

1 0

[Random] Bernoulli generalization.
by Rodolfo Federico Gamarra 17 Jan '09

17 Jan '09

Hi!! I was working with boost::bernoulli_distribution, and needed a generalization which instead of receiving a single probability (and return true/false) would receive N probabilities (adding less than 1) and would return a whole number in the interval [0 N]. It seems that's usually called "categorial distribution" and that could be easily implemented, generalizing boost::bernoulli_distribution. For now, it seems that the workaround, so to say, is to use a uniform [0 1] (boost::uniform_01) and then externally to the distro compare its results with the N probabilities. Thanks a lot to you all. -- Rodolfo Federico Gamarra

1 0

[pool] swap function
by Simon Brown 17 Jan '09

17 Jan '09

Hi, I'm using boost::pool for unordered malloc/free and find myself wanting two additional features: * A nothrow swap function (c.f. scoped_ptr) to swap two pools with equal chunk size. This is a bit of a show-stopper for me at the moment, as I don't want to add the extra level of indirection from allocating the pool object itself on the heap. Has anyone already implemented this for boost::pool, or know if it is on the roadmap for a future release? * A function to reset the pool, but without actually deallocating the memory blocks. This would be the same functionality as purge_memory, but without deallocation. Perhaps "purge_chunks" is a reasonable name for this feature? This isn't a show-stopper, but I want to reset everything and allocate a similar numbe of objects, and having good cache coherency for the allocations would be a benefit. Again, before I delve into the internals, has anyone already had a go at this? Many thanks, Simon

1 0

Accumulators: Adding features at runtime
by dhruva 17 Jan '09

17 Jan '09

Hello, Accumulator features can be marked as droppable so that at runtime, one could drop some calculations from being performed. Is there some way to add features at runtime. I need to do something like this in a generic method. The caller will provide me the calculations they would want to perform in a bitwise ORed format. Based on that, I need to create an accumulator_set object in my constructor. The accumulator_set object will be a member of my class. A crude way I can think of is to add all features that I intend to support and drop them based on user input. Is there a better way of doing it, is this not an optimal way to do it? Looking forward for your feedback. // Some pseudo code to show my intentions class calcstat { public: void SetCalc(int type) { // I want to add features here based on user input } void compute(void) { // If I cannot add based on user input, I will drop based on // user input. I will then not be able to add if the user input // changes. For now, I am not interested in its reuse! } private: accumulator_set<double> m_acc; }; -dhruva -- Contents reflect my personal views only!

1 0

Correctlt installing libboost*
by Robert Denton 17 Jan '09

17 Jan '09

Hi there. I am attempting to get the facebook thrift/scribe framework installed on an ubuntu 8.10 server which requires boost and libboost. I thought I'd installed boost correctly, simply by downloading the most recent tarball and doing a ./configure --prefix=/usr/local/boost and then a make install (which took about 30 minutes). However, when attempting to configure scribe with the following params, ./configure --with-boost=/usr/local/boost -with-boost-system=boost_system-gcc42-mt-1_37 -with-boost-filesystem=boost_filesystem-gcc42-mt-1_37 I ended up with an error like this as the last line of the configure output: configure: error: Could not link against boost_system-boost_system-gcc42-mt1_37 ! I am wondering if this is a known problem with this version of boost, or if anyone who listens to this list might have some advice for me. Thanks!

2 1

[graph] topological sort of subgraph?
by Emit Sorrels 16 Jan '09

16 Jan '09

Hello, Using the File Dependency sample as an example, if I wanted the topo sorted list of dependencies for *just* libfoobar.a, is there an obvious way to do it without constructing another mini graph and calling topological_sort on it? TIA, Emit

3 6

Re: [Boost-users] [serialization] link error and exception onget_key
by Daniel Roberts 16 Jan '09

16 Jan '09

I got the test to work but in my own code I am getting an "unregistered void cast" exception when trying to serialize the derived type. I moved the relevant classes into a separate test and made sure everything was identical to the test I made that does work (e.g. macro placement, include order) and I still get the exception. If I move the derived class definition into the header file it works. The function definitions don't even have to be inlined, they just need to be in the header. This is very weird. I am not sure you can help but if you have any ideas I would appreciate it. Thanks, Daniel Roberts I just separated things out and things seemed to work fine. The only thing that might or might not be an issue is header order: #include <boost/serialization/type_info_implementation.hpp> #include <boost/serialization/extended_type_info_no_rtti.hpp> #include <boost/serialization/export.hpp> #include "polymorphic_derived1.hpp" BOOST_CLASS_EXPORT(polymorphic_derived1) const char * polymorphic_derived1::get_key() const { return boost::serialization::type_info_implementation< polymorphic_derived1 >::type::get_const_instance().get_key(); } Notice I specified extended_type_info_no_rtti.hpp before export.hpp. If I remember correctly, if no type id system header is specified before export is encountered the system may take the rtti one as the default. Since we're not using defaults in this example, its probably not an issue. As far as I know, no one has ever asked a question about using EXPORT without rtti before - at least no one has ever had any questions about it. You may be treading new ground here. Robert Ramey

1 0

boost concept creation
by Zach 16 Jan '09

16 Jan '09

Can someone give me a high level explanation of the idea behind how concepts work? I'm trying to write a new concept class which enforces that two types are the same and it's not quite clicking. Strangely gcc has this concept built in, so I was surprised that boost didn't. I noticed a boost::is_same<> template, but it's not a concept, so it's not usable inside a BOOST_CONCEPT_ASSERT() macro.

2 1

[Singleton] When CRTP won't work
by Alexander 16 Jan '09

16 Jan '09

The current version of Boost candidate Signelton as well as other implementation is CRTP base. However, one may want to use it as local class my_class& get_something(std::string const& param) { struct local : singleton<local> { ... }; return local::instance->some_method(param); }

2 1

can't build threads on msvc-7.1
by Larry E. Ramey 16 Jan '09

16 Jan '09

I can't build the thread library. I have no idea why. ( What gregorian date is doing in the thread lib eludes me ) I have changed boost/config/user.hpp to #define BOOST_ALL_DYN_LIN, of course, that shouldn't effect threads.... but whatever.... Anyone got a clue? C:\RTI\devroot\packages-src\boost_1_37_0>cl.exe Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 13.10.6030 for 80x86 Copyright (C) Microsoft Corporation 1984-2002. All rights reserved. usage: cl [ option... ] filename... [ /link linkoption... ] C:\RTI\devroot\packages-src\boost_1_37_0>bjam --version Boost.Build V2 (Milestone 12) Boost.Jam 03.1.17 C:\RTI\devroot\packages-src\boost_1_37_0>bjam --with-thread toolset=msvc-7.1 var iant=release link=shared WARNING: No python installation configured and autoconfiguration failed. See http://www.boost.org/libs/python/doc/building.html for configuration instructions or pass --without-python to suppress this message and silently skip all Boost.Python targets ...patience... ...found 716 targets... ...updating 2 targets... msvc.link.dll bin.v2\libs\thread\build\msvc-7.1\release\threading-multi\boost_thread-vc71-mt-1_37.dll Creating library bin.v2\libs\thread\build\msvc-7.1\release\threading-multi\boost_thread-vc71-mt-1_37.lib and object bin.v2\libs\thread\build\msvc-7.1\release\threading-multi\boost_thread-vc71-mt-1_37.exp thread.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall boost::gregorian::greg_month::greg_month(unsigned short)" (__im p_??0greg_month@gregorian@boost@@QAE@G@Z) referenced in function "public: __thiscall 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-7.1\release\threading-multi\boost_thread-vc71-mt-1_37.dll : fatal error LNK1120: 1 unresolved externals call "C:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\bin\vcvars32.bat" >nul link /NOLOGO /INCREMENTAL:NO /DLL /subsystem:console /out:"bin.v2\libs\thread\build\msvc-7.1\release\threading-multi\boost_thread-vc71-mt-1_37.dll" /IMPLIB:"bin .v2\libs\thread\build\msvc-7.1\release\threading-multi\boost_thread-vc71-mt-1_37.lib" @"bin.v2\libs\thread\build\msvc-7.1\release\threading-multi\boost_threa d-vc71-mt-1_37.dll.rsp" if %ERRORLEVEL% NEQ 0 EXIT %ERRORLEVEL% if exist "bin.v2\libs\thread\build\msvc-7.1\release\threading-multi\boos t_thread-vc71-mt-1_37.dll.manifest" ( mt -nologo -manifest "bin.v2\libs\thread\build\msvc-7.1\release\threading-multi\boost_thread-vc71-mt-1_37.dll.manifest" "-outputresource:bin.v2\libs\thread\build\msvc-7.1\release\threading-multi\boost_thread-vc71-mt-1_37.dll;2" ) ...failed msvc.link.dll bin.v2\libs\thread\build\msvc-7.1\release\threading-multi\boost_thread-vc71-mt-1_37.dll bin.v2\libs\thread\build\msvc-7.1\release\threading-multi\boost_thread-vc71-mt-1_37.lib... ...removing bin.v2\libs\thread\build\msvc-7.1\release\threading-multi\boost_thread-vc71-mt-1_37.lib ...failed updating 2 targets...

3 5

Why there are accepted libraries that doesn't included in boost distribution yet ?
by Kamil Zubair 16 Jan '09

16 Jan '09

I just perused the formal review lists in boost website and I noticed there are some libraries like scope exit and factory that's been flagged as accepted but not in included in current boost distribution. Why is that ? One more thing, where can I find information about libraries that will be added to the next boost release ? Selalu bersama teman-teman di Yahoo! Messenger. Tambahkan mereka dari email atau jaringan sosial Anda sekarang! http://id.messenger.yahoo.com/invite/

1 0

Re: [Boost-users] boost compilation error
by Dmitry V. Krivenok 16 Jan '09

16 Jan '09

Bijay Panda wrote: > Hi, > when i try like this i got error like bellow > bijay@cmp1:~/boost$ g++ -o second boostThread.cpp > -lboost_filesystem-gcc42-1_34_1 > /usr/bin/ld: cannot find -lboost_filesystem-gcc42-1_34_1 > collect2: ld returned 1 exit status It can't find libboost_filesystem-gcc42-1_34_1.so You may create it: ln -s /usr/lib/libboost_filesystem-gcc42-1_34_1.so.1.34.1 /usr/lib/libboost_filesystem-gcc42-1_34_1.so > so i tried like this > bijay@cmp1: g++ -o second boostThread.cpp -L/boost_filesystem-gcc42-1_34_1 Read about -I and -L options in gcc manual page :) > > then it's showing error like bellow Your program doesn't depend on boost filesystem library. It depends on boost thread library. > > /tmp/cclxXala.o: In function `main': > boostThread.cpp:(.text+0xeb): undefined reference to > `boost::thread::thread(boost::function0<void, > std::allocator<boost::function_base> > const&)' > boostThread.cpp:(.text+0x101): undefined reference to > `boost::thread::join()' > boostThread.cpp:(.text+0x132): undefined reference to > `boost::thread::~thread()' > boostThread.cpp:(.text+0x148): undefined reference to > `boost::thread::~thread()' > collect2: ld returned 1 exit status > Your program is compiled without any problems as follows: krivenok@develop2 15:31:21 /tmp $ cat example.cpp #include <boost/thread/thread.hpp> #include <exception> #include <stdlib.h> #include <iostream> using namespace std; class callable { public: void run() { try { cout << "Throwing" <<std:: endl; throw string("error"); } catch(string &e) { cout << "Error: " << e << endl; } } void operator()() { this->run(); } }; int main() { callable c; cout<<"inside main"<<endl; boost::thread thd(boost::ref(c)); thd.join(); return 0; } krivenok@develop2 15:31:28 /tmp $ g++ example.cpp -lboost_thread-gcc43-mt-1_37 -L/usr/local/dev/boost-1.37.0/lib -I/usr/local/dev/boost-1.37.0/include krivenok@develop2 15:31:44 /tmp $ ./a.out inside main Throwing Error: error krivenok@develop2 15:31:47 /tmp $ ldd ./a.out linux-gate.so.1 => (0xb7fa0000) libboost_thread-gcc43-mt-1_37.so.1.37.0 => /usr/local/dev/boost-1.37.0/lib/libboost_thread-gcc43-mt-1_37.so.1.37.0 (0xb7f90000) libstdc++.so.6 => /usr/lib/gcc/i686-pc-linux-gnu/4.1.2/libstdc++.so.6 (0xb7e90000) libm.so.6 => /lib/libm.so.6 (0xb7e6a000) libgcc_s.so.1 => /usr/lib/gcc/i686-pc-linux-gnu/4.1.2/libgcc_s.so.1 (0xb7e5e000) libc.so.6 => /lib/libc.so.6 (0xb7d2e000) librt.so.1 => /lib/librt.so.1 (0xb7d24000) libpthread.so.0 => /lib/libpthread.so.0 (0xb7d0d000) /lib/ld-linux.so.2 (0xb7fa1000) krivenok@develop2 15:31:55 /tmp $ > ////////////////////Here is my program/////////// > #include <exception> > #include <boost/thread/thread.hpp> > #include <stdlib.h> > #include <iostream> > using namespace std; > > class callable { > public: > void run() > { > try > { > cout << "Throwing" <<std:: endl; > throw string("error"); > } > catch(string &e) > { > cout << "Error: " << e << endl; > } > } > > void operator()() { > this->run(); > } > }; > > int main() { > callable c; > cout<<"inside main"<<endl; > boost::thread thd(boost::ref(c)); > thd.join(); > return 0; > } > > Plz help me out. > > On Fri, Jan 16, 2009 at 4:41 PM, Dmitry V. Krivenok > <krivenok(a)orangesystem.ru <mailto:krivenok@orangesystem.ru>> wrote: > > Bijay Panda wrote: > > Hi, > when i try this locate libboost_filesystem i get path like bellow > > bijay@cmp1:~/boost$ locate libboost_filesystem > /usr/lib/libboost_filesystem-gcc41-mt-1_34_1.so.1.34.1 > /usr/lib/libboost_filesystem-gcc42-1_34_1.so.1.34.1 > /usr/lib/libboost_filesystem-gcc42-mt-1_34_1.so.1.34.1 > /usr/lib/libboost_filesystem-gcc41-1_34_1.so.1.34.1 > /var/cache/apt/archives/libboost_filesystem-gcc41-mt-1_34_1.so.1.34.1 > /var/cache/apt/archives/libboost_filesystem-gcc42-1_34_1.so.1.34.1 > /var/cache/apt/archives/libboost_filesystem-gcc42-mt-1_34_1.so.1.34.1 > /var/cache/apt/archives/libboost_filesystem-gcc41-1_34_1.so.1.34.1 > bijay@cmp1:~/boost$ > then i tried to compile like this > > g++ -o second boostThread.cpp -lboost_filesystem > -L/usr/lib/libboost_filesystem-gcc41-1_34_1.so.1.34.1 > > > The option "-L" specifies the directory containing the library > (not the library itself). > /usr/lib is standard path, so you can omit passing "-L" option. > > Try this: > g++ -o second boostThread.cpp -lboost_filesystem-gcc42-1_34_1 > > I always create symlinks like > /usr/lib/libboost_filesystem.so ---> > /usr/lib/libboost_filesystem-gcc42-1_34_1.so > after boost installation. > > This results to something like this: > > /usr/local/dev/boost-1.37.0/lib/libboost_filesystem.so -> > /usr/local/dev/boost-1.37.0/lib/libboost_filesystem-gcc43.so // > MANUALLY CREATED > /usr/local/dev/boost-1.37.0/lib/libboost_filesystem-gcc43.so -> > libboost_filesystem-gcc43-1_37.so.1.37.0 // AUTOMATICALLY CREATED > BY BOOST > > This approach allows write Makefiles independent of gcc and boost > versions. > Instead of writing -lboost_filesystem-gcc42-1_34_1 you write > -lboost_filesystem. > > > It's strange that locate didn't find > > /usr/lib/libboost_filesystem-gcc42-1_34_1.so > It should be symlink to > /usr/lib/libboost_filesystem-gcc42-1_34_1.so.1.34.1 > > > it throws the same error. > > /usr/bin/ld: cannot find -lboost_filesystem > collect2: ld returned 1 exit status > > Can u plz help me out. > > On Fri, Jan 16, 2009 at 1:14 PM, Dmitry V. Krivenok > <krivenok(a)orangesystem.ru <mailto:krivenok@orangesystem.ru> > <mailto:krivenok@orangesystem.ru > <mailto:krivenok@orangesystem.ru>>> wrote: > > Bijay Panda wrote: > > Hi All, > I am trying to run boost1.34.1 in ubuntu 7.10. > Compiling the program like this > > g++ -o fst boostThread.cpp -lboost_filesystem > > throws error like bellow. > > /usr/bin/ld: cannot find -lboost_filesystem > collect2: ld returned 1 exit status > > Can any one please tell me how to get rid of this. > > > g++ can't find shared library libboost_filesystem.so > > Provide the path to the library using -L option. > For example > g++ -o fst boostThread.cpp -lboost_filesystem > -L/usr/local/boost-1.34.1/lib > > If you don't know where library located try the following > commands: > sudo updatedb > locate libboost_filesystem.so > > On my system this command produces this output: > krivenok@develop2 10:44:55 > ~/dev_builds/boost-trunk/boost/date_time $ locate > libboost_filesystem.so > /usr/local/old_dev/boost-1.34.1/lib/libboost_filesystem.so > /usr/local/dev/boost-1.37.0/lib/libboost_filesystem.so > /usr/lib/libboost_filesystem.so > krivenok@develop2 10:45:02 > > > -- Thanks & Regards > Bijay Kumar Panda > > > ------------------------------------------------------------------------ > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > <mailto:Boost-users@lists.boost.org> > <mailto:Boost-users@lists.boost.org > <mailto:Boost-users@lists.boost.org>> > > http://lists.boost.org/mailman/listinfo.cgi/boost-users > > > > -- Sincerely yours, Dmitry V. Krivenok > Orange System Company > Saint-Petersburg, Russia > work phone: +7 812 332-32-40 > cellular phone: +7 921 576-70-91 > e-mail: krivenok(a)orangesystem.ru > <mailto:krivenok@orangesystem.ru> > <mailto:krivenok@orangesystem.ru > <mailto:krivenok@orangesystem.ru>> > > web: http://www.orangesystem.ru > skype: krivenok_dmitry > jabber: krivenok_dmitry(a)jabber.ru > <mailto:krivenok_dmitry@jabber.ru> > <mailto:krivenok_dmitry@jabber.ru > <mailto:krivenok_dmitry@jabber.ru>> > > icq: 242-526-443 > > > > > -- > Thanks & Regards > Bijay Kumar Panda > Mob-9739591816 > bijaykumar.mail(a)gmail.com <mailto:bijaykumar.mail@gmail.com> > <mailto:bijaykumar.mail@gmail.com > <mailto:bijaykumar.mail@gmail.com>> > bijaykumar_panda(a)yahoo.com <mailto:bijaykumar_panda@yahoo.com> > <mailto:bijaykumar_panda@yahoo.com > <mailto:bijaykumar_panda@yahoo.com>> > > > > -- > Sincerely yours, Dmitry V. Krivenok > Orange System Co., Ltd. > > Saint-Petersburg, Russia > work phone: +7 812 332-32-40 > cellular phone: +7 921 576-70-91 > e-mail: krivenok(a)orangesystem.ru <mailto:krivenok@orangesystem.ru> > web: http://www.orangesystem.ru > skype: krivenok_dmitry > jabber: krivenok_dmitry(a)jabber.ru <mailto:krivenok_dmitry@jabber.ru> > icq: 242-526-443 > > > > > -- > Thanks & Regards > Bijay Kumar Panda > Mob-9739591816 > bijaykumar.mail(a)gmail.com <mailto:bijaykumar.mail@gmail.com> > bijaykumar_panda(a)yahoo.com <mailto:bijaykumar_panda@yahoo.com> > -- Sincerely yours, Dmitry V. Krivenok Orange System Co., Ltd. Saint-Petersburg, Russia work phone: +7 812 332-32-40 cellular phone: +7 921 576-70-91 e-mail: krivenok(a)orangesystem.ru web: http://www.orangesystem.ru skype: krivenok_dmitry jabber: krivenok_dmitry(a)jabber.ru icq: 242-526-443

1 0

ASIO COM Port & Pins
by Jens Weller 16 Jan '09

16 Jan '09

Hi, I have to read from an (virtual) comport to receive the event from a photosensor. There is no protocol, just if something passes through, there is at pin x power (pins 4,6 and 7,8). I've seen the example for the COM Port usage with asio, sofar I've not seen anything to monitor a single/multiple pins. http://www.nabble.com/Simple-serial-port-demonstration-with-boost-asio-asyn… Also I am not sure, if I need to, would it be enough, to just connect and then perform an async_read on the comport? Actually I don't have to get the data really, as its probably not really "data", all I need to know is when data comes in. Is asio the right library to handle this? Are there other options? regards Jens Weller -- Psssst! Schon vom neuen GMX MultiMessenger gehört? Der kann`s mit allen: http://www.gmx.net/de/go/multimessenger

2 3

Re: [Boost-users] boost compilation error
by Dmitry V. Krivenok 16 Jan '09

16 Jan '09

Bijay Panda wrote: > Hi, > when i try this locate libboost_filesystem i get path like bellow > > bijay@cmp1:~/boost$ locate libboost_filesystem > /usr/lib/libboost_filesystem-gcc41-mt-1_34_1.so.1.34.1 > /usr/lib/libboost_filesystem-gcc42-1_34_1.so.1.34.1 > /usr/lib/libboost_filesystem-gcc42-mt-1_34_1.so.1.34.1 > /usr/lib/libboost_filesystem-gcc41-1_34_1.so.1.34.1 > /var/cache/apt/archives/libboost_filesystem-gcc41-mt-1_34_1.so.1.34.1 > /var/cache/apt/archives/libboost_filesystem-gcc42-1_34_1.so.1.34.1 > /var/cache/apt/archives/libboost_filesystem-gcc42-mt-1_34_1.so.1.34.1 > /var/cache/apt/archives/libboost_filesystem-gcc41-1_34_1.so.1.34.1 > bijay@cmp1:~/boost$ > then i tried to compile like this > > g++ -o second boostThread.cpp -lboost_filesystem > -L/usr/lib/libboost_filesystem-gcc41-1_34_1.so.1.34.1 The option "-L" specifies the directory containing the library (not the library itself). /usr/lib is standard path, so you can omit passing "-L" option. Try this: g++ -o second boostThread.cpp -lboost_filesystem-gcc42-1_34_1 I always create symlinks like /usr/lib/libboost_filesystem.so ---> /usr/lib/libboost_filesystem-gcc42-1_34_1.so after boost installation. This results to something like this: /usr/local/dev/boost-1.37.0/lib/libboost_filesystem.so -> /usr/local/dev/boost-1.37.0/lib/libboost_filesystem-gcc43.so // MANUALLY CREATED /usr/local/dev/boost-1.37.0/lib/libboost_filesystem-gcc43.so -> libboost_filesystem-gcc43-1_37.so.1.37.0 // AUTOMATICALLY CREATED BY BOOST This approach allows write Makefiles independent of gcc and boost versions. Instead of writing -lboost_filesystem-gcc42-1_34_1 you write -lboost_filesystem. It's strange that locate didn't find /usr/lib/libboost_filesystem-gcc42-1_34_1.so It should be symlink to /usr/lib/libboost_filesystem-gcc42-1_34_1.so.1.34.1 > > it throws the same error. > > /usr/bin/ld: cannot find -lboost_filesystem > collect2: ld returned 1 exit status > > Can u plz help me out. > > On Fri, Jan 16, 2009 at 1:14 PM, Dmitry V. Krivenok > <krivenok(a)orangesystem.ru <mailto:krivenok@orangesystem.ru>> wrote: > > Bijay Panda wrote: > > Hi All, > I am trying to run boost1.34.1 in ubuntu 7.10. > Compiling the program like this > > g++ -o fst boostThread.cpp -lboost_filesystem > > throws error like bellow. > > /usr/bin/ld: cannot find -lboost_filesystem > collect2: ld returned 1 exit status > > Can any one please tell me how to get rid of this. > > > g++ can't find shared library libboost_filesystem.so > > Provide the path to the library using -L option. > For example > g++ -o fst boostThread.cpp -lboost_filesystem > -L/usr/local/boost-1.34.1/lib > > If you don't know where library located try the following commands: > sudo updatedb > locate libboost_filesystem.so > > On my system this command produces this output: > krivenok@develop2 10:44:55 > ~/dev_builds/boost-trunk/boost/date_time $ locate > libboost_filesystem.so > /usr/local/old_dev/boost-1.34.1/lib/libboost_filesystem.so > /usr/local/dev/boost-1.37.0/lib/libboost_filesystem.so > /usr/lib/libboost_filesystem.so > krivenok@develop2 10:45:02 > > > -- > Thanks & Regards > Bijay Kumar Panda > > ------------------------------------------------------------------------ > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org <mailto:Boost-users@lists.boost.org> > http://lists.boost.org/mailman/listinfo.cgi/boost-users > > > > -- > Sincerely yours, Dmitry V. Krivenok > Orange System Company > Saint-Petersburg, Russia > work phone: +7 812 332-32-40 > cellular phone: +7 921 576-70-91 > e-mail: krivenok(a)orangesystem.ru <mailto:krivenok@orangesystem.ru> > web: http://www.orangesystem.ru > skype: krivenok_dmitry > jabber: krivenok_dmitry(a)jabber.ru <mailto:krivenok_dmitry@jabber.ru> > icq: 242-526-443 > > > > > -- > Thanks & Regards > Bijay Kumar Panda > Mob-9739591816 > bijaykumar.mail(a)gmail.com <mailto:bijaykumar.mail@gmail.com> > bijaykumar_panda(a)yahoo.com <mailto:bijaykumar_panda@yahoo.com> > -- Sincerely yours, Dmitry V. Krivenok Orange System Co., Ltd. Saint-Petersburg, Russia work phone: +7 812 332-32-40 cellular phone: +7 921 576-70-91 e-mail: krivenok(a)orangesystem.ru web: http://www.orangesystem.ru skype: krivenok_dmitry jabber: krivenok_dmitry(a)jabber.ru icq: 242-526-443

1 0

STLport + Boost + 64bit linux m/c - compilation error
by Ashish Lahane 16 Jan '09

16 Jan '09

Hi, I'm trying to build boost against STLport-5.2.1 on 64-bit linux m/c with 64-bit gcc-4.3.2, but I get following error: ---------------------------------------------------------------------------- /app/home/vgupta20/software/STLport-5.2.1/stlport/assert.h:35:6: error: #error assert has been defined before inclusion of assert.h header. ---------------------------------------------------------------------------- I'm building using following steps which worked fine with STLport-5.1.5 and on 32-bit linux m/c: ---------------------------------------------------------------------------- If boost is needed to be used with stlport, it should be compiled against stlport as follows: 1. Download or build 'bjam'. Copy it to the root dir of boost. 2. bjam is a tool to compile boost. Before we compile we need to give the paths to stlport include and lib directories. It can be specified in the file: './tools/build/v2/user-config.jam', also uncomment the line 'using gcc' in this file. Go to the boost root dir. Then run ./bjam stdlib=stlport --toolset=gcc --build-type=complete stage Otherwise we can give it online arguments as ./bjam stdlib=stlport -sSTLPORT_INCLUDE_DIRECTORY=$STLPORT/stlport -sSTLPORT_LIB_DIRECTORY=$STLPORT/lib --toolset=gcc --build-type=complete stage If only 'regex' library is needed, add '--with-regex' to the above commands. 3. After compilation we must get the libraries with '-p' flag in the name. For e.g. regex library file compiled against stlport will have name 'libboost_regex-gcc42-mt-p-1_37.a' These '-p' libs are to be used for the linking in our projects that use stlport and boost both. ---------------------------------------------------------------------------- Is there something wrong I'm doing? -- View this message in context: http://www.nabble.com/STLport-%2B-Boost-%2B-64bit-linux-m-c---compilation-e… Sent from the Boost - Users mailing list archive at Nabble.com.

2 1

Fwd: boost compilation error
by Bijay Panda 16 Jan '09

16 Jan '09

Hi, when i try this locate libboost_filesystem i get path like bellow bijay@cmp1:~/boost$ locate libboost_filesystem /usr/lib/libboost_filesystem-gcc41-mt-1_34_1.so.1.34.1 /usr/lib/libboost_filesystem-gcc42-1_34_1.so.1.34.1 /usr/lib/libboost_filesystem-gcc42-mt-1_34_1.so.1.34.1 /usr/lib/libboost_filesystem-gcc41-1_34_1.so.1.34.1 /var/cache/apt/archives/libboost_filesystem-gcc41-mt-1_34_1.so.1.34.1 /var/cache/apt/archives/libboost_filesystem-gcc42-1_34_1.so.1.34.1 /var/cache/apt/archives/libboost_filesystem-gcc42-mt-1_34_1.so.1.34.1 /var/cache/apt/archives/libboost_filesystem-gcc41-1_34_1.so.1.34.1 bijay@cmp1:~/boost$ then i tried to compile like this g++ -o second boostThread.cpp -lboost_filesystem -L/usr/lib/libboost_filesystem-gcc41-1_34_1.so.1.34.1 it throws the same error. /usr/bin/ld: cannot find -lboost_filesystem collect2: ld returned 1 exit status Can u plz help me out. On Fri, Jan 16, 2009 at 1:14 PM, Dmitry V. Krivenok < krivenok(a)orangesystem.ru> wrote: > Bijay Panda wrote: > >> Hi All, >> I am trying to run boost1.34.1 in ubuntu 7.10. >> Compiling the program like this >> >> g++ -o fst boostThread.cpp -lboost_filesystem >> >> throws error like bellow. >> >> /usr/bin/ld: cannot find -lboost_filesystem >> collect2: ld returned 1 exit status >> >> Can any one please tell me how to get rid of this. >> > > g++ can't find shared library libboost_filesystem.so > > Provide the path to the library using -L option. > For example > g++ -o fst boostThread.cpp -lboost_filesystem -L/usr/local/boost-1.34.1/lib > > If you don't know where library located try the following commands: > sudo updatedb > locate libboost_filesystem.so > > On my system this command produces this output: > krivenok@develop2 10:44:55 ~/dev_builds/boost-trunk/boost/date_time $ > locate libboost_filesystem.so > /usr/local/old_dev/boost-1.34.1/lib/libboost_filesystem.so > /usr/local/dev/boost-1.37.0/lib/libboost_filesystem.so > /usr/lib/libboost_filesystem.so > krivenok@develop2 10:45:02 > > >> -- >> Thanks & Regards >> Bijay Kumar Panda >> >> ------------------------------------------------------------------------ >> >> _______________________________________________ >> Boost-users mailing list >> Boost-users(a)lists.boost.org >> http://lists.boost.org/mailman/listinfo.cgi/boost-users >> > > > -- > Sincerely yours, Dmitry V. Krivenok > Orange System Company > Saint-Petersburg, Russia > work phone: +7 812 332-32-40 > cellular phone: +7 921 576-70-91 > e-mail: krivenok(a)orangesystem.ru > web: http://www.orangesystem.ru > skype: krivenok_dmitry > jabber: krivenok_dmitry(a)jabber.ru > icq: 242-526-443 > > -- Thanks & Regards Bijay Kumar Panda

1 0

ASIO, UDP and multiple Ethernet interfaces
by Jeff Diewald 16 Jan '09

16 Jan '09

I have a machine with two Ethernet interfaces. I want to create a UDP socket for each interface, so that I can send datagrams out separately over each interface. I have the IP addresses for each interface. How do I connect these up to the sockets so that they use the proper Ethernet interface? Thanks, Jeff Diewald JEOL USA

2 1

boost compilation error
by Bijay Panda 16 Jan '09

16 Jan '09

Hi All, I am trying to run boost1.34.1 in ubuntu 7.10. Compiling the program like this g++ -o fst boostThread.cpp -lboost_filesystem throws error like bellow. /usr/bin/ld: cannot find -lboost_filesystem collect2: ld returned 1 exit status Can any one please tell me how to get rid of this. -- Thanks & Regards Bijay Kumar Panda

2 1

date_time examples problem
by Andrew Maclean 16 Jan '09

16 Jan '09

In building the examples for boost date_time I have come across the following issue: example/tutorial/io_tutorial.cpp:2: /usr/local/include/boost-1_37/boost/date_time/tz_db_base.hpp:161: error: declaration of 'typedef class boost::date_time::dst_adjustment_offsets<typename time_zone_type::time_duration_type> boost::date_time::tz_db_base<time_zone_type, rule_type>::dst_adjustment_offsets' /usr/local/include/boost-1_37/boost/date_time/time_zone_base.hpp:76: error: changes meaning of 'dst_adjustment_offsets' from 'class boost::date_time::dst_adjustment_offsets<typename time_zone_type::time_duration_type>' This also occurs for anywhere #include <boost/date_time/local_time/local_time.hpp> occurs. E.g. in /example/local_time I am using boost-1_37 and gcc 4.3. Is there a fix for this? Andrew -- ___________________________________________ Andrew J. P. Maclean Centre for Autonomous Systems The Rose Street Building J04 The University of Sydney 2006 NSW AUSTRALIA Ph: +61 2 9351 3283 Fax: +61 2 9351 7474 URL: http://www.acfr.usyd.edu.au/ ___________________________________________

2 1

Re: [Boost-users] [serialization] link error and exception onget_key
by Daniel Roberts 16 Jan '09

16 Jan '09

Thanks, I had both macros in the header file. I moved the BOOST_CLASS_EXPORT macro to the cpp file and that seems to have fixed it. Now I just need to get things working in my own code. Thanks again. does the header file of polymorphic_derived1's include the following? BOOST_CLASS_TYPE_INFO( polymorphic_derived1, extended_type_info_no_rtti<polymorphic_derived1> ) Also, the *.cpp file of polymorphic_derived1 should contain BOOST_CLASS_EXPORT(polymorphic_derived1) Robert Ramey

2 1

[serialization] link error and exception on get_key
by Daniel Roberts 16 Jan '09

16 Jan '09

I have a derived class that exports its type and overrides get_key for serialization through a base class pointer. If I move the definition of the overridden get_key function out of the header into a cpp file, an assertion fails on line 49 of extended_type_info.cpp. If I define any other functions in the cpp file, I get a linker error saying that the get_key symbol is already defined. It looks to me that any serializable derived class must be completely defined in the header file. Is this correct? If so, why does such a limitation exist? Thank you

2 3

[Graph] - Do bundled properties break the named parameters paradigm?
by David Conner 16 Jan '09

16 Jan '09

I was trying to work with astar-cities.cpp example and convert to using bundled property maps for the edge properties. This caused numerous issues (see yesterdays post for one example). I found that if I bypass the named parameters and make an explicit call to astar_search( ) then it works OK. Does anyone know if the bundle property maps causes general issues with named parameters? thanks, David --- More info ----------------------------------- Normally, the named parameters would created the property maps that are needed; e.g. thru the use of choose_param(cost, make_iterator_property_map (cost_map.begin(), index_map, cost_map[0])), This appears to break if I use a bundled parameter because of some issues with the limit templates among other things. If I explicitly create all of the parameters, things work fine. e.g. boost::astar_search (g, start, distance_heuristic<mygraph_t, cost, location*>(locations, goal), astar_goal_visitor<vertex>(goal), // Only the first of named parameters needs boost:: &pred_map[0] ,//boost::predecessor_map( ), &cost_map[0] ,//boost::rank_map( ), &dist_map[0] ,//boost::distance_map( ), weightmap,//boost::weight_map( ), =========<<<<< This was the bundled property &index_map[0],//boost::vertex_index_map( ),//IndexMap, &clr_map[0] ,//boost::color_map( ) , std::less<cost>(), boost::closed_plus<cost>(), std::numeric_limits<cost>::max BOOST_PREVENT_MACRO_SUBSTITUTION (), std::numeric_limits<cost>::min() );//.

2 1

Boost:multi-index Question on usage of project & modify_key
by Ramesh 16 Jan '09

16 Jan '09

Hello. I am using projection technique & modify_key in one of my member functions: Assuming I have the following data in the container: ObjId ObjIp ObjIndex pMyObj ------------------------------------------------------------------------------------- ID1 10.10.1.2 1 0x10239032 ID2 10.10.1.3 2 0x23423423 ID3 10.10.1.4 3 0x23132423 The member function 'UpdateKeyObjId' accepts the value on column 3 as key & changes the corresponding value for the field in Column 1. My code seems to work fine for all rows except the last row. When I use modify key on the last record, the app crashes at the highlighted line. I am not sure if my usage of project & modify_key right, could someone please point out if there are any errors in the usage? Thanks /R struct MyMap { std::string ObjId; unsigned long ObjIp; unsigned long ObjIndex; MyObj *pMyObj; MyMap(std::string param_ObjId, unsigned long param_ObjIp, unsigned long param_ObjIndex, MyObj* param_pMyObj): ObjId(param_ObjId), ObjIp(param_ObjIp), ObjIndex(param_ObjIndex), pMyObj(param_pMyObj) {} ~MyMap(){ ObjId.erase(); ObjIp = 0; ObjIndex = 0; pMyObj = 0; } }; struct ObjId{}; struct ObjIp{}; struct ObjIndex{}; typedef multi_index_container< MyMap, indexed_by< ordered_unique< tag <ObjId>, BOOST_MULTI_INDEX_MEMBER(MyMap,std::string,ObjId)>, ordered_non_unique< tag<ObjIp>,BOOST_MULTI_INDEX_MEMBER(MyMap,unsigned long,ObjIp)>, ordered_unique< tag<ObjIndex>,BOOST_MULTI_INDEX_MEMBER(MyMap,unsigned long,ObjIndex)> > > tMyObjMap; class MyObjContainer{ private: tMyObjMap MyContainer; public: UpdateKeyObjId(unsigned long, std::string); }; bool MyObjContainer::UpdateKeyObjId(unsigned long param_ObjIndex, std::string param_ObjId) { typedef tMyObjMap::index<ObjIndex>::type tMyObjMapByIndex; tMyObjMapByIndex& ObjIndex_index = MyContainer.get<ObjIndex>(); tMyObjMap::index_iterator<ObjIndex>::type it = ObjIndex_index.find(param_ObjIndex); typedef tMyObjMap::index<ObjId>::type tMyObjMapById; tMyObjMapById::iterator ObjIdit = MyContainer.project<0>(it); // Use the modify_key method to update the ObjIp key with new value return MyContainer.get<0>().modify_key(ObjIdit, ll::_1 = param_ObjId); ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ }

2 2

[graph] Modifying properties in a visitor?
by James C. Sutherland 15 Jan '09

15 Jan '09

Can a visitor modify properties in a graph? I would like to use the following visitor with the breadth_first_search algorithm: struct ExecPriorityVisitor : public boost::default_dfs_visitor { ExecPriorityVisitor(); void start_vertex( Vertex v, Graph& g ){ g[v].priority = 0; } void examine_edge( Edge e, Graph& g ){ const Vertex src = boost::source(e,g); Vertex dest = boost::target(e,g); int& priority = g[dest].priority; priority = std::max( priority, g[src].priority + 1 ); } }; However, it fails to compile because apparently the graph argument must be const. That implies that I cannot modify graph properties from within the visitor? Why not? Is the suggested approach to record the modifications in yet another object and later impose that on the graph, or is there a way to accomplish this through a visitor? James

2 1

program_options.hpp issue
by S Josh 15 Jan '09

15 Jan '09

I am having compilation problem with program_options.hpp. I believe fix is simple. Current code: #if _MSC_VER > 1200 Proposed code: #if defined(_MSC_VER) && (_MSC_VER>1200) How dO I get this change incorporated into the boost source code? regards, Sandeep

1 0

Re: [Boost-users] large enum and native array indexing
by Hicham Mouline 15 Jan '09

15 Jan '09

>I would say that the easiest way is to use the preprocessor. >#define BOOST_PP_LOCAL_MACRO(n) template<> struct >Position<BOOST_PP_CAT(OP, n)> { static const size_t value = n - 1; }; >#define BOOST_PP_LOCAL_LIMITS (1, MAX_OP) >#include BOOST_PP_LOCAL_ITERATE() >In Christ, >Steven Watanabe I think I wasn't clear enough: the 3rd party lib (which I can't change of course) provides, enum Op { OPone = 7, OPtwo = 9, OPthree = 45, OPfour = 7667 // there is no pattern in the names nor the numbers. }; // in fact, there are a hundred entries and I wished to generate from Op template<> struct Position<OPone> { static const int value = 0; } template<> struct Position< OPtwo > { static const int value = 1; } template<> struct Position< OPthree > { static const int value = 2; } template<> struct Position< OPfour > { static const int value = 2; } I suppose there is no way to automagically generate the template specs from the enum? regards,

2 1

[lambda] Understanding placeholders
by Robert Jones 15 Jan '09

15 Jan '09

Why is this wrong? #include "boost/lambda/lambda.hpp" #include "boost/lambda/bind.hpp" #include <iostream> int main( ) { using namespace boost :: lambda; int i = 2, j = 3; bind( bind( protect( _1 = _2 ), _2, _1 ), _1, _2 )( i, j ); std :: cout << "i = " << i << ", j = " << j << "\n"; } Thanks, Rob.

2 1

[gil] io extensions
by Jan Boehme 15 Jan '09

15 Jan '09

Hi, I need to use the bmp io extension and tried the 'old' one from the googlecode repo which doesn't work against boost 1.37. Should I use the 'io_new' stuff and if so is there a bit of sample code how to use it in case the user interface has changed? Thanks, Jan.

2 2

program options: unrecognized command-line options
by Deane Yang 15 Jan '09

15 Jan '09

I'm using the program options library to parse both command-line and configuration file parameters. I'd like to know how to find command-line arguments that are *not* registered and therefore not recognized by the parser. I want to be able to print a warning message like "Following arguments were ignored:....".

3 5

boost::enable_shared_from_this why?
by Germán Diago 15 Jan '09

15 Jan '09

Hello, reading the documentation for enable_shared_from_this, I can't understand why this kind of base class is needed. In the example code in the documentation, we have: class Y: public enable_shared_from_this<Y> { public: shared_ptr<Y> f() { return shared_from_this(); } } int main() { shared_ptr<Y> p(new Y); shared_ptr<Y> q = p->f(); assert(p == q); assert(!(p < q || q < p)); // p and q must share ownership } Isn't this piece of code equivalent (since the two pointers share ownership): class Y { }; int main(int argc, char * argv[]) { shared_ptr<Y> p(new Y); shared_ptr<Y> q(p); ... }

2 3

Re: [Boost-users] [thread] assertion error in timed_lock
by Ernst Murnleitner 14 Jan '09

14 Jan '09

Dear Anthony, > > pthread_mutex_timedlock returned ETIMEDOUT. > > This bug has already been fixed. > Of cource, bugs happen. I used boost 1.36.0. Is the fix in 1.37.0? I had installed opensuse 11.1 which was released in december 2008. Boost 1.36.0 was released already in april 2008. Was the error detected so late or are there bug fixes somewhere which could be downloaded? I think there is no 1.36.1? Greetings Ernst > Anthony > -- > Anthony Williams | Just Software Solutions Ltd > Custom Software Development | http://www.justsoftwaresolutions.co.uk > Registered in England, Company Number 5478976. > Registered Office: 15 Carrallack Mews, St Just, Cornwall, TR19 7UL > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users > > > -- Dr.-Ing. Ernst Murnleitner T +49 8761 722 00 67 F +49 8761 722 00 59 Awite Bioenergie GmbH Firmensitz: Angerstr. 9 a, D-85416 Langenbach Registergericht München, HRB 162652 Geschäftsführer: Dr.-Ing. Martin Grepmeier, Dr. Ing. Ernst Murnleitner *** Als Anti-Spam-Massnahme können uns EMails von Mail-Servern ohne gültigen ptr-record (Reverse DNS) nicht erreichen ***

3 3

[serialization] Boost STATIC_WARNING when serializing shared_ptr of a type
by Daniel Roberts 14 Jan '09

14 Jan '09

I am trying to serialize a std::vector< boost::shared_ptr<SomeType> > but I am getting a boost STATIC_WARNING in get_derived_extended_type_info, when compiling the cpp file of the class that owns the vector. Here are the first few lines of the warning: 1>c:\program files (x86)\boost\boost_1_36_0\boost\serialization\extended_type_info_typeid.hpp(88) : warning C4099: 'boost::static_warning_impl<false>::STATIC_WARNING' : type name first seen using 'struct' now seen using 'class' 1> c:\program files (x86)\boost\boost_1_36_0\boost\static_warning.hpp(110) : see declaration of 'boost::static_warning_impl<false>::STATIC_WARNING' 1> c:\program files (x86)\boost\boost_1_36_0\boost\serialization\extended_type_info_typeid.hpp(85) : while compiling class template member function 'const boost::serialization::extended_type_info *boost::serialization::extended_type_info_typeid<T>::get_derived_extended_type_info(const T &) const' 1> with 1> [ 1> T=SomeNamespace::SomeType 1> ] If I create a std::vector<SomeType*>, then the warning goes away. I am including the serialization headers for std::vector and boost::shared_ptr. SomeType itself serializes a std::vector<boost::shared_ptr<SomeOtherType> >, where SomeOtherType IS polymorphic, and I get NO warnings for that one. The warning, to me, suggests that the compiler thinks that SomeType is polymorphic. Is the compiler really referring to SomeOtherType? Any assistance would be appreciated. Thanks

2 1

[General] Warnings and pragmas in MSVC
by Robert Jones 14 Jan '09

14 Jan '09

I've written some code using the Lambda & Lambda.bind libraries, although I don't think that really matters, which produce a page ful of C4503 warnings, *4503 'identifier' : decorated name length exceeded, name was truncated* In my code I've tried using pragma disable around the lines which I altered to cause the warnings, but it makes no difference. Is it necessary to apply these pragmas within the Boost library code, or is there a better way? Thanks, Rob.

4 8

Re: [Boost-users] [LibrariesUnderConstruction] update of LibrariesUnderConstruction wiki page
by vicente.botet 14 Jan '09

14 Jan '09

Hi, The wiki page Libraries Under Construction contains now much more entries. Good trip, Vicente ----- Original Message ----- From: "vicente.botet" <vicente.botet(a)wanadoo.fr> To: <boost(a)lists.boost.org>; <boost-announce(a)lists.boost.org>; <boost-users(a)lists.boost.org> Sent: Sunday, December 07, 2008 5:50 PM Subject: [LibrariesUnderConstruction] new LibrariesUnderConstruction wiki page Hi, I have created a new wiki page containing some of the libraries under construction for Boost. You can access this page from the Boost Trac wiki https://svn.boost.org/trac/boost/wiki > Projects > Libraries Under Construction or directly https://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction The contents of this page is by nature incomplete and outdated. Please help to maintain this page updated by modifying it directly (if you have the rights) or posting on the Boost mailing lists boost(a)lists.boost.org or boost-users(a)lists.boost.org with the prefix [LibrariesUnderConstruction]. If you're the author of one of these libraries and desire that all or part of the information related to your library be removed or modified, please send a mail or you can do it directly if you prefer. If you're a library author and plan on submitting a library but don't know when it will be ready for review, and you want to include your library in this list, please add it directly (if you have the rights) or send a mail. If you're a library author and plan on submitting a library for review in the next 3-6 months, email Ron Garcia or John Phillips ("garcia at osl dot iu dot edu" and "phillips at mps dot ohio-state dot edu" respectively) a short description of your library and they will add it to the Review Wizard Report Libraries Under Construction section. HTH, Vicente

1 0

Using iostream to create ZIP archive
by Peter Json 14 Jan '09

14 Jan '09

Hi, I'm trying to use boost to create a "zip" file containing more than one file. To my understanding I should use boost::iosteams to do this. In the boost documentation I there is only an example on how to unzip a file ..... http://www.boost.org/doc/libs/1_37_0/libs/iostreams/doc/classes/zlib.html#e… ... but I dont understand how I could do the opposite (create a zip-archive) Especially how to do the naming of the files inside the archive. Does anyone have an example on howto do create a zip-archive containing a couple of text files? Thanx /Peter/ -- View this message in context: http://www.nabble.com/Using-iostream-to-create-ZIP-archive-tp21461391p21461… Sent from the Boost - Users mailing list archive at Nabble.com.

2 1

large enum and native array indexing
by Hicham Mouline 14 Jan '09

14 Jan '09

hello, we have a 3rd party lib which provides an enum OP with some hundred members, but each member is defined with numbers that are not contiguous. enum OP { op1=56, op2=6, op3=5 ..... }; We have a performance critical function f that looks like this: status f( double& result, OP , int thing ); typical usage calls f( result0, op0 ) then f(result1, op1) .... f(resultn, opn) on the same thing. these calls, if merged, could have some speedup as there is some repetitive work done for say op3 and op7. I then thought of doing void f( std::map< Op, pair<status, result> >& output, const std::set<OP>&, int thing ) to collapse the above calls to 1. Inside this f, we set results in output with the [] operator. then I compared this to void f( double results[], status statues[], const std::set<OP>&, int thing ), thanks to the native array contiguous access, it was 4 times faster. therefore i wrote a numerical pseudo-metafunction "Position" to take the enum OP as an input and return a size_t, reflecting the index for the array. A call would be like: std::set<OP> opset; opset.set( op1 ); opset.set( op2 ); ... opset.set( op7 ); double results[7]; status statuses[7]; f( results, statuses, opset, thing ); // then to read output results[ Position<OP5>::value ]; Now, the question is about defining the metafunction Position. template< OP op > struct Position {}; template<> struct Position<OP5> { const size_t value=4; }; .... The 3rd party enum OP in the header file I can't change. Is there a way to generate my metafunction automatically? Any facility in mpl or fusion instead of defining my own metafunction? regards,

2 1

[ASIO/1.35.0]: Exception thrown in epoll_reactor::run (async API)
by Slawomir Lisznianski 14 Jan '09

14 Jan '09

Running on RedHat Linux, compiled with gcc 4.x. Program terminates with "Transport endpoint is not connected" -- io_service::run (processing loop) ends with exception thrown. I'm using asynchronous API. Stack trace of optimized debug (-02 -g) binary shows: #0 0x0000003a15a30155 in raise () from /lib64/libc.so.6 #1 0x0000003a15a31bf0 in abort () from /lib64/libc.so.6 #2 0x0000003a15a6a38b in __libc_message () from /lib64/libc.so.6 #3 0x0000003a15a71634 in _int_free () from /lib64/libc.so.6 #4 0x0000003a15a74c5c in free () from /lib64/libc.so.6 #5 0x00000000005093b0 in boost::asio::detail::epoll_reactor<false>::cleanup_operations_and_timers () #6 0x000000000050e6aa in boost::asio::detail::epoll_reactor<false>::run () #7 0x000000000050ebe3 in boost::asio::detail::task_io_service<boost::asio::detail::epoll_reactor<false> >::run () The problem occurs sporadically, under moderate load (about 30 client connections). Appears to be coming from cleanup_operations_and_timers() I can catch exceptions leaking from io_service::run, but would appreciate more info on why this occurs and whether it has other side-effects. Thanks, Slawomir

1 0

Boost graph add vertex
by Damian 14 Jan '09

14 Jan '09

Just as in add_edge(1,2,graph) you get to choose the numbers which represent the vertex is it possible to do the same with add_vertex where i actually choose the vertex number. I guess the syntax might be like add_vertex(3,graph) Cheers Damian

2 1

[boost-users][Milti-Index] labmda and composite key
by Igor R 14 Jan '09

14 Jan '09

Hello, I've got the following data structure: struct Service; typedef shared_ptr<Service> ServicePtr; struct Event { ServicePtr service() const; ptime time() const; }; typedef shared_ptr<Event> EventPtr; struct Cache { struct time_tag{}; typedef mi::multi_index_container< EventPtr, mi::indexed_by< mi::ordered_non_unique< mi::tag<time_tag>, mi::composite_key< EventPtr, mi::const_mem_fun<Event, ServicePtr, &Event::service> mi::const_mem_fun<Event, pt::ptime, &Event::time> > > > > type; typedef type::index<time_tag>::type ByTime; }; Cache cache_; ServicePtr servicePtr = ...; period = ...; I try to extract all the events belonging to some service and bounded by "period": namespace bl=boost::lambda; pair<Cache::type::iterator, Cache::type::iterator> byPeriod = cache_.get<Cache::time_tag>().range(bl::_1 >= make_tuple(servicePtr, period.begin()), bl::_1 <= make_tuple(servicePtr, period.last())); The cache contains lots of matching events, but for some reason, this expression always returs empty region, i.e. byPeriod.first==byPeriod.second. So I'd like to know if the above expression is correct or I'm doing something wrong? Thank you.

2 3

[gil] any_image* conversion to concrete type
by Jan Boehme 14 Jan '09

14 Jan '09

Hi, the following sample code introduces my problem: #include <boost/gil/extension/dynamic_image/dynamic_image_all.hpp> #include <boost/mpl/vector.hpp> #include <boost/gil/extension/io/jpeg_dynamic_io.hpp> int main() { using namespace boost::gil; typedef boost::mpl::vector<rgb8_image_t, cmyk16_planar_image_t> images_t; typedef any_image<images_t> any_image_t; typedef any_image_view<boost::mpl::vector2<rgb8_view_t, cmyk16_planar_view_t > > any_view_t; typedef any_image_view<boost::mpl::vector2<rgb8c_view_t, cmyk16c_planar_view_t> > any_const_view_t; any_image_t img; jpeg_read_image("test2.jpg", img); any_const_view_t cview( img ); rgb8c_view_t rgb_view = cview; } In the last line I want to convert the any_const_view to a concrete type what runs fail in lack of a member named 'pixels'. Does anyone know about that kind of conversion as the documentation imho doesn't contain such a sample. Right now I have to copy the pixels in the following form but I can't believe that this is necessary: rgb8_image_t rgb_image(img.dimensions()); copy_pixels(color_converted_view<rgb8_pixel_t>(const_view(img)), view(rgb_image)); rgb8c_view_t rgb8c_view( const_view(rgb_image) ); Thanks a lot, Jan.

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multi_array resize question
by Wilfried Holzke 14 Jan '09

14 Jan '09

Hi, The documentation from multi_array says that if elements are added while reszize is called, the new elements are initialized with the default constructor. I have the following: typedef boost::multi_array<Object*, 2> Array_Type; What is the default constructor of a pointer? Or do need to do the following: class ptr { public: ptr() { p = 0; } Object *p; } typedef boost::multi_array<ptr, 2> Array_Type; ... to get all new elements to bee zero-pointers? Thanks for help. regards W. Holzke

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[serializaton] namespace issues with extended type info
by Daniel Roberts 14 Jan '09

14 Jan '09

If I nest macro calls such as: namespace SomeNamespace { BOOST_SERIALIZATION_ASSUME_ABSTRACT(SomeClass) BOOST_CLASS_TYPE_INFO(SomeClass, extended_type_info_no_rtti<SomeClass>) BOOST_CLASS_EXPORT(SomeClass) } inside the namespace containing the type I get a TON of compiler errors. The wackiest is that the compiler thinks boost is a namespace inside of my namespace. Things improve (not fully tested) if I move the macros outside of my namespace and qualify the type with namespace name: BOOST_SERIALIZATION_ASSUME_ABSTRACT(SomeNamespace::SomeClass) BOOST_CLASS_TYPE_INFO(SomeNamespace::SomeClass, extended_type_info_no_rtti<SomeNamespace::SomeClass>) BOOST_CLASS_EXPORT(SomeNamespace::SomeClass) Can someone explain please? Thanks

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Joining two forward ranges
by er 13 Jan '09

13 Jan '09

Hello, I'm looking to create an iterator which iterates over two joined ranges: [b0,e0)[b1,e1) I'm sure there's a way to do it with an iterator adapter. I was wondering, however, if someone knew of an already available implementation. Thank you.

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boost[thread] in win32 we have API like WaitForMultipleObjects.How can we implement the same using boost thread
by Mrudul Mahurkar 13 Jan '09

13 Jan '09

Hi, i am working on boost::asio and boost thread library.I am creating client application that will work against any server.In that application am using threads and for their synchronisation i need the APIs like WaitForSingleObject and WaitForMultipleObject given by win32.so is there any API in boost ::thread library so that it can work like that. Mrudul Mahurkar Mumbai.India. Add more friends to your messenger and enjoy! Go to http://messenger.yahoo.com/invite/

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[lambda] Does Boost.Lambda support local variables?
by Robert Jones 13 Jan '09

13 Jan '09

If so, can anyone point me at the relevant bit of documentation. If not, are there some 'standard' techniques to produce a similar effect? Many Thanks, Rob.

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class composition
by Hicham Mouline 13 Jan '09

13 Jan '09

hello, There is an example listed in "C++ template metaprogramming" to generate a class with its members from an mpl sequence: template <typename T> struct wrap { typedef T value; }; typedef mpl::vector< type1, type2, type3 > member_types; mpl::inherit_linearly< member_types, mpl::inherit< wrap<_2>, _1 > >::type generated; but then, the generated class did not look like this: class C { type1 t1; type2 t2; type3 t3; }; Can one do that with BOOST_PP and sequences from preprocessor libs instead? regards,

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Can BOOST 1.37 be built without using stlport in Solaris 5.9 Sunstudio 11
by Saibal 13 Jan '09

13 Jan '09

Hi, I am trying to build BOOST without using stlport library, I am getting some errors? Is it possible to build? Have anybody try that earlier? regards, Saibal

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stream error thrown in boost serialization
by Lee MacDonald 13 Jan '09

13 Jan '09

Guys, I'm having a bit of trouble with boost serialisation using boost 1.35 I am writing out my objects to a text file fine. I see the text_oarchive destructor get called and I get the required new line added to the end of the file. However when I read the objects back in, they get created fine, but as the archive reaches the end of file, it throws a stream error. I have tested the example code and that works fine, so I'm stuck at the mo. Unfortunately i can't try writing/reading the objects as binary easily. I presume the archive is trying to read past the end of the stream, but I don't know why as the newline exists? I've tried the following to make sure the stream is good, but archive still throws. while(stream.good()) { archive >> object; } Any help would be appreciated. Thanks. Lee MacDonald Schneider Trading 4th Floor, 25 Copthall Avenue London EC2R 7BP -------------------------------------------------------- Message from: lee.macdonald(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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about delete elements from compressed_matrix
by Peng Wang 13 Jan '09

13 Jan '09

Hi, Dear all, Suppose I want to delete those elements whose values are smaller than 0.5 from compressed_matrix. I have looked for the mailing list but could not find a solution. Could you tell me how I can do this? Thank you very much in advance. Sincerely yours, Wang

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Random Numbers using Boost.
by Atul Kulkarni 13 Jan '09

13 Jan '09

Hi All, I am using boost::random for generating random numbers I am using the default quick start code given up on the web page. I want to generate random numbers between range 1 - n so that they do not repeat themselves for at least n numbers. 1. Is it possible using boost::random? 2. If it is possible what do I need to do except the below code. == boost::mt19937 rng1; boost::uniform_int<> six1(1,30); boost::variate_generator<boost::mt19937&, boost::uniform_int<> > die1(rng1, six1); for(int i=0; i < 29; i++) { cout<<die1()<<endl; } == Thanks in advance. -- Regards, Atul Kulkarni Teaching Assistant, Department of Computer Science, University of Minnesota Duluth Duluth. 55805. www.d.umn.edu/~kulka053

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boost installation problem
by Bijay Panda 13 Jan '09

13 Jan '09

Hi All, I am trying to install boost 1.34.1 in ubuntu 7.10 by the command below. apt-get install libboost-date-time-dev libboost-date-time1.34.1 libboost-dev libboost-doc libboost-filesystem-dev libboost-filesystem1.34.1 libboost-graph-dev libboost-graph1.34.1 libboost-iostreams-dev libboost-iostreams1.34.1 libboost-program-options-dev libboost-program-options1.34.1 libboost-python-dev libboost-python1.34.1 libboost-regex-dev libboost-regex1.34.1 libboost-signals-dev libboost-signals1.34.1 libboost-test-dev libboost-test1.34.1 libboost-thread-dev libboost-thread1.34.1 It's reading all packages from the related sites during installation but finally it's throwing an error like Internal Error, Could not perform immediate configuration (2) on libc6 Can any one suggest how to get rid of this. -- Thanks & Regards Bijay Kumar Panda Mob-9739591816 bijaykumar.mail(a)gmail.com bijaykumar_panda(a)yahoo.com

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Boost.Parameter: copy constructor gets "mistaken" for constructor(const ArgPack& ) in parent class.
by er 13 Jan '09

13 Jan '09

Hello, I have a situation which I can summarize as: #include <boost/parameter/keyword.hpp> #include <boost/parameter/name.hpp> #include <boost/parameter/parameters.hpp> #include <boost/parameter/preprocessor.hpp> BOOST_PARAMETER_KEYWORD(tag, xx) struct A{ template<typename ArgPack> A(const ArgPack& arg):x_(arg[xx|0]){} A(const A&){} A& operator=(const A& that){ if(&that!=this){ x_ = that.x_; return *this; } } unsigned x_; }; 3 copy constructors are shown below, on the last of which works. However it's really the first one that I'd like to get to work. struct B : public A{ template<typename ArgPack> B(const ArgPack& arg):A(arg){} B& operator=(const B& that){ if(&that!=this){ A::operator=(that); return *this; } } //B(const B& that):A(that){} //no match for 'operator[]' in 'arg[(+<unnamed>::xx)->boost::parameter::keyword<T>::operator| [with Default = int, Tag = tag::xx](((const int&)((const int*)(&0))))]'| //B(const B& that):A(static_cast<A>(that)){} //fails too B(const B& that):A((xx=that.x_)){} //requires knowledge of A's members, not satisfactory. }; Any suggestion, please?

2 2

find substring and substring position
by M 13 Jan '09

13 Jan '09

hello all --------- In: http://www.boost.org/doc/libs/1_37_0/doc/html/string_algo/usage.html#id3676… there is an example: Find Iterator = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = string str1("abc-*-ABC-*-aBc"); // Find all 'abc' substrings (ignoring the case) // Create a find_iterator typedef find_iterator<string::iterator> string_find_iterator; for(string_find_iterator It= make_find_iterator(str1, first_finder("abc", is_iequal())); It!=string_find_iterator(); ++It) { cout << copy_range<std::string>(*It) << endl; } // Output will be: // abc // ABC // aBC = = = = = = = = = = = = = = = = = = = = = = = = = = = = = = how do i find the position of each "abc" in: str1 ? thank's meir

2 1

more Boost::Units questions
by Mark Volkmann 12 Jan '09

12 Jan '09

My biggest issue is that my recent software development experience has involved using Java much more than C++ and I'm trying to learn how to use a C++ library that makes pretty heavy use of templates. Is there a tutorial somewhere that shows examples of doing basic things with this library? The kind of things I'm trying to figure out are: - What is the difference between a "measurement" and a "quantity"? Is it that the former doesn't specify a unit? - Does the library provide functions for converting between different units? ... for example, converting from miles to kilometers. If not, is there a recommended way to do this? - Can I only add quantities that have the same unit or can I add ones with different units and the library will handle conversions for me? - How can I extract the numeric value from a quantity? - How can I extract the unit type from a quantity? Thanks! --- Mark Volkmann

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Help with a generic algorithm using boost::MultiArray/Multiple nested range traversal
by Jesse Perla 12 Jan '09

12 Jan '09

Steven: >int index_of(const multi_array<int, 3>& m, int* iter, int dimension) { > int offset = iter - m.origin(); > return(offset / m.strides()[dimension] % m.shape()[dimension] + >m.index_bases()[dimension]); } Thanks for the code suggestion. Does this code work for N dimensions? it appears to. I would prefer to keep a tight count of the indices in the iterator itself to ensure that we don't need to do this expensive calculation each time, but this looks like a pretty good starting point and would work similarly for my sequential ublas::matrix iteration as well. -Jesse

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Help with a generic algorithm using boost::MultiArray/Multiple nested range traversal
by Jesse Perla 12 Jan '09

12 Jan '09

Hi Rob, Thanks for the response. I also think this is a pretty important use case for this great library. Let me justify why I think an Iterator based approach is the best: * For maximum efficiency (I will be using this in numerical simulations), we will want have an incrementing pointer within the data structure pointing to the actual object, and not just the iterator. * Also, if we have a single forward iterator, then we should be able to reuse a bunch of standard algorithms in the cases where we do not need the actual index values or the order of execution doesn't matter. * In the iterator algorithm, I would love to check the ordering of the data from the template parameters. If it is fortran ordering then we would do the loops in the opposite order for example, and this should be based on querying the data structure in the iterator code. * As for your range based use case, I don't know enough about how iterators and ranges interact to see how that would work. * As to implementation of this, thanks for the pointer to Fusion. This indeed seems to be the best approach since the loops can be generated at compile time, and compilers could then do some very fancy optimization on them. Sadly, I am not a template metaprogrammer, or a very good C++ programmer in general, and am terrified to learn it and lose sight of my non-CS research. Now for the semantics of this, it seems to me that the way the iterator concepts are designed, the distance() function is intended to pass back the related index information. Now my question is whether it is OK for the semantics of distance to pass back a boost::array<NUMDIMS> instead? Seems reasonable to me that it would not be based on passing back a scalar value in this case because that is arbitrarily dependent on the column vs. row ordering. And we can easily generate a boost::array from the distance function by looking at the distance between the .begin() for all of our current positions in the sub-iterators? If the iterator framework was there and the distance implemented as vectors, I can imagine the code looking like: int n1 = 3; int n2 = 4; int n3 = 5; boost::multi_array<double, 3> A(boost::extents[n1][n2][n3]); //NOTE SURE OF THE RIGHT SEMANTICS FOR GETTING AN ITERATOR OUTSIDE OF ONE GENERATED BY THE CONTAINER. multi_array_iterator<double, 3> begin = mult_sequential_iterator_begin(A); multi_array_iterator<double, 3> end = mult_sequential_iterator_end(A); for(mult_sequential_iterator<double, 3> iter = begin; iter != end; ++iter) *iter = f(distance(begin, iter); //POSSIBLE IMPLEMENTATION OF DISTANCE template<int NUMDIMS> boost::array<NUMDIMS> distance(const mult_sequential_iterator& iter1, const mult_sequential_iterator& iter1) const { static_assert(iter1::dimensionality == iter2::dimensionality) boost::array<NUMDIMS> dist; foreach dimension //PSEUDOCODE, FROM FUSION???? array<dimension> = distance(iter1.get_sub_iter<dimension>(), iter2.get_position<dimension>()); //here get_sub_iter returns the sub-iterator stored for that current dimension in the iterator. } template<int NUMDIMS> //HERE THE FUNCTION WOULD BE BASED ON A BOOST::ARRAY. double f(const boost::array<NUMDIMS>& indices) { ...} //AND LETS SAY WE WANTED TO NEGATE THE ENTIRE DATA STRUCTURE, NOW CAN USE STD: int n1 = 3; int n2 = 4; int n3 = 5; boost::multi_array<double, 3> A(boost::extents[n1][n2][n3]); boost::multi_array<double, 3> B(boost::extents[n1][n2][n3]); std::transform(mult_sequential_iterator_begin(A), mult_sequential_iterator_end(A), mult_sequential_iterator_begin(B), negate<double>()); //AND IF WE ADDED THIS ITERATOR TO THE CODE FOR THE MULTDIM: A.begin_sequential() could return the sequential iterator...

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what are the different problems that can occur in network connections and send/recive, what are the related exceptions & errors, and what are the solutions (boost.asio)?
by Saeed Aliakbarian 12 Jan '09

12 Jan '09

While working with boost.asio networking features, in many cases problems may occur due to network connection erros, programmin errors, etc. In each case a different event occurs in the program. Most of the times, and error code is returned or an exception is thrown. I could not find a list of this error causes and their corresponding error codes or exceptions. The only way I could mange only a part of this problem was trough testing, creating a specific error manually, catching the exception or the error code, and the try to manage it in the correct way I suggested myself!!!! If there is not such a page containing my required information, do you agree there is a need for one? Can anyone help me find a better way to do what I am trying to do? Regards Saeed Aliakbarian

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