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How well does Boost support cross-compilation?
by n.torrey.pines＠gmail.com 19 Oct '07

19 Oct '07

I'm dreaming of compiling MinGW, OS X (Intel and PowerPC) and Linux x86 versions of my program in one go, perhaps on Linux. The program uses little other than several Boost libraries. Is this a possible and reliable usage scenario? This doesn't seem like a particularly original idea, so I'm sure others explored it. Are there any how-to's? I couldn't find any.

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Boost Regex use of &*string.begin()
by Sudarshan Gaikaiwari 19 Oct '07

19 Oct '07

Hi The boost regex library makes liberal use of &*string.begin() For example ---------------------------------------------------------------------------------------- std::string result(++bytes, '\0'); bytes = ::LCMapStringW( id, // locale identifier LCMAP_SORTKEY, // mapping transformation type p1, // source string static_cast<int>(p2 - p1), // number of characters in source string reinterpret_cast<wchar_t*>(&*result.begin()), // destination buffer *of bytes* bytes // size of destination buffer ); -------------------------------------------------------------------------------------------------------------------- Is this construct safe? Are its semantics specified by the standard? regards Sudarshan -- Sudarshan Gaikaiwari www.sudarshan.org sudarshan(a)acm.org

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[xpressive] crash again :(
by Ovanes Markarian 19 Oct '07

19 Oct '07

Well, sorry I did not check mails before. Actually, I should have thought about it, that token_iterator applies a transformation on each iteration. Many thanks. It was already late in the night, when I faced this. Sorry for disturbing your sister's wedding. Hope you will enjoy it! Best wishes to your sister and her husband! With Kind Regards, Ovanes On 10/18/07, Eric Niebler <eric(a)boost-consulting.com> wrote: > > Eric Niebler wrote: > > Eric Niebler wrote: > >> Ovanes Markarian wrote: > >>> Hello Eric, > >>> > >>> sorry for bothering. I use xpressive in the following context: > >> <snip> > >> > >> I can't get your code to compile. Please send a minimal and complete > >> source file that demonstrates the problem. > > > > After fiddling with your code a bit, I got it to compile, but I'm not > > seeing any assertions, exceptions or crashes. What version are you > using? > > Me again. I realized I wasn't seeing the problem because I hadn't put > any strings in the vector over which you were iterating. When I do, I > can reproduce the assert. This is not a bug in xpressive, it is a bug in > your code. The problem is here: > > std::tr1::bind(&apply_regex, sem_separated, td::tr1::placeholders::_1) > > In this call to bind, you pass sem_separated to bind() *by value*. You > return a regex_token_iterator, which holds a reference to the > (temporary) regex object. When the temporary regex object goes away, the > regex_token_iterators are left holding dangling references. > > The lifetime of a regex_token_iterator cannot exceed the lifetime of the > regex it holds. > > If you change the code to ... > > std::tr1::bind(&apply_regex, std::tr1::ref(sem_separated), > td::tr1::placeholders::_1) > > ... it works just fine. > > HTH, > > -- > Eric Niebler > Boost Consulting > www.boost-consulting.com > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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Feature request for serialization
by Robert Bielik 19 Oct '07

19 Oct '07

It would be nice to be able to specify a callback that can notify how far a serialization (at loading) has come. I have a structure that can take a LONG time to load, and it would be good to be able to present a progress bar for the user. /R

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visual studio 2005/2008: example runs in debug-mode, does not run in release mode
by Vincent Vega 19 Oct '07

19 Oct '07

Hi there! - used the BoostPro Binary Installer for Visual C++ to obtain boost 1.34.1 - downloaded the following example for maximum_cardinality_matching: http://www.boost.org/libs/graph/example/matching_example.cpp - created an project using VS2005 as well as VS2008 Got the following problem (using both studios): - everythings fine while using the debug-mode - project runs but produces wrong results when in release-mode Anybody has an idea what causes my problem? Thanks in advance Dirk -- Ist Ihr Browser Vista-kompatibel? Jetzt die neuesten Browser-Versionen downloaden: http://www.gmx.net/de/go/browser

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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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Re: [Boost-users] Boost Spirit and C++/CLI
by Hansi Hansi 17 Oct '07

17 Oct '07

When you use windows forms programs you can't use the standard main entry point with mixed unmanaged code. There is a bug in the initialization of the CRT in VS2005. It seems that the bug is not anymore in VS2008. Test it with the entry point '?mainCRTStartupStrArray@@$$FYMHP$01AP$AAVString@System@@@Z' Best regards Hansjörg _______________________________________________________________________ Jetzt neu! Schützen Sie Ihren PC mit McAfee und WEB.DE. 3 Monate kostenlos testen. http://www.pc-sicherheit.web.de/startseite/?mc=022220

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boost::serialization(1.34.1) Can not link 64-bit example.
by Oleg Udovenko 16 Oct '07

16 Oct '07

Hi, Now I'm trying to use the "serialization" library on 64-bit(x64, Visual C++ 8.0). And faced some troubles with that. First I've converted a Visual Studio 2003 solution (vc7ide) to Visual Studio 2005, and compiled 64-bit static library release/debug. It passed the compilation with lots of warnings. But when I tried build a 64-bit example demo_xml_load.cpp I've got a lots of linker errors. - Is somebody tried the "serialization" library on 64-bit? Thanks, Oleg.

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What would happen if boost::shared_ptr is reset to an address in the stack
by Peng Yu 16 Oct '07

16 Oct '07

Hi, The following program runs well in my system. However, if I change 1 to 0, it will terminate at the line with "delete". Does this mean that boost::shared_ptr can tell if the pointer is from the stack or the heap and does different things based on where the pointer is from? Thanks, Peng #include <iostream> #include <boost/shared_ptr.hpp> int main() { #if 1//try change this to 0 int a[100]; boost::shared_ptr<int> p(a); std::cout << std::endl; #else int a[100]; delete a; // would terminate here std::cout << std::endl; #endif }

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[shared_ptr] class ... has pointer data members but does not override ...
by Klaus Backert 16 Oct '07

16 Oct '07

Hello, a Boost newbie question: Arch: PPC, OS: Mac OS X 10.4.10, Compiler: GCC 4.0.1 In a C++ dynamic library, I'm just developing, I have: #include <boost/shared_ptr.hpp> namespace MyNameSpace { typedef boost::shared_ptr<std::string> StringPtr; } I get the following warning: /usr/local/include/boost/shared_ptr.hpp: In instantiation of 'boost::shared_ptr<std::string>': /Volumes/blablabla/MyClass.cpp:81: instantiated from here /usr/local/include/boost/shared_ptr.hpp:131: warning: 'class boost::shared_ptr<std::string>' has pointer data members /usr/local/include/boost/shared_ptr.hpp:131: warning: but does not override 'boost::shared_ptr<std::string>(const boost::shared_ptr<std::string>&)' The incriminated line in MyClass.cpp is the second line here: __attribute__((visibility("default"))) MyNameSpace::StringPtr MyClass::myFunction() const { /* .......... */ } I have experienced the same with classes of my own instead of std::string, i.e. with typedef boost::shared_ptr<MyOtherClass> MyOtherClassPtr; etc. May be it's just me, but the boost documentation and Google don't help. Can I ignore the warnings or should I do something? Thanks in advance Klaus

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How to add a type to is_arithmetic
by Peng Yu 16 Oct '07

16 Oct '07

Hi, Suppose I define a class fixed_point as class fixed_point{ ....some operations are defined here private: int _integer_part; unsigned _fractional_part } I want is_arithmetic<fixed_point>::type to be true_ Of cause, I can partially specialize the template class as template <> struct is_arithmetic<fixed_point> { ... blah blah }; If I use the above approach, shall I put it into the namespace boost or not? Also, I'm wondering if there is any generic way to do this? Thanks, Peng

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[optional] documentation errors
by Edward Diener 16 Oct '07

16 Oct '07

In the 1.34.1 documentation for optional<T>, in the Synopsis section, it is currently written: -------------------------------------------------------------------------- template<class InPlaceFactory> explicit optional ( InPlaceFactory const& f ) ; template<class TypedInPlaceFactory> explicit optional ( TypedInPlaceFactory const& f ) ; AND template<class InPlaceFactory> optional& operator = ( InPlaceFactory const& f ) ; template<class TypedInPlaceFactory> optional& operator = ( TypedInPlaceFactory const& f ) ; -------------------------------------------------------------------------- Since InPlacefactory and TypedInPlacePlactory are actual classes, these should be: template<InPlaceFactory> explicit optional ( InPlaceFactory const& f ) ; template<TypedInPlaceFactory> explicit optional ( TypedInPlaceFactory const& f ) ; AND template<InPlaceFactory> optional& operator = ( InPlaceFactory const& f ) ; template<TypedInPlaceFactory> optional& operator = ( TypedInPlaceFactory const& f ) ; ------------------------------------------------------------------------- In the Detailed Semantics these are shown correctly.

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[fusion] subset view
by Chris Weed 16 Oct '07

16 Oct '07

Hi, I would like to make a subset view of the element in a tuple. It would, for example, give me a view into the first, third, and fifth element of the tuple. It isn't clear how to do this with the available views. Thanks, Chris

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[serialization]-- serialize binary data to a memory buffer?
by Rich Peters 16 Oct '07

16 Oct '07

I saw an example where boost serialized a text archive to a strstream for sending via a socket. I would like to do something similar, but for binary data. Is there a way to do the binary serialization to a memory buffer, and then send it elsewhere? It doesnt seem like strstream and boost::archive::binary_oarchive would mix correctly. I have also seen some discussion regarding a binary_iostreams library, but its doesnt look like that exists yet. thanks Rich

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Re: [Boost-users] [continued][boost::fusion v2 and xpressive] versioning conflicts...
by Ovanes Markarian 16 Oct '07

16 Oct '07

Eric, I changed the files. Should I zip them and post via mailinglist? Or should I submit them somewhere else? List of files which were changed: detail/core/linker.hpp detail/core/matcher/alternate_matcher.hpp detail/static/productions/alt_compilers.hpp detail/utility/any.hpp detail/utility/cons.hpp proto/op_base.hpp proto/proto_fwd.hpp xpressive.hpp One problem is that xpressive.hpp has info about boost version, but this is the mostly used file for inclusion. Therefore I believe this check fill fail even in boost 1.35: #if BOOST_VERSION >= 103500 # ifndef BOOST_XPRESSIVE_FUSION_V2 # define BOOST_XPRESSIVE_FUSION_V2 # endif //BOOST_XPRESSIVE_FUSION_V2 #endif //BOOST_VERSION I also executed your examples from the boost/lib directory and they produced in both cases same results. Your answer today is highly appreciated, since I will be on vacation from tomorrow on. thanks, Ovanes > On 9/24/07, Ovanes Markarian < om_boost(a)keywallet.com> wrote: > > > > Eric, > > > > sorry for the delay. I only now found some time to work on that issue: > > http://lists.boost.org/boost-users/2007/08/30120.php > > > > > > After analysing your post and investigation what's going on, I would > > like to write my opinion: > > > > changing xpressive_fwd.hpp or proto_fwd.will not help. > > > > I grepped where fusion includes are used and need to enclose these in > > some conditional statements: > > > > #ifdef BOOST_XPRESSIVE_FUSION_V2 > > # include ... //fusion 2 headers > > #else > > # include ... // fusion 1 headers > > #endif > > > > Actually this can be done using some kind of a macro function like: > > > > #include BOOST_XPRESSIVE_FUSION_ROOT(sequence/cons.hpp) > > ... > > > > The macro function will deliver the root dependent on the predefined > > macros like: > > 1. if !defined XPRESSIVE_FUSION_ROOT and use V2 > > => choose the root for V2 > > else => choose the root for V1 > > > > As I found out the following files need to be changed: > > linker.hpp > > alternate_matcher.hpp > > alt_compilers.hpp > > any.hpp > > cons.hpp > > arg_traits.hpp > > op_base.hpp > > proto_fwd.hpp > > > > If you give me your green light I will do it and submit a patch. > > > > > > With Kind Regards, > > Ovanes > > > > > >

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Problem using Boost Graph Library - Python Bindings
by Camilo La Rota 16 Oct '07

16 Oct '07

Hello all, I have just installed the Boost Graph Library - Python Bindings. Everything seemed to be ok, I can read a graph from the example "mst.dot" file and from my own ".dot" files, I can write them back to a file. However, when I try the example script (at the end of the following page: http://www.osl.iu.edu/~dgregor/bgl-python/) -------------------------------------------------------------------- import boost.graph as bgl # Load a graph from the GraphViz file 'mst.dot' graph = bgl.Graph.read_graphviz('mst.dot') # Convert the weight into floating-point values weight = graph.convert_property_map(graph.edge_properties['weight'], 'float') ... etc ------------------------------------------------------------------- it stops at the third line with the following error: ---------------------------------------------------------------------------- Traceback (most recent call last): File "<pyshell#17>", line 1, in <module> weight = graph.convert_property_map(graph.edge_properties['weight'],'float') KeyError: 'weight' ------------------------------------------------------------------------ I receive the same error message if I write only: graph.edge_properties['weight'] The content of the example mst.dot file is: -------------------------------------------------- graph G { A -- C [weight="1.0"] B -- D [weight="1.0"] B -- E [weight="2.0"] C -- B [weight="7.0"] C -- D [weight="3.0"] D -- E [weight="1.0"] E -- A [weight="1.0"] E -- B [weight="1.0"] } -------------------------------------------------- Does any one have any idea about the source of this error. Thanks a lot in advance, Camilo

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