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[xpressive] crash again :(
by Ovanes Markarian 18 Oct '07

18 Oct '07

Hello Eric, sorry for bothering. I use xpressive in the following context: typedef x::sregex regex_type; const regex_type non_semicolon = ~x::as_xpr(';'); const regex_type sem_separated = *non_semicolon; typedef boost::iterator_range<x::sregex_token_iterator> regex_tokens; typedef ::std::vector<regex_tokens> regex_transformed_collection; inline regex_tokens apply_regex(regex_type const& re, std::string const& item) { typedef x::sregex_token_iterator sre_iter; return boost::make_iterator_range(sre_iter(item.begin(), item.end(), re), sre_iter()); } // usage: std::vector<std::string> v; //vector is filled with strings of type: some_part;some_other_part typedef regex_transformed_coll::const_iterator re_citer; regex_transformed_collection sep_strings; ::std::transform ( v.begin(), v.end(), ::std::back_inserter(sep_strings) , ::std::tr1::bind(&apply_regex, sem_separated, tr1::placeholders::_1) ); //v is in the same scope and valid for(re_citer curr=sep_strings.begin(), end=sep_strings.end(); curr!=end; ++curr) { regex_tokens const& toks = *curr; std::string source = toks.front(); //this line is fine and returns me the first part of a string... // all subsequent line will raise an assertion std::string includes = *++toks.begin(); size_t sz = toks.size(); } Is there smth. I did not take in account? This code crashes in: regex_token_iterator.hpp: regex_token_iterator<BidiIter> &operator ++() { ->>HERE>> this->fork_(); // un-share the implementation And is caused by regex_token_iterator_impl ctor. I know this code is not very efficient, since it iterates through the collection of strings twice instead of doing smth. within one run, but it is just an example. Many thanks, Ovanes

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Scalability test overBGL
by abhishek.v＠tcs.com 18 Oct '07

18 Oct '07

Hi.. I m performing scalability test over BGL . Means i m checking out how big a graph can be constructed using BGL. For the moment i m considering complete graph. I m able to construct a complete graph with 3000 vertices but beyond that it crashes. Anybody who has done scalability test over BGL Kindly help. As this can be treated as a benchmark for BGL and then we can improve on this in near future... Following is my code.. #include <cstdlib> #include <iostream> #include<vector> #include <iostream> #include <fstream> #include <string> #include <boost\config.hpp> #include <boost\graph\adjacency_list.hpp> #include<boost\property_map.hpp> #include<vector> #include<string> #include<algorithm> using namespace std; using namespace boost; typedef unsigned long long ullong; typedef adjacency_list < vecS, vecS, undirectedS, property < vertex_name_t, std::string >, property < edge_name_t, std::string ,property < edge_weight_t, int > > > Graph; Graph g; typedef graph_traits < Graph >::vertex_descriptor Vertex; std::vector<vector<int> > adj_matrix; fstream file_op("C:\\Scalability\\output\\debug.out",ios::out); int main(int argc, char *argv[]) { int SIZE; cout<<"\n Enter the matrix size"; cin>>SIZE; cout<<"\n The matrix is "<<SIZE<<"x"<<SIZE; Vertex u; for(int i=0;i<SIZE;i++) { u=add_vertex(g); } for(ullong i=0;i<SIZE;i++) { for(ullong j=0;j<SIZE;j++) { if(i!=j) { add_edge(i,j,g); } } } file_op<<"\n Number of vertices in the graph "<<num_vertices(g); long double nume=num_edges(g); file_op<<"\n Number of edges in the graph "<<nume; system("PAUSE"); return EXIT_SUCCESS; } Thanks Abhishek Vyas Tata Consultancy Services Mailto: abhishek.v(a)tcs.com Website: http://www.tcs.com ____________________________________________ Experience certainty. IT Services Business Solutions Outsourcing ____________________________________________ =====-----=====-----===== Notice: The information contained in this e-mail message and/or attachments to it may contain confidential or privileged information. If you are not the intended recipient, any dissemination, use, review, distribution, printing or copying of the information contained in this e-mail message and/or attachments to it are strictly prohibited. If you have received this communication in error, please notify us by reply e-mail or telephone and immediately and permanently delete the message and any attachments. Thank you

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[BGL, Serialization] Serialization of vertex|edege properties
by David Angelo 18 Oct '07

18 Oct '07

Hi folks, I am using the BGL and now I want to serialize the graph. Serialization of the vertices and edges works fine, but how do I serialize the vertex|edge properties? My properties and graph definition are the following: <code> struct vertex_cId_t { typedef vertex_property_tag kind; }; struct vertex_cType_t { typedef vertex_property_tag kind; }; struct vertex_cShape_t { typedef vertex_property_tag kind; }; struct edge_cType_t { typedef vertex_property_tag kind; }; struct edge_cColor_t { typedef vertex_property_tag kind; }; namespace boost { BOOST_INSTALL_PROPERTY(vertex, cId); BOOST_INSTALL_PROPERTY(vertex, cType); BOOST_INSTALL_PROPERTY(vertex, cShape); BOOST_INSTALL_PROPERTY(edge, cType); BOOST_INSTALL_PROPERTY(edge, cColor); } typedef property<vertex_cId_t, std::string> CVertexId; typedef property<vertex_cShape_t, std::string, CVertexId> CVertexShape; typedef property<vertex_cType_t, int, CVertexShape> CVertexAttribute; typedef property<edge_cColor_t, string> CEdgeColor; typedef property<edge_cType_t, int, CEdgeColor> CEdgeAttribute; typedef adjacency_list<vecS, vecS, undirectedS, CVertexAttribute, CEdgeAttribute> Graph; </code> How must the serialize functions for CVertexAttribute and CEdgeAttribute look like? Thanks in advance. David

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Re: [Boost-users] [serialization]-- (corrected) serialize binary data to a memory buffer?
by Rich Peters 18 Oct '07

18 Oct '07

I have been having some issues trying to get this relatively simple binary memory based serialization to work. If I use a byte type below, I get errors with not finding a matching ctor: If I use a char, it compiles and thows an exception in binary_iarchive_impl.hpp at line 52: this->basic_binary_iarchive<Archive>::init(); which appears to be related to char string processing. can anyone help me sort this out? thanks Rich ====================== #include <boost/archive/binary_oarchive.hpp> #include <boost/archive/binary_iarchive.hpp> #include <boost/iostreams/device/array.hpp> #include <boost/iostreams/stream_buffer.hpp> #include <boost/iostreams/stream.hpp> .... std::vector<byte> store(1000, 0x00) ; // std::vector<char> store(1000, 0x00) ; // other test boost::iostreams::stream <boost::iostreams::array > theStream(&store[0], &store[0]+store.size()) ; // save data to archive { boost::archive::binary_oarchive oa(theStream); oa & theInfo; // archive closed when destructors are called } c:\Program Files\boost\boost_1_34_1\boost\iostreams\stream.hpp(112) : error C2665: 'boost::iostreams::basic_array<Ch>::__ctor' : none of the 5 overloads can convert parameter 1 from type 'unsigned char *__w64 const ' with [ Ch=char ] and [ Ch=char ] c:\Program Files\boost\boost_1_34_1\boost\iostreams\device\array.hpp(90): could be 'boost::iostreams::basic_array<Ch>::basic_array(boost::iostreams::basic_array<Ch>::char_type *,boost::iostreams::basic_array<Ch>::char_type *)' with [ Ch=char ] c:\Program Files\boost\boost_1_34_1\boost\iostreams\device\array.hpp(90): or 'boost::iostreams::basic_array<Ch>::basic_array(boost::iostreams::basic_array<Ch>::char_type *,size_t)' with [ Ch=char ] c:\Program Files\boost\boost_1_34_1\boost\iostreams\device\array.hpp(90): or 'boost::iostreams::basic_array<Ch>::basic_array(const boost::iostreams::basic_array<Ch>::char_type *,const boost::iostreams::basic_array<Ch>::char_type *)' with [ Ch=char ] c:\Program Files\boost\boost_1_34_1\boost\iostreams\device\array.hpp(90): or 'boost::iostreams::basic_array<Ch>::basic_array(const boost::iostreams::basic_array<Ch>::char_type *,size_t)' with [ Ch=char ] while trying to match the argument list '(unsigned char *__w64 const , unsigned char *__w64 const )' c:\Dev\Shared-ADL Integration\UnitTest\BoostSerialization\BoostSerialization\Serialize.h(194) : see reference to function template instantiation 'boost::iostreams::stream<Device>::stream<std::allocator<_Ty>::value_type*__w64 ,std::allocator<_Ty>::value_type*__w64 >(const U0 & ,const U1 & )' being compiled with [ Device=boost::iostreams::array, _Ty=unsigned char, U0=std::allocator<unsigned char>::value_type *__w64 , U1=std::allocator<unsigned char>::value_type *__w64 ] thanks Rich Matthias Troyer wrote: You can use the Boost IOstreams library to create an iostream using a memory buffer and use that with the binary archives Matthias

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[mpl] at_c type compiler error
by Chris Weed 18 Oct '07

18 Oct '07

Hi, I can't figure out why the following code generates a compile error with gcc 3.4: #include <boost/mpl/vector_c.hpp> #include <boost/mpl/at.hpp> #include <boost/tuple/tuple.hpp> template<typename E,typename T> typename boost::tuples::element<boost::mpl::at_c<E,0>::type::value,T>::type foo(E e,T t) { return t.get<0>(); } int main() { typedef boost::mpl::vector_c<int,0,1> elements; boost::tuple<int> t(1); foo(elements(),t); } main.cpp: In function `typename boost::tuples::element< boost::mpl::at_c<E,0l>::#`typename_type' not supported by pp_cxx_unqualified_id#::value, T>::type foo(E, T)': main.cpp:10: error: expected primary-expression before ')' token main.cpp: In function `typename boost::tuples::element< boost::mpl::at_c<E,0l>::#`typename_type' not supported by pp_cxx_unqualified_id#::value, T>::type foo(E, T) [with E = boost::mpl::vector_c<int, 0l, 1l, 2147483647l, 2147483647l, 2147483647l, 2147483647l, 2147483647l, 2147483647l, 2147483647l, 2147483647l, 2147483647l, 2147483647l, 2147483647l, 2147483647l, 2147483647l, 2147483647l, 2147483647l, 2147483647l, 2147483647l, 2147483647l>, T = boost::tuples::tuple<int, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type>]': main.cpp:17: instantiated from here main.cpp:10: error: invalid use of member (did you forget the `&' ?)

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Pattern-matching by metaprogramming - possible?
by Ovanes Markarian 18 Oct '07

18 Oct '07

I don't think that meta-programming will help check you the values. This can only be the case if the values are available (as const with external linkage) at compile time. If you need the checking pattern to be generated during the compilation than take a look at boost::xpressive. With Kind Regards, Ovanes On 10/18/07, Zeljko Vrba <zvrba(a)ifi.uio.no> wrote: > > On Thu, Oct 18, 2007 at 09:04:39AM +0200, Ovanes Markarian wrote: > > > > Hello Zeljko, > > > > may be another approach? Why not using a template method and static > concepts > > inside a function, which ensure that a parameter is of correct type? > > > Hmm, I didn't quite get you. But I want to match both on *type* and > *value* > as shown in this rule: > > > > > > | (Insn "addq", Reg "%rsp") -> (* do something *) > > > > The type here is (Insn, Reg) [particular types of larger variants]; > each component is also matched on the particular value ("addq" and > "%rsp" strings). > > > > > > | (_, Imm x) -> (* any 1st item; the 2nd must be Imm type, and > > > > the x variable is bound to the value carried by the > 2nd > > > > The type here is doesn't matter and (Imm x) - this is a match only > on type where the variable x gets bound to the value carried by > the variant type. > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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Pattern-matching by metaprogramming - possible?
by Zeljko Vrba 18 Oct '07

18 Oct '07

A short introduction: the ML language has a variant data type, tuples, and pattern matching construct. For example type operand = Imm of int | Reg of string type instruction = Insn of string | Pseudo of string Now, we can create tuples, e.g. (Insn "push", Reg "%rbp") is of type operand * instruction (a tuple of two typed elements). In function definitions, it is possible to do pattern matching as (it could be written slightly better in ML, but I want to show the match syntactic construct): let f x = match x with | (Insn "addq", Reg "%rsp") -> (* do something *) | (_, Imm x) -> (* any 1st item; the 2nd must be Imm type, and the x variable is bound to the value carried by the 2nd item *) | (_, Reg "%rsp") -> (* any value for 1st item _except_ Insn "addq" which has already been handled in the first alternative - alternatives are matched in order and first matching is taken *) | _ -> (* default case for anything else *) This is only a simplified example; but even this example would be much more ugly if rewritten with if/else statements, even if tuple tiers were used. Boost provides both the safe variant type and the tuple type. Would it be possible to construct pattern matching with syntax similar to the above in C++ ? [Yes, there are also other problems - incomplete matches: ML just throws an exception in that case; or redundant cases - nothing happens.]

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Quasi-random
by Joel C. Salomon 17 Oct '07

17 Oct '07

I've found some mention of this in the archives, but it seems it's never been done. How much work would it be to add the quasi-random sequence generators (faure, halton, hammersley, sobol, &c.) from the code at <http://people.scs.fsu.edu/~burkardt/cpp_src/cpp_src.html>? --Joel

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Problem lboost_filesystem-mgw-mt-s-l_33_l
by question boost 17 Oct '07

17 Oct '07

Hi , compiling a project under Code Blocks I get the following message: ld.exe:cannot find -lboost_filesystem-mgw-mt-s-l_33_l I go there http://www.boost.org/doc/html/jam/building.html I do:C:\Documents and Settings\src\boost\tools\jam\src>build mingw --debug (like explained) A new folder named bin.ntx86.debug is added after I go there http://www.boost.org/doc/html/bbv2/installation.html : 1:(done) 2:I do:C:\Documents and Settings\src\boost\tools\build\v2> bjam --version 3:I open the user-config.jam file (like explained) and I modify the file, the modification is the following: import toolset : using ; # GCC configuration # Configure gcc (default version) using gcc : : "C:\mingw\bin\g++" ; 4:I copy bjam.exe from C:\Documents and Settings\src\boost\tools\build\v2 to C:\Documents and Settings\src\boost\tools\build\v2\example\hello and I run bjam (like explained): C:\Documents and Settings\src\boost\tools\build\v2\example\hello>bjam I get the following message: "C:mingwbing++ n'est pas reconnu en tant que commande interne ou externe, un programme executable ou un fichier de commandes .." ..... "...failled gcc.compile.c++ bin\gcc\debug\hello.o... ...skipped <pbin\gcc\debug>hello.exe for lack of<pbin\gcc\debug>hello.o... ...failed updating one target.. ...skipped one target..." Where is my error (4)? Thanks, David _________________________________________________________________ Votez pour vos séries TV préférées et tentez de gagner un voyage à Hawaï ! http://messengerawards.divertissements.fr.msn.com/

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[ref] tying references between objects
by Robbie Morrison 17 Oct '07

17 Oct '07

Hi all The following kind of code is probably quite common. It involves: * using individual Register objects containing construction parameters to help factory-create new Entity objects * and, in the process, "tying" key object state variables so that each associated Registry object can watch these And yes, I know this breaks encapsulation! I chose C++ references and my code seems quite complicated for what should be a relatively straightforward task. Pointers were rejected because the dereferencing syntax can lead to really obscure numerical expressions (particularly for non-C/C++ programmers). However, boost::ref() seemed to offer a simpler solution and I experimented with this for quite some time to no avail. I also considered using a boost::ptr_vector and 1-tuples. In addition, adding cout statements to ctors and dtors led to more activity than I would have expected. Moreover, there were more dtor calls than ctor calls. Any comments or suggestions gratefully received! Also an explanation of the differences between a "type conversion" operator and an "address-of" operator. Is this simply related to role or is there a distinction? More information follows the program listing. many thanks in advance Robbie --- Robbie Morrison PhD student -- policy-oriented energy system simulation Institute for Energy Engineering (IET) Technical University of Berlin (TU-Berlin), Germany [from IMAP client] // --------------------------------------------------------- // Copyright: (c) 2007 Robbie Morrison. All rights reserved. // License: Unrestricted reuse in any form, for any purpose. // Version: $Id: frag-xeona-registers-9.cc,v 1.3 2007/10/17 15:23:43 robbie Exp $ // Tested using g++ 4.1.2 (-Wall -Weffc++ -pedantic), boost // 1.34.1 (source build), and valgrind (memory checker) on // Ubuntu 6.10 (7.04 is current) using Linux 2.6.17-12-generic. #include <iostream> // standard io #include <string> // C++ strings #include <vector> // STL sequence container #include <iomanip> // setw() and family #include <tr1/memory> // TR1 smart pointers using std::tr1::shared_ptr; // for convenience // --------------------------------------------------------- template <typename T> class Value // just for type conversion operator T&() { public: explicit Value(T v) : _value(new T(v)) { } operator T&() { return *_value; } // return aliasable value private: shared_ptr<T> _value; // pointer usage is essential }; // --------------------------------------------------------- class Register // initializes and watches selected { // .. Entity variables public: explicit Register() : _vec() { } // explicit for testing template <typename T> // would normally support int,double,bool Value<T> tieRef(const std::string& tag) // would normally search on tag! { T temp = 0.45; // would normally obtain value from user shared_ptr<Value<T> > val(new Value<T>(temp)); // actual object is shared _vec.push_back(val); // crude "last on" indexing for testing report(); return *_vec.back(); // given aforementioned "last on" indexing } void report() // just for doubles (could be templated) { double temp = *_vec.back(); // this line is interesting! std::cout << "Register : value : " << temp << std::endl; } private: std::vector<shared_ptr<Value<double> > > _vec; // data mirror }; // --------------------------------------------------------- class Entity // represents simulation 'things' { public: explicit // explicit for testing Entity(Register& r) : // pass-by-reference necessary _register(r), // for testing purposes _coeff(r.tieRef<double>("coeff")), // intuitive syntax _notInteresting() // rely on default construction { report(); } void modify(double d) { _coeff = d; // normal syntax (no pointer derefs) report(); // display this modification _register.report(); // confirm the modification propagated } void report() { std::cout << "Entity : value : " << _coeff << std::endl; } private: Register& _register; double& _coeff; // watched variable int _notInteresting; // ignored variable }; // --------------------------------------------------------- int main(int argc, char* argv[]) { std::cout << std::fixed << std::setprecision(2); std::cout << " creating a register" << std::endl; Register reg; std::cout << " creating an entity" << std::endl; Entity ent(reg); std::cout << " modifying the entity" << std::endl; ent.modify(0.01); ent.modify(2.0); } // ---- end-of-program ------------------------------------- // OUTPUT // creating a register // creating an entity // Register : value : 0.45 // Entity : value : 0.45 // modifying the entity // Entity : value : 0.01 // Register : value : 0.01 // Entity : value : 2.00 // Register : value : 2.00 // Development environment // // boost : 1.34.1 (via ./configure; make all; make install) // gcc : 4.1.2 20060928 (prerelease) (Ubuntu 4.1.1-13ubuntu5) // os : Ubuntu 6.10, Linux 2.6.17-12-generic (7.04 is current) // hardware : Toshiba Tecra A2 330 laptop (purchased 27-Aug-2004) // specs : 1.4GHz Intel Celeron M (32-bit) / 512MiB RAM / 40GB HDD // // Problem // // The problem involves sharing data between Entity objects, // used to represent various 'things' in my simulation -- // and Register objects ('register' in the sense of a book // recording important information), used to help construct // and then watch the state of Entity objects. A concrete // ObjectFactory object (not relevant to this discussion) // will be used to create the Entity objects (Alexandrescu // 2001 pp179-217). // // I would also like a relatively clear syntax for // programming the Entity's as there are lots of these and // they contain numerical expressions -- for instance, // dereferencing (smart) pointers would yield lines like: // // *_perf = 2.1 * local * *_coeff; // // Solution (provisional) // // The chosen strategy is to declare all to-be-observed // Entity object data members as references and then bind // these to the relevant Register object element upon // construction. // // An alternative approach could be to utilize the Memento // pattern (which relies on friendship) in conjunction with // the Iterator pattern (for traversing a population of // objects) (Gamma etal 1995 pp283-291 and pp257-271 // respectively). // // Design notes // // In relation to C++, a reference data member must be // initialized in the constructor's initializer list // (Lischner 2003 p36). And a reference may not be bound to // a class member (data member or member function) (p35). // // Class Value<T> is instead used to avoid an "invalid // initialization .. from a temporary" error when // initializing Entity::_coeff using the Register::tie<T> // member function. // // Class Value supplies a "type conversion operator" // (Lischner 2003 p112), in this case, Value::operator T&, // which binds to the non-const reference data member in // Entity. The code for Value derives from Lischner (2003 // p119 example 5-21). // // References // // Alexandrescu, Andrei. 2001. Modern C++ design : // generic programming and design patterns applied. // Addison-Wesley, Boston, USA. ISBN 0-201-70431-5. // // Gamma, Erich, Richard Helm, Ralph Johnson, and John // Vlissides. 1995. Design patterns : elements of // reusable object-oriented software. Addison-Wesley, // Boston, USA. ISBN 0-201-63361-2. // // Lischner, Ray. 2003. C++ in a nutshell : a language // and library reference, O'Reilly and Associates, // Sebastopol, California, USA. ISBN 0-596-00298-X.

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