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

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; }

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[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

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