November 2002 - Boost-users - lists.preview.boost.org

RE: [Boost-Users] MSVC++, bind and namespaces
by Antoine Boivin Filion 28 Nov '02

28 Nov '02

Hi, FYI, the code below compiles and runs OK on MSVC++7... so you might just be right! Regards, Antoine -----Original Message----- From: Andre Hentz [mailto:ahentz@cariden.com] Sent: November 28, 2002 09:42 To: Boost-Users(a)yahoogroups.com Subject: [Boost-Users] MSVC++, bind and namespaces I've just encountered this problem and it looks like a MS bug. Not sure it deserves a Boost workaround but I thought it would be nice to let you know (in case you don't already). Here's the code: #include <boost/bind.hpp> namespace A{ struct c{ void setName(const char*) {} }; } namespace B{ struct c{ void setName(const char*) {} }; } using namespace B; using namespace A; int main() { boost::bind(&A::c::setName, _1, _2); return 0; } It looks legal to me but I'm no expert. GCC compiles with no warnings but MSVC++ 6sp5 gives the error below. boost/bind/mem_fn_vw.hpp(29) : error C2872: 'c' : ambiguous symbol boost/bind.hpp(875) : see reference to class template instantiation 'boost::_mfi::mf1<void ,struct A::c,char const *>' being compiled boost/bind.hpp(886) : see reference to class template instantiation 'boost::_bi::bind_t_generator<void>::implementation<struct boost::_mfi::mf1<void,struct A::c,char const *>,class boost::_bi::list2<class boost::arg<1>,class boost::arg<2> > >' being compiled test.cpp(15) : see reference to class template instantiation 'boost::_bi::bind_t<void,struct boost::_mfi::mf1<void,struct A::c,char const *>,class boost::_bi::list2<class boost::arg<1>,cla ss boost::arg<2> > >' being compiled boost/bind/mem_fn_vw.hpp(31) : error C2872: 'c' : ambiguous symbol boost/bind.hpp(875) : see reference to class template instantiation 'boost::_mfi::mf1<void,struct A::c,char const *>' being compiled boost/bind.hpp(886) : see reference to class template instantiation 'boost::_bi::bind_t_generator<void>::implementation<struct boost::_mfi::mf1<void,struct A::c,char const *>,class boost::_bi::list2<class boost::arg<1>,class boost::arg<2> > >' being compiled test.cpp(15) : see reference to class template instantiation 'boost::_bi::bind_t<void,struct boost::_mfi::mf1<void,struct A::c,char const *>,class boost::_bi::list2<class boost::arg<1>,class boost::arg<2> > >' being compiled Best, Andre Hentz Yahoo! Groups Sponsor ADVERTISEMENT <http://rd.yahoo.com/M=237459.2675695.4055211.2225243/D=egroupweb/S=17050067 88:HM/A=1267611/R=0/*http://ad.doubleclick.net/jump/N2524.Yahoo/B1071650;sz= 300x250;ord=1038499880908608?> <http://us.adserver.yahoo.com/l?M=237459.2675695.4055211.2225243/D=egroupmai l/S=:HM/A=1267611/rand=601430356> Info: < http://www.boost.org <http://www.boost.org> > Wiki: < http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> > Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service <http://docs.yahoo.com/info/terms/> . [Non-text portions of this message have been removed]

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Re: [Boost-Users] ublas::matrix sharing storage with ublas::vecto r
by Toon Knapen 28 Nov '02

28 Nov '02

On Wednesday 27 November 2002 20:46, Stephen Crowley wrote: > What do you mean by "just use it as" ? > > For example.. I have a matrix<double> m(5,5); > > In some code I actually need to use it as a 5x5 matrix.. but other parts > must reference it as a vector (to pass to another library). OK, So as to get to the bottom of this. Do you really want to perform vector operations on a vector that consists of a concatenation of all rows (or columns) of the matrix do you want to get access to the storage to pass your information to another library. The latter case is dealt with in the boost-sandbox/boost/numeric/bindings. There we've spend effort to be able to extract the begin- and end-pointer (not iterator) from any vector or matrix. (In the bindings it's used to pass these pointers to e.g. BLAS) In the former case, could you enlighten me what kind of numeric operations you're dealing with ? toon -------------------------------------------------------

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MSVC++, bind and namespaces
by Andre Hentz 28 Nov '02

28 Nov '02

I've just encountered this problem and it looks like a MS bug. Not sure it deserves a Boost workaround but I thought it would be nice to let you know (in case you don't already). Here's the code: #include <boost/bind.hpp> namespace A{ struct c{ void setName(const char*) {} }; } namespace B{ struct c{ void setName(const char*) {} }; } using namespace B; using namespace A; int main() { boost::bind(&A::c::setName, _1, _2); return 0; } It looks legal to me but I'm no expert. GCC compiles with no warnings but MSVC++ 6sp5 gives the error below. boost/bind/mem_fn_vw.hpp(29) : error C2872: 'c' : ambiguous symbol boost/bind.hpp(875) : see reference to class template instantiation 'boost::_mfi::mf1<void ,struct A::c,char const *>' being compiled boost/bind.hpp(886) : see reference to class template instantiation 'boost::_bi::bind_t_generator<void>::implementation<struct boost::_mfi::mf1<void,struct A::c,char const *>,class boost::_bi::list2<class boost::arg<1>,class boost::arg<2> > >' being compiled test.cpp(15) : see reference to class template instantiation 'boost::_bi::bind_t<void,struct boost::_mfi::mf1<void,struct A::c,char const *>,class boost::_bi::list2<class boost::arg<1>,cla ss boost::arg<2> > >' being compiled boost/bind/mem_fn_vw.hpp(31) : error C2872: 'c' : ambiguous symbol boost/bind.hpp(875) : see reference to class template instantiation 'boost::_mfi::mf1<void,struct A::c,char const *>' being compiled boost/bind.hpp(886) : see reference to class template instantiation 'boost::_bi::bind_t_generator<void>::implementation<struct boost::_mfi::mf1<void,struct A::c,char const *>,class boost::_bi::list2<class boost::arg<1>,class boost::arg<2> > >' being compiled test.cpp(15) : see reference to class template instantiation 'boost::_bi::bind_t<void,struct boost::_mfi::mf1<void,struct A::c,char const *>,class boost::_bi::list2<class boost::arg<1>,class boost::arg<2> > >' being compiled Best, Andre Hentz

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Re: [Boost-Users] ublas::matrix sharing storage with ublas::vecto r
by Toon Knapen 28 Nov '02

28 Nov '02

On Wednesday 27 November 2002 20:46, Stephen Crowley wrote: > What do you mean by "just use it as" ? > > For example.. I have a matrix<double> m(5,5); > > In some code I actually need to use it as a 5x5 matrix.. but other parts > must reference it as a vector (to pass to another library). OK, So as to get to the bottom of this. Do you really want to perform vector operations on a vector that consists of a concatenation of all rows (or columns) of the matrix do you want to get access to the storage to pass your information to another library. The latter case is dealt with in the boost-sandbox/boost/numeric/bindings. There we've spend effort to be able to extract the begin- and end-pointer (not iterator) from any vector or matrix. (In the bindings it's used to pass these pointers to e.g. BLAS) In the former case, could you enlighten me what kind of numeric operations you're dealing with ? toon

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RE: [Boost-Users] Is intrusive_ptr the thing to use?
by Hickman, Greg 28 Nov '02

28 Nov '02

From: Peter Dimov [mailto:pdimov@mmltd.net] > From: "Hickman, Greg" <greg.hickman(a)lmco.com> > > > From: Peter Dimov [mailto:pdimov@mmltd.net] > > > If 'f' is virtual, have the object store a weak_ptr to itself: > > > > > > class X > > > { > > > private: > > > > > > weak_ptr<X> weak_this; > > > > > > X(); > > > X(X const &); > > > X& operator=(X const &); > > > > > > public: > > > > > > static shared_ptr<X> create() > > > { > > > shared_ptr<X> px(new X); > > > px->weak_this = px; > > > return px; > > > } > > > > I must be missing something here, because it appears as though you > > can't derive a Y from X and still initialize X::weak_this. > > You could simply make X::weak_this and X::X() protected... > although if you follow the design rule that says that > non-leaf classes should be abstract (and if possible contain > no data) this shouldn't be necessary, as X as pictured above > would be a leaf. Its seems the leaf itself must implement the factory method/weak_this idiom. This initially didn't seem like a good idea in our case since clients write the leaves - we only provide X. But on second thought, perhaps two alternatives are (1) provide a helper template for clients to use when deriving from X to automatically declare the static create()/weak_this pair, or (2) use an intrusive reference counting approach for X. If an intrusive approach ultimately works better for us, what should I do as a boost 1.29.0 user: use counted_base/shared_from_this, or intrusive_ptr (which I admittedly haven't even looked at)? Any suggestions you have are more than welcome. -Greg

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RE: [Boost-Users] ublas::matrix sharing storage with ublas::vecto r
by Scott Sinclair 28 Nov '02

28 Nov '02

Sorry, I obviously misunderstood your original question :( On 28/11/2002 03:46 Stephen Crowley wrote: > What do you mean by "just use it as" ? > For example.. I have a matrix<double> m(5,5); > > In some code I actually need to use it as a 5x5 matrix.. but > other parts > must reference it as a vector (to pass to another library). > > Currently I am doing something like this > > matrix<double> m(5,5); > // do stuff to m > vector<double> v(25); > v.data() = m.data(); > // pass v to library > // get results back > m.data() = v.data(); > > This is obviously not optimal.. and if both m.data() and > v.data() pointed to > the same location in memory the problem would be solved. > > I suppose I might be able to get around it by making my own > storage class > that allows you to specify a location and size instead of > allocating one > itself. > > --Stephen The contents of this email may be confidential. Unauthorised use is prohibited. Umgeni Water does not accept liability for any statements and opinions which are the sender's own view and not expressly made on its behalf.

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RE: [Boost-Users] Is intrusive_ptr the thing to use?
by Hickman, Greg 27 Nov '02

27 Nov '02

> -----Original Message----- > From: Peter Dimov [mailto:pdimov@mmltd.net] > Sent: Tuesday, November 26, 2002 6:49 AM > To: Boost-Users(a)yahoogroups.com > Subject: Re: [Boost-Users] Is intrusive_ptr the thing to use? > If 'f' is virtual, have the object store a weak_ptr to itself: > > class X > { > private: > > weak_ptr<X> weak_this; > > X(); > X(X const &); > X& operator=(X const &); > > public: > > static shared_ptr<X> create() > { > shared_ptr<X> px(new X); > px->weak_this = px; > return px; > } I must be missing something here, because it appears as though you can't derive a Y from X and still initialize X::weak_this. -Greg

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solaris gcc 3.2 stlport regexp (bug?)
by c_twiner 27 Nov '02

27 Nov '02

Hi all, When I use bjam to compile the regexp library it compiles seems happy and then no code works properly, seg faults, rubbish results etc. When I compile using a modified make file of the shared-gcc.mak (modifications follow): INCLUDES= -I/export/home/ctwiner/STLport-4.5.3/stlport -L/export/home/ctwiner/STLport-4.5.3/lib LIBS= -lstlport_gcc_stldebug # compiler: CXX=g++ LINKER=g++ -shared -fPIC # # compiler options for release build: # C1=-c -O2 -I../../../ -fPIC # # compiler options for debug build: # C2=-c -g -I../../../ -fPIC It builds but even linking to the .so created causes a seg fault. I know that stlport is ok because I have programs linking to the new version using std::map's vectors and strings. I posted another message using 2.95 which had the same/similar problems. Everything seems to build fine but running causes seg faults. The solaris version is 2.8. When using the bjam built files and trying to run the compiled regexp_tests the locale_impl.h of stlports asserts at line 60. latest downloads of all librarys have been used. TIA Chris

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ublas::matrix sharing storage with ublas::vector
by Stephen Crowley 27 Nov '02

27 Nov '02

It is possible for a vector and a matrix to share the same storage, as long as the dimensions agree? Some of the algorithms I am implementing require some objects to be treated as an arbitrarily sized matrix, and sometimes as a vector, and it would be convient to have a matrix and a vector share the same memory. -- Stephen

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Link problem with boost::signals and console applications in MS Visual C++ 6 / Windows
by Klaus Nowikow 26 Nov '02

26 Nov '02

Hi all, a colleague asked me to post the following question: When using the boost signal lib in VC6 (Win32 Console Application), the linker produces the following errors: msvcprt.lib(MSVCP60.dll) : error LNK2005: "public: __thiscall std::_Lockit::~_Lockit(void)" (??1_Lockit@std@@QAE@XZ) already defined in libcpd.lib(iostream.obj) msvcprt.lib(MSVCP60.dll) : error LNK2005: "public: __thiscall std::_Lockit::_Lockit(void)" (??0_Lockit@std@@QAE@XZ) already defined in libcpd.lib(iostream.obj) MSVCRT.lib(MSVCRT.dll) : error LNK2005: "public: __thiscall exception::exception(class exception const &)" (??0exception@@QAE@ABV0@@Z) already defined in LIBCD.lib(stdexcpt.obj) MSVCRT.lib(MSVCRT.dll) : error LNK2005: "public: __thiscall exception::exception(void)" (??0exception@@QAE@XZ) already defined in LIBCD.lib(stdexcpt.obj) MSVCRT.lib(MSVCRT.dll) : error LNK2005: "public: virtual __thiscall exception::~exception(void)" (??1exception@@UAE@XZ) already defined in LIBCD.lib(stdexcpt.obj) LINK : warning LNK4098: defaultlib "MSVCRT" conflicts with use of other libs; use /NODEFAULTLIB:library Debug/boost.exe : fatal error LNK1169: one or more multiply defined symbols found There seems to be a conflict between the libraries signals.lib, libcpd.lib and libcd.lib. When I try to ignore the libraries libcpd.lib and libcd.lib in the project settings, other linker errors occur when I use std::cout for example: main.obj : error LNK2001: unresolved external symbol "class std::basic_ostream<char,struct std::char_traits<char> > std::cout" (?cout@std@@3V?$basic_ostream@DU?$char_traits@D@std@@@1@A) Is there a way to use the boost::signals library in a Win32 Console Application in VC6? Regards, Klaus

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