November 2006 - Boost-users - lists.preview.boost.org

Re: [Boost-users] Suggestion for boost`s smart pointers
by Sohail Somani 29 Nov '06

29 Nov '06

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Maitre Bart > Sent: Wednesday, November 29, 2006 8:50 AM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users]Suggestion for boost`s smart pointers > > Richard Hadsell <hadsell <at> blueskystudios.com> writes: > > > David Klein wrote: > > [...] If you can implement the feature without adding any data > > members, fine. Otherwise, please create a new class. > > I agree too! > Why not calling it raii_ptr? I like this idea. Defaults to delete?

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Re: [Boost-users] Suggestion for boost`s smart pointers
by Sohail Somani 29 Nov '06

29 Nov '06

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of > Sohail Somani > > The deleter feature in shared_ptr is very useful for raii > > with any kind of > > resource (variables, functions, objects, etc.). Having it in > > scoped_ptr will > > offer the same advantage for noncopyable pointers. > > > > Thank you. > > +1 from me too but I think the reason is that people wanted > sizeof(scoped_ptr<T>) to be sizeof(T *) (or they don't want it to > change) A part solution could be a second template parameter but of course there can be no state.

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serialize explicit template instantiation
by Jan Boehme 29 Nov '06

29 Nov '06

Hi, I want to use a non inline serialize method of a class. When instantiating it not explicitly the linker quits with undefined symbols. So I tried to instantiate it that way and it does not work anyway. Here is my code. Does anyone see what I've done wrong? I did also try to use export.hpp but it doesn't help too. Thank you very much, Jan. // Class.hpp #include <boost/archive/xml_oarchive.hpp> #include <boost/archive/xml_iarchive.hpp> #include <boost/serialization/string.hpp> #include <boost/serialization/base_object.hpp> #include <boost/serialization/utility.hpp> class CSerTest { std::string a_, b_, c_; friend class boost::serialization::access; template<class Archive> void serialize( Archive & ar, const unsigned int ); public: CSerTest(); }; BOOST_CLASS_VERSION(CSerTest, 1); // Class.cpp #include "Class.hpp" CSerTest::CSerTest() : a_("1"), b_("2"), c_("3") { } template<class Archive> void CSerTest::serialize( Archive & ar, const unsigned int ) { ar & BOOST_SERIALIZATION_NVP(a_) & BOOST_SERIALIZATION_NVP(b_) & BOOST_SERIALIZATION_NVP(c_); } // main.cpp #include <fstream> #include "Class.hpp" ///////////////////////// without effect //////////////////////////////////// template void CSerTest::serialize<boost::archive::xml_oarchive>(boost::archive::xml_oarchive&, unsigned int ); int main() { CSerTest instance; std::ofstream ofs( "out_file.txt" ); boost::archive::xml_oarchive oxa( ofs ); oxa << BOOST_SERIALIZATION_NVP(instance); } The linker (MS version 8) returns with: --- Creating library mytest.lib and object mytest.exp Main.obj : error LNK2019: unresolved external symbol "private: void __thiscall CSerTest::serialize<class boost::archive::xml_oarchive>(class boost::archive::xml_oarchive &,unsigned int)"(??$serialize@ Vxml_oarchive@archive@boost@@@CSerTest@@AAEXAAVxml_oarchive@archive@boost@@ I@Z) referenced in function "public: static void __cdeclboost::serialization::access::serialize<class boost::archive::xml_oarchive,class CSerTest>(class boost::archive::xml_oarchive &,class CSerTest &,unsigned int)"(??$serialize@ Vxml_oarchive@archive@boost@@VCSerTest@@@access@serialization@boost@@ SAXAAVxml_oarchive@archive@2@AAVCSerTest@@I@Z)mytest.exe : fatal error LNK1120: 1 unresolved externals

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using lambda's pointer to member function and boost::function
by rodolfo＠rodsoft.org 29 Nov '06

29 Nov '06

Hi, I'm trying to put a simple lambda functor which uses pointer to member function into a boost::function like this: struct aux { int a() const { return 5; } }; int main() { function<int(const aux &)> f = &_1->*&aux::a; } But the compiler chokes at the assignment with the error: /usr/include/boost/function/function_template.hpp:119: error: cannot convert 'boost::lambda::detail::member_pointer_caller<int, const aux*, int (aux::*)()const>' to 'int' in return I think it should be able to convert the member_pointer_caller to boost::function, as its result (int) is the same of function's result, as well as its only argument is the one that makes the lambda functor valid. According to the documentation, something like this should work because it says that boost::function<int(int, int)> f = _1 + _2 works. Am I missing something? Thank you, Rodolfo Lima.

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FW: Suggestion for boost`s smart pointers
by Sohail Somani 29 Nov '06

29 Nov '06

Hi, Please see the following email about additional template parameters for scoped_ptr. The quick hack I wrote for it is below (I've used this in previous project as well). I think it would be very useful to many users and wouldn't change any source using scoped_ptr. Thanks, Sohail ==== I've been thinking something like (just something I hacked together just now). Not sure if there is a nicer way. #include <string> #include <cstdio> #include <iostream> template<typename T> struct DeletingDeleter { DeletingDeleter(T * p) { delete p; std::cout << "DeletingDeleter" << std::endl; } }; struct FileCloser { FileCloser(FILE * f) { std::cout << "Closing file" << std::endl; fclose(f); } }; template<typename T, typename Deleter=DeletingDeleter<T> > struct scoped_ptr { scoped_ptr():p_(0){} scoped_ptr(T * p):p_(p){} ~scoped_ptr() { Deleter d(p_); } T * get() {return p_;} // regular stuff private: T * p_; }; typedef scoped_ptr<FILE,FileCloser> file_ptr; int main() { scoped_ptr<int> a; // maintain old interface scoped_ptr<int> b(new int(5)); file_ptr p(fopen("myfile.txt","w")); fprintf(p.get(),"Hello world!\n"); } > -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of David Klein > Sent: Tuesday, November 28, 2006 4:55 PM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Suggestion for boost`s smart pointers > > Sohail Somani wrote: > >> -----Original Message----- > >> From: boost-users-bounces(a)lists.boost.org > >> [mailto:boost-users-bounces@lists.boost.org] On Behalf Of > David Klein > >> > >> Sohail Somani wrote: > >> > >>>> -----Original Message----- > >>>> From: boost-users-bounces(a)lists.boost.org > >>>> [mailto:boost-users-bounces@lists.boost.org] On Behalf > Of mark cox > >>>> > >>>> wow, this seems like a great idea, a scoped_ptr with deleter > >>>> would be v.useful. > >>>> mark > >>>> > >>>> > >>> I've been thinking something like (just something I hacked > >>> > >> together just > >> > >>> now). Not sure if there is a nicer way. > >>> > >>> > > [snip] > > > >> +1 vote for this idea :) > >> > >> i actually kind of did this for my current project, > >> because i needed a custom deleter for scoped_ptr, > >> when shared_ptr was to much overhead... > >> > > > > As did I, but it was not for performance but for readability. Shared > > pointers mean... Shared. Scoped don't. > > _______________________________________________ > > Boost-users mailing list > > Boost-users(a)lists.boost.org > > http://lists.boost.org/mailman/listinfo.cgi/boost-users > > > > > > yep exactly, > thatswhy i "ripped" scoped_ptr out of boost and added my > custom_deleter > stuff. > (i only *thought* about shared_ptr to do the job) > > so are there any objections about adding this feature to scoped_ptr? > > -- > regards dave > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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[multiIndex] modify_key
by Jeffrey Holle 29 Nov '06

29 Nov '06

I'm using boost version 1.33.1 and am contemplating using a multiIndex container in my application. The held object will be something like: class element { int x; int y; Object *pObject; }; I need 2 ordered_non_unique indices using x and y and one ordered_unique index on pObject. The problem is that the values of x and y will need to be modified during the life of this container. Since the documentation says these indices are implemented using red-black trees, I think I'm heading for trouble. However, the multiIndex container seems to have a "modify_key" method. I can guarantee that the pObject value will not change, so if I obtain an iterator to an element based on this index, will I be able to modify either x or y and expect their related indices to still work?

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Re: [Boost-users] Suggestion for boost`s smart pointers
by Sohail Somani 28 Nov '06

28 Nov '06

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Maitre Bart > Sent: Tuesday, November 28, 2006 12:36 PM > To: boost-users(a)lists.boost.org > Subject: [Boost-users] Suggestion for boost`s smart pointers > > I am assuming I am at the right tribune! (Let me know otherwise) > > I would suggest to add a constructor (as well as the > supporting members and > rules) to scoped_ptr<> that could allow specifying a deleter, as per: > > template<class Y, class D> scoped_ptr(Y * p, D d); > > as the same exists for shared_ptr<>. > > The deleter feature in shared_ptr is very useful for raii > with any kind of > resource (variables, functions, objects, etc.). Having it in > scoped_ptr will > offer the same advantage for noncopyable pointers. > > Thank you. +1 from me too but I think the reason is that people wanted sizeof(scoped_ptr<T>) to be sizeof(T *) (or they don't want it to change)

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Suggestion for boost`s smart pointers
by Maitre Bart 28 Nov '06

28 Nov '06

I am assuming I am at the right tribune! (Let me know otherwise) I would suggest to add a constructor (as well as the supporting members and rules) to scoped_ptr<> that could allow specifying a deleter, as per: template<class Y, class D> scoped_ptr(Y * p, D d); as the same exists for shared_ptr<>. The deleter feature in shared_ptr is very useful for raii with any kind of resource (variables, functions, objects, etc.). Having it in scoped_ptr will offer the same advantage for noncopyable pointers. Thank you.

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boost + linux + mingw ( g++: unrecognized option `-pthread' , cannot find -lrt )
by sfinks 28 Nov '06

28 Nov '06

Hi. Has anyone compiled boost on linux+mingw ? I have Debian Etch, mingw32 mingw32-binutils mingw32-runtime installed. mingw binaries linked as so: (CHROOT-wine-386)root@kroko386:~/boost_1_33_1# find /usr/bin/ -type l -ls|grep 586 9601281 0 lrwxrwxrwx 1 root root 26 Nov 24 08:16 /usr/bin/gcc-3.4.5 -> i586-mingw32msvc-gcc-3.4.5 9601293 0 lrwxrwxrwx 1 root root 24 Nov 24 08:16 /usr/bin/windres -> i586-mingw32msvc-windres 9601260 0 lrwxrwxrwx 1 root root 19 Nov 24 08:16 /usr/bin/cc -> i586-mingw32msvc-cc 9601282 0 lrwxrwxrwx 1 root root 23 Nov 24 08:16 /usr/bin/gccbug -> i586-mingw32msvc-gccbug 9601259 0 lrwxrwxrwx 1 root root 20 Nov 24 08:16 /usr/bin/c++ -> i586-mingw32msvc-c++ 9601275 0 lrwxrwxrwx 1 root root 20 Nov 24 08:14 /usr/bin/i586-mingw32msvc-cc -> i586-mingw32msvc-gcc 9601264 0 lrwxrwxrwx 1 root root 24 Nov 24 08:16 /usr/bin/c++filt -> i586-mingw32msvc-c++filt 9601284 0 lrwxrwxrwx 1 root root 19 Nov 24 08:16 /usr/bin/ld -> i586-mingw32msvc-ld 9601290 0 lrwxrwxrwx 1 root root 21 Nov 24 08:16 /usr/bin/size -> i586-mingw32msvc-size 9601278 0 lrwxrwxrwx 1 root root 20 Nov 24 08:16 /usr/bin/gcc -> i586-mingw32msvc-gcc 9601292 0 lrwxrwxrwx 1 root root 22 Nov 24 08:16 /usr/bin/strip -> i586-mingw32msvc-strip 9601285 0 lrwxrwxrwx 1 root root 19 Nov 24 08:16 /usr/bin/nm -> i586-mingw32msvc-nm 9601286 0 lrwxrwxrwx 1 root root 24 Nov 24 08:16 /usr/bin/objcopy -> i586-mingw32msvc-objcopy 9601283 0 lrwxrwxrwx 1 root root 21 Nov 24 08:16 /usr/bin/gcov -> i586-mingw32msvc-gcov 9601291 0 lrwxrwxrwx 1 root root 24 Nov 24 08:16 /usr/bin/strings -> i586-mingw32msvc-strings 9601271 0 lrwxrwxrwx 1 root root 24 Nov 24 08:16 /usr/bin/dllwrap -> i586-mingw32msvc-dllwrap 9601277 0 lrwxrwxrwx 1 root root 20 Nov 24 08:16 /usr/bin/g++ -> i586-mingw32msvc-g++ 9601287 0 lrwxrwxrwx 1 root root 24 Nov 24 08:16 /usr/bin/objdump -> i586-mingw32msvc-objdump 9601258 0 lrwxrwxrwx 1 root root 19 Nov 24 08:16 /usr/bin/as -> i586-mingw32msvc-as 9601027 0 lrwxrwxrwx 1 root root 26 Nov 24 08:16 /usr/bin/addr2line -> i586-mingw32msvc-addr2line 9601265 0 lrwxrwxrwx 1 root root 20 Nov 24 08:16 /usr/bin/cpp -> i586-mingw32msvc-cpp 9601289 0 lrwxrwxrwx 1 root root 24 Nov 24 08:16 /usr/bin/readelf -> i586-mingw32msvc-readelf 9601223 0 lrwxrwxrwx 1 root root 19 Nov 24 08:16 /usr/bin/ar -> i586-mingw32msvc-ar 9601266 0 lrwxrwxrwx 1 root root 24 Nov 24 08:16 /usr/bin/dlltool -> i586-mingw32msvc-dlltool 9601288 0 lrwxrwxrwx 1 root root 23 Nov 24 08:16 /usr/bin/ranlib -> i586-mingw32msvc-ranlib (CHROOT-wine-386)root@kroko386:~/boost_1_33_1# now I try to build with command: ~/bjam -sTOOLS=mingw -sGCC_INCLUDE_DIRECTORY=/usr/i586-mingw32msvc/include/ -sGCC_STDLIB_DIRECTORY=/usr/i586-mingw32msvc/lib/ --prefix=/opt/ gcc-C++-action bin/boost/libs/date_time/build/libboost_date_time.so/mingw/debug/shared-linkable-true/threading-multi/greg_month.o g++: unrecognized option `-pthread' /root/boost_1_33_1/libs/date_time/build/../src/gregorian/greg_month.cpp:1: warning: -fPIC ignored for target (all code is position independent) gcc-C++-action bin/boost/libs/date_time/build/libboost_date_time.so/mingw/debug/shared-linkable-true/threading-multi/greg_weekday.o g++: unrecognized option `-pthread' /root/boost_1_33_1/libs/date_time/build/../src/gregorian/greg_weekday.cpp:1: warning: -fPIC ignored for target (all code is position independent) gcc-C++-action bin/boost/libs/date_time/build/libboost_date_time.so/mingw/debug/shared-linkable-true/threading-multi/date_generators.o g++: unrecognized option `-pthread' /root/boost_1_33_1/libs/date_time/build/../src/gregorian/date_generators.cpp:1: warning: -fPIC ignored for target (all code is position independent) gcc-Link-action bin/boost/libs/date_time/build/libboost_date_time.so/mingw/debug/shared-linkable-true/threading-multi/libboost_date_time-mgw-mt-d-1_33_1.so g++: unrecognized option `-pthread' /usr/lib/gcc/i586-mingw32msvc/3.4.5/../../../../i586-mingw32msvc/bin/ld: cannot find -lrt collect2: ld returned 1 exit status What about those: 1) g++: unrecognized option `-pthread' 2) /usr/lib/gcc/i586-mingw32msvc/3.4.5/../../../../i586-mingw32msvc/bin/ld: cannot find -lrt collect2: ld returned 1 exit status Thanks..

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Re: [Boost-users] Boost-Jam - Building Boost.Python extensions
by Lawrence Spector 28 Nov '06

28 Nov '06

Oops. Thanks for the assistance and quick response! =) -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Vladimir Prus Sent: Monday, November 27, 2006 9:54 AM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] Boost-Jam - Building Boost.Python extensions Lawrence Spector wrote: > Hello all. Quick question on boost-jam, because I couldn't get it work > right on my system. When I went into the > $BOOST_ROOT_DIR\libs\python\example\tutorial directory and build as > follows: > > > > bjam -sTOOLS=vc-7_1 > > > > It built with no problems. > > > I then took the tutorial example and moved it outside the boost tree. I > edited the Jamrules so that: > > > > path-global BOOST_ROOT : ../../../.. ; You need to *also* set BOOST_ROOT in environment. The above is Boost.Build definition, and for it to have any effect, or be even read, bjam must be able to find Boost.Build first. - Volodya _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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