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

[Review][Ratio] Boost.Ratio has been ACCEPTED
by Anthony Williams 02 Nov '10

02 Nov '10

The following message is a courtesy copy of an article that has been posted to gmane.comp.lib.boost.devel as well. Hi, I am pleased to announce that Boost.Ratio has been ACCEPTED into Boost. There were not as many reviews for Boost.Ratio as for some libraries, but they were overwhelmingly positive. Boost.Ratio is an important building block for other upcoming submissions, and provides an implementation of the C++0x rational arithmetic facilities. A few changes were requested by the reviewers, which I will list below. I know that Vicente has already started working on some of these. These changes should be addressed before the library appears in a Boost release. * Some of the macros had names with RATIO_RATIO in. These should be changed to just RATIO * The ratio_add, ratio_sub, ratio_multiply and ratio_divide templates should derive from the resulting ratio type as well as providing the nested ::type member, in order to closely emulate the template alias facility from C++0x * The typos in the documentation should be fixed, and the documentation reviewed for correctness and clarity (though several of the reviewers made positive comments on the quality of the documentation). * The library needs more tests under the Boost Software License. * All references to names from the boost namespace should be qualified with boost:: to avoid potential name clashes and ambiguity with names from the global namespace. * Sections commented out with #if 0 should be removed * The extensions beyond the facilities required by the C++0x draft should be able to be enabled or disabled through use of a configuration macro. * References to the tests, examples and documentation from within the code should be checked for correctness. I would like to thank Vicente for submitting the library and those that took the time to write a review. Anthony -- Author of C++ Concurrency in Action http://www.stdthread.co.uk/book/ just::thread C++0x thread library http://www.stdthread.co.uk Just Software Solutions Ltd http://www.justsoftwaresolutions.co.uk 15 Carrallack Mews, St Just, Cornwall, TR19 7UL, UK. Company No. 5478976

2 1

how to build non-boost asio without boost
by Jeff Graham 02 Nov '10

02 Nov '10

Everyone, I need a header-only version of ASIO for a stripped-down embedded system. I downloaded the latest and greatest asio version 1.4.5 from Chris Kohlkoff's think-asyn.com website. This version is supposedly the "boost-free" version. But I cannot get it to configure without boost. The web page certainly suggests "building" asio boost-free is possible. The release notes do not indicate otherwise. OTOH, the documentation only mentions configuring WITH boost. And, as mentioned in other discussions, the headers are full of #includes for boost files. I tried several obvious variations for configure that all fail, insisting on using boost (which does not exist on my system): ./configure -without-boost ./configure -without-boost ./configure -with-boost=no ./configure -with-boost= Could some kind soul please explain what I am doing wrong? I don't have bcp, but if I did, would that work? Thanks

2 1

Removing edges using remove_edge in adjacency list
by giridhar 02 Nov '10

02 Nov '10

Hello All, I am completely new to using BGL and STL. I know the concept of STL but had never used it before. I have to implement an algorithm for my thesis and I am trying to use BGL for that. I have made use of Dijkstra's algorithm that is inbuilt in BGL. Below is the code, which is similar to that in the reference manual with few changes. #include <iostream> #include <boost/config.hpp> #include <boost/graph/graph_traits.hpp> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/dijkstra_shortest_paths.hpp> using namespace std; using namespace boost; /*struct flow_t { typedef edge_property_tag kind; }; struct capacity_t { typedef edge_property_tag kind; }; namespace boost { enum edge_flow_t { edge_flow}; enum edge_capacity_t {edge_capacity}; BOOST_INSTALL_PROPERTY(edge,capacity); } */ int main() { typedef property<vertex_distance_t,int, property <vertex_name_t,std::string> > VertexProperty; // typedef property<flow_t,capacity_t, int> Cap; typedef property<edge_weight_t,int> EdgeProperty; typedef adjacency_list < listS, vecS, directedS, VertexProperty, EdgeProperty > graph_t; typedef graph_traits < graph_t >::vertex_descriptor vertex_descriptor; // typedef graph_traits < graph_t >::edge_descriptor edge_descriptor; typedef std::pair<int, int> Edge; const int num_nodes = 5; enum nodes { A, B, C, D, E }; char name[] = "ABCDE"; Edge edge_array[] = { Edge(A, B), Edge(A, C), Edge(B, E), Edge(C, B), Edge(C, D), Edge(D, E) // , Edge(D, E), Edge(E, A), Edge(E, B) }; int weights[] = { 4, 1, 3, 2, 2, 3}; int num_arcs = sizeof(edge_array) / sizeof(Edge); graph_t g( edge_array, edge_array+num_arcs, weights, num_nodes); std::vector<vertex_descriptor> p(num_vertices(g)); std::vector<int> d(num_vertices(g)); vertex_descriptor s= vertex(A,g); dijkstra_shortest_paths(g,s,predecessor_map(&p[0]).distance_map(&d[0])); // std::cout<<"timepass"<<s<<std::endl; std::cout<<"Distaces and Parents"<<std::endl; graph_traits<graph_t>::vertex_iterator vi,vend; for(tie(vi,vend)=vertices(g);vi!=vend;++vi) { std::cout<<"distance("<<name[*vi]<<")= "<<d[*vi]<<","; std::cout<<"parent("<<name[*vi]<<")= "<<name[p[*vi]]<<std::endl; } std::cout<<std::endl; graph_traits<graph_t>::vertex_iterator i,iend; // std::cout<<"testing iterators "<<i<<","<<iend<<std::cout; for(tie(i,iend)=vertices(g);i!=iend;++i) { if(s==*i) continue; else remove_edge(name[*i],name[p[*i]],g); } cout<<"After removal of working path"<<std::endl; vertex_descriptor s1= vertex(A,g); std::vector<vertex_descriptor> p1(num_vertices(g)); std::vector<int> d1(num_vertices(g)); dijkstra_shortest_paths(g,s1,predecessor_map(&p1[0]).distance_map(&d1[0])); std::cout<<"Distaces and Parents"<<std::endl; graph_traits<graph_t>::vertex_iterator i1,end1; for(tie(i1,end1)=vertices(g);i1!=end1;++i1) { std::cout<<"distance("<<name[*i1]<<")= "<<d1[*i1]<<","; std::cout<<"parent("<<name[*i1]<<")= "<<name[p1[*i1]]<<std::endl; } std::cout<<std::endl; } Now I want to remove the edges that has been found by Dijkstra's algorithm or alter the weights of those edges found by dijkstra's to some high value. This is mainly to find different route to target. I know I am doing something wrong with iterator's. But I am not able to figure it out due to lack of knowledge in STL. I tried to find it online, but could not find satisfactory explanation. If someone could give some explanation, it would be really helpful for me. Please help. -- Regards, Giridhar

3 2

boost::pool segfault
by Robert Dean 02 Nov '10

02 Nov '10

Hello, I attempted to use the boost::pool STL allocators for a work project which uses millions of objects as part of a memory resident data store. Unfortunately, this caused the program to always segfault with a std::bad_alloc error during initialization. Looking into the problem, it seems to be due to the "next_size <<= 1;" line found in malloc_need_resize and ordered_malloc_need_resize methods. Near as I can tell, every-time boost::pool allocates a new storage chunk it doubles the size request for the next allocation. For an application which uses gigabytes of storage, this means the memory pool requests more memory than the application uses without the pool, as well as sizes larger than the kernel can supply. Is there any way to control this behavior? Or do I have to write my own memory pool? Thanks you, Bob

1 0

Is it possible to use boost:serialization with Managed c++?
by سیّد امین میرزایی 02 Nov '10

02 Nov '10

We have a native c++ class that is serialized perfectly using * boost::serialization*. Now we want to change some of its member fields to *property*, so we could use them in *PropertyGrids*. When we changed the class definiction to *ref class X*, we got a huge number of these compilation errors: #1: error C2893: Failed to specialize function template 'boost::archive::text_oarchive &boost::archive::detail::interface_oarchive<Archive>::operator <<(T &)' d:\someAddress\someFile.cpp 58 #2: error C2784: 'std::basic_ostream<_Elem,_Traits> &std::operator <<(std::basic_ostream<_Elem,_Traits> &,const std::_Smanip<_Arg> &)' : could not deduce template argument for 'std::basic_ostream<_Elem,_Traits> &' from 'boost::archive::text_oarchive' d:\someAddress\someFile.cpp 58 We have a lot of tiny classes here, so it would be a pain to write a wrapper for each of them! Here is the sample class we used: ref class gps_position2 { public: template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & seconds; } public: gps_position(){}; gps_position(float s) { this->seconds = s; } property float seconds; }; And here is the main test code: int main() { std::ofstream ofs("out.txt"); gps_position2 g(24.567f); // save data to archive { boost::archive::text_oarchive oa(ofs); // write class instance to archive oa << g; } // ................ return 0; } Is it even possible to use *boost::serialization* with managed classes? p.s. If we change the class usage code to this: ... gps_position2^ g = gcnew gps_position2(24.567f); ... then we get only 1 error: error C2027: use of undefined type 'boost::STATIC_ASSERTION_FAILURE<x>' D:\path\to\Boost\boostw\boost\archive\detail\check.hpp 60

2 1

[lexical_cast] fails to convert between basic_strings with different traits
by Paul Graphov 01 Nov '10

01 Nov '10

Hello Boost Users, boost::lexical_cast fails to compile when both Target and Source template parameters are std::basic_string instantiations with different traits because deduce_char_traits class template has two suitable instantiations which are ambiguous. This is example where I use custom basic_string that is case insensitive: http://pastebin.com/jGF0yN2m Thanks.

2 1

Re: [Boost-users] Spirit Porting
by Avi Bahra 01 Nov '10

01 Nov '10

Bryce Lelbach wrote: >Regarding IBM's compiler, I tried to obtain a testing version/demo. The vague >link to trial/demo stuff on their website seems to be broken (I tried it in IE >8 on Windows and w3m on Linux. I lack the supercomputing power needed to run >Firefox). >Avi, I'd love to try to help support you here, but I can't do much without at least >access to a trial version of the compiler. I've sent an email to IBM asking for >the production version of their compiler, but I doubt that will end well. I have had contact with Michael, from IBM, and took part in providing feedback for beta version of their latest v11.1 compiler. My number one issue was to make sure boost serialisation worked. To that end, they had devoted resources to make sure this worked. So on the whole I am happy with what they provided. There is however still a couple of outstanding issues with regards serialisation: o portable binary archive is broken o release mode of the compiler, crashes I have provided them test samples which show these issue, but I am not sure if any resource has been put to address this. Currently I use spirit classic and boost serialisation on AIX. I am very keen to move to spirit v2/Qi . So its also critical for me that IBM does address the issue at some point in the near future.(performance of spirit classic AST is really bad) I will contact Michael Wong and request that they look into this issue(Spirit V2) or make the compiler available to you. However their are no guarantees. If there any progress , I will report back on this mailing group. Best regards, Ta, Avi

2 1

Segmentation fault boost::re_detail::perl_matcher
by manju k 01 Nov '10

01 Nov '10

Hello all, My application is using boost regular expression library. When my application calls regex_replace it seg faults in in this function. (gdb) where #0 0x00007f6e83cdf998 in boost::re_detail::perl_matcher<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::find_imp() () from ../../../ThirdParty/redhat64/lib64/libboost_regex.so.5 #1 0x00007f6e83cdff15 in bool boost::regex_search<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >(__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, __gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::match_results<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > >&, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags, __gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >) () from ../../../ThirdParty/redhat64/lib64/libboost_regex.so.5 #2 0x00007f6e83a5c5ef in boost::regex_replace<boost::re_detail::string_out_iterator<std::string>, __gnu_cxx::__normal_iterator<char const*, std::string>, boost::regex_traits<char, boost::cpp_regex_traits<char> >, char> () I am using boost 64bit library on 64bit RHEL 6. Has anyone faced the same problem earlier ? regards, manju

1 0

std::string corrupt after including boost
by Simon Adler 01 Nov '10

01 Nov '10

Hello, I think the behavior of the std::string is just an example but in my application it seems to me the first stl element that is used. I have a larger project working with CLR in MC++. I included boost, because of boost::thread. Because auf the .net and CLR linking I compiled boost als shared libs and included BOOST_DYN_LINK in the preprocessor definitions. Compilation works fine. If i start the application in Debug mode i get strange behavior of my strings which results in a crash. For example an assignment like std::string test = "123"; will result in a string representation with additional malformed signs in front of the "123". I knew some behavior like this because of the Flags: #define _HAS_ITERATOR_DEBUGGING 0 #define _SECURE_SCL 0 #define _SCL_SECURE_NO_WARNINGS I usually not using them, but i have the suspicion that boost is using them and i got errors from there. Has anyone an idea what are possible solutions? Is boost introducing additional Macros that were changing the stl? Greetings Simon Adler

9 15

Boost.Regex for variable argument term?
by Joost Kraaijeveld 01 Nov '10

01 Nov '10

Hi, I am trying to make a regex that matches a term with an arbitrary number of arguments. It has the format: TERM KEY(-?PRE:COL[,-?PRE:COL]*) with at least 1 PRE:COL and at most N (comma separated) PRE:COL, each of them possible prefixe with 1 '-' char I have the following: ^([[:word:]])[[:blank:]]*KEY\\(-?[[:word:]]+:[[:word:]]+(,-?([[:word:]])+:([[:word:]]+))*\\) But this does not work: e.g. the string KEY1 KEY(TEK:KDE),NOCASE,OPT,PRIMARY has the following matches (notice the empty matches): what[0] = KEY1 KEY(TEK:KDE),NOCASE,OPT,PRIMARY what[1] = KEY1 what[2] = TEK what[3] = KDE what[4] = what[5] = what[6] = and the string KEY1 KEY(RKM:KEN,RKM:REL,RKM:VAL),NOCASE,OPT,PRIMARY has the following matches (notice match 4 and the lack of the last PRE:COL pair): auxWhat[0] = KEY1 KEY(RKM:KEN,RKM:REL,RKM:VAL),NOCASE,OPT,PRIMARY auxWhat[1] = KEY1 auxWhat[2] = RKM auxWhat[3] = KEN auxWhat[4] = ,RKM:VAL auxWhat[5] = RKM auxWhat[6] = VAL Is there a regex that sort of does does what I want? TIA -- Met vriendelijke groeten, Joost Kraaijeveld Askesis B.V. Molukkenstraat 14 6524NB Nijmegen tel: 024-3888063 / 06-51855277 fax: 024-3608416 web: www.askesis.nl

2 1