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serialization problem with strings
by Doug Henry 17 Jun '05

17 Jun '05

I have a custom stream that I am adaptiing to, so I build oarchive and iarchive classes derived from boost::archive::detail::common_xarchive according to the documentation. I have a function that looks like the following to handle the specifics of loading and saving. template<class T> void load(T & t) { // load data... } This seems to work for everything except std::string's. I noticed it when writing out a std::map<std::string, std::string>. The map is handled properly by the boost/serialization/map.hpp routines, but the strings are sent to my load function instead of being handled by boost/serialization/string.hpp. Any insight in to what I could possibly be doing wrong would be greatly appreciated. -doug

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changing variant type in a visitor
by james.jones＠firstinvestors.com 16 Jun '05

16 Jun '05

Is it possible to change a variant's type within a visitor function? What I'd like to do is something like this: typedef boost::make_recursive_variant< int, std::string, std::vector<boost::recursive_variant_> >::type json_t; Then I'd like to be able to write something like this: class vector_assign : public boost::static_visitor<json_t&> { public: vector_assign(int key, const json_t& value); json_t& operator()(int&); json_t& operator()(std::string&); json_t& operator()(vector_t&); private: int key; json_t& value; }; json_t& vector_assign::operator(vector_t& v) { // the canonical case - we assign a value to a slot in the vector if(key>=v.size()) v.reserve(key); v[key] = value; return v; } json_t& map_assign::operator(int& i) { // here we want to discard the int value and convert the variant into a new vector with a single value - but how? } Thanks, - James Jones Administrative Data Mgmt. (v)732-510-1806 375 Raritan Center Pkwy, Suite A (f)732-510-1855 Edison, NJ 08837

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waiting for david_abrahams's lock in /cvsroot/boost/boost/tools/build/test
by Steven T. Hatton 16 Jun '05

16 Jun '05

It looks like there's a hung lock on one of the files in the CVS: waiting for david_abrahams's lock in /cvsroot/boost/boost/tools/build/test It's been over ten minutes since I first hit it, and it has not been released. -- Regards, Steven

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How to check for implicit type conversion WITHOUT checking the source object's interface
by Stephen Gross 16 Jun '05

16 Jun '05

I'm trying to find a way to see if a given object is convertible to std::string, but with certain restrictions. Normally, is_convertible<> would be fine, but in this case it doesn't work for my needs. Here's the situation in more detail. I've got a class Foo with a string conversion operator: class Foo { public: operator std::string () const; }; I want some kind of is_convertible<Foo, std::string> to return FALSE, but something like is_convertible<char*, std::string> to return TRUE. Basically, I want is_convertible to check to see if the target type (std::string) has an implicit constructor taking the input type; I *don't* want is_convertible to check to see if the input type has a conversion-to-target-type function. Is there a way to do this? --Steve

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Serialization: how to serialize c style strings?
by Tom Thorne 16 Jun '05

16 Jun '05

I'm trying to understand how to go about serializing allocated c style string buffers using the serialization library. The example code below gives a compile error (see bottom) "left of '.serialize' must have class/struct/union type" and I don't see how to fix this. Could someone point me in the right direction? In the meantime I'm using std::string, but this doesn't meet my needs. Many thanks for any help. Tom ----------------------------- #include <boost/serialization/string.hpp> #include <fstream> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> template<class T> class test { public: template<class Archive> void serialize(Archive &ar, const unsigned int version) { ar & boost::serialization::make_nvp("p", p); } test() { p = 0; } ~test() { delete p; } explicit test(const T *t) { size_t len = std::char_traits<T>::length(t); p = new T[len+1]; std::char_traits<T>::copy(p, t, len+1); } const T *get() const { return p; } private: T *p; }; void sertest() { test<char> t("Hello"); std::ofstream ofs("test.txt"); boost::archive::text_oarchive oa(ofs); oa << t; ofs.close(); } ------------------------------ ------ Build started: Project: test, Configuration: Debug Win32 ------ Compiling... sertest.cpp c:\Proj\boost\include\boost-1_32\boost\serialization\access.hpp(106) : error C2228: left of '.serialize' must have class/struct/union type type is 'type' c:\Proj\boost\include\boost-1_32\boost\serialization\serialization.hpp(7 8) : see reference to function template instantiation 'void boost::serialization::access::serialize<Archive,T>(Archive &,T &,const unsigned int)' being compiled with [ Archive=boost::archive::text_oarchive, T=type ] c:\Proj\boost\include\boost-1_32\boost\serialization\serialization.hpp(1 21) : see reference to function template instantiation 'void boost::serialization::serialize<Archive,T>(Archive &,T &,const unsigned int)' being compiled with [ Archive=boost::archive::text_oarchive, T=type ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(15 2) : see reference to function template instantiation 'void boost::serialization::serialize_adl<Archive,T>(Archive &,T &,const unsigned int)' being compiled with [ Archive=boost::archive::text_oarchive, T=type ] c:\Proj\boost\include\boost-1_32\boost\serialization\extended_type_info_ typeid.hpp(100) : while compiling class-template member function 'void boost::archive::detail::oserializer<Archive,T>::save_object_data(boost:: archive::detail::basic_oarchive &,const void *) const' with [ Archive=boost::archive::text_oarchive, T=type ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(16 3) : see reference to class template instantiation 'boost::archive::detail::oserializer<Archive,T>' being compiled with [ Archive=boost::archive::text_oarchive, T=type ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(16 2) : while compiling class-template member function 'const boost::archive::detail::basic_oserializer &boost::archive::detail::pointer_oserializer<T,Archive>::get_basic_seria lizer(void) const' with [ T=type, Archive=boost::archive::text_oarchive ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(53 0) : see reference to class template instantiation 'boost::archive::detail::pointer_oserializer<T,Archive>' being compiled with [ T=type, Archive=boost::archive::text_oarchive ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\interface_oarchive .hpp(65) : see reference to function template instantiation 'const boost::archive::detail::basic_pointer_oserializer &boost::archive::detail::instantiate_pointer_oserializer<Archive,T>(Arch ive *,T *)' being compiled with [ Archive=boost::ar chive::text_oarchive, T=type ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(33 2) : see reference to function template instantiation 'const boost::archive::detail::basic_pointer_oserializer *boost::archive::detail::interface_oarchive<Archive>::register_type<T>(T *)' being compiled with [ Archive=boost::archive::text_oarchive, T=type ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(33 1) : while compiling class-template member function 'const boost::archive::detail::basic_pointer_oserializer *boost::archive::detail::save_pointer_type<Archive,TPtr>::non_abstract<T >::register_type(Archive &)' with [ Archive=boost::archive::text_oarchive, TPtr=char *, T=type ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(34 9) : see reference to class template instantiation 'boost::archive::detail::save_pointer_type<Archive,TPtr>::non_abstract<T >' being compiled with [ Archive=boost::archive::text_oarchive, TPtr=char *, T=type ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(47 5) : see reference to function template instantiation 'const boost::archive::detail::basic_pointer_oserializer *boost::archive::detail::save_pointer_type<Archive,TPtr>::register_type< T>(Archive &,T &)' being compiled with [ Archive=boost::archive::text_oarchive, TPtr=char *, T=char ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(46 2) : while compiling class-template member function 'void boost::archive::detail::save_pointer_type<Archive,TPtr>::invoke(Archive &,const TPtr)' with [ Archive=boost::archive::text_oarchive, TPtr=char * ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(55 1) : see reference to class template instantiation 'boost::archive::detail::save_pointer_type<Archive,TPtr>' being compiled with [ Archive=boost::archive::text_oarchive, TPtr=char * ] c:\Proj\boost\include\boost-1_32\boost\archive\basic_text_oarchive.hpp(7 1) : see reference to function template instantiation 'void boost::archive::save<Archive,T>(Archive &,const T & )' being compiled with [ Archive=boost::archive::text_oarchive, T=char * ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\interface_oarchive .hpp(80) : see reference to function template instantiation 'void boost::archive::basic_text_oarchive<Archive>::save_override<T>(const T & ,int)' being compiled with [ Archive=boost::archive::text_oarchive, T=char * ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\interface_oarchive .hpp(110) : see reference to function template instantiation 'Archive &boost::archive::detail::interface_oarchive<Archive>::operator <<<T>(const T & )' being compiled with [ Archive=boost::archive::text_oarchive, T=char * ] c:\Proj\boost\include\boost-1_32\boost\serialization\nvp.hpp(58) : see reference to function template instantiation 'Archive &boost::archive::detail::interface_oarchive<Archive>::operator &<T>(T & )' being compiled with [ Archive=boost::archive::text_oarchive, T=char * ] c:\Proj\boost\include\boost-1_32\boost\serialization\access.hpp(106) : see reference to function template instantiation 'void boost::serialization::nvp<T>::serialize<Archive>(Archive &,const unsigned int) const' being compiled with [ T=char *, Archive=boost::archive::text_oarchive ] c:\Proj\boost\include\boost-1_32\boost\serialization\serialization.hpp(7 8) : see reference to function template instantiation 'void boost::serialization::access::serialize<Archive,T>(Archive &,T &,const unsigned int)' being compiled with [ Archive=boost::archive::text_oarchive, T=boost::serialization::nvp<char *> ] c:\Proj\boost\include\boost-1_32\boost\serialization\serialization.hpp(1 21) : see reference to function template instantiation 'void boost::serialization::serialize<Archive,T>(Archive &,T &,const unsigned int)' being compiled with [ Archive=boost::archive::text_oarchive, T=boost::serialization::nvp<char *> ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(22 7) : see reference to function template instantiation 'void boost::serialization::serialize_adl<Archive,T>(Archive &,T &,const unsigned int)' being compiled with [ Archive=boost::archive::text_oarchive, T=boost::serialization::nvp<char *> ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(22 2) : while compiling class-template member function 'void boost::archive::detail::save_non_pointer_type<Archive,T>::save_only::inv okex(Archive &,const T &)' with [ Archive=boost::archive::text_oarchive, T=boost::serialization::nvp<char *> ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(30 9) : see reference to class template instantiation 'boost::archive::detail::save_non_pointer_type<Archive,T>::save_only' being compiled with [ Archive=boost::archive::text_oarchive, T=boost::serialization::nvp<char *> ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(23 7) : while compiling class-template member function 'void boost::archive::detail::save_non_pointer_type<Archive,T>::invoke(Archive &,const T &)' with [ Archive=boost::archive::text_oarchive, T=boost::serialization::nvp<char *> ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(55 1) : see reference to class template instantiation 'boost::archive::detail::save_non_pointer_type<Archive,T>' being compiled with [ Archive=boost::archive::text_oarchive, T=boost::serialization::nvp<char *> ] c:\Proj\boost\include\boost-1_32\boost\archive\basic_text_oarchive.hpp(7 1) : see reference to function template instantiation 'void boost::archive::save<Archive,T>(Archive &,const T &)' being compiled with [ Archive=boost::archive::text_oarchive, T=boost::serialization::nvp<char *> ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\interface_oarchive .hpp(87) : see reference to function template instantiation 'void boost::archive::basic_text_oarchive<Archive>::save_override<T>(const T &,int)' being compiled with [ Archive=boost::archive::text_oarchive, T=boost::serialization::nvp<char *> ] c:\Proj\lnp\core\test\sertest.cpp(14) : see reference to function template instantiation 'Archive &boost::archive::detail::interface_oarchive<Archive>::operator &<boost::serialization::nvp<T>>(const boost::serialization::nvp<T> &)' being compiled with [ Archive=boost::archive::text_oarchive, T=char * ] c:\Proj\boost\include\boost-1_32\boost\serialization\access.hpp(106) : see reference to function template instantiation 'void test<T>::serialize<Archive>(Archive &,const unsigned int)' being compiled with [ T=char, Archive=boost::archive::text_oarchive ] c:\Proj\boost\include\boost-1_32\boost\serialization\serialization.hpp(7 8) : see reference to function template instantiation 'void boost::serialization::access::serialize<Archive,T>(Archive &,T &,const unsigned int)' being compiled with [ Archive=boost::archive::text_oarchive, T=test<char> ] c:\Proj\boost\include\boost-1_32\boost\serialization\serialization.hpp(1 21) : see reference to function template instantiation 'void boost::serialization::serialize<Archive,T>(Archive &,T &,const unsigned int)' being compiled with [ Archive=boost::archive::text_oarchive, T=test<char> ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(15 2) : see reference to function template instantiation 'void boost::serialization::serialize_adl<Archive,T>(Archive &,T &,const unsigned int)' being compiled with [ Archive=boost::archive::text_oarchive, T=test<char> ] c:\Proj\boost\include\boost-1_32\boost\serialization\extended_type_info_ typeid.hpp(100) : while compiling class-template member function 'void boost::archive::detail::oserializer<Archive,T>::save_object_data(boost:: archive::detail::basic_oarchive &,const void *) const' with [ Archive=boost::archive::text_oarchive, T=test<char> ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(23 4) : see reference to class template instantiation 'boost::archive::detail::oserializer<Archive,T>' being compiled with [ Archive=boost::archive::text_oarchive, T=test<char> ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(23 3) : while compiling class-template member function 'void boost::archive::detail::save_non_pointer_type<Archive,T>::save::invokex( Archive &,const T &)' with [ Archive=boost::archive::text_oarchive, T=test<char> ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(30 9) : see reference to class template instantiation 'boost::archive::detail::save_non_pointer_type<Archive,T>::save' being compiled with [ Archive=boost::archive::text_oarchive, T=test<char> ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(23 7) : while compiling class-template member function 'void boost::archive::detail::save_non_pointer_type<Archive,T>::invoke(Archive &,const T &)' with [ Archive=boost::archive::text_oarchive, T=test<char> ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\oserializer.hpp(55 1) : see reference to class template instantiation 'boost::archive::detail::save_non_pointer_type<Archive,T>' being compiled with [ Archive=boost::archive::text_oarchive, T=test<char> ] c:\Proj\boost\include\boost-1_32\boost\archive\basic_text_oarchive.hpp(7 1) : see reference to function template instantiation 'void boost::archive::save<Archive,T>(Archive &,const T &)' being compiled with [ Archive=boost::archive::text_oarchive, T=test<char> ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\interface_oarchive .hpp(80) : see reference to function template instantiation 'void boost::archive::basic_text_oarchive<Archive>::save_override<T>(const T &,int)' being compiled with [ Archive=boost::archive::text_oarchive, T=test<char> ] c:\Proj\boost\include\boost-1_32\boost\archive\detail\interface_oarchive .hpp(105) : see reference to function template instantiation 'Archive &boost::archive::detail::interface_oarchive<Archive>::operator <<<test<T>>(const test<T> &)' being compiled with [ Archive=boost::archive::text_oarchive, T=char ] c:\Proj\lnp\core\test\sertest.cpp(55) : see reference to function template instantiation 'Archive &boost::archive::detail::interface_oarchive<Archive>::operator <<<test<T>>(test<T> &)' being compiled with [ Archive=boost::archive::text_oarchive, T=char ] test - 1 error(s), 0 warning(s) ---------------------- Done ---------------------- Build: 0 succeeded, 1 failed, 0 skipped

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date_time: << operator for time_duration
by Donato Petrino 16 Jun '05

16 Jun '05

Hello, one short question regarding the 'operator<<' on time_durations (which in turn calls 'duration_put' in time_formatting_streams.hpp): The stream's filler is changed via the manipulator 'std::setfill' to zero ('0'), but without setting it back to the one the stream had when entering to this function (in my case blank (' ')). This results in undesired leading blanks on the subsequent usage of the same stream object. Question: Is it a bug or is it the common way how streams are used (which would mean that is't up to me resetting it to blank again). Thank you in advance! -- Donato Petrino

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Random numbers: problem with uniform_real random distribution
by Dave Steffen 15 Jun '05

15 Jun '05

Hi Folks, I'm getting some very odd results out of the random uniform_real distribution. The distribution uniform_real<> rdouble (-1, 3); returns a sequence of number that looks like 1.28327e+10 2.34686e+09 1.29337e+10 1.25118e+10 1.54783e+10 1.13449e+10 which certainly doesn't meet the requirement of returning values in [-1,3)! I don't see any mention of this on the bug tracker; has anyone else seen this? ---------------------------------------------------------------------- Dave Steffen, Ph.D. "There are two ways to write error-free Software Engineer IV programs; only the third one works." Numerica Corporation ph (970) 419-8343 x27 "Pie are not square. Pie are round. fax (970) 223-6797 Cornbread are square" dgsteffen(a)numerica.us ... anon (usenet)

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Re: [Boost-users] Reference information for mpl::for_each
by Stephen Gross 15 Jun '05

15 Jun '05

>Maybe > template <class Sequence, class T> struct contains_convertible_type : mpl::not_< boost::is_same< typename mpl::find_if< type_sequence , boost::is_convertible<T,_1> >::type , typename mpl::end<Sequence>::type > > {}; Cool--thanks for the info; I'll work on it... Thanks, --Steve

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Boost.mpl suggestion: variation of find_if
by Vyacheslav Kononenko 15 Jun '05

15 Jun '05

Hi, I could not come with usable name for such thing but it could be usable anyway. So it is like find_if but applies a function to an sequence and return first non void type that function returned. So implementation would be trivial: template< typename Sequence, typename Func > struct find_type : fold< Sequence, void_, if_< is_void_< _1 >, Func< _2 >, _1 > {}; If it can be implemented by current set of algorithms please point me out. Regards, Vyacheslav

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fatal error LNK1104: cannot open file 'libboost_regex-vc71-sgd-1_32.lib'
by John Lucas 15 Jun '05

15 Jun '05

Hi boost New to C++ and boost so please bear with me. I have downloaded the boost library (1.3.2) from sf.net on to a Windows XP platform running Visual Studio .NET. I've started a C++ project however when I compile it, having added the regex class, I get the following error: fatal error LNK1104: cannot open file 'libboost_regex-vc71-sgd-1_32.lib' I have include the lib path for boost and that worked OK with the other libraries but not this one. Any one got any ideas? John Lucas Director of Operations MI International UK Tel: +44 (0)1642 356138 Mobile: +44 (0)7884 181828 Email: <mailto:john.lucas@mi-int.com> john.lucas(a)mi-int.com URL: <http://www.mi-int.com/> www.mi-int.com <http://www.mi-int.com/images/logo3.JPG> First for European POI and business data In association with D&B DISCLAIMER: this email and any files transmitted with it are confidential and intended solely for the use of the individual or entity to whom they are addressed. If you have received this email in error, please notify the system manager. Please note that any views or opinions presented in this email are solely those of the author and do not necessarily represent those of the company. If you are not the intended recipient, please email postmaster(a)mi-int.com, along with a copy of the email. Finally, the recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email. E&OE

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