March 2004 - Boost-users - lists.preview.boost.org

RE: [Boost-users] regular expression searching for Glib::ustring??
by Ben Hutchings 18 Mar '04

18 Mar '04

Paul Elliott <pelliott(a)io.com> wrote: > I am using Gtkmm. I want to do boost regular expression searching on > Glib::ustring. > http://www.gtkmm.org/gtkmm2/docs/reference/html/classGlib_1_1ustring.htm l > > This class represents characters in UTF-8, so each character in the > buffer is represented by a varriable number of bytes. But it does > have a bidirectional iterator. > > How would you set up boost regex to search if both the regular > expression and the string to be searched is a ustring? > > Does one need to override any of the types defiened in regex_traits? The character type should be gunichar. > Thank you. > > BTW. > Quote from:http://www.boost.org/libs/regex/doc/regex_traits.html > > "Under construction. > The current boost.regex traits class design will be migrated to > that specified in the regular expression standardization proposal." > > This is not very useful to someone trying to use the boost_regex > library now! I am using Boost 1.30, in which the traits are documented in <boost/libs/regex/traits_class_ref.htm>. I don't know whether that documentation still applies to 1.31. You don't necessarily need custom traits to use custom iterator types. However, you do need to define custom traits to make character classes, case folding and so on work for all Unicode characters. To create a regex from a ustring I would write something like this: boost::reg_expression<gunichar, unicode_regex_traits> re; re.assign(s.begin(), s.end(), flags); When searching in a ustring I would write code like: my_predicate pred; boost::regex_grep(pred, s.begin(), s.end(), re, flags); boost::match_results<Glib::ustring::const_iterator, std::allocator<gunichar> > results; boost::regex_search<Glib::ustring::const_iterator, std::allocator<gunichar>, gunichar, unicode_regex_traits, std::allocator<gunichar> >( s.begin(), s.end(), results, re, flags); Glib::ustring result; boost::regex_merge( std::back_inserter(result), source.begin(), source.end(), re, std::basic_string<gunichar>(repl.begin(), repl.end())), flags); (The above is untested as we're not actually using Gtkmm but it's based on what we're doing with our own UTF-8 and UTF-16 strings.)

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RE: [Boost-users] regular expression searching for Glib::ustring??
by Yarwood, Martin (UK) 18 Mar '04

18 Mar '04

> "Under construction. > The current boost.regex traits class design will be migrated to > that specified in the regular expression standardization proposal." > > This is not very useful to someone trying to use the boost_regex > library now! > I'm sure they'll give you a full refund ******************************************************************** This email and any attachments are confidential to the intended recipient and may also be privileged. If you are not the intended recipient please delete it from your system and notify the sender. You should not copy it or use it for any purpose nor disclose or distribute its contents to any other person. ********************************************************************

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adjacency_matrix BGL problem
by Gustavo Sánchez 18 Mar '04

18 Mar '04

Hi everybody, Is it posible to resize a graph with this representation?. The idea is start with an empty matrix and add vertex based on the new vertices and edges we read. That is, we read a new edge and if their vertex aren't in the graph we add them and then the edge. Is this posible in an adjacency_matrix representation??? Thanks a lot. --------------------------------- Antivirus Filtros antispam 6 MB gratis ¿Todavía no tienes un correo inteligente?

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problem with vertex properties in BGL
by Gustavo Sánchez 17 Mar '04

17 Mar '04

I have to build a graph from data in a file, some information is strings which are related to vertexes. I want to prove if those vertexes already exist in the graph before the insert operation. Next is the source: typedef adjacency_matrix<undirectedS,VertexProperty,EdgeProperty> UGraph; // an undirected graph UGraph g(0); // start from scratch property_map<UGraph, edge_name_t>::type ename = get(edge_name, g); // not sure if this is right (the graph have no elements at this point) property_map<UGraph, vertex_name_t>::type vname = get(vertex_name, g); typedef property_map<UGraph, vertex_name_t>::type vname_type; typedef boost::property_traits<vname_type>::key_type vktype; typedef boost::property_traits<vname_type>::value_type vvtype; vktype indice_nombre; vvtype valor_nombre; for(i=0;i<datgen.NumHilos;i++){ valor_nombre = hiloNormal[i].viaOrigen; /// here we get the string indice_nombre = vname[valor_nombre]; /// here I try to get the index /// I think this is not posible because there isn't [] operator in this way valor_nombre = vname[1]; /// if I do this the compiler is right but that isn't useful for me because the information I have is the string not the index.I can use vertex iterators and search for the string, but if posible i prefer not to do that. thanks a lot. --------------------------------- Antivirus Filtros antispam 6 MB gratis ¿Todavía no tienes un correo inteligente?

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Bug in Boost Graph Library?
by Heiko Bauke 17 Mar '04

17 Mar '04

Dear all, today I was engaged in searching for a bug in my program. After a while I figured out that boost::num_egdes behaves not as I expected. If G is an undirected adjacency matrix graph boost::num_egdes(G) returns the number of edges in the graph G plus the number of edges in G that are no self edges. That means almost all edges are counted twice in undirected adjacency matrix graphs. In my oppinion this behaviour is a bug. At least it makes the BGL-user's live unnecessary difficult. Let's considder the following program: #include <cstdlib> #include <iostream> #include <boost/tuple/tuple.hpp> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/adjacency_matrix.hpp> template <typename Graph> void add_edges(const char * const c) { std::cout << c; Graph G(6); boost::graph_traits<Graph>::vertex_iterator v, vbegin, vend; boost::tie(vbegin, vend)=boost::vertices(G); for (v=vbegin; v!=vend; ++v) { boost::add_edge(*vbegin, *v, G); std::cout << ' ' << boost::num_edges(G); } std::cout << std::endl; } int main() { typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::undirectedS> adjacency_list; typedef boost::adjacency_matrix<boost::undirectedS> adjacency_matrix; add_edges<adjacency_list>("adjacency list graph :"); add_edges<adjacency_matrix>("adjacency matrix graph :"); return EXIT_SUCCESS; } It prints to stdout: adjacency list graph : 1 2 3 4 5 6 adjacency matrix graph : 1 3 5 7 9 11 So the result of the template function add_edges in the program above depends of the graph container that the function add_edges is applied to. I think this is verry unintuitive and boost::num_edges should be changed, so that alls edges in undirected adjacency matrix graphs are counted only once. Or is there a special reason that boost::num_edges is implemented in this way? with regards, Heiko -- -- Gute Sitten haben für die Gesellschaft mehr Wert als alle -- Berechnungen Newtons. (Friedrich II., der Große, 1712-1786) -- Supercomputing in Magdeburg @ http://tina.nat.uni-magdeburg.de -- Heiko Bauke @ http://www.uni-magdeburg.de/bauke

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RE: [Boost-users] boost::thread problem
by Ben Hutchings 17 Mar '04

17 Mar '04

Pete <petehug(a)paradise.net.nz> wrote: > I'm having a problem with my boost multithreaded application. > My app runs fine as a Windows Service, but as a Unix daemon it > stops responding after some time. I noticed that the fewer > threads I have available, the quicker the application stops > responding: HP-UX(64) after 20mins, RH8(256) after >1hr, Linux > RH9(1024) >5hrs. This led me to assume that perhaps the threads > are not cleaned up properly. That could well be right. Perhaps there is some kind of deadlock at thread exit? > Therefore, I wrote a little test app which ought to demonstrate > the problem. To my surprise, the test application showed an > entirely different problem, but again, only under Unix (it > works as expected under Windows). I'm totally lost what the > reason is and appreciate any help. > > Expected: Actual: > --------------- --------------- > Start running Start running > Start swimming Finish running > Start cycling Start swimming > Finish swimming Finish swimming > Finish cycling Start cycling > Finish running Finish cycling > > In windows I get the actual output but under Linux RH9, I get > the Actual output. Under RH9, the first five lines of the > actual output appear immediately, but the last one takes > approx. 4secs. In other words, only the last threads don't > sleep the number of secs specified. According to the manual page: "sleep() makes the current process sleep until seconds sec- onds have elapsed or a signal arrives which is not ignored." (Note that each POSIX thread is/was implemented as a process in Linux.) If thread creation involves receiving a signal then that would explain the above behaviour. I would expect it under RH8 because that has the old LinuxThreads implementation of pthreads that uses signals heavily, but not in RH9 which has NPTL. Still, you would be better off using boost::thread::sleep() instead.

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boost::thread_group design flaw
by Pete 17 Mar '04

17 Mar '04

I'm pretty convinced that there is a serious design flaw in boost::thread_group or at the very minimum, the documentation should better address the issue. Let's take a look at the thread_group.cpp example provided with boost::thread: #include <boost/thread/thread.hpp> #include <iostream> int count = 0; boost::mutex mutex; void increment_count() { boost::mutex::scoped_lock lock(mutex); std::cout << "count = " << ++count << std::endl; } int main(int argc, char* argv[]) { boost::thread_group threads; for (int i = 0; i < 10; ++i) threads.create_thread(&increment_count); threads.join_all(); } This example works fine until I make the following small change to main() which breaks it: int main(int argc, char* argv[]) { boost::thread_group threads; for (int j = 0; j < 2; ++i) { for (int i = 0; i < 10; ++i) threads.create_thread(&increment_count); threads.join_all(); } } The above code will break the second time threads.join_all() is called. The problem is that all boost::thread objects created in the first iteration survive the join_all() call. Worse still, the 2nd join_all() call sends another join() message to each thread it created but boost::thread::join() does not check the m_joinable flag and simply tries to free the system resources it previously freed again causing a system fault. To correct the problem above, I can change the code as follows: int main(int argc, char* argv[]) { boost::thread* pt[10]; boost::thread_group threads; for (int j = 0; j < 2; ++i) { for (int i = 0; i < 10; ++i) pt[i] = threads.create_thread(&increment_count); threads.join_all(); for (int i = 0; i < 10; ++i) threads.remove_thread(pt[i]); } } While this code no longer causes a GPF, I do not believe that the boost::thread objects created by boost::thread_group::create_thread() actually ever get destroyed. I have set a break point in boost::thread::~thread() but this breakpoint is never reached. If I physically delete each pt[i] after removing it from the thread_group I'm getting an assertion error telling me that the pointer I'm trying to delete is not a valid debug-heap pointer, but this error will most likely disappear if I stop using the debug heap (I haven't tried yet). As a boost::thread_group user, I made the following assumptions: - a boost::thread created through boost::thread_group::create_thread will be removed and cleaned up properly when a) the thread terminates or b) the thread_group is deleted - after returning from a call to join_all() the boost::thread_group has no boost::thread object members - I need not specifically keep track of boost::thread objects created by boost::thread_group and destruction of these objects is encapsulated within boost::thread_group I now find that none of these assumptions is quite correct. Perhaps I good immediate remedy would be to implement a boost::thread_group::clear() method which would throw an error if any of the threads where still in a running state and else would clear its threads collection and destroy the objects? How about thread objects "remembering" their membership in a thread_group so that the thread group can be informed when a thread terminates?

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boost::thread problem
by Pete 17 Mar '04

17 Mar '04

I'm having a problem with my boost multithreaded application. My app runs fine as a Windows Service, but as a Unix daemon it stops responding after some time. I noticed that the fewer threads I have available, the quicker the application stops responding: HP-UX(64) after 20mins, RH8(256) after >1hr, Linux RH9(1024) >5hrs. This led me to assume that perhaps the threads are not cleaned up properly. Therefore, I wrote a little test app which ought to demonstrate the problem. To my surprise, the test application showed an entirely different problem, but again, only under Unix (it works as expected under Windows). I'm totally lost what the reason is and appreciate any help. Expected: Actual: --------------- --------------- Start running Start running Start swimming Finish running Start cycling Start swimming Finish swimming Finish swimming Finish cycling Start cycling Finish running Finish cycling In windows I get the actual output but under Linux RH9, I get the Actual output. Under RH9, the first five lines of the actual output appear immediately, but the last one takes approx. 4secs. In other words, only the last threads don't sleep the number of secs specified. #include <string> #include <list> #include <iostream> #include <unistd.h> #include <boost/thread/thread.hpp> class MyThread { protected: std::string m_strName; int m_iDuration; public: MyThread(const std::string & s, int i) : m_strName(s), m_iDuration(i) {} void operator()() { std::cout << "Start " << m_strName << std::endl; sleep(m_iDuration); std::cout << "Finish " << m_strName << std::endl; } }; int main(int argc, char *argv[]) { std::list<MyThread*> lst; std::list<MyThread*>::iterator itr; MyThread* pT; boost::thread_group tg; lst.push_back(new MyThread("running", 6)); lst.push_back(new MyThread("swimming", 2)); lst.push_back(new MyThread("cycling", 4)); for (itr = lst.begin(); itr != lst.end(); itr++) { pT = *itr; tg.create_thread(boost::ref(*pT)); } tg.join_all(); while (!lst.empty()) { delete lst.front(); lst.pop_front(); } return 1; }

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Trouble building libbgl-viz.a
by Steve Juranich 16 Mar '04

16 Mar '04

Here's my system specs (let me know if I'm leaving something out): SuSE Linux 8.2 gcc v. 3.3 barbet (juranich)$ g++ -v Reading specs from /usr/lib/gcc-lib/i486-suse-linux/3.3/specs Configured with: ../configure --enable-threads=posix --prefix=/usr --with-local-prefix=/usr/local --infodir=/usr/share/info --mandir=/usr/share/man --libdir=/usr/lib --enable-languages=c,c++,f77,objc,java,ada --disable-checking --enable-libgcj --with-gxx-include-dir=/usr/include/g++ --with-slibdir=/lib --with-system-zlib --enable-shared --enable-__cxa_atexit i486-suse-linux Thread model: posix gcc version 3.3 20030226 (prerelease) (SuSE Linux) flex v. 2.5.4 bison v. 1.75 Description of problem: When I cd into $BOOST/libs/graph/src and type 'make', I get the following errors: barbet:/local/src/boost_1_31_0/libs/graph/src # make flex -Pbgl_undir_ -ographviz_graph_lex.cpp graphviz_lex.ll bison -p bgl_undir_ -d -v -o graphviz_graph_parser.cpp graphviz_parser.yy graphviz_parser.yy: warning: 1 shift/reduce conflict g++ -ftemplate-depth-50 -DGRAPHVIZ_DIRECTED=0 -I../../.. -g -c graphviz_graph_lex.cpp graphviz_lex.ll: In function `int bgl_undir_lex(yystype*)': graphviz_lex.ll:85: error: request for member `ptr' in `*lvalp', which is of non-class type `int' graphviz_lex.ll:87: error: request for member `ptr' in `*lvalp', which is of non-class type `int' make: *** [graphviz_graph_lex.o] Error 1 So, line 85 in graphviz_lex.ll looks like this: I've looked at the source with a friend who (unlike myself) actually has some experience with lex and yacc, but he couldn't spot the problem either. I know that the caveat at the top of the file says that the makefile probably won't work on my system, so are there any suggestions on what I could do to make it work? Thanks a lot. -- Stephen W. Juranich Science Applications Intl. Corp. (SAIC) (520) 570-7706

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RE: [Boost-users] VC 7.1 & boost.thread
by Ben Hutchings 16 Mar '04

16 Mar '04

raja <raja(a)genesyslab.com> wrote: > Hi, > I am getting the following error. I see that it is trying to link to > the static library, but I still get this error. It's not trying to link to the static library - you are. > Would appreciate if someone can correct my usage. > Linking to lib file: lib"boost_thread"-vc71-mt-sgd-1_31.lib > > c:\Boost\include\boost-1_31\boost\config\auto_link.hpp(269) : > fatal error > C1189: #error : "Mixing a dll boost library with a static runtime is a > really bad idea..." <snip> In your project's properties, under C/C++ > Code Generation, set the Runtime Library to be "Multi-threaded DLL" in the release configuration and "Multi-threaded Debug DLL" in the debug configuration. If you are not using the Visual Studio IDE then use the /MD and /MDd compiler switches respectively.

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General problem on compiling a boost regex code...
by Benjamin Kaiser [gamigo AG] 16 Mar '04

16 Mar '04

Hello, I'm using the boost library for the first time, and I get a compiler error. :-( I don't know why, because I think the boost library is installed successful (I have tested the SuSE rpm file and the download version from boost.org) I'm using gcc 3.x and boost 1.30 on SuSE Linux 9.0... Header file: ------------------------------------------- #include <string> #include <fstream> #include <syslog.h> #include <boost/regex.hpp> #include <vector> using namespace boost; ------------------------------------------- CPP file: ------------------------------------------- ... regex expression("([0-9]+)(\\-| |$)(.*)"); ... ------------------------------------------- Thats all I do alluded to the boost regex library... if I want to compile the files, I get the following compiling error: ------------------------------------------- #g++ -ansi -pedantic-errors -Wall -o statd ./projekt/statd.cpp compiling C++ using -ansi -pedantic-errors -Wall -o statd /tmp/cc2KYvxs.o(.text+0x1951): In function `Accounting::SaveTraffic()': : undefined reference to `boost::reg_expression<char, boost::regex_traits<char>, std::allocator<char> >::reg_expression[in-charge](char const*, unsigned, std::allocator<char> const&)' /tmp/cc2KYvxs.o(.text+0x1994): In function `Accounting::SaveTraffic()': : undefined reference to `boost::reg_expression<char, boost::regex_traits<char>, std::allocator<char> >::~reg_expression [in-charge]()' collect2: ld returned 1 exit status ------------------------------------------- It would be nice if someone can help me with this problem... I'm new at C++ and don't know how to fix this. :-( If I only include the regex.hpp and do the "using namespace boost" everything is compiling fine. Only if I do the "regex expression(...)" in the CPP File I get the errors... :-( Many thanks for help! If someone will help me via ICQ: 20320644 Mit freundlichen Grüßen / With best regards Benjamin Kaiser Systemprogrammierer gamigo® AG -Deutschland - Butterstr. 13 48431 Rheine Tel. +49 5971-899060 Fax +49 5971-8990611 bkaiser(a)gamigo.de (DH/DSS) PGP-Key auf Anfrage / PGP-Key on request! -------------------------------------------------- Diese E-Mail enthält vertrauliche und / oder rechtlich geschützte Informationen. Wenn Sie nicht der richtige Adressat sind oder diese E-Mail irrtümlich erhalten haben, informieren Sie bitte sofort den Absender und vernichten Sie diese Mail. Das unerlaubte Kopieren sowie die unbefugte Weitergabe dieser Mail ist nicht gestattet. This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and destroy this e-mail. Any unauthorised copying, disclosure or distribution of the material in this e-mail is strictly forbidden.

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Re: [Boost-users] regex with msvc-stlport
by Juan Casanueva 16 Mar '04

16 Mar '04

Hi John, I removed BOOST_REGEX_DECL from re_custom_error_messages, re_ten_w, and re_zero_w and It now works perfectly thanks! Juan >Date: Mon, 15 Mar 2004 13:49:51 -0000 >From: "John Maddock" <john(a)johnmaddock.co.uk> >Subject: Re: [Boost-users] regex with msvc-stlport1 >To: <boost-users(a)lists.boost.org> >Message-ID: <03ff01c40a94$68740cd0$ce810252@fuji> >Content-Type: text/plain; charset="iso-8859-1" > > > I have installed stlport 4.6 and tryed to compile regex but I get the >same > > error. > > > > it creates the .lib fine, but then give some unresolved externals when > > creating the dll.. > > what are your setting in regex\user.hpp??? > >Nothing don't change it. > > > if anyone has any idea, I would apreciate it > > thanks > >The only thing I notice is that the errors are only coming from the release >dll build (and not the debug version), is that correct? > >If so it explains why I can't reproduce it, as I only have the standard >edition of vc6 available to me (which doesn't create optimised builds). > >I also notice that the symbols that the linker is complaining about, >probably don't need to be exported anyway, so can you go into both >c_regex_traits.cpp and w32_regex_traits.cpp and remove the BOOST_REGEX_DECL >specifier from the following identifiers: > >re_custom_error_messages >re_ten_w >re_zero_w > >and see if that fixes the issue? If it does be sure to let me know so that >I can patch up the source, > >Thanks, > >John. > > > >------------------------------ > >_______________________________________________ >Boost-users mailing list >Boost-users(a)lists.boost.org >http://lists.boost.org/mailman/listinfo.cgi/boost-users > >End of Boost-users Digest, Vol 144, Issue 2 >******************************************* _________________________________________________________________ Add photos to your messages with MSN 8. Get 2 months FREE*. http://join.msn.com/?page=features/featuredemail

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random library fibonacci bug
by Martin Wartens 16 Mar '04

16 Mar '04

There seems to be a bug in the fibonacci random generators. Only the smaller lagged_fibonacci generators work. Code Sample (tested with VC7.1) follows. The debugger says: Run-Time Check Failure #0 - The value of ESP was not properly saved across a function call. This is usually a result of calling a function declared with one calling convention with a function pointer declared with a different calling convention. //lagged_fibonacci4423 and smaller works, //>=9689 fails typedef boost::lagged_fibonacci9689 rng_type; rng_type rng; rng.seed((unsigned)time( NULL )); boost::uniform_int<size_t> uni(0,len-1); //crashes on this line. boost::variate_generator<rng_type, boost::uniform_int<size_t> > die(rng, uni);

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RE: [Boost-users] boost::thread and std::system
by Ben Hutchings 16 Mar '04

16 Mar '04

Jerry Swan <jeremiah.s(a)ntlworld.com> wrote: > I'd like to be able to issue a call to std::system that will time-out > after a specified period. Is it possible to achieve this using the > boost::threads library? You can stop waiting for it to complete, but you can't terminate the external program. > If so could someone kindly sketch how this might be achieved? You need to have the calling thread create a synchronised flag (bool with condition, protected by mutex) and a child thread that calls system() and then sets the flag when that returns. The original thread then performs a timed wait for the flag to be set. Here's my solution. The synchronised flag can be encapsulated as an "event" like this: struct one_time_event { public: one_time_event() : flag(false) { } void trigger() { boost::mutex::scoped_lock lock(mutex); flag = true; cond.notify_all(); } void wait() { boost::mutex::scoped_lock lock(mutex); while (!flag) cond.wait(lock); } bool timed_wait(boost::xtime & time) { boost::mutex::scoped_lock lock(mutex); while (!flag) if (!cond.timed_wait(lock, time)) return false; return true; } private: boost::mutex mutex; boost::condition cond; bool flag; }; (This is a basic event that you use once and then throw away. More complex event classes are possible but harder to use correctly.) Using this class it's really very easy: void call_system(const char * command, one_time_event & event) { std::system(command); event.trigger(); } bool system_with_time_limit(const char * command, boost::xtime & time) { one_time_event event; boost::thread thread( boost::bind(call_system, command, boost::ref(event))); return event.timed_wait(time); } Ben.

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RE: [Boost-users] Re: Using shared_ptr across shared library boun dary
by Ferdinand Prantl 16 Mar '04

16 Mar '04

> From: David Abrahams [mailto:dave@boost-consulting.com] > > "Jim.Hyslop" <Jim.Hyslop(a)Leitch.com> writes: > > It's been my experience > > (with Visual Studio, at least) that allocating memory in > > one DLL and > > deallocating it in another leads to problems. Sometimes it > > doesn't go > > noticed, but when it does, it's really noticeable. > > The library cleverly avoids that, provided the first > shared_ptr to take ownership of the memory does so in the > same DLL where the object was allocated. Actually, I came into the same problem as Jim - I had to ensure the same version of the msvcrt and moreover its debug/release versions to get the code working well. All classes in checked_delete.hpp, smart_count.hpp and shared_ptr.hpp are either templates or completely in headers. The operations with new/delete and allocators are translated/inlined by the compiler into every unit, IMHO. I could not find the trick in the implementation, how to force the deletion of the pointer by the same runtime, if new() was performed in one DLL and delete() in another one. Could you, please, point me to the right direction to the explatation? Thanks, Ferda

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Newbie Q: Boost Graph stuff
by Ori 16 Mar '04

16 Mar '04

Hi everyone, I have a question concerning the Boost Graph library, specifically with strongly connected components. My problem is this: I have a graph that I need to collapse into strongly connected components, then topologically sort the resulting DAG of components. Then I want to traverse the sorted DAG (in order), and for each component (now just a vertex I guess), look up into the original graph to find all the vertices that belong to this component. The application here is a rigid body simulator, and I'm constructing a graph of contact points between bodies. The idea is to find an ordering to apply collision impulses, which logically means from the ground up. Vertices are thus bodies, and edges denote a contact (collision) case. I've constructed the original graph, and using the example online, performed the strong_components algorithm on it. However, I'm unsure of how to correctly create a graph of the components. I presume using the root_map is somehow involved, but I'm kind of at a loss. Here's what I got: // typedefs, most stolen from graph introduction at boost.org typedef std::pair<int, int> Edge; struct pen_index_t { typedef edge_property_tag kind; }; typedef property<pen_index_t, int> PenProperty; typedef adjacency_list<vecS, vecS, directedS, no_property, PenProperty> Graph; typedef adjacency_list<setS, vecS, directedS, no_property, PenProperty> ComponentGraph; typedef graph_traits<Graph>::vertex_descriptor Vertex; ... // actual code Graph contactGraph(NUM_BODIES); ... various junk to fill up the graph ... // now, collapse strongly connected components vector<int> component(num_vertices(contactGraph)); vector<Vertex> root(num_vertices(contactGraph)); bgl_named_params< Vertex*, vertex_root_t, no_property> rootMap = root_map(&root[0]); int num = strong_components(contactGraph, &component[0], rootMap); // create a new graph with each component as a vertex... // ...how? I tried variations on get(...) on the rootMap and such, but was met with the usual nightmarish stl/boost compiler errors when you mess up something involving templates : ) Any help someone out there can give is really appreciated. Thanks! ~ Ori

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BUG: boost::lexical_cast ignores virtual functions.
by John F Meinel Jr 16 Mar '04

16 Mar '04

I found that when I call boost::lexical_cast<std::string>() with an object that has virtual functions, it fails to dereference the virtual functions. It also cannot use an Abstract base type. Attached is example code. I think the problem is simply that the file boost/lexical_cast.hpp, on line 185 has: Target lexical_cast(Source arg) This should be Target lexical_cast(Source& arg) At least, this fixes all of my problems. John =:-> #include <iostream> #include <string> #include <boost/lexical_cast.hpp> struct A { virtual int f() const = 0; }; struct B : A { virtual int f() const { return 1; } }; struct C : B { virtual int f() const { return 2; } }; std::ostream& operator<<(std::ostream& os, const A& a) { return os << a.f(); } int main() { C c; std::string s; std::cout << c << std::endl; //This should print 2 s = boost::lexical_cast<std::string>(c); std::cout << s << std::endl; //This should print 2 s = boost::lexical_cast<std::string, B>(c); std::cout << s << std::endl; //This returns 1, not 2 //This fails because it tries to instantiate an object of type A. Why??? s = boost::lexical_cast<std::string, A>(c); std::cout << s << std::endl; }

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Problems building Boost
by Ulf Johansson 15 Mar '04

15 Mar '04

I've downloaded Boost 1.31.0 and tried to build it using the standard bjam procedure from the getting started document. I have WinXP/Home and the standard edition of VC7.1 (.NET 2003). I've tried both the vc7.1 and the vc7.1-stlport toolsets. In both cases the following libraries are generated: boost_date_time boost_filesystem boost_signals boost_thread libbost_date_time libbost_prg_exec_monitor libbost_regex libbost_signals libbost_test_exec_monitor libbost_unit_test_framework During the build process I get compiler warnings because the standard version of VC won't do advanced optimizations, but otherwise there seems to be no problem. Bjam stops after having generated the above libraries. Shouldn't there be more? What's the difference between those starting with boost and those starting with libboost? Do I have to somehow generate the remaining libraries separately? Thanks!

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VC 7.1 & boost.thread
by raja 15 Mar '04

15 Mar '04

Hi, I am getting the following error. I see that it is trying to link to the static library, but I still get this error. Would appreciate if someone can correct my usage. Linking to lib file: lib"boost_thread"-vc71-mt-sgd-1_31.lib c:\Boost\include\boost-1_31\boost\config\auto_link.hpp(269) : fatal error C1189: #error : "Mixing a dll boost library with a static runtime is a really bad idea..." Here is my sample: #define _MSC_VER 1310 #define BOOST_LIB_NAME "boost_thread" #define BOOST_LIB_DIAGNOSTIC "on"// Show library file details. #include <boost/config/auto_link.hpp> #include <boost/thread/thread.hpp> #include <iostream> void hello() { std::cout << "Hello world, I'm a thread!" << std::endl; } int main(int argc, char* argv[]) { boost::thread thrd(&hello); thrd.join(); return 0; }

1 0

[BGL] Determining if a graph has a particular internal property?
by Douglas Gregor 15 Mar '04

15 Mar '04

Is this possible? A well-defined return type from get(p, g) when p is not an internal property of graph g would suffice. Doug

3 2

Re: [Boost-users] regex with msvc-stlport1
by Juan Casanueva 15 Mar '04

15 Mar '04

Hi John, I have installed stlport 4.6 and tryed to compile regex but I get the same error. vc-Link ..\..\..\bin\boost\libs\regex\build\boost_regex.dll\msvc-stlport\release\stlport-cstd-namespace-global\stlport-iostream-on\boost_regex-vc6-mt-p-1_31.dll ..\..\..\bin\boost\libs\regex\build\boost_regex.dll\msvc-stlport\release\stlport-cstd-namespace-global\stlport-iostream-on\boost_regex-vc6-mt-p-1_31.lib Creating library ..\..\..\bin\boost\libs\regex\build\boost_regex.dll\msvc-stlport\release\stlport-cstd-namespace-global\stlport-iostream-on\boost_regex-vc6-mt-p-1_31.lib and object ..\..\..\bin\boost\libs\regex\build\boost_regex.dll\msvc-stlport\release\stlport-cstd-namespace-global\stlport-iostream-on\boost_regex-vc6-mt-p-1_31.exp boost_regex-vc6-mt-p-1_31.exp : error LNK2001: unresolved external symbol "?re_custom_error_messages@?%C:\Program" (?re_custom_error_messages@?%C:\Program) boost_regex-vc6-mt-p-1_31.exp : error LNK2001: unresolved external symbol "?re_ten_w@?%C:\Program" (?re_ten_w@?%C:\Program) boost_regex-vc6-mt-p-1_31.exp : error LNK2001: unresolved external symbol "?re_zero_w@?%C:\Program" (?re_zero_w@?%C:\Program) ..\..\..\bin\boost\libs\regex\build\boost_regex.dll\msvc-stlport\release\stlport-cstd-namespace-global\stlport-iostream-on\boost_regex-vc6-mt-p-1_31.dll : fatal error LNK1120: 3 unresolved externals "link" /nologo /INCREMENTAL:NO /DLL /subsystem:console /out:"..\..\..\bin\boost\libs\regex\build\boost_regex.dll\msvc-stlport\release\stlport-cstd-namespace-global\stlport-iostream-on\boost_regex-vc6-mt-p-1_31.dll" /IMPLIB:"..\..\..\bin\boost\libs\regex\build\boost_regex.dll\msvc-stlport\release\stlport-cstd-namespace-global\stlport-iostream-on\boost_regex-vc6-mt-p-1_31.lib" /LIBPATH:"C:\Program Files\Microsoft Visual Studio\STLport-4.6\lib" /LIBPATH:"C:\PROGRA~1\MICROS~2\VC98\lib" @"..\..\..\bin\boost\libs\regex\build\boost_regex.dll\msvc-stlport\release\stlport-cstd-namespace-global\stlport-iostream-on\boost_regex-vc6-mt-p-1_31.CMD" it creates the .lib fine, but then give some unresolved externals when creating the dll.. what are your setting in regex\user.hpp??? if anyone has any idea, I would apreciate it thanks Juan >>Date: Sat, 13 Mar 2004 12:31:07 -0000 >From: "John Maddock" <john(a)johnmaddock.co.uk> >Subject: Re: [Boost-users] regex with msvc-stlport >To: <boost-users(a)lists.boost.org> >Message-ID: <022501c408f7$128de550$1a520252@fuji> >Content-Type: text/plain; charset="iso-8859-1" > > > I am trying to build de regex boost library with msvc and stlport4.6.1, >with > > no success!!! > >I regularly test regex with msvc+STLPort and it works for me with >Boost.1.31.0 (OK, I use STLPort 4.6, but otherwise the same settings as you >are using). > > > I use the following to compile (release version): > >The static libs have built OK, but the dll build failed for some strange >reason, I really don't understand that... > >John. > _________________________________________________________________ STOP MORE SPAM with the new MSN 8 and get 2 months FREE* http://join.msn.com/?page=features/junkmail

2 1

Problem using Boost with Dinkumware STL library
by Darren Cox 15 Mar '04

15 Mar '04

2 1

Re: [Boost-users] mpl rational_c and fixed_c
by Aleksey Gurtovoy 15 Mar '04

15 Mar '04

Matt Calabrese writes: > A couple of days ago I started work on a library where I need a way to > represent rational numbers and fixed point precision numbers at > compile time, so I started creating a compile-time rational number type > following the style of integral_c in boost::mpl. After completing most > operations, I notices that in the mpl/math directory there were already > the beginnings of rational_c and fixed_c types, however, they are far > from complete (in rational_c there are just two static constants for > numerator and denominator and a self typedef, with no specialized > operations). Are these types still in development or are they > abandoned? They are waiting for somebody to pick them up. To some extent, that already happened with rational numbers. There are a couple of more or less complete implementations laying around: * http://tinyurl.com/2qrpq, 'rational_c' implementation by Hugo Duncan; * http://tinyurl.com/39mjl, "static_rational.hpp" by Matthias Schabel (it's a part of YANL, his dimensional analysis library). The main reason one of them is not in the library yet is that their notation for arithmetic operations leaves something to be desired -- you have to write something like rational_plus<r1,r2> instead of mpl::plus<r1,r2> Besides this issue, AFAIK these are already usable. Of course, if you would like to improve them/contribute more optimal/clean/better in any other regard implementation, please do. As for 'fixed_c', I am not aware of any publicly available implementation. Again, contributions are more than welcome! > I'd like to continue my project using > mpl::rational_c and mpl::fixed_c as I need to make them work with the > mpl integral constants anyways. > > So is development on these templates halted, meaning I should just go > ahead and finish my types, or are the types coming soon enough so I > just should just hold off and wait for the cavalry to arrive? No, please go ahead! Cavalry have enough on their plates already (among other things, a new version of the library is upcoming, with plenty of new exciting and useful stuff like associative sequences), so progress on these two is totally in your hands. -- Aleksey Gurtovoy MetaCommunications Engineering

3 5

date_time formatting compilation error
by Keith MacDonald 14 Mar '04

14 Mar '04

I'm trying to convert a gregorian::date to a string, as shown in the following code: // Build: cl /EHsc /I \CVS\boost dt.cpp #include <iostream> #include <boost/date_time/gregorian/gregorian.hpp> int main() { boost::gregorian::date today(2004, boost::gregorian::Mar, 14); std::cout << today << std::endl; return 0; } When I compile it with Visual C++ 7.1, using Boost from CVS head, I get the following error: \CVS\boost\boost\lexical_cast.hpp(150) : error C2679: binary '>>' : no operator found which takes a right-hand operand of type 'boost::date_time::date_formatter <date_type,format_type,charT>::string_type' (or there is no acceptable conversion) with [ date_type=boost::gregorian::date, format_type=boost::date_time::simple_format, charT=wchar_t ] The same thing happens when using to_simple_string and to_simple_string_type<char>, rather than operator<<. I actually want the result as a basic_string<wchar_t>, but all variations produce this same error. What am I doing wrong? Thanks, Keith MacDonald

5 11

mpl rational_c and fixed_c
by Matt Calabrese 14 Mar '04

14 Mar '04

A couple of days ago I started work on a library where I need a way to represent rational numbers and fixed point precision numbers at compile time, so I started creating a compile-time rational number type following the style of integral_c in boost::mpl. After completing most operations, I notices that in the mpl/math directory there were already the beginnings of rational_c and fixed_c types, however, they are far from complete (in rational_c there are just two static constants for numerator and denominator and a self typedef, with no specialized operations). Are these types still in development or are they abandoned? I'd like to continue my project using mpl::rational_c and mpl::fixed_c as I need to make them work with the mpl integral constants anyways. So is development on these templates halted, meaning I should just go ahead and finish my types, or are the types coming soon enough so I just should just hold off and wait for the cavalry to arrive?

1 0