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Re: Re: [Boost-users] Warnings in date_time
by John Eddy 28 Jan '05

28 Jan '05

Jeff, Actually, they turned up at warning level 3. If you would like, I can send you the warnings for level 4. John On Thu, 27 Jan 2005 19:28:53 -0500, John Eddy wrote >> Hello, >> >> I just started using the date-time library and it is a great >> library. > > Thanks. >> There are a few warnings that I have noticed so far that >> could be avoided with some explicit casts. I am using VC .NET 2003. > > Yes, thanks. Turns out it's hard for us to see these because warnings have come out in the regression tests. I notice these still aren't coming out -- I assume this is warning level 4? We'll take care of them, eventually. Some of this code is being redone for 1.33... Jeff

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Re: [string_algo] Split and Predicates
by David Brownell 28 Jan '05

28 Jan '05

Thanks for your quick response, Pavol, this did the trick and cleared up my misunderstanding. Might I suggest an overloaded version of split that takes a string/character string as a delimiter. Althought the implementation details are different, I still think it fits well into the intent of the split algorithm and may clear up issue for others have the same problem as I did. Thanks again for your help! David Brownell "Pavol Droba" <droba(a)topmail.sk> wrote in message news:<20050128071103.GC31065(a)lenin.felcer.sk>... > Hi, > > > It is possible to achieve what you want quite easily. However, split algorithm > is not the right tool for this. > Split is a high level wrapper over the split_iterator and it is quite specialized. > > So this is the code, that should work for you: > > #include <boost/algorithm/string/find_iterator.hpp> > #include <boost/algorithm/string/finder.hpp> > > static char const STRING[] = "this\r\nis\r\n\r\na test!"; > > typedef boost::split_iterator<const char*> char_split_iterator; > > for(char_split_iterator It=char_split_iterator(STRING, boost::first_finder("\r\n"); > It!=char_split_iterator(); > ++It) > { > cout << *It << endl; > } >

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Date-Time gregorian::date construction question
by Wolfgang Fertsak 28 Jan '05

28 Jan '05

If a date object is constructed from an invalid date(e.g. Feb 29th, 2005) and the values are specified in the constructor, an exception is thrown. If the object is constructed from a string representation with from_string(), no exception is thrown and the object has the next valid date (in this case Mar 1st, 2005). Is this a bug or a feature? Best regards, Wolfgang #include <iostream> #include <boost/date_time/gregorian/gregorian.hpp> using namespace boost::gregorian; using namespace std; int main() { try { // throws exception date Date1(2005,2,29); string strDate("2005-02-29"); // throws no exception date Date2 = from_string(strDate); // output is 2005-03-01 cout << to_iso_extended_string(Date2) << endl; } catch(std::exception&e) { cout << e.what() << endl; } return 0; }

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Warnings in date_time
by John Eddy 28 Jan '05

28 Jan '05

Hello, I just started using the date-time library and it is a great library. There are a few warnings that I have noticed so far that could be avoided with some explicit casts. I am using VC .NET 2003. Here are the ones I've noticed so far: in microsec_time_clock.hpp on line 102 which reads: boost::uint32_t sub_sec = (filetime % 10000000) / 10; // microseconds same file, line 118 which reads: int adjust = resolution_traits_type::res_adjust()/1000000; in time_system_counted.hpp on line 57 which reads: typename calendar_type::date_int_type dc = day_count(); in date_parsing.hpp on line 211 which reads: ss << ss.narrow(*beg++, 'X'); // 'X' will cause exception to be thrown Thanks, John

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Error Compiling Boost Graph example/graphviz.cpp
by Welson Sun 28 Jan '05

28 Jan '05

Hi, I would like to parse the graphviz dot file using your read_graphviz in the boost graph library. However, when I compiling the example/graphviz.cpp file, I got the following error: $ g++ graphviz.cpp /cygdrive/c/DOCUME~1/welson/LOCALS~1/Temp/cctY52MA.o(.text+0x602):graphviz.c pp: undefined reference to `boost::read_graphviz(std::basic_string<char, std::char_ raits<char>, std::allocator<char> > const&, boost::subgraph<boost::adjacency_li t<boost::vecS, boost::vecS, boost::directedS, boost::property<boost::vertex_att ibute_t, std::map<std::basic_string<char, std::char_traits<char>, std::allocato <char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> , std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char > >, std::allocator<std::pair<std::basic_string<char, std::char_traits<char>, td::allocator<char> > const, std::basic_string<char, std::char_traits<char>, st ::allocator<char> > > > >, boost::no_property>, boost::property<boost::edge_att ibute_t, std::map<std::basic_string<char, std::char_traits<char>, std::allocato <char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> , std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char > >, std::allocator<std::pair<std::basic_string<char, std::char_traits<char>, td::allocator<char> > const, std::basic_string<char, std::char_traits<char>, st ::allocator<char> > > > >, boost::property<boost::edge_index_t, int, boost::no_ roperty> >, boost::property<boost::graph_graph_attribute_t, std::map<std::basic string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string< har, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_strin <char, std::char_traits<char>, std::allocator<char> > >, std::allocator<std::pa r<std::basic_string<char, std::char_traits<char>, std::allocator<char> > const, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, b ost::property<boost::graph_vertex_attribute_t, std::map<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::ch r_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std:: har_traits<char>, std::allocator<char> > >, std::allocator<std::pair<std::basic string<char, std::char_traits<char>, std::allocator<char> > const, std::basic_s ring<char, std::char_traits<char>, std::allocator<char> > > > >, boost::propert <boost::graph_edge_attribute_t, std::map<std::basic_string<char, std::char_trai s<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char> std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<cha >, std::allocator<char> > >, std::allocator<std::pair<std::basic_string<char, s d::char_traits<char>, std::allocator<char> > const, std::basic_string<char, std :char_traits<char>, std::allocator<char> > > > >, boost::property<boost::graph_ ame_t, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, oost::no_property> > > >, boost::listS> >&)' collect2: ld returned 1 exit status However, I can use the write_graphviz to generate the .dot file from a graph, which means I have compiled the library correctly. Do you have any idea what is going on here? Best Regards, Welson Sun ------------------------------------- Electrical and Computer Engineering Brigham Young Unversity 461 CB, Provo, Utah 84602 Office: (801) 422-7206 Email: welson(a)et.byu.edu -------------------------------------

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exception safety of boost graph library
by Ovidiu Deac 28 Jan '05

28 Jan '05

Hello everybody, We are going to use boost graph library within our application and I would like to know if there are any known issues regarding the exception safety. Is the basic guarantee satisfied? Is the strong guarantee satisfied? (see Herb Sutter's definition of basic/strong guarantee in Exceptional C++) "Basic guarantee: Even in the presence of exceptions thrown by T or other exceptions, Stack objects don't leak resources. Note that this also implies that the container will be destructible and usable even if an exception is thrown while performing some container operation. However, if an exception is thrown, the container will be in a consistent, but not necessarily predictable, state. Containers that support the basic guarantee can work safely in some settings. Strong guarantee: If an operation terminates because of an exception, program state will remain unchanged. This always implies commit-or-rollback semantics, including that no references or iterators into the container be invalidated if an operation fails. For example, if a Stack client calls Top and then attempts a Push that fails because of an exception, then the state of the Stack object must be unchanged and the reference returned from the prior call to Top must still be valid." (Herb Sutter, Exceptional C++) Thank you, vidu

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[string_algo] Split and Predicates
by David Brownell 28 Jan '05

28 Jan '05

I am attempting to split a string with the string_algo library, using the code below. It appears that the split algorithm is designed to split on instances of individual characters rather than sequences of characters. Is there something I can do to split on a substring? The code below illustrates the problem, where I am forces to use the is_any_of predicate rather than something that implies equality. It seems like this is a trivial use of the algorithm, so there could easily be something that I am missing. typedef std::vector<boost::iterator_range<char const *> > ResultsType; ResultsType results; static char const STRING[] = "this\r\nis\r\n\r\na test!"; boost::split(results, boost::iterator_range<char const *>(STRING, STRING + sizeof(STRING)), boost::is_any_of("\r\n")); // The problem is here. I would like to be able // to use something like equals, but split requires // a predicate that takes a single argument rather than // a range. for(ResultsType::const_iterator rptr = results.begin(); rptr != results.end(); ++rptr) std::cout << "'" << std::string(rptr->begin(), rptr->end()) << "'\n"; Thanks! David Brownell

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Graphs (boost1.32.0) Trouble with dijkstra visitor and VC 7.1
by Tony Juricic 28 Jan '05

28 Jan '05

Has anybody created custom dijkstra_shortest_paths algorithm visitor for discover_vertex event? I am having all sorts of compilation errors using MSVC 7.1 and defining my visitor using example code. Reshuffling the code (but at this point I hardly know what am I really doing) I got the following to compile: // define visitor for discover_vertex event template <class Vertex, class Tag> struct target_visitor : public default_dijkstra_visitor { target_visitor(Vertex u) : v(u) { } template <class Vertex, class Graph> void discover_vertex(Vertex u, Graph& g) { if ( u==v ) assert(0); } private: Vertex v; }; template <class Vertex, class Tag> target_visitor<Vertex, Tag> target_visit(Vertex u, Tag) { return target_visitor<Vertex, Tag>(u); } ... // call dijkstra_shortest_paths with custom visitor // parameters below are defined as in dijkstra-example.cpp dijkstra_shortest_paths(g, s, predecessor_map(&p[0]).distance_map(&d[0]).visitor(target_visit(D, on_discover_vertex()))); Tony Confused

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error in boost/graph/fruchterman_reingold.hpp
by Jamie Wilkinson 28 Jan '05

28 Jan '05

The doc at http://boost-consulting.com/boost/libs/grpah/doc/fruchterman_reingold.html suggests that there is a 4 argument version of the function, taking only the graph, a position map, width and height; but attempts to compile such a function against the headers from the latest CVS results in a compile error: error: no matching function for call to ` fruchterman_reingold_force_directed_layout(Umbrella::Document&, Umbrella::View::load_from_document()::PositionMap&, double&, double&)' Removing the typenames Param, Tag, and Rest from lines 371-372 of the header allows the compile to continue. Index: boost/graph/fruchterman_reingold.hpp =================================================================== RCS file: /cvsroot/boost/boost/boost/graph/fruchterman_reingold.hpp,v retrieving revision 1.5 diff -u -c -r1.5 fruchterman_reingold.hpp cvs diff: conflicting specifications of output style *** boost/graph/fruchterman_reingold.hpp 29 Dec 2004 16:53:05 -0000 1.5 --- boost/graph/fruchterman_reingold.hpp 12 Jan 2005 09:18:16 -0000 *************** *** 368,375 **** params); } ! template<typename Graph, typename PositionMap, typename Dim, typename Param, ! typename Tag, typename Rest> void fruchterman_reingold_force_directed_layout(const Graph& g, PositionMap position, --- 368,374 ---- params); } ! template<typename Graph, typename PositionMap, typename Dim> void fruchterman_reingold_force_directed_layout(const Graph& g, PositionMap position,

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Bind Overload Workaround?
by Duane Murphy 28 Jan '05

28 Jan '05

How do I work around this problem with bind? #include <boost/bind.hpp> namespace { class functions { public: int func( int ); int func( int, int ); }; void test() { functions a_func; boost::bind( functions::func, a_func, 1, _1 ); } } Bind can't determine which function to call because it is overloaded and it doesn't know the context in which it will be called. With CodeWarrior 8 on Mac OS X I get "illegal use of template argument dependent type 'T::result_type' It references an "unspecified" template deep in the bowels of bind. As I recall there was some way of helping bind to pick one of the overloaded functions using a typedef or something similar. (Maybe that was function?). Thanks for any tips, ...Duane

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boost serialization
by Daniel Goller 28 Jan '05

28 Jan '05

are there any problems with boost serialization including linker errors or does this indicate a broken install i have heard of problems with boost serialization but do not know which they might be before running off in the wrong direction i figured i would gather information here to solve this: http://bugs.gentoo.org/show_bug.cgi?id=78043 problem any help on this will be appreciated Daniel

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Regex lib and thread safety
by Leon Mergen 27 Jan '05

27 Jan '05

Hello, I am sorry if this is a stupid question, or simply inappropriatie for this list. I am currently camping with this bug for way too long, so I decided to ask this mailinglist. I am currently in the process of finding out where a segfault is, and how to fix it. Now, I am using the boost regex library to parse my regexes, and for some reason when multiple threads use this regex library, it seems to mess up and generate segfaults (it works perfectly with only one thread). Since it also doesn't always occur on the same place, and doesn't even occur /all/ the times, I have a strong feeling this has something to do with thread safety. On the Boost website is was able to find out that the boost regex library should be thread safe when BOOST_HAS_THREADS is defined; I've tested this, and this worked. ( http://www.boost.org/libs/regex/doc/thread_safety.html ) However, I also was able to find a mailinglist message that provides some instructions on how to make certain boost regex functions thread-safe : ( http://lists.boost.org/MailArchives/boost/msg59110.php ) Now, I am confused; is the boost regex library thread-safe or not ? The solution provided in the mailinglist message ( move the regex_replace () function inside its own scope ) can't be applied here... :( I've posted the stacktrace when the problem occurs and the source of the code 'that matters' below. It also occurs in another function, I've posted the other function too. I hope anyone has any experience with this, or is able to help. Thanks in advance! Regards, Leon Mergen One stacktrace: --- #0 std::string::compare(char const*) const (this=0x0, __s=0x40338b81 "C") at /root/gcc-3.3.2/i686-pc-linux-gnu/libstdc++-v3/include/bits/basic_string.h:257 #1 0x4004b101 in boost::c_regex_traits<char>::update() () from /usr/local/lib/libboost_regex-gcc-1_31.so.1.31.0 #2 0x40084cd9 in boost::reg_expression<char, boost::regex_traits<char>, std::allocator<char> >::set_expression(char const*, char const*, unsigned) () from /usr/local/lib/libboost_regex-gcc-1_31.so.1.31.0 #3 0x080648aa in unsigned boost::reg_expression<char, boost::regex_traits<char>, std::allocator<char> >::set_expression<std::char_traits<char>, std::allocator<char> >>(std::basic_string<char, std::char_traits<char>, >>std::allocator<char> > const&, unsigned) (this=0x413d29cc, >>p=@0x413d2adc, f=34055) at basic_regex.hpp:110 #4 0x080647bf in reg_expression<std::char_traits<char>, std::allocator<char> > (this=0x413d29cc, p=@0x413d2adc, f=33031, a=@0x413d29bc) at basic_regex.hpp:114 #5 0x0806474c in basic_regex<std::char_traits<char>, std::allocator<char> > (this=0x413d29cc, p=@0x413d2adc, f=33031, a=@0x413d29bc) at basic_regex.hpp:361 #6 0x080633ee in RegexEngine::parseReplaceRegex(std::string*, std::string*, std::string*) (this=0x80d1160, regex=Cannot look up value of a typedef) at RegexEngine.cc:8 #7 0x0808070a in ModuleDigitsToText::applyModule(std::string*, std::string) (this=0x80d3190, data=0x80d16e0, language= {static npos = 4294967295, _M_dataplus ={<allocator<char>> = {<No data fields>}, _M_p = 0x80d244c "en"}, static _S_empty_rep_storage = {0, 0, 77, 0}}) at ModuleDigitsToText.cc:565 #8 0x08080270 in ModuleDigitsToText::applyModule(InputData*) (this=0x80d3190, inputData=0x80d16d8) at ModuleDigitsToText.cc:527 #9 0x08062200 in ModuleParser::parse(InputData*) (this=0x80d1150, inputData=0x80d16d8) at ModuleParser.cc:105 #10 0x0805e1db in Normaliser::normalise() (this=0x80d1698) at Normaliser.cc:107 #11 0x080831f4 in Client::operator()() (this=0x80ca808) at Client.cc:44 #12 0x080542bf in boost::detail::function::void_function_obj_invoker0<Client, void>::invoke(boost::detail::function::any_pointer) (function_obj_ptr= {obj_ptr = 0x80ca808, const_obj_ptr = 0x80ca808, func_ptr = 0x80ca808, data = "\b"}) at function_template.hpp:128 #13 0x400a69f4 in boost::thread_group::join_all() () from /usr/local/lib/libboost_thread-gcc-mt-1_31.so.1.31.0 #14 0x401cff60 in pthread_start_thread () from /lib/i686/libpthread.so.0 #15 0x401d00fe in pthread_start_thread_event () from /lib/i686/libpthread.so.0 #16 0x402f7327 in clone () from /lib/i686/libc.so.6 --- And are the two functions where the segfault occurs. Line 8 of RegexEngine.cc is the "boost::regex expression(*regex);" line of the parseReplaceRegex() function. --- std::string RegexEngine::parseReplaceRegex (const std::string * regex, const std::string * replace, const std::string * subject) { // Create an expression out of the regex boost::regex expression(*regex); // Return the replaced regex { return boost::regex_replace(*subject, expression, *replace, boost::match_default | boost::format_sed); } } bool RegexEngine::parseMatchRegex (std::string * regex, std::string * subject, RegexResultSet * what) { #ifdef DEBUG std::cout << "+ RegexEngine::parseMatchRegex[long] ( " << *regex << ", " << *subject << " )" << std::endl; #endif // DEBUG // Prepare result set boost::match_results <std::string::const_iterator> results; // Create string iterators std::string::const_iterator start = subject->begin(); std::string::const_iterator end = subject->end(); // Initialise boolean to know wether a match was reached bool success = false; // Create an expression out of the regex boost::regex expression(*regex); std::vector < std::string > regexResults; // Iterate over the results while (boost::regex_search(start, end, results, expression, boost::match_default)) { regexResults.clear(); for (boost::match_results<std::string::const_iterator>::iterator i = results.begin(); i != results.end(); ++i) { regexResults.push_back(*i); } // Push back a result what->push_back(regexResults); // Set new string iterator start = results[0].second; // Mark that a match was reached success = true; } #ifdef DEBUG std::cout << "- RegexEngine::parseMatchRegex ()" << std::endl; #endif // DEBUG // Return wether a match was reached return success; } ---

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time_period constructor question
by Stuart Siegel 27 Jan '05

27 Jan '05

Can anyone tell me why the line: time_period t4(t2); in the attached cpp file doesn't compile but the line: time_period t3(t1); does? it seems like i should be calling the same copy constructor in both cases but g++ 3.3.4 complains: error: no matching function for call to ` boost::date_time::period<boost::posix_time::ptime, boost::posix_time::time_duration>::period(boost::posix_time::time_period (&)(boost::posix_time::ptime, boost::posix_time::ptime))' /usr/include/boost/date_time/period.hpp:64: error: candidates are: boost::date_time::period<boost::posix_time::ptime, boost::posix_time::time_duration>::period(const boost::date_time::period<boost::posix_time::ptime, boost::posix_time::time_duration>&) /usr/include/boost/date_time/period.hpp:109: error: boost::date_time::period<point_rep, duration_rep>::period(point_rep, duration_rep) [with point_rep = boost::posix_time::ptime, duration_rep = boost::posix_time::time_duration] /usr/include/boost/date_time/period.hpp:99: error: boost::date_time::period<point_rep, duration_rep>::period(point_rep, point_rep) [with point_rep = boost::posix_time::ptime, duration_rep = boost::posix_time::time_duration] //--------------------------------cut here------------------- #include "boost/date_time/posix_time/posix_time_types.hpp" #include "boost/date_time/gregorian/gregorian_types.hpp" int main() { using namespace boost::posix_time; using namespace boost::gregorian; //---------------------------------------------- date dmin( min_date_time) ; ptime tmin( dmin ); date dmax( max_date_time) ; ptime tmax( dmax ); time_period t1( tmin, tmax ); //--------------------------------------------- time_period t2( ptime(min_date_time), ptime(max_date_time) ); //why does this compile (on g++ 3.3.4) time_period t3(t1); //but this doesn't? i.e., why isn't a time_period a time_period a time_period? time_period t4(t2); return 0; } __________________________________ Do you Yahoo!? All your favorites on one personal page � Try My Yahoo! http://my.yahoo.com

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analogy to mem_fun_ref to member variables
by Chris Goller 27 Jan '05

27 Jan '05

I have a struct that contains two values. struct box { double width; double length; } vector<box> boxes; I want to accumlate all the widths of the boxes. The only solution I've found is to create a member function get_width that will return the width for use in mem_fun_ref eg: accumulate(make_transform_iterator(boxes.begin(), mem_fun_ref(&boxes::get_width)), make_transform_iterator(boxes.end(), mem_fun_ref(&boxes::get_width)), 0.0, plus<double>())); Is there a boost way of not using mem_fun_ref, but rather returns the public member variable. Something that could be named mem_var_ref that would look like this: accumulate(make_transform_iterator(boxes.begin(), mem_var_ref(&boxes::width)), make_transform_iterator(boxes.end(), mem_fun_ref(&boxes::width)), 0.0, plus<double>())); This way I wouldn't need to add extra get logic to a structure that doesn't really need it othewise. Thanks, Chris

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boost/graph 1.32.0 : compilation errors on a SUN machine
by laurent de Vito 26 Jan '05

26 Jan '05

Hello, I cannot compile the boost/graph library 1.32.0 on a SUN machine using Sun C++ 5.5. I get the following error message : boost_1_32_0/boost/graph/depth_first_search.hpp", line 377: Error: Default arguments cannot be added in later declarations of the template function in the same scope. which does make sense since the compiler cannot decide which routine depth_first_visit to use if the second routine (line 371) has an extra template but the the extra template has a default value. So in boost/graph/depth_first_search.hpp, I simply deleted the default argument : template <class IncidenceGraph, class DFSVisitor, class ColorMap, class TerminatorFunc> void depth_first_visit (const IncidenceGraph& g, typename graph_traits<IncidenceGraph>::vertex_descriptor u, DFSVisitor vis, ColorMap color, TerminatorFunc func = TerminatorFunc()) becomes template <class IncidenceGraph, class DFSVisitor, class ColorMap, class TerminatorFunc> void depth_first_visit (const IncidenceGraph& g, typename graph_traits<IncidenceGraph>::vertex_descriptor u, DFSVisitor vis, ColorMap color, TerminatorFunc func) Unfortunately the compilation was afterwards not successful; this time I got "boost_1_32_0/boost/graph/named_function_params.hpp", line 500: Error: Cannot return const boost::bgl_named_params<boost::detail::components_recorder<int*>, boost::graph_visitor_t, boost::no_property> from a function that should return boost::detail::error_property_not_found. "boost_1_32_0/boost/graph/depth_first_search.hpp", line 354: Where: While instantiating "boost::get_param<boost::graph_visitor_t, boost::root_vertex_t, boost::detail::components_recorder<int*>, boost::no_property>(const boost::bgl_named_params<boost::detail::components_recorder<int*>, boost::graph_visitor_t, boost::no_property>&, boost::root_vertex_t)". "boost_1_32_0/boost/graph/depth_first_search.hpp", line 354: Where: Instantiated from non-template code. "boost_1_32_0/boost/graph/depth_first_search.hpp", line 355: Error: Could not find a match for boost::vertices<boost::T>(const boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS, boost::no_property, boost::no_property, boost::no_property, boost::listS>). big thanks for any help, Laurent

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uBLAS, Inverse of Matrices -- Urgent
by Hossein Haeri 26 Jan '05

26 Jan '05

Dear all, Am I missing anything? Isn't there any mechinary in uBLAS which can compute the inverse of a matrix? That being the case, isn't that hilarious? Or, if there is, what's that? All of the Best, --Hossein ___________________________________________________________ ALL-NEW Yahoo! Messenger - all new features - even more fun! http://uk.messenger.yahoo.com

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(?) MPL vs boost.lambda concerning lambda expressions
by Roman 26 Jan '05

26 Jan '05

Hi. Has anybody a suggestion about MPL vs boost.lambda concerning lambda expressions?

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VC7.1 Internal Compiler error compiling Graphviz 1-32
by Alessandro Cossetto 26 Jan '05

26 Jan '05

I tried to compile graphviz library but compiling graphviz_digraph_parser.cpp (and graphviz_graph_parser.cpp ) VC7.1 gave me an internal compiler error (compiler file 'msc1.cpp', line 2701). The error occours in boost\gaph\properties.hpp at line 203: template <class Graph, class Property> struct property_map { private: typedef typename property_kind<Property>::type Kind; typedef typename detail::property_map_kind_selector<Kind>::type Selector; ==> typedef typename Selector::template bind_<Graph, Property> Bind; typedef typename Bind::type Map; public: typedef typename Map::type type; typedef typename Map::const_type const_type; }; It happens when compiler tries to resolve the graph_traits instance (line 124 in graphviz_digraph_parser.cpp) namespace graphviz { ==> typedef boost::graph_traits<GRAPHVIZ_GRAPH>::vertex_descriptor Vertex; typedef boost::graph_traits<GRAPHVIZ_GRAPH>::edge_descriptor Edge; typedef GRAPHVIZ_GRAPH Subgraph; Using GCC I compiled the library wihtout problem. I was not able to find a workarount. Can anyone help me? Alessandro

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[ANN] Interfaces Library
by Jonathan Turkanis 26 Jan '05

26 Jan '05

I am pleased to announce the much anticipated (by me) release of a preliminary version of my interfaces library. The download page and online docs are here: http://www.kangaroologic.com/interfaces/ (For fun, click on "Online Documentation" and then on the Boost logo.) The library is an implementation of Christopher Diggins's proposal to add interfaces to C++, which was posted on comp.std.c++ early last year and later was described in the C/C++ User Journal. It provides a macro-based Interface Definition Language (IDL) which can be used to define C++ class types called interfaces. An interface is a lightweight value type associated with a set of named function signatures. An interface instance can be bound at runtime to any object which implements the interface, i.e., to any object of a type with accessible non-static member functions having the same name and signature as the set of functions associated with the interface. The functions of the bound object can then be invoked through the interface instance using the "dot" operator. Binding is completely non-intrusive: the object's type need not declare any virtual functions or derive from any particular base class. Current applications include: * Non-intrusive dynamic polymorphism - interfaces can often be used in place of abstract base classes, and are sometimes much faster. * Dynamic inheritance - allows function calls to be forwarded automatically to an object specified at runtime. * Smart Interface Pointers - smart pointers which can manage the lifetime of any object whose type implements a given interface. * Smart References - like smart interface pointers, but the managed object is accessed using the dot operator. * The Object Oriented Template Library, a project in the initial stages of development, by Christopher Diggins. Planned future applications include: * Runtime reflection - will allow an interface's functions to be enumerated and looked up by name at runtime * Aspect Oriented Programming as described in a August 2004 Dr. Dobb's Journal article by Christopher Diggins. Possible future applications include: * Integration with component architectures such as COM and CORBA. * Boost.Names - by abstracting the various uses of identifiers in C++ into preprocessor generated types called names, C++ classes and functions can be constructed in a straightforward manner using template metaprogramming. Best Regards, Jonathan

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what does BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP
by Kevin Lee 25 Jan '05

25 Jan '05

I need some expert's opinion on this: When I try to use the boost 1.32.0 in my work env, if i don't define this flag BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP, the lib/smart_ptr/test/intrusive_ptr_test.cpp fails to compile. if i do define it, my compiler would be happy (HP aCC) on intrusive_ptr_test. My questions are: 1) What is the BOOST_NO_ARGUMENT_DEPENDENT_LOOKUP? 2) What will be the other impacts if I do define it in my code globally besides the intrusive_ptr_test? Thanks in advance! Kevin Lee ----------------------------------------- This message and its attachments may contain privileged and confidential information. If you are not the intended recipient(s), you are prohibited from printing, forwarding, saving or copying this email. If you have received this e-mail in error, please immediately notify the sender and delete this e-mail and its attachments from your computer.

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Weak_ptr lost its operator==
by Brian McCandless 25 Jan '05

25 Jan '05

Hi, I just upgraded from boost 1.29 to boost 1.32, and found that operator== for weak_ptr has been dropped between these versions. My code uses std::find to find a weak_ptr in a container. This no longer compiles (g++-3.4.1) since find uses operator==. Has anyone else encountered this kind of problem? What are some good workarounds? Could operator== be put back? Thanks, Brian

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RE: [Boost-users] Serialization problem loading a vector of items
by Foster, Gareth 25 Jan '05

25 Jan '05

I seem to remember being told that std::string was not meant to be inherited from, could it be the same in your case? -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Bill Lear Sent: 24 January 2005 13:43 To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] Serialization problem loading a vector of items On Friday, January 21, 2005 at 12:29:37 (-0600) Bill Lear writes: >I am curious why loading a vector of items from an input stream fails >using one method but works using a slightly different method. >... I have not seen a response to this post. Along similar lines, I am having problems with sub-classing the std::vector class. I've tried multiple ways, but can't get it to load (de-serialize) properly. I've used private inheritance (my first choice), public inheritance. Neither work. Here is my attempt at public inheritance: template <class T> class RingBuffer: public std::vector<T> { public: RingBuffer() : _first_ind(0), _last_ind(0) { } double first() { return (*this)[_first_ind]; } double last() { return (*this)[_last_ind]; } void add(T v) { _last_ind = (_last_ind + 1) % size(); (*this)[_last_ind] = v; if (_last_ind == _first_ind) { _first_ind = (_first_ind + 1) % size(); } } private: int _first_ind; int _last_ind; friend class boost::serialization::access; template<class Archive> void serialize(Archive& ar, const unsigned int) { ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(std::vector<T>) & BOOST_SERIALIZATION_NVP(_first_ind) & BOOST_SERIALIZATION_NVP(_last_ind); } }; As before, I can save this to a stream, but cannot get it to load from a stream. I am using boost 1.32, with gcc 3.2. Bill _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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[string_algo] replace repeated char with single instance?
by Jeff Flinn 25 Jan '05

25 Jan '05

Am I required to use regex_finder to replace repeated chars with a single instance? I'm trying to cleanup a string for use with filesystem::path, for example: C:\\abc///def\\ghi => C:\abc\def\ghi There may be mixed forward and back-slashes. These are from environment variables that apparently are required by our use of NutCracker to support legacy apps under windows. If I need to use regex_finder what are the benefits of the string_algo versus just using the regex library? Thanks, Jeff

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C++ Template Metaprogramming - factorial example
by Brad Austin 25 Jan '05

25 Jan '05

Aleksey Gurtovoy wrote: > > Also, the first argument to eval_if is supposed to be an integral > > constant, and T4 is an expression of the form mpl::equal_to<T7,T8>, > > which again is just a nullary function, not an integral constant. > > Not if T7 and T8 are Integral Constants, see > http://www.boost.org/libs/mpl/doc/refmanual/equal-to.html. Okay, I see that now. Sorry, my mistake.

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Re: C++ Template Metaprogramming - factorial example
by Brad Austin 24 Jan '05

24 Jan '05

I wrote: > I recently purchased David Abrahams' and Aleksey Gurtovoy's new book > on the MPL, "C++ Template Metaprogramming" (obviously recently since > it's only been out a couple of weeks), and am working through some of > the examples. I'm having trouble with the factorial example in section > 8.3.1, page 160: > > #include <boost/mpl/int.hpp> > #include <boost/mpl/multiplies.hpp> > #include <boost/mpl/equal.hpp> > #include <boost/mpl/eval_if.hpp> > #include <boost/mpl/prior.hpp> > #include <boost/static_assert.hpp> > > namespace mpl = boost::mpl; > > template <class N> > struct factorial > : mpl::eval_if< > mpl::equal_to<N,mpl::int_<0> > // check N == 0 > , mpl::int_<1> // 0! == 1 > , mpl::multiplies< // N! == N * (N-1)! > N > , factorial<typename mpl::prior<N>::type> > > > > > { > BOOST_STATIC_ASSERT(N::value >= 0); // for nonnegative N > }; > > There's a minor issue in that equal.hpp is (apparently) mistakenly > included instead of equal_to.hpp, but even after fixing that, I can't > get this to compile in the form in which it's written. Should it, or > is it broken? After spending some more time on this I now believe the code is broken. There's some uncertainty because mpl::multiplies<> has apparently been either renamed or replaced with mpl::times<>, and only the latter is documented in the MPL Reference Manual, so I'm not certain whether or not the two behave identically. However changing "multiplies" to "times" didn't seem to make any difference in terms of the compilation errors, so in the analysis that follows I'm making the assumption that if there is any difference, it isn't doesn't change anything relevant to the problem at hand. According to the MPL Reference Manual, in an expression of the form mpl::times<T1,T2>, T1 and T2 must meet the requirements of an integral constant, not merely the weaker requirements of a nullary metafunction. In this case T2 is an expression of the form factorial<T3>, so for this to be vaild factorial<> must model an integral constant, not merely a metafunction *returning* an integral constant. However factorial<> derives from an expression of the form mpl::eval_if<T4,T5,T6>, and doesn't add any nested types or a value of its own. Therefore factorial<> only models an integral constant if mpl::eval_if<T4,T5,T6> does, which it doesn't. mpl::eval_if<T4,T5,T6>::type models an integral constant (provided T5:type and T6::type do), but mpl::eval_if<T4,T5,T6> is merely a metafunction returning that constant. Also, the first argument to eval_if is supposed to be an integral constant, and T4 is an expression of the form mpl::equal_to<T7,T8>, which again is just a nullary function, not an integral constant. So technically this would appear to be wrong, even though eval_if doesn't seem to mind in this case. FWIW, here's the final version of factorial<> I came up with. This version models an integral constant, and accepts for its argument either an integral constant or a nullary metafunction returning an integral constant: template <class N> struct factorial : mpl::if_< typename mpl::equal_to< typename N::type, mpl::int_<0> >::type, mpl::int_<1>, mpl::times< typename N::type , factorial< typename mpl::prior<typename N::type>::type > > >::type::type {}; Anyway, is this mailing list an appropriate place to bring up issues like this? I know David and Aleksey are members, but I'm not clear on whether their book qualifies as an official Boost product.

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