- Boost-users - lists.boost.org

Re: [Boost-users] [Boost][multi_index] proper way to make a complex query
by JOAQUIN LOPEZ MU?Z 08 Aug '06

08 Aug '06

Sebastien Fortier ha escrito: > I will try to make this as simple as possible, > I have the following struct > > struct meteo_record { > public: > [...ctor...] > [...getters and setters...] > private: > string var_name; > string grid_type; > float ip1; > float ip2; > float ip3; > float ig1; > float ig2; > float ig3; > int ip1Kind; > int data_key; > }; > > All these attributes are non-unique except for the data_key > which is not a sorting criteria. > > What I need to do is to be able to iterate over the whole > set by certain criteria. [...] > my criterias are > sort by same gryd_type group by var_name with same ip2 and > same ip1kind ordered on ip1 [...] Hello Sebastien, I'm not sure I've fully understood all the details of your problem, but seems to me that composite keys ( http://tinyurl.com/hdf3q ) might be of help here. A composite key accepts several attributes and presents the records sorted in lexicographical order with respect to them. In your particular case, suppose you've got an index (non-unique) whose key is composite_key< meteo_record, const_mem_fun<meteo_record,const string&,&meteo_record::get_grid_type>, const_mem_fun<meteo_record,const string&,&meteo_record::get_var_name>, const_mem_fun<meteo_record,float,&meteo_record::get_ip2>, const_mem_fun<meteo_record,int,&meteo_record::get_ip1Kind>, const_mem_fun<meteo_record,float,&meteo_record::get_ip1> > (where I've used some imaginary names for the attribute getters). This index sorts records lexicographically by grid_type,var_name,ip2,ip1Kind,ip1 which looks like what you're after, from what I understand about the description of your current query process. The different groups can be then traversed like follows (for simplicity I assume the composite key is used in index #0, you'll probably want to have it in an additional index): for(recordIter=set.begin();recordIter!=set.end();) { recordIter2=set.upper_range( boost::make_tuple( it->get_grid_type(), it->get_var_name(), it->get_ip2(), it->get_ipKind(), ) ); // [recorditer1,recorditer2) is a range of elements with equal // grid_type,var_name,ip2 and ipKind, sorted by ip1 process(recordIter1,recordIter2); recordIter1=recordIter2; } Is this what you were looking for? Thank you for using Boost.MultiIndex, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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[mpl] - erro if mpl::map ist included
by Oliver.Kowalke＠qimonda.com 08 Aug '06

08 Aug '06

Hello, if I only include (no instantiation) the header <boost/mpl/map.hpp> I get the following error: /opt/boost/include/boost-1_33_1/boost/mpl/map/aux_/iterator.hpp:45: error: template argument 1 is invalid /opt/boost/include/boost-1_33_1/boost/mpl/map/aux_/iterator.hpp:45: error: template argument 1 is invalid /opt/boost/include/boost-1_33_1/boost/mpl/map/aux_/iterator.hpp:48: error: expected `{' before '>' token /opt/boost/include/boost-1_33_1/boost/mpl/map/aux_/iterator.hpp:48: error: expected unqualified-id before '>' token /opt/boost/include/boost-1_33_1/boost/mpl/map/aux_/iterator.hpp:66: error: expected nested-name-specifier before 'item_by_order' /opt/boost/include/boost-1_33_1/boost/mpl/map/aux_/iterator.hpp:66: error: expected ';' before '<' token g++ -v: Using built-in specs. Target: i486-linux-gnu Configured with: ../src/configure -v --enable-languages=c,c++,fortran,objc,obj-c++,treelang --prefix=/usr --enable-shared --with-system-zlib --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --enable-nls --program-suffix=-4.1 --enable-__cxa_atexit --enable-clocale=gnu --enable-libstdcxx-debug --enable-mpfr --with-tune=i686 --enable-checking=release i486-linux-gnu Thread model: posix gcc version 4.1.2 20060729 (prerelease) (Debian 4.1.1-10) Any suggestion? regards, Oliver

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Re: [Boost-users] [Serialization] Problem serializingviabaseclassptr
by Guy Létourneau 08 Aug '06

08 Aug '06

Hello Robert, Just to let you know that everything works fine now. Thanks for your help, Guy -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Robert Ramey Sent: Monday, August 07, 2006 1:18 PM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] [Serialization] Problem serializingviabaseclassptr Guy Létourneau wrote: > Hello Robert, > > Sorry for not giving you feedback earlier, I was on vacation. I've > included your proposed changes in my test application but I still get > the same compile error: > > C:/Boost/include/boost-1_33_1/boost/archive/detail/oserializer.hpp: > In function `void boost::archive::save(Archive&, T&) [with Archive = > boost::archive::text_oarchive, T = const A*]': > C:/Boost/include/boost-1_33_1/boost/archive/basic_text_oarchive.hpp:78: > instantiated from `void > boost::archive::basic_text_oarchive<Archive>::save_override(T&, int) > [with T = const A*, Archive = boost::archive::text_oarchive]' > C:/Boost/include/boost-1_33_1/boost/archive/detail/interface_oarchive.hpp:78: > instantiated from `Archive& > boost::archive::detail::interface_oarchive<Archive>::operator<<(T&) > [with T = const A*, Archive = boost::archive::text_oarchive]' > ../main.cpp:101: instantiated from here > C:/Boost/include/boost-1_33_1/boost/archive/detail/oserializer.hpp:567: > error: incomplete type `boost::STATIC_ASSERTION_FAILURE<false>' does > not have member `value' > make: *** [main.o] Error 1 > > Could you tell me what I'm missing? > > Thanks again for your help, > > Guy Letourneau > > > Test application: > > #include <iostream> > #include <fstream> > > #include <boost/archive/text_oarchive.hpp> > #include <boost/archive/text_iarchive.hpp> > #include <boost/serialization/export.hpp> > > class A > { > public: > > A() > { > i = 1; > }; > > virtual ~A() > { > }; > > virtual void Dummy() = 0; > > private: > > int i; > > friend > class boost::serialization::access; > > template <class Archive> > void serialize( Archive& ar, const unsigned int version ) > { > std::cout << "Serialization of A" << std::endl; > std::cout.flush(); > } > }; > BOOST_IS_ABSTRACT(A) > > > class B : public A > { > public: > > B() > { > }; > > virtual ~B() > { > }; > > void Dummy() > { > }; > > void SetValue( std::string& value ) > { > Data = value; > } > > private: > > friend > class boost::serialization::access; > > template <class Archive> > void serialize( Archive& ar, const unsigned int version ) > { > ar & boost::serialization::base_object<A>( *this ); > ar & Data; > std::cout << "Serialization of B" << std::endl; > std::cout.flush(); > } > > std::string Data; > }; > BOOST_CLASS_EXPORT(B) > > > int main() > { > // Create a B object > B* Child = new B; > > // Set some data > std::string Data = "test"; > Child->SetValue( Data ); > > // Assign it to a A ptr **** // > const A* Parent = Child; // Parent is now const // nope- Parent is not const - it points to a const A - not the same thing !!! // try const A * const Parent = Child; // const pointer to a const A // also the following will work - I believe A * const Parent = Child; > > // create and open a character archive for output > std::ofstream ofs( "filename" ); > > // save data to archive > { > try > { > boost::archive::text_oarchive oa( ofs ); > // write class instance to archive > oa << Parent; // Ptr dereferencing is performed by the > library } > catch( boost::archive::archive_exception& e ) > { > std::cout << "Save failed! : " << e.what(); > std::cout.flush(); > > return false; > } > catch( ... ) > { > std::cerr << "Unknown Exception " << std::endl; > > return false; > } > > // archive and stream closed when destructors are called > } > > delete Child; > } > > -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Robert > Ramey > Sent: Saturday, July 22, 2006 6:43 PM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] [Serialization] Problem > serializingviabaseclassptr > > Three show stopping problems in this code: > > a) A doesn't have serialize method even though > such a method is invoked by base object. see: > http://www.boost.org/libs/serialization/doc/serialization.html > > b) saving a non-const object - see rationale section > > c) Main show stopper: > >> int main() >> { >> // Create a B object >> B* Child = new B; >> >> // Set some data >> std::string Data = "test"; >> Child->SetValue( Data ); >> >> // Assign it to a A ptr >> // const A* Parent = Child; // ****** note new const - see >> rationale >> >> // create and open a character archive for output >> std::ofstream ofs( "filename" ); >> >> // save data to archive >> { >> try >> { >> boost::archive::text_oarchive oa( ofs ); >> // write class instance to archive > // *** big problem here. Dereferecing pointer to A > yields a > ref > // *** to an A - regardless that ptr was a B. What you > really want is: > oa << Parent; // *** let serialization handle > dererencing // *** instead of: >> //oa << *Parent; >> } >> catch( boost::archive::archive_exception& e ) >> { >> std::cout << "Save failed! : " << e.what(); >> std::cout.flush(); >> >> return false; >> } >> catch( ... ) >> { >> std::cerr << "Unknown Exception " << std::endl; >> >> return false; >> } >> >> // archive and stream closed when destructors are called >> } >> >> delete Child; >> } >> > > > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Re: [Boost-users] Ownership of Boost IP?
by Sohail Somani 08 Aug '06

08 Aug '06

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Nat > Goodspeed > Sent: Tuesday, August 08, 2006 7:36 AM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Ownership of Boost IP? > > Well, I've talked this over with my boss, and he's at least willing to > go to bat for this. Many thanks for all your helpful suggestions! Looks like you got a good one then :)

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Re: [Boost-users] Ownership of Boost IP?
by Nat Goodspeed 08 Aug '06

08 Aug '06

Well, I've talked this over with my boss, and he's at least willing to go to bat for this. Many thanks for all your helpful suggestions!

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[Boost][multi_index] proper way to make a complex query
by Sebastien Fortier 08 Aug '06

08 Aug '06

I will try to make this as simple as possible, I have the following struct struct meteo_record { public: [...ctor...] [...getters and setters...] private: string var_name; string grid_type; float ip1; float ip2; float ip3; float ig1; float ig2; float ig3; int ip1Kind; int data_key; }; All these attributes are non-unique except for the data_key which is not a sorting criteria. What I need to do is to be able to iterate over the whole set by certain criteria. lets say I have the following records [var_name grid_type ip1 ip2 ip3 ig1 ig2 ig3 ip1kind] >> 12345 12 34 5 0 0 0 1 ^^ 12345 12 34 5 0 0 0 1 GZ 12345 645 24 1 12 34 5 1 GZ 12345 646 24 1 12 34 5 1 GZ 12345 647 24 1 12 34 5 1 GZ 12345 645 24 1 12 34 5 2 GZ 12345 646 24 1 12 34 5 2 GZ 12345 647 24 1 12 34 5 2 GZ 12345 645 26 1 12 34 5 1 GZ 12345 646 26 1 12 34 5 1 GZ 12345 647 26 1 12 34 5 1 GZ 12345 645 26 1 12 34 5 2 GZ 12345 646 26 1 12 34 5 2 GZ 12345 647 26 1 12 34 5 2 TT 12345 645 24 1 12 34 5 1 TT 12345 646 24 1 12 34 5 1 TT 12345 647 24 1 12 34 5 1 TT 12345 645 24 1 12 34 5 2 TT 12345 646 24 1 12 34 5 2 TT 12345 647 24 1 12 34 5 2 TT 12345 645 26 1 12 34 5 1 TT 12345 646 26 1 12 34 5 1 TT 12345 647 26 1 12 34 5 1 TT 12345 645 26 1 12 34 5 2 TT 12345 646 26 1 12 34 5 2 TT 12345 647 26 1 12 34 5 2 [...same sequence again with different grid_type...] >> 33345 33 34 5 0 0 0 1 ^^ 33345 33 34 5 0 0 0 1 TT 33345 647 26 1 33 34 5 2 [...] the grid_type is derived from ip1 ip2 and ip3 in some cases and from ig1 ig2 and ig3 in some other cases my criterias are *sort by same _gryd_type_ group by _var_name_ with same _ip2_ and same _ip1kind_ ordered on _ip1_* What I have done is create a multi_index with the grid_type as an index and then I created views for all the other attributes. I first iterate over the grid_types and keep the unique ones in an array (only the keys) /// probably the wrong way to do this in this case I would keep 12345 and 33345 /// for (recordIter = set.begin(); recordIter != set.end(); recordIter = set.upper_bound( (*recordIter)->getgrid_type() ) ) /// /// returns only one of each duplicate grid_type /// for each grid_type I then create the var_name view and iterate over the unique var_names and so on and so on... until i get a grouping that looks like this [var_name grid_type ip1 ip2 ip3 ig1 ig2 ig3 ip1kind] GZ 12345 645 24 1 12 34 5 1 GZ 12345 646 24 1 12 34 5 1 GZ 12345 647 24 1 12 34 5 1 Once I get a grouping like this one, I extract the data_key for each record and read the data from a file. Then I construct a matrix for this grouping from the corresponding data that was read. There must be a better way of doing this, any help will be greatly appreciated! -- Sébastien Fortier

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[threads] extension proposal
by Ovanes Markarian 08 Aug '06

08 Aug '06

Hello, I would like to ask if it makes sence to introduce a data structure in boost::threads library, which implements a threads pool. Sometimes a system design can look like: Create a maximum of N threads and execute these threads with different tasks. If there more than N threads running then the threads_pool::get_thread(...) operation should block until one of threads gets ready. It is also possible to implement threads_pool::get_thread to use a policy which can block if the N is reached or return N+1 created thread. What I miss now in the threading library is the ability to reuse the thread. I think thread creation in the OS is an expensive task. If one has created thread, there should be a possiblity to reuse it. I understand it is possible to pass a function to the thread which executes tasks from the queue and therefore reuses threads, but this involves user implementation of such a function each time this programming pattern needs to be fullfilled. Would not it be a better idea to define a thread pool interface which has a synchronized queue (priority or not, should be customizeable) of tasks and pool of threads which are able to execute these tasks (boost::function0<void>) instances? I don't think I am the first person who comes up with this question... Would be really nice to hear your input on this issues or at least some links pointing to explanation, why this should not be done. With Kind Regards, Ovanes Markarian

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[Asio]How to compile the HelloWorld ?
by SP Z 08 Aug '06

08 Aug '06

Maybe this is a stupid problem , but I really don't konw how to find the right way. My compile environment is WinXP, Msys , MinGw , G++ 3.4.2, Boost 1.33.1, asio_0_3_7, bjam 3.1.13. I have already copy the header files of boost and asio into mingw/include I write the helloWorld.cpp follow the tutorial. #include <iostream> #include <boost/asio.hpp> #include <boost/date_time/posix_time/posix_time.hpp> int main() { boost::asio::io_service io; boost::asio::deadline_timer t(io, boost::posix_time::seconds(5)); t.wait(); std::cout << "Hello, world!\n"; return 0; } I write Jamroot as follow: exe hello : hello.cpp ; then I compile it in Msys, but link wrong happened(wrong messages see the end of this Email). Would you please help me to solve this problem . Thank you for(;;){} //forever $ bjam ...found 11 targets... ...updating 5 targets... MkDir1 bin MkDir1 bin\gcc MkDir1 bin\gcc\debug gcc.compile.c++ bin\gcc\debug\hello.o In file included from e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/detail/win_local_free_on_block_exit.hpp:27, from e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/system_exception.hpp:33, from e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/detail/win_mutex.hpp:26, from e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/detail/mutex.hpp:27, from e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/detail/service_registry.hpp:25, from e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/io_service.hpp:32, from e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/basic_io_object.hpp:20, from e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/basic_socket.hpp:20, from e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/basic_datagram_socket.hpp:25, from e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio.hpp:18, from hello.cpp:11: e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/detail/socket_types.hpp:31:5: warning: #warning Please define _WIN32_WINNT or _WIN32_WINDOWS appropriately e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/detail/socket_types.hpp:32:5: warning: #warning Assuming _WIN32_WINNT=0x0500 (i.e. Windows 2000 target) hello.cpp:24:2: warning: no newline at end of file gcc.link bin\gcc\debug\hello.exe bin\gcc\debug\hello.o: In function `ZN5boost4asio6detail31reactive_deadline_timer_serviceINS0_11time_traitsINS_10posix_time5ptimeEEENS1_14select_reactorILb1EEEE16shutdown_serviceEv':e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/deadline_timer_service.hpp:(.text$_ZN5boost4asio6detail12winsock_initILi2ELi0EE7do_initC1Ev[boost::asio::detail::winsock_init<2, 0>::do_init::do_init()]+0x1f): undefined reference to `WSAStartup@8' :e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/deadline_timer_service.hpp:(.text$_ZN5boost4asio6detail10socket_ops6selectEiP6fd_setS4_S4_P7timeval[boost::asio::detail::socket_ops::select(int, fd_set*, fd_set*, fd_set*, timeval*)]+0xc9): undefined reference to `select@20' :e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/deadline_timer_service.hpp:(.text$_ZN5boost4asio6detail10socket_ops13error_wrapperIiEET_S4_[int boost::asio::detail::socket_ops::error_wrapper<int>(int)]+0x8): undefined reference to `WSAGetLastError@0' :e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/deadline_timer_service.hpp:(.text$_ZN5boost4asio6detail10socket_ops9set_errorEi[boost::asio::detail::socket_ops::set_error(int)]+0x17): undefined reference to `WSASetLastError@4' :e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/deadline_timer_service.hpp:(.text$_ZN5boost4asio6detail12winsock_initILi2ELi0EE7do_initD1Ev[boost::asio::detail::winsock_init<2, 0>::do_init::~do_init()]+0x7): undefined reference to `WSACleanup@0' :e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/deadline_timer_service.hpp:(.text$_ZN5boost4asio6detail10socket_ops5closeEj[boost::asio::detail::socket_ops::close(unsigned int)]+0x19): undefined reference to `closesocket@4' bin\gcc\debug\hello.o: In function `main':e:/job/word-online/source/cpp/hello.cpp:15: undefined reference to `inet_addr@4' :e:/job/word-online/source/cpp/hello.cpp:23: undefined reference to `getsockname@12' bin\gcc\debug\hello.o: In function `ZN5boost4asio6detail31reactive_deadline_timer_serviceINS0_11time_traitsINS_10posix_time5ptimeEEENS1_14select_reactorILb1EEEE16shutdown_serviceEv':e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../.. o `closesocket@4' bin\gcc\debug\hello.o: In function `main':e:/job/word-online/source/cpp/hello.cpp:15: undefined reference to `inet_addr@4' :e:/job/word-online/source/cpp/hello.cpp:23: undefined reference to `getsockname@12' bin\gcc\debug\hello.o: In function `ZN5boost4asio6detail31reactive_deadline_timer_serviceINS0_11time_traitsINS_10posix_time5ptimeEEENS1_14select_reactorILb1EEEE16shutdown_serviceEv':e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/deadline_timer_service.hpp:(.text$_ZN5boost4asio6detail10socket_ops5ioctlEjlPm[boost::asio::detail::socket_ops::ioctl(unsigned int, long, unsigned long*)]+0x27): undefined reference to `ioctlsocket@12' :e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/deadline_timer_service.hpp:(.text$_ZN5boost4asio6detail10socket_ops6acceptEjP8sockaddrPi[boost::asio::detail::socket_ops::accept(unsigned int, sockaddr*, int*)]+0x27): undefined reference to `accept@12' :e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/deadline_timer_service.hpp:(.text$_ZN5boost4asio6detail10socket_ops13error_wrapperIjEET_S4_[unsigned int boost::asio::detail::socket_ops::error_wrapper<unsigned int>(unsigned int)]+0x8): undefined reference to `WSAGetLastError@0' :e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/deadline_timer_service.hpp:(.text$_ZN5boost4asio6detail10socket_ops7connectEjPK8sockaddri[boost::asio::detail::socket_ops::connect(unsigned int, sockaddr const*, int)]+0x27): undefined reference to `connect@12' :e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/deadline_timer_service.hpp:(.text$_ZN5boost4asio6detail10socket_ops6listenEji[boost::asio::detail::socket_ops::listen(unsigned int, int)]+0x20): undefined reference to `listen@8' :e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/deadline_timer_service.hpp:(.text$_ZN5boost4asio6detail10socket_ops4bindEjPK8sockaddri[boost::asio::detail::socket_ops::bind(unsigned int, sockaddr const*, int)]+0x27): undefined reference to `bind@12' :e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/deadline_timer_service.hpp:(.text$_ZN5boost4asio6detail10socket_ops10setsockoptEjiiPKvj[boost::asio::detail::socket_ops::setsockopt(unsigned int, int, int, void const*, unsigned int)]+0x35): undefined reference to `setsockopt@20' :e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/deadline_timer_service.hpp:(.text$_ZN5boost4asio6detail10socket_ops9get_errorEv[boost::asio::detail::socket_ops::get_error()]+0x7): undefined reference to `WSAGetLastError@0' :e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/deadline_timer_service.hpp:(.text$_ZN5boost4asio6detail10socket_ops6socketEiii[boost::asio::detail::socket_ops::socket(int, int, int)]+0x3f): undefined reference to `WSASocketA@24' :e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/deadline_timer_service.hpp:(.text$_ZN5boost4asio6detail10socket_ops4recvEjP7_WSABUFji[boost::asio::detail::socket_ops::recv(unsigned int, _WSABUF*, unsigned int, int)]+0x58): undefined reference to `WSARecv@28' :e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/deadline_timer_service.hpp:(.text$_ZNK5boost4asio6detail14fd_set_adapter6is_setEj[boost::asio::detail::fd_set_adapter::is_set(unsigned int) const]+0x14): undefined reference to `__WSAFDIsSet@8' :e:/program/mingw/mingw/bin/../lib/gcc/i686-pc-mingw32/3.4.2/../../../../include/boost/asio/deadline_timer_service.hpp:(.text$_ZN5boost4asio6detail10socket_ops4sendEjPK7_WSABUFji[boost::asio::detail::socket_ops::send(unsigned int, _WSABUF const*, unsigned int, int)]+0x58): undefined reference to `WSASend@28' collect2: ld returned 1 exit status "g++" -o "bin\gcc\debug\hello.exe" -Wl,--start-group "bin\gcc\debug\hello.o" -Wl,--end-group -g ...failed gcc.link bin\gcc\debug\hello.exe... ...failed updating 1 target... ...updated 4 targets... -- I'm Earth-Man. 我是地球人. --zsp(张沈鹏)

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[Serialization] Non-standard extensions used.
by Stephen Hewitt 08 Aug '06

08 Aug '06

The following is a dead simple example of using Boost.Serialization using an XML output archive which follows the patterns laid down in examples: /* \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/ */ #include <iostream> #include <boost/archive/xml_oarchive.hpp> #include <boost/serialization/nvp.hpp> // Warning level 4. #pragma warning(push, 4) #pragma message("********") struct MyData { MyData(int val) : m_Value(val) {} template<typename Archive> void serialize(Archive & ar, const unsigned int) { ar & BOOST_SERIALIZATION_NVP(m_Value); // <-- Warning here. } int m_Value; }; void main() { using namespace std; MyData d(3); boost::archive::xml_oarchive oa(cout); oa << BOOST_SERIALIZATION_NVP(d); <-- Warning here. } // Warning level back to normal. #pragma warning(pop) /* \/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/\/ */ When compiling this code I get the following error: "warning C4239: nonstandard extension used : 'argument' : conversion from 'struct boost::serialization::nvp<struct MyData>' to 'struct boost::serialization::nvp<struct MyData> &' A reference that is not to 'const' cannot be bound to a non-lvalue" I tried MSVC 6 and "Visual C++ 2005" which can be downloaded from here: http://msdn.microsoft.com/vstudio/express/visualC/default.aspx Interestingly I could not get it to happen with "Microsoft Visual C++ Toolkit 2003". The warning seems valid to me. The "BOOST_SERIALIZATION_NVP" looks like this: -------------------------------------------------------------------------------------------------------------------------- #define BOOST_SERIALIZATION_NVP(name) \ boost::serialization::make_nvp(BOOST_PP_STRINGIZE(name), name) -------------------------------------------------------------------------------------------------------------------------- The "make_nvp" function looks like as follows: ------------------------------------------------------- nvp<T> make_nvp(const char * name, T & t){ return nvp<T>(name, t); } ------------------------------------------------------- "Operator<<", which is used in "main" is reproduced below: -------------------------------------------------------------------------------------- template<class Archive> class interface_oarchive { // ... Code removed ... // template<class T> Archive & operator<<(T & t){ this->This()->save_override(t, 0); return * this->This(); } // ... Code removed ... // }; -------------------------------------------------------------------------------------- So, to cut to the chase, "BOOST_SERIALIZATION_NVP" expands to a call to make_nvp" which returns a temporary which is bound to a non-const reference in "interface_oarchive::operator<<": this is not legal in standard C++ (unless I'm mistaken). It seems that if you follow to documentation and examples the resulting code isn't standard C++!?!

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[bgl] problem with topological_sort
by Renaud Lepere 08 Aug '06

08 Aug '06

I would like to use a graph and add/remove vertices frequently so i try to use a list for the vertices. At the begining, i would like to sort my vertices using dfs or topological_sort. But my program refuses to compile, apparently there is a problem with a property map for the colors. (c:/Boost/include/boost-1_33_1/boost/property_map.hpp:319: instantiated from `void boost::put....'). How can i make a dfs with such a graph ? Are there special requirements for using dfs or topologic_sort on a graph ? Thanks, Renaud. Following is a small example illlustrating the problem. #include <boost/graph/graph_traits.hpp> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/depth_first_search.hpp> #include <boost/graph/visitors.hpp> #include <boost/graph/topological_sort.hpp> #include <iterator> typedef boost::adjacency_list<boost::vecS, boost::listS, boost::bidirectionalS, int, int > Graph; typedef boost::graph_traits<Graph>::vertex_descriptor Vertex; typedef std::vector< Vertex > Vertices; int main() { Graph g; Vertices vs; boost::topological_sort(g, back_inserter(vs)); }

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