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unique sorted vector
by Michael Marcin 10 Aug '07

10 Aug '07

I have a need for a low memory set. Essentially I want an always sorted unique vector. Is such a wrapper around vector and/or deque available in Boost? Thanks, Michael Marcin

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Avoid thread locking with boost::condition
by Sam Lievesley 10 Aug '07

10 Aug '07

Hi, I am trying to avoid thread locking problems when waiting using a boost::condition pseudo code: Main thread -- Start a worker thread -- boost::mutex::scoped_lock lock(m_Mutex); m_Condition.notify_one(); Worker thread boost::mutex::scoped_lock lock(m_Mutex); while (IsAlive()) { // do some work m_Condition.wait(lock); } As we can't predict which thread gets the mutex lock first lets assume that its the main thread. If this happens then m_Condition.wait will wait indefinitely as notify was called before wait. The only reliable way (that I can see) to prevent this is to never use wait, use a timed_wait instead and a loop. Why isn't the notification signal queued in the boost::condition object? Then the order of wait / notification would not be important. thanks Sam

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Visual Studio 2005 ptr_list visualizer?
by Michael Marcin 10 Aug '07

10 Aug '07

Hello I've seen Visual Studio 2005 visualizers for various boost containers on here before. Has anyone written one for ptr_list that they can share? Thanks, Michael Marcin

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Problem with boost::bind and boost::lambda::bind
by Stefano Peluchetti 10 Aug '07

10 Aug '07

I'm a newbie to the boost library so I need some help with the following problem: Take the following code: class EaSde // Abstract class. { ... public: inline virtual double unitDiffusionInverseMap( double x ) const = 0; inline virtual void unitDiffusionInverseMap( Path& path ) const; .... }; void EaSde::unitDiffusionInverseMap( Path& path ) const { std::transform( path.values.begin(), path.values.end(), path.values.begin(), boost::bind<double>( &sde::EaSde::unitDiffusionInverseMap, this, _1 ) ); } This code works fine. However if I use boost::bind::lambda instead of boost::bind I get: 1>Compiling... 1>sdefunctionalmc.cpp 1>c:\develop\nsde\nsde\abstracteasde.hpp(58) : error C2664: 'const boost::lambda::lambda_functor<T> boost::lambda::bind<double,const sde::EaSde*,const boost::lambda::placeholder1_type>(const Arg1 &,const Arg2 &,const Arg3 &)' : cannot convert parameter 1 from 'overloaded-function' to 'const double &' 1> with 1> [ 1> T=boost::lambda::lambda_functor_base<boost::lambda::action<3,boost::lambda::function_action<3>>,boost::tuples::tuple<const double,const sde::EaSde *const ,const boost::lambda::lambda_functor<boost::lambda::placeholder<1>>,boost::lambda::detail::bind_traits<boost::tuples::null_type>::type,boost::lambda::detail::bind_traits<boost::tuples::null_type>::type,boost::lambda::detail::bind_traits<boost::tuples::null_type>::type,boost::lambda::detail::bind_traits<boost::tuples::null_type>::type,boost::lambda::detail::bind_traits<boost::tuples::null_type>::type,boost::lambda::detail::bind_traits<boost::tuples::null_type>::type,boost::lambda::detail::bind_traits<boost::tuples::null_type>::type>>, 1> Arg1=double, 1> Arg2=const sde::EaSde *, 1> Arg3=const boost::lambda::placeholder1_type 1> ] 1> Reason: cannot convert from 'overloaded-function' to 'const double' 1> Context does not allow for disambiguation of overloaded function 1>c:\develop\nsde\nsde\abstracteasde.hpp(58) : error C2780: '_OutIt std::transform(_InIt1,_InIt1,_InIt2,_OutIt,_Fn2)' : expects 5 arguments - 4 provided 1> c:\programmi\microsoft visual studio 8\vc\include\algorithm(797) : see declaration of 'std::transform' Why in this case is boost::bind working and boost::lambda::bind not working? Where can I find more informations on the differences about the two? On a side note I'm wondering if I can expect different performance of the two implementations.... I'm actually moving everything to boost::lambda::bind to 1) avoid the conflict of boost::lambda::_1 and _1 2) have binders that are "lambda ready" if needed Thank you in advance for your reply.

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Using lambda for sort
by Olaf van der Spek 10 Aug '07

10 Aug '07

Hi, I'm trying to sort a map based on second, but I get all kinds of compiler errors and I have no idea what's wrong. A simple _1 > _2 works fine, but that compares the maps themselves. Also, is there a better way to write the copy from map to vector or to sort the map in general? Note that I'm using a map because I'm counting how often an integer or string occurs. #include <boost/lambda/lambda.hpp> #include <boost/lambda/bind.hpp> #include <algorithm> #include <map> #include <vector> using namespace std; using namespace boost::lambda; int _tmain(int argc, _TCHAR* argv[]) { typedef std::map<int, int> countries_t; countries_t countries; countries[0] = 5; countries[1] = 3; countries[2] = 1; typedef vector<countries_t::const_iterator> countries1_t; countries1_t countries1; for (countries_t::const_iterator i = countries.begin(); i != countries.end(); i++) countries1.push_back(i); sort(countries1.begin(), countries1.end(), _1->second > _2->second); return 0; } ------ Build started: Project: Lambda Test, Configuration: Debug Win32 ------ Compiling... Lambda Test.cpp c:\vc\temp\lambda test\lambda test.cpp(23) : error C2819: type 'boost::lambda::lambda_functor<T>' does not have an overloaded member 'operator ->' with [ T=boost::lambda::placeholder<1> ] did you intend to use '.' instead? c:\vc\temp\lambda test\lambda test.cpp(23) : error C2039: 'second' : is not a member of 'boost::lambda::lambda_functor<T>' with [ T=boost::lambda::placeholder<1> ] c:\vc\temp\lambda test\lambda test.cpp(23) : error C2819: type 'boost::lambda::lambda_functor<T>' does not have an overloaded member 'operator ->' with [ T=boost::lambda::placeholder<2> ] did you intend to use '.' instead? c:\vc\temp\lambda test\lambda test.cpp(23) : error C2039: 'second' : is not a member of 'boost::lambda::lambda_functor<T>' with [ T=boost::lambda::placeholder<2> ] c:\vc\temp\lambda test\lambda test.cpp(23) : error C2780: 'void std::sort(_RanIt,_RanIt)' : expects 2 arguments - 3 provided c:\program files\microsoft visual studio 8\vc\include\algorithm(3109) : see declaration of 'std::sort' Lambda Test - 5 error(s), 0 warning(s) ========== Build: 0 succeeded, 1 failed, 0 up-to-date, 0 skipped ==========

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boost::variant/visitor problem
by Joe 10 Aug '07

10 Aug '07

Hi, Can someone help me. I have defined a boost::variant<long long,double,std::string> with a visitor which issues an increment. The visitor derived class below works fine for std::string and long long only within the visitor, but as soon as I add a double, I get an ambiguous call compile error (error below). I'm guessing when T within the prop_increment class is an int, the compiler doesn't know whether to use the long long version of the operator() or the double version. Does anyone know how I can get around this when I apply the visitor? Interestingly enough, if I add an int to the boost::variant template list the error goes away. ------ Compile Error ------ Error 44 error C2668: 'boost::detail::variant::make_initializer_node::apply<BaseIndexPair,Iterator>::initializer_node::initialize' : ambiguous call to overloaded function \boost\variant\variant.hpp 1273 ----------------------------- ------ Visitor Class ----------- class prop_increment : public boost::static_visitor<> { public: template <typename T, typename U> void operator()( T &, const U & ) const { return; } template<typename T> void operator()(T & lhs, const T& rhs) const { lhs += rhs; } }; ------------------------------------ boost::apply_visitor(prop_increment(),prop1,prop2); ---- Visitor Call ------------------- Thanks

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boost::iostreams::gzip_compressor and multiple files
by Robert Caldecott 10 Aug '07

10 Aug '07

I have been experimenting with the boost::iostreams to create a gzip file, for example the following works fine: using namespace boost::iostreams; filtering_ostream out; out.push(gzip_compressor()); out.push(file_sink("test.gz", std::ios::binary)); out << "This is a gz file\n"; This will create a gz file containing a single compressed file (called 'test'). I can change the name of this internal file using a gzip_params struct and all is well. However, I want to create a single gzip file that contains multiple compressed files, each with a different filename. Does anyone know how to achieve this? Thanks in advance.

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Re: [Boost-users] Serialization of hashmap
by Hansi Hansi 10 Aug '07

10 Aug '07

My system is using the dinkumware.hpp header as stdlib. There the BOOST_HAS_HASH is not set. But olso if I set this it doesn't work. Because it doesn't has the resize function and the bucket_count. Best regards Hansjörg > -----Ursprüngliche Nachricht----- > Von: boost-users(a)lists.boost.org > Gesendet: 10.08.07 08:25:39 > An: boost-users(a)lists.boost.org > Betreff: Re: [Boost-users] Serialization of hashmap > > Hansi Hansi wrote: > > > the BOOST_HAS_HASH makro wosn't set. > > OK - that macro should be set automatically by > including "config..hpp" > > I believe that I've had problem in the past in this > area. If you find out why it wasn't set, let us > know so we can fix it in the next release. > > Robert Ramaey > > > > > Best regards > > Hansjörg > > > > > > > > <hr> > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users > _________________________________________________________________________ In 5 Schritten zur eigenen Homepage. Jetzt Domain sichern und gestalten! Nur 3,99 EUR/Monat! http://www.maildomain.web.de/?mc=021114

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boost static assert and is_base_of question.
by chun ping wang 10 Aug '07

10 Aug '07

Hi, how would I ensured that class U of template class is a dervied class of boost::operators<U> using BOOST_STATIC_ASSERT and boost::is_base_of... template <T> myFunc(const T& a) { typedef boost::operators<T> operatorT; BOOST_STATIC_ASSERT(is_integral<T>::value || is_base_of<operatorT, T>::value); // ... other codes. } doing this gives me an error. arguments, but takes just 1 ./cs512/c++/cppdef/DiffieHellman.cpp: In function `T boost::random_prime(boost:: function<bool ()(const T&, const T&), std::allocator<void> >, int)': ./cs512/c++/cppdef/DiffieHellman.cpp:23: error: `BOOST_STATIC_ASSERT' was not de clared in this scope ./cs512/c++/cppdef/DiffieHellman.cpp:49:78: macro "BOOST_STATIC_ASSERT" passed 2 arguments, but takes just 1 ./cs512/c++/cppdef/DiffieHellman.cpp: In function `boost::tuples::tuple<T, T, bo ost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boos t::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost: :tuples::null_type, boost::tuples::null_type> boost::dh_init(const boost::any&)' : ./cs512/c++/cppdef/DiffieHellman.cpp:49: error: `BOOST_STATIC_ASSERT' was not de clared in this scope ./cs512/c++/cppdef/DiffieHellman.cpp:64:78: macro "BOOST_STATIC_ASSERT" passed 2 arguments, but takes just 1 ./cs512/c++/cppdef/DiffieHellman.cpp: In function `T boost::dh_secret(const T&, const T&, const T&)': ./cs512/c++/cppdef/DiffieHellman.cpp:64: error: `BOOST_STATIC_ASSERT' was not de clared in this scope make[1]: *** [lib/DiffieHellman.o] Error 1 make[1]: Leaving directory `/c/CPW/cs_classes' make: *** [all-before] Error 2

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Re: [Boost-users] Serialization of hashmap
by Hansi Hansi 10 Aug '07

10 Aug '07

> > > Hansi Hansi wrote: > > Hello, > > > > I don't know If I'm wrong. To install boost I have used the installer > > from boost-consulting. At the moment I'm using version 1.34.0. > > I have set the configuration makros in the follwing way > > > > #define BOOST_HAS_HASH > > #define BOOST_STD_EXTENSION_NAMESPACE stdext > > #define STD BOOST_STD_EXTENSION_NAMESPACE > > You shouldn't have to set any macros. These should be set by > boost/config.hpp which sets them properly for each compiler. > I don't know if these are in fact set. If not, > the fact that these tests are passing on my system and on the > release tests wouldn't mean much. > > I'm too busy right now to look further into it. > > Robert Ramey > > the BOOST_HAS_HASH makro wosn't set. Best regards Hansjörg > > > > The problem is that during compiling I get 2 errors: > > > > Error 133 error C2039: 'resize' : is not a member of > > 'stdext::hash_map<_Kty,_Ty,_Tr>' > > C:\boost_1_34_0\boost\serialization\hash_collections_load_imp.hpp 46 > > Error 134 error C2039: 'bucket_count' : is not a member of > > 'stdext::hash_map<_Kty,_Ty,_Tr>' > > C:\boost_1_34_0\boost\serialization\hash_collections_save_imp.hpp 43 > > > > The test program doesn't work to compile too. There are problems > > with the following lines: > > > > namespace BOOST_STD_EXTENSION_NAMESPACE { > > template<> > > struct hash<random_key>{ > > <<<<<<<<<------------- line 156 > > std::size_t operator()(const random_key& r) const { > > return (std::size_t)r; > > } > > }; > > } // namespace BOOST_STD_EXTENSION_NAMESPACE > > > > > > Error 9 error C2143: syntax error : missing ';' before '<' > > c:\boost_1_34_0\libs\serialization\test\test_map.cpp 156 > > > > Is there some other makro that I have to define? > > > > Best Regards and many thanks for your help > > > > Hansjörg > > > >> -----Ursprüngliche Nachricht----- > >> Von: boost-users(a)lists.boost.org > >> Gesendet: 09.08.07 08:54:35 > >> An: boost-users(a)lists.boost.org > >> Betreff: Re: [Boost-users] Serialization of hashmap > > > > > >> > >> There is a test program - test_map which should demonstrate the > >> functionality. > >> > >> It depends upon standard boost macros for stdext: so if the test > >> doesnt invoke the hash map, you might check to see if the config > >> system is correct. > >> > >> Let me know what you find out. > >> > >> Robert Ramey > >> > >> Hansi Hansi wrote: > >>> Hello, > >>> > >>> Sorry I have forgotten to write the subject in the last post. > >>> > >>> is there a possibility to serialize a hash_map with the vc8.0 > >>> compiler? this compiler has defined a hash_map under the stdext > >>> namespace. It seems that the implementation in boost doesn't work at > >>> the moment for this class. > >>> > >>> Or is there another hash_map implementation available which can be > >>> serialized? > >>> > >>> Best regards > >>> Hansjörg > >>> > >>> > >>> _____________________________________________________________________ > >>> Der WEB.DE SmartSurfer hilft bis zu 70% Ihrer Onlinekosten zu > >>> sparen! > >>> http://smartsurfer.web.de/?mc=100071&distributionid=000000000066 > >> > >> > >> > >> > >> > >> <hr> > >> _______________________________________________ > >> Boost-users mailing list > >> Boost-users(a)lists.boost.org > >> http://lists.boost.org/mailman/listinfo.cgi/boost-users > >> > > > > > > __________________________________________________________________________ > > Erweitern Sie FreeMail zu einem noch leistungsstärkeren > > E-Mail-Postfach! > > Mehr Infos unter http://produkte.web.de/club/?mc=021131 > > > > > > <hr> > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users > _______________________________________________________________________ Jetzt neu! Schützen Sie Ihren PC mit McAfee und WEB.DE. 3 Monate kostenlos testen. http://www.pc-sicherheit.web.de/startseite/?mc=022220

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