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

boost::bind problem
by Agoston Bejo 05 Jun '04

05 Jun '04

Hi, Please take a look at the code below. The point is that for_each_treenode calls for_each_treenode_child. It seems to me that bind(Print, ref(cout), _1)(&t); is not the same as Print(cout, &t); But if this is the case, how come that for_each_treenode_child(&t, bind(Print, ref(cout), _1)); compiles and works without problem? The compiler I use is VC 7.1. Thx, Gus ---------------------------------------------------------------------- // xBindTemplFuncPtr.cpp : Defines the entry point for the console application. // #include "stdafx.h" #include <iostream> #include <vector> #include <string> #include <boost/bind.hpp> #include <boost/ref.hpp> using namespace std; using namespace boost; template<typename TTree, typename TFunc> void for_each_treenode_child(TTree* t, TFunc f) { for_each(t->children.begin(), t->children.end(), f ); } template<typename TTree, typename TFunc> void for_each_treenode(TTree *t, TFunc f) { void (*thisFunc)(TTree*, TFunc) = for_each_treenode; // COMPILER BUG WORKAROUND - NOT RELEVANT NOW for_each_treenode_child( t, boost::bind(thisFunc, _1, f) ); f(t); } struct Tree { typedef vector<Tree*> Container; typedef Container::const_iterator const_iterator; typedef Container::iterator iterator; const_iterator begin() const { return children.begin(); } const_iterator end() const { return children.end(); } iterator begin() { return children.begin(); } iterator end() { return children.end(); } Tree(const string& sData):data(sData) {} vector<Tree*> children; string data; }; void Print(ostream& out, const Tree* pTree) { out << pTree->data << " "; } void PrintStd(const Tree* pTree) { Print(cout, pTree); } int _tmain(int argc, _TCHAR* argv[]) { Tree t("t"), t1("t1"), t2("t2"), t11("t11"), t12("t12"), t21("t21"); t.children.push_back(&t1); t1.children.push_back(&t11); t1.children.push_back(&t12); t.children.push_back(&t2); t2.children.push_back(&t21); Print(cout, &t); // WORKS bind(Print, ref(cout), _)(&t); // GENERATES ERROR (1) for_each_treenode(&t, bind(Print, ref(cout), _1)); // GENERATES ERROR (2) cout << endl; for_each_treenode(&t, PrintStd); // WORKS cout << endl; for_each_treenode_child(&t, bind(Print, ref(cout), _1)); // WORKS cout << endl; return 0; } ------------------------------------------------------------------------ Error for (1): error C2664: 'boost::_bi::bind_t<R,F,L>::result_type boost::_bi::bind_t<R,F,L>::operator ()<Tree*__w64 >(A1 & ) const' : cannot convert parameter 1 from 'Tree *__w64 ' to 'Tree *__w64 & ' with [ R=void, F=void (__cdecl *)(std::ostream &,const Tree *), L=boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ostr eam>,boost::arg< 1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost:: arg<1>>::B2>, A1=Tree *__w64 ] A reference that is not to 'const' cannot be bound to a non-lvalue Error for (2): c:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\include\boost\bind.hpp(246) : error C2664: 'void (TTree *,TFunc)' : cannot convert parameter 2 from 'boost::_bi::result_traits<R,F>::type' to 'boost::_bi::bind_t<R,F,L>' with [ TTree=Tree, TFunc=boost::_bi::bind_t<void,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost: :arg<1>>::B2>> ] and [ R=void, F=void (__cdecl *)(std::ostream &,const Tree *) ] and [ R=void, F=void (__cdecl *)(std::ostream &,const Tree *), L=boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ostr eam>,boost::arg< 1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost:: arg<1>>::B2> ] Expressions of type void cannot be converted to other types c:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\include\boost\bind\bind_template.hpp(33) : see reference to function template instantiation 'R boost::_bi::list2<A1,A2>::operator ()<boost::_bi::bind_t<R,F,L>::result_type,void(__cdecl *)(TTree *,TFunc),boost::_bi::list1<Tree & >>(boost::_bi::type<T>,void,A &)' being compiled with [ R=boost::_bi::bind_t<void,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost: :arg<1>>::B2>>:: result_type, A1=boost::_bi::list_av_2<boost::arg<1>,boost::_bi::bind_t<void,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost: :arg<1>>::B2>>>: :B1, A2=boost::_bi::list_av_2<boost::arg<1>,boost::_bi::bind_t<void,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost: :arg<1>>::B2>>>: :B2, F=void (__cdecl *)(std::ostream &,const Tree *), L=boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ostr eam>,boost::arg< 1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost:: arg<1>>::B2>, TTree=Tree, TFunc=boost::_bi::bind_t<void,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost: :arg<1>>::B2>>, T=boost::_bi::bind_t<void,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,bo ost::arg<1>>::B2>>::result_type, A=boost::_bi::list1<Tree *& > ] c:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\include\algorithm(21) : see reference to function template instantiation 'boost::_bi::bind_t<R,F,L>::result_type boost::_bi::bind_t<R,F,L>::operator ()<std::allocator<_Ty>::value_type>(A1 & )' being compiled with [ R=void, F=void (__cdecl *)(Tree *,boost::_bi::bind_t<void,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost: :arg<1>>::B2>>), L=boost::_bi::list2<boost::_bi::list_av_2<boost::arg<1>,boost::_bi::bind_t<v oid,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost: :arg<1>>::B2>>>: :B1,boost::_bi::list_av_2<boost::arg<1>,boost::_bi::bind_t<void,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost: :arg<1>>::B2>>>: :B2>, _Ty=Tree *, A1=std::allocator<Tree *>::value_type ] c:\PROG\VCPP\xBindTemplFuncPtr\xBindTemplFuncPtr.cpp(18) : see reference to function template instantiation '_Fn1 std::for_each<std::vector<_Ty>::iterator,TFunc>(_InIt,_InIt,_Fn1)' being compiled with [ _Fn1=boost::_bi::bind_t<void,void (__cdecl *)(Tree *,boost::_bi::bind_t<void,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost: :arg<1>>::B2>>), boost::_bi::list2<boost::_bi::list_av_2<boost::arg<1>,boost::_bi::bind_t<voi d,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost: :arg<1>>::B2>>>: :B1,boost::_bi::list_av_2<boost::arg<1>,boost::_bi::bind_t<void,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost: :arg<1>>::B2>>>: :B2>>, _Ty=Tree *, TFunc=boost::_bi::bind_t<void,void (__cdecl *)(Tree *,boost::_bi::bind_t<void,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost: :arg<1>>::B2>>), boost::_bi::list2<boost::_bi::list_av_2<boost::arg<1>,boost::_bi::bind_t<voi d,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost: :arg<1>>::B2>>>: :B1,boost::_bi::list_av_2<boost::arg<1>,boost::_bi::bind_t<void,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<s td::ostream>,boost::arg<1>>::B2>>>::B2>>, _InIt=std::vector<Tree *>::iterator ] c:\PROG\VCPP\xBindTemplFuncPtr\xBindTemplFuncPtr.cpp(29) : see reference to function template instantiation 'void for_each_treenode_child<TTree,boost::_bi::bind_t<R,F,L>>(TTree *,TFunc)' being compiled with [ TTree=Tree, R=void, F=void (__cdecl *)(Tree *,boost::_bi::bind_t<void,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost: :arg<1>>::B2>>), L=boost::_bi::list2<boost::_bi::list_av_2<boost::arg<1>,boost::_bi::bind_t<v oid,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost: :arg<1>>::B2>>>: :B1,boost::_bi::list_av_2<boost::arg<1>,boost::_bi::bind_t<void,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost: :arg<1>>::B2>>>: :B2>, TFunc=boost::_bi::bind_t<void,void (__cdecl *)(Tree *,boost::_bi::bind_t<void,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost: :arg<1>>::B2>>), boost::_bi::list2<boost::_bi::list_av_2<boost::arg<1>,boost::_bi::bind_t<voi d,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost: :arg<1>>::B2>>>: :B1,boost::_bi::list_av_2<boost::arg<1>,boost::_bi::bind_t<void,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::refere nce_wrapper<std::ostream>,boost::arg<1>>::B2>>>::B2>> ] c:\PROG\VCPP\xBindTemplFuncPtr\xBindTemplFuncPtr.cpp(68) : see reference to function template instantiation 'void for_each_treenode<Tree,boost::_bi::bind_t<R,F,L>>(TTree *,TFunc)' being compiled with [ R=void, F=void (__cdecl *)(std::ostream &,const Tree *), L=boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ostr eam>,boost::arg< 1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost:: arg<1>>::B2>, TTree=Tree, TFunc=boost::_bi::bind_t<void,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost: :arg<1>>::B2>> ] c:\Program Files\Microsoft Visual Studio .NET 2003\Vc7\include\boost\bind.hpp(246) : error C2664: 'void (TTree *,TFunc)' : cannot convert parameter 1 from 'boost::_bi::result_traits<R,F>::type' to 'Tree *' with [ TTree=Tree, TFunc=boost::_bi::bind_t<void,void (__cdecl *)(std::ostream &,const Tree *),boost::_bi::list2<boost::_bi::list_av_2<boost::reference_wrapper<std::ost ream>,boost::arg <1>>::B1,boost::_bi::list_av_2<boost::reference_wrapper<std::ostream>,boost: :arg<1>>::B2>> ] and [ R=void, F=void (__cdecl *)(std::ostream &,const Tree *) ] Expressions of type void cannot be converted to other types

5 6

Boost.Threads && MFC?
by Philip, Tim 04 Jun '04

04 Jun '04

Has anyone ever used Boost.Threads in combination with MFC? MFC requires that threads using MFC functionality be created with AfxCreateThread(). What I'm wondering is if it is safe to create threads using AfxCreateThread() (instead of the Boost.Thread functionality) but then use the Boost.Threads mutexs and locking mechanisms to manage the thread activity. >From my brief perusal of the source it looks like it might work. But I was hoping I could find someone who had actually tried it and might have some experiences to share. :) Any information greatly appreciated! Thanks! Tim.

2 1

BGL: Pajek utility?
by Rui Carvalho 04 Jun '04

04 Jun '04

I'm looking for an utility to import/export graphs between the BGL and Pajek: http://vlado.fmf.uni-lj.si/pub/networks/pajek/ Does anyone know of such utility? Thanks, Rui ___________________________________ Dr. Rui Carvalho Research Fellow The Bartlett School of Graduate Studies 1-19 Torrington Place University College London Gower Street London WC1E 6BT United Kingdom

1 0

Thread usage question.
by Paul Gregory 04 Jun '04

04 Jun '04

Hello all, I am currently using Boost threads in a project I'm working on that involves a server/client type communications system. The project is a 3D renderer, the particular component is the communications between the renderer core, and any number of interested display clients, which are responsible for either displaying or storing the resulting image. Within the main program I have a listener thread that waits for requests from the display clients, and when it recieves one, launches another thread to handle the response. The responder thread can often just construct and send the response immediately. But if the request is for data that hasn't yet been rendered, it needs to wait for the data to be available. The responder is implemented as a class which has an operator() overload for the thread function. I would like for the responder thread to first query the system to see if the data is ready, and if not, block waiting for a signal from the system to indicate it is ready. So I need a way for the thread to 'register' it's interest in a particular data item with the main system, then wait for the signal. I presume there is a neat way of doing this using boost::mutexes and boost::condition's but I can't quite work out how, I freely admint I'm not very experienced when it comes to threaded programming. I've looked at the Boost bounded_buffer.cpp tutorial and it does something similar, but I can't work out how to apply the principles to my situation. Any help is greatly appreciated. Cheers Paul Gregory +---------------------------+---------------------------+ | email: pgregory(a)aqsis.com | Web: http://www.aqsis.com | | ICQ: 156088409 | AIM: aqsis1 | +---------------------------+---------------------------+ | GnuPG: http://aqsis.sourceforge.net/0x9176E46C.asc | +-------------------------------------------------------+

1 0

Some bad links on the web site
by Ross Boylan 04 Jun '04

04 Jun '04

The web site contains a bad link: http://lists.boost.org/mailman/listinfo.cgi/boost-announce directs you to http://lists.boost.org/MailArchives/boost-announce for the archives. That gives a 404 Not Found error. I think there was another bad link related to mailing lists, but I can't find it again. By the way, it would be good if the web site had where to send web-site related queries and bugs on the bottom of every page. As far as I could tell, this list is the place to go.

2 1

Date time Library: ptime and special_values
by Matthew_Schuckmann＠amat.com 04 Jun '04

04 Jun '04

The documentation for the date_time library states that a ptime can be constructed from a special value e.g. ptime(special_values sv) ptime t1(neg_infin); ptime t2(pos_infin); ptime t3(not_a_date_time); However when I try this with the Cygwin GNU compiler I get a no matching function for call error (see errors below) Am I missing something here or is the documentation wrong? Thanks Matt ../../logview.cpp:1843: error: no matching function for call to ` boost::posix_time::ptime::ptime(boost::date_time::special_values)' c:/cygwin/usr/local/include/boost-1_31/boost/date_time/posix_time/ptime.hpp: 32: error: candidates are: boost::posix_time::ptime::ptime(const boost::posix_time::ptime&) c:/cygwin/usr/local/include/boost-1_31/boost/date_time/posix_time/ptime.hpp: 45: error: boost::posix_time::ptime::ptime(const boost::posix_time::int64_time_rep&) c:/cygwin/usr/local/include/boost-1_31/boost/date_time/posix_time/ptime.hpp: 42: error: boost::posix_time::ptime::ptime(boost::gregorian::date) c:/cygwin/usr/local/include/boost-1_31/boost/date_time/posix_time/ptime.hpp: 39: error: boost::posix_time::ptime::ptime(boost::gregorian::date, boost::posix_time::time_duration)

2 1

Compiling with "Visual C++ Toolkit"?
by Wolfgang Meyer 03 Jun '04

03 Jun '04

Has anyone already successfully built Boost with the "Visual C++ Toolkit 2003", aka the free command line version of VC 7.1? I adjusted VC71_ROOT and copied "vcvars32.bat" to "bin". But there are still a lot of errors, the first one being: greg_month.obj : error LNK2019: unresolved external symbol "__declspec(dllimport) public: __thiscall std ::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >::basic_string<char,struct std::char_traits<char>,class std::allocator<char> >(char const *)" (__imp_??0?$basic_string@DU?$char_tr aits@D@std@@V?$allocator@D@2@@std@@QAE@PBD@Z) referenced in function "public: static class boost::shared _ptr<class std::map<class std::basic_string<char,struct std::char_traits<char>,class std::allocator<char > >,unsigned short,struct std::less<class std::basic_string<char,struct std::char_traits<char>,class std ::allocator<char> > >,class std::allocator<struct std::pair<class std::basic_string<char,struct std::cha r_traits<char>,class std::allocator<char> > const ,unsigned short> > > > __cdecl boost::gregorian::greg_ month::get_month_map_ptr(void)" (?get_month_map_ptr@greg_month@gregorian@boost@@SA?AV?$shared_ptr@V?$map @V?$basic_string@DU?$char_traits@D@std@@V?$allocator@D@2@@std@@GU?$less@V?$basic_string@DU?$char_traits@ D@std@@V?$allocator@D@2@@std@@@2@V?$allocator@U?$pair@$$CBV?$basic_string@DU?$char_traits@D@std@@V?$allo cator@D@2@@std@@G@std@@@2@@std@@@3@XZ) Similar errors occur if I try to use the (successfully built) boost_thread-vc71-mt-1_31.lib with a sample project. Any ideas? Regards, Wolfgang Meyer

1 1

Re: boost regex support for 64-bit
by Itay Eliaz 03 Jun '04

03 Jun '04

Hi, We compiled the latest RegEx library on: 1. SunOS 5.8 Workshop 6: We used the sunpro.mak makefile. Unfortunately, we received many error messages regarding conversions from enum to int and vice versa. 2. HP-UX 11.11 aCC 3.33: We used the generic.mak makeilfe. We got an error regarding dynamic_cast from char*& to char*. In both cases, we didn't run the configure script in libs/config, because if we do, we get many compilation errors (probably because of the #define-s in the created user.hpp). Are you aware of these problems? or are we doing something wrong? Is it imperative that we run the configure script and not use the default user.hpp? On top of that, we managed to overcome the problems I mentioned by simply specifing explicit conversion and casting, and we compiled RegEx on Forte 6 with the 64-bit compilation flag. The compilation worked, but unfortunately, the tests failed. (I mean, the compiled okay and run, but they say that tests.txt contains errors - something that didn't happen when compiling the 32-bit version). What can we do to make it work in 64-bits? Thanks, Yaron "John Maddock" <john(a)johnmaddock.co.uk> wrote in message news:<016d01c43808$4e99e9a0$9cec0352@fuji>... > > does boost regex support 64-bit for SunOS 5.8, HP-UX 11i (native > compilers), > > WIN (MSVC-6) ? > > we are using an old(?) version - regexpp version 3.12. > > Is it recommended to upgrade to the latest version ? > > Is it essential to upgrade to the latest version with relevance to 64-bit > > compilation ? > > 64-bit support should be fine in most recent versions (there was a 64-bit > related bug in one release, but I forget which one now, it was some time ago > now). However the compilers you mention are particularly broken when it > come to compiling any kind of vaguely advanced C++ : The sun compiler should > just about handle regex, as will MSVC 6, but HP aCC is just so broken we've > never been able to port even the most basic Boost libraries to it, sorry... > but see also http://lists.boost.org/MailArchives/boost/msg63570.php > > John.

2 1

Bind and shared_ptr
by Robin 03 Jun '04

03 Jun '04

Hi, The current bind defines the placeholder _1, _2 etc. I was wondering if there is another placeholder that will deference the placeholder if the container is holding pointers instead of copies? Usually I store shared_ptrs in containers instead of direct copies as they are polymorphic class C; // this is our object we are storing typedef boost::shared_ptr<C> CSP; std::vector<CSP> C_List; Now we have a function that operates on C void Operate(C &c); C_List clist; // the list of shared_ptrs to C // this won't compile std::for_each (clist.begin (), clist.end (), boost::bind (Operator,_1)); I have to make an auxillary function to compile void Wrap_Operate (CSP &c) { Operate(*c); } std::for_each (clist.begin (), clist.end (), boost::bind (Wrap_Operate, _1)); Is there to avoid making the additional function and have a placeholder that will dereference directly (eg *_1, *_2)? Can I have the cake and eat it? Robin

1 0

(no subject)
by Mike Feldmeier 02 Jun '04

02 Jun '04

Hi everyone, Could someone please point me in the right direction with this one? : class data { int x; }; class worker { void run(&data d); }; void run_worker(worker& w, data& d) { boost::thread(boost::bind(&worker::run, &my_worker, _1)(boost:ref(my_data))); } void main() { worker my_worker; data my_data; run_worker(my_worker, my_data); } Compiling this yields.. test.cpp(24) : error C2440: 'type cast' : cannot convert from 'boost::_bi::bind_t<R,F,L>::result_type' to 'boost::thread' with [ R=void, F=boost::_mfi::mf1<void,worker,data &>, L=boost::_bi::list2<boost::_bi::list_av_2<worker *,boost::arg<1>>::B1,boost::_bi::list_av_2<worker *,boost::arg<1>>::B2> ] Expressions of type void cannot be converted to other types Can I not bind to functions with a void return type? Changing it to int, produces a similar message. Any help appreciated! Thanks, Mike _________________________________________________________________ FREE pop-up blocking with the new MSN Toolbar get it now! http://toolbar.msn.click-url.com/go/onm00200415ave/direct/01/

2 1

bjam failed to build (mingw)
by krejci.lukas＠volny.cz 02 Jun '04

02 Jun '04

Hi, I have updated from CVS today, set the dev-cpp bin directory into PATH and run: build.bat mingw. This build has failed, attachment '1.txt' contains stdout&stderr outputs. Then I set two additional environment variables: set MINGW_ROOT_DIRECTORY=C:\Dev-Cpp set BOOST_JAM_TOOLSET_ROOT=C:\Dev-Cpp\ and again run: build.bat mingw. This build failed too, attachment '2.txt' contains stdout&stderr outputs. Am I something missing? Have a nice day, L.

4 8

BGL: "degree" with listS
by Bayle Shanks 02 Jun '04

02 Jun '04

I have another question. The following code won't compile. But if you change the first "listS" to "vecS", then it does. I can't find anything in the docs which forbids the use of "degree" with adjacency_list <listS, listS, ... ------------- #include <boost/config.hpp> #include <list> #include <boost/graph/adjacency_list.hpp> using namespace boost; using namespace std; typedef property<vertex_color_t, default_color_type, property<vertex_distance_t,std::size_t, property<vertex_degree_t,std::size_t, property<vertex_in_degree_t, std::size_t, property<vertex_out_degree_t,std::size_t> > > > > VertexProperty; typedef adjacency_list<listS, listS, bidirectionalS, VertexProperty> Graph; typedef boost::graph_traits<Graph>::vertex_descriptor vertexType; int main(int, char*[]) { Graph g; vertexType v0; v0 = add_vertex(g); out_degree(v0, g); } ----------- the compile error is: ----------- /usr/include/boost/iterator/iterator_traits.hpp: In function `void std::distance(_InputIterator, _InputIterator, _Distance&) [with _InputIterator = std::_List_iterator<boost::detail::sei_<size_t, std::_List_iterator<boost::list_edge<size_t, boost::no_property>, boost::list_edge<size_t, boost::no_property>&, boost::list_edge<size_t, boost::no_property>*>, boost::no_property>, const boost::detail::sei_<size_t, std::_List_iterator<boost::list_edge<size_t, boost::no_property>, boost::list_edge<size_t, boost::no_property>&, boost::list_edge<size_t, boost::no_property>*>, boost::no_property>&, const boost::detail::sei_<size_t, std::_List_iterator<boost::list_edge<size_t, boost::no_property>, boost::list_edge<size_t, boost::no_property>&, boost::list_edge<size_t, boost::no_property>*>, boost::no_property>*>, _Distance = size_t]': /usr/include/g++-v3/bits/stl_list.h:307: instantiated from `size_t std::list<_Tp, _Alloc>::size() const [with _Tp = boost::detail::sei_<size_t, std::_List_iterator<boost::list_edge<size_t, boost::no_property>, boost::list_edge<size_t, boost::no_property>&, boost::list_edge<size_t, boost::no_property>*>, boost::no_property>, _Alloc = std::allocator<boost::detail::sei_<size_t, std::_List_iterator<boost::list_edge<size_t, boost::no_property>, boost::list_edge<size_t, boost::no_property>&, boost::list_edge<size_t, boost::no_property>*>, boost::no_property> >]' /usr/include/boost/graph/detail/adjacency_list.hpp:1409: instantiated from `typename Config::degree_size_type boost::out_degree(typename Config::vertex_descriptor, const boost::adj_list_helper<Config, Base>&) [with Config = boost::detail::adj_list_gen<boost::adjacency_list<boost::listS, boost::vecS, boost::bidirectionalS, VertexProperty, boost::no_property, boost::no_property, boost::listS>, boost::vecS, boost::listS, boost::bidirectionalS, VertexProperty, boost::no_property, boost::no_property, boost::listS>::config, Base = boost::bidirectional_graph_helper_with_property<boost::detail::adj_list_gen<boost::adjacency_list<boost::listS, boost::vecS, boost::bidirectionalS, VertexProperty, boost::no_property, boost::no_property, boost::listS>, boost::vecS, boost::listS, boost::bidirectionalS, VertexProperty, boost::no_property, boost::no_property, boost::listS>::config>]' graph2.cpp:26: instantiated from here /usr/include/boost/iterator/iterator_traits.hpp:54: `template<Iterator> struct boost::iterator_category' is not a function, /usr/include/g++-v3/bits/stl_iterator_base_types.h:196: conflict with `template<_Iter> typename std::iterator_traits::iterator_category std::iterator_category(const _Iter&)' /usr/include/g++-v3/bits/stl_iterator_base_funcs.h:102: in call to `iterator_category' ----------- thanks, bayle

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BGL: multigraphs with remove_edge_if
by Bayle Shanks 01 Jun '04

01 Jun '04

Hi, I have a question about the BGL. I'm trying to get remove_edge_if to work with a multigraph. The documentation doesn't seem to prohibit this: http://www.boost.org/libs/graph/doc/MutableGraph.html http://www.boost.org/libs/graph/doc/adjacency_list.html However, the following sample code crashes. It is intended to add two vertices v0 and v1, and to add two edges from v0 to v1, and then to remove all of the edges by passing an always-true predicate to remove_edge_if. ------------------- #include <boost/config.hpp> #include <iostream> // for std::cout #include <utility> // for std::pair #include <boost/utility.hpp> // for boost::tie #include <boost/graph/graph_traits.hpp> // for boost::graph_traits #include <boost/graph/adjacency_list.hpp> #include <boost/graph/graphviz.hpp> using namespace std; using namespace boost; typedef adjacency_list<vecS, vecS, bidirectionalS > UnderlyingGraphType; typedef boost::graph_traits<UnderlyingGraphType>::vertex_descriptor vertexType; typedef boost::graph_traits<UnderlyingGraphType>::edge_descriptor edgeType; class truePredicate { public: truePredicate() {} bool operator()(edgeType e){ cout << "edgePred got " << e <<endl; cout << "about to return true!!!" << endl; return true; } }; int main(int,char*[]) { UnderlyingGraphType G = UnderlyingGraphType(); vertexType v0, v1; edgeType e01_1, e01_2; bool inserted; v0 = boost::add_vertex(G); v1 = boost::add_vertex(G); cout << "v0: " << v0 << endl; cout << "v1: " << v1 << endl; boost::tie(e01_1, inserted) = boost::add_edge(v0,v1,G); cout << "e1: " << e01_1 << endl; cout << "ins1: " << inserted << endl; boost::tie(e01_2, inserted) = boost::add_edge(v0,v1,G); cout << "e2: " << e01_1 << endl; cout << "ins2: " << inserted << endl; boost::write_graphviz(cout,G); boost::remove_edge_if(truePredicate(), G); boost::write_graphviz(cout,G); } ------------------- I'm using Boost 1_31_0 on Debian GNU/Linux with g++-3.0. The result of running the above code on my system is: ------------------- v0: 0 v1: 1 e1: (0,1) ins1: 1 e2: (0,1) ins2: 1 digraph G { 0; 1; 0->1 ; 0->1 ; } edgePred got (0,1) about to return true!!! edgePred got (0,1) about to return true!!! edgePred got (0,1) about to return true!!! edgePred got (4294967295,1919379812) about to return true!!! Segmentation fault ------------------- thanks for your help, bayle p.s. btw, i'm in the process of wrapping BGL for Python using Boost::Python, in case anyone is interested.

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Graph Serialization
by Daniel Z 01 Jun '04

01 Jun '04

Hello, i'm trying to use the serialization library. I manage to serialize simple class, but now i would like to serialize a boost graph, but i can't find how to do it. Anyone can tell me how to begin? Thx. Plus simple, plus fiable, plus rapide : découvrez le nouveau Caramail - http://www.caramail.lycos.fr

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boost::variant: need help with 'get'
by Caleb Epstein 01 Jun '04

01 Jun '04

I'm trying to use the "get" template with boost::variant but can't figure out how to get my compiler to recognize it. Here's a simple test program: --- #include <iostream> #include <cmath> #include <string> #include <boost/variant.hpp> using namespace boost; using namespace std; typedef variant<int, double, string> elem_t; int main () { elem_t pi = M_PI; double d = get (pi); cout << "pi =~ " << d << endl; return 0; } --- But my compiler (gcc 3.3.2) tells me: g++ -I/home/tools/boost-1.31.0 test.cpp -o test test.cpp: In function `int main()': test.cpp:15: error: no matching function for call to `get(elem_t&)' I'm using Boost 1.31.0. Thanks for any help, -- Caleb Epstein | bklyn . org | The Golden Rule of Arts and Sciences: cae at | Brooklyn Dust | He who has the gold makes the rules. bklyn dot org | Bunny Mfg. |

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