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boost::tokenizer problem, maybe a bug.
by Jarl Friis 27 Jul '05

27 Jul '05

Hi. I discovered the following problem using boost::tokenizer. The following program should print "hello", but it prints "hell": #include <iostream> #include <boost/tokenizer.hpp> int main(){ typedef boost::tokenizer<boost::char_separator<char> > tokenizer; boost::char_separator<char> sep(",", ""); tokenizer values(std::string(",hello,"), sep); for( tokenizer::iterator valueI = values.begin(); valueI != values.end(); ++valueI){ std::cout << "\"" << *valueI << "\"" << std::endl; } } Problem is confirmed using boost 1.32.0 and both GCC 3.3.4 and GCC 3.3.5 If anybody have a newer GCC installed, I would like to hear if the problems also exists in later GCC releases. I believe it is a bug in the std::string::assign implementation (i.e. not boost directly), but a the workaround for msvc in boost/token_functions.hpp, line 215-228 has also been tried for the GCC but it just moves the problem; it will mibehave when the line tokenizer values(std::string(",hello,"), sep); is replaced with tokenizer values(std::string("hello,"), sep); since it will then print "hel". So maybe another boost workaround is needed for GCC for the lines 215-228 in boost/token_functions.hpp Jarl -- Jarl Friis Softace ApS Omøgade 8, 2.sal 2100 København Ø. Denmark Phone: +45 26 13 20 90 E-mail: jarl(a)softace.dk

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Re: [Boost-users] Simple Boost Lambda problem using argument as object. part II
by Tino S. 27 Jul '05

27 Jul '05

Hi Thaddeus, this code works for me... Greetings Tino int main() { std::string in; std::vector<A *> alist; std::vector<A *> longAList; typedef std::vector<A *> myType; // std::back_insert_iterator< myType > inserter(longAList); while(in!="end") { in=""; std::getline(std::cin,in); alist.push_back(new A(in)); } std::for_each(alist.begin(),alist.end(), //*inserter++ = &(*_1) boost::lambda::if_then( bind(&A::isLong,_1), bind(&myType::push_back ,&longAList, _1) )); return 1; } ___________________________________________________________ Gesendet von Yahoo! Mail - Jetzt mit 1GB Speicher kostenlos - Hier anmelden: http://mail.yahoo.de

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[Iterators] Change in transform_iterator from 1.31 to 1.32?
by Nat Goodspeed 27 Jul '05

27 Jul '05

We have a class that contains a std::map. This class wants to provide its clients with iterators over just the values in the map, hiding the fact that there's a map under the covers at all. transform_iterator seems like just the ticket, and with Boost 1.31 we used these methods: typedef std::map<KEYTYPE, VALUETYPE> MapType; typedef boost::transform_iterator< boost::function<const MapType::mapped_type&(const MapType::value_type&)>, MapType::const_iterator > const_iterator; const_iterator begin() const { return boost::make_transform_iterator(mymap.begin(), boost::bind(&MapType::value_type::second, _1)); } const_iterator end() const { return boost::make_transform_iterator(mymap.end(), boost::bind(&MapType::value_type::second, _1)); } The above compiled cleanly, except when it caused a compiler ICE, and the instances that compile seem to run okay. Now we're trying to upgrade to Boost 1.32 -- I know, a little late in the 1.32 lifespan. The same code now produces an ominous warning (full text at end of message): c:/videobranch\boost\boost\function\function_template.hpp(111) : warning C4172: returning address of local variable or temporary When it finally gets around to mentioning a line number in our own source code, the indicated line is the return statement in the above begin() method. The reason I'm concerned is that when compiled with Boost 1.32, our program suffers mysterious crashes that it did not when compiled with Boost 1.31. :-( I don't *know* that this warning is related, but I thought it prudent to try to eliminate such warnings to see if that might help. I can't figure out what temporary is driving the warning, though. I tried factoring out our own code a couple of different ways without making the warning go away. Can you suggest anything? Platform: Microsoft Windows XP Pro Compiler: Microsoft Visual C++ .NET, aka 7.1 *** Message ends; what follows is Microsoft warning output *** cl /EHsc /I c:/videobranch/boost $FF Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 13.10.3077 for 80x86 Copyright (C) Microsoft Corporation 1984-2002. All rights reserved. WrapMap.cpp c:/videobranch\boost\boost\function\function_template.hpp(111) : warning C4172: returning address of local variable or temporary c:/videobranch\boost\boost\function\function_template.hpp(109) : while compiling class-template member function 'const int boost::detail::function::function_obj_invoker1<FunctionObj,R,T0>::invoke (boost::detail::function::any_pointer,T0)' with [ FunctionObj=boost::_bi::bind_t<int,boost::_mfi::dm<int,std::pair<const std::string,int>>,boost::_bi::list1<boost::_bi::list_av_1<boost::arg<1>> ::B1>>, R=const int &, T0=const std::pair<const std::string,int> & ] c:/videobranch\boost\boost\function\function_template.hpp(482) : see reference to class template instantiation 'boost::detail::function::function_obj_invoker1<FunctionObj,R,T0>' being compiled with [ FunctionObj=boost::_bi::bind_t<int,boost::_mfi::dm<int,std::pair<const std::string,int>>,boost::_bi::list1<boost::_bi::list_av_1<boost::arg<1>> ::B1>>, R=const int &, T0=const std::pair<const std::string,int> & ] c:/videobranch\boost\boost\function\function_template.hpp(433) : see reference to function template instantiation 'void boost::function1<R,T0,Allocator>::assign_to<Functor>(FunctionObj,boost:: detail::function::function_obj_tag)' being compiled with [ R=const int &, T0=const std::pair<const std::string,int> &, Allocator=std::allocator<void>, Functor=boost::_bi::bind_t<int,boost::_mfi::dm<int,std::pair<const std::string,int>>,boost::_bi::list1<boost::_bi::list_av_1<boost::arg<1>> ::B1>>, FunctionObj=boost::_bi::bind_t<int,boost::_mfi::dm<int,std::pair<const std::string,int>>,boost::_bi::list1<boost::_bi::list_av_1<boost::arg<1>> ::B1>> ] c:/videobranch\boost\boost\function\function_template.hpp(289) : see reference to function template instantiation 'void boost::function1<R,T0,Allocator>::assign_to<Functor>(Functor)' being compiled with [ R=const int &, T0=const std::pair<const std::string,int> &, Allocator=std::allocator<void>, Functor=boost::_bi::bind_t<int,boost::_mfi::dm<int,std::pair<const std::string,int>>,boost::_bi::list1<boost::_bi::list_av_1<boost::arg<1>> ::B1>> ] c:/videobranch\boost\boost\function\function_template.hpp(649) : see reference to function template instantiation 'boost::function1<R,T0,Allocator>::function1<UnaryFunction>(Functor,boos t::enable_if_c<B,T>::type)' being compiled with [ R=const int &, T0=const std::pair<const std::string,int> &, Allocator=std::allocator<void>, UnaryFunction=boost::_bi::bind_t<int,boost::_mfi::dm<int,std::pair<const std::string,int>>,boost::_bi::list1<boost::_bi::list_av_1<boost::arg<1>> ::B1>>, Functor=boost::_bi::bind_t<int,boost::_mfi::dm<int,std::pair<const std::string,int>>,boost::_bi::list1<boost::_bi::list_av_1<boost::arg<1>> ::B1>>, B=true, T=int ] c:/videobranch\boost\boost\iterator\transform_iterator.hpp(130) : see reference to function template instantiation 'boost::function<Signature>::function<UnaryFunction>(Functor,boost::enab le_if_c<B,T>::type)' being compiled with [ Signature=const std::map<std::string,int>::mapped_type &(const std::map<std::string,int>::value_type &), UnaryFunction=boost::_bi::bind_t<int,boost::_mfi::dm<int,std::pair<const std::string,int>>,boost::_bi::list1<boost::_bi::list_av_1<boost::arg<1>> ::B1>>, Functor=boost::_bi::bind_t<int,boost::_mfi::dm<int,std::pair<const std::string,int>>,boost::_bi::list1<boost::_bi::list_av_1<boost::arg<1>> ::B1>>, B=true, T=int ] WrapMap.cpp(20) : see reference to function template instantiation 'boost::transform_iterator<UnaryFunction,Iterator>::transform_iterator<b oost::_bi::bind_t<R,F,L>,std::_Tree<_Traits>::const_iterator,boost::use_ default,boost::use_default>(const boost::transform_iterator<boost::_bi::bind_t<R,F,L>,Iterator,Reference,V alue> &,boost::iterators::enabled<__formal>::base<T>::type *)' being compiled with [ UnaryFunction=boost::function<const std::map<std::string,int>::mapped_type &(const std::map<std::string,int>::value_type &)>, Iterator=std::map<std::string,int>::const_iterator, R=int, F=boost::_mfi::dm<int,std::pair<const std::string,int>>, L=boost::_bi::list1<boost::_bi::list_av_1<boost::arg<1>>::B1>, _Traits=std::_Tmap_traits<std::string,int,std::less<std::string>,std::al locator<std::pair<const std::string,int>>,false>, Reference=boost::use_default, Value=boost::use_default, __formal=true, T=boost::detail::enable_type ]

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Re: [Boost-users] [Iterators] Change in transform_iterator from1.31 to1.32?
by Nat Goodspeed 27 Jul '05

27 Jul '05

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org [mailto:boost-users- > bounces(a)lists.boost.org] On Behalf Of David Abrahams > Sent: Tuesday, July 26, 2005 5:41 PM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] [Iterators] Change in transform_iterator > from1.31 to1.32? > > If Nat were using the actual type of the bind expression as the first > argument to transform_iterator, this wouldn't be a problem (except -- > not sure if you care -- that it would be returned by value from the > iterator). Presumably, the bind object has an appropriate > non-reference nested result_type. [Nat] I must be missing something here -- but I'm eager for enlightenment. boost::bind() is a runtime expression. I need to write a typedef for const_iterator before we get anywhere near that point. How can I use a type defined on the bind object for the typedef I need? > Nat, what you are doing looks _really_ inefficient. The result of > make_transform_iterator is some iterator type that's very different > from, but convertible to, your const_iterator type. Going through > that extra layer using boost::function means you are doing a lot of > extra copying -- and potentially, dynamic memory allocation -- > whenever you ask for an iterator. [Nat] I would be very happy to do it better, once I discover how.

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Re: [Boost-users] [Iterators] Change in transform_iterator from1.31 to1.32?
by Nat Goodspeed 26 Jul '05

26 Jul '05

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org [mailto:boost-users- > bounces(a)lists.boost.org] On Behalf Of David Abrahams > Sent: Tuesday, July 26, 2005 5:41 PM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] [Iterators] Change in transform_iterator > from1.31 to1.32? > > Nat, what you are doing looks _really_ inefficient. The result of > make_transform_iterator is some iterator type that's very different > from, but convertible to, your const_iterator type. Going through > that extra layer using boost::function means you are doing a lot of > extra copying -- and potentially, dynamic memory allocation -- > whenever you ask for an iterator. [Nat] Truth to tell, I'm looking forward to when you introduce the equivalent of transform_iterator in Boost.Range... that will remove a lot of redundant declaration! ;-)

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date_time: from local time to UTC
by J Liu 26 Jul '05

26 Jul '05

I am using Boost 1.31 data time library with MSVC6. I want to use local TZ setting to transfer a local time to utc time. I noticed that we can use boost::date_time::c_local_adjustor<ptime>::utc_to_local() to change a utc time to local time based on local TZ settings. But this class does not have local_to_utc(). While boost::date_time::local_adjustor<ptime, -5, us_dst>::local_to_utc() works, it does not use local TZ settings. Is there anyway I can use local TZ setting to do the translation? Thanks

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Simple Boost Lambda problem using argument as object. part II
by Thaddeus Olczyk 26 Jul '05

26 Jul '05

Thank you for your quick replies, and apologies for asking what are probably quite simple questions. However I find the documentation of Lambda a bit confusing. Another sample I am having problems with: #include <boost/lambda/lambda.hpp> #include <boost/lambda/bind.hpp> #include <boost/lambda/if.hpp> #include <vector> #include <string> #include <iostream> using boost::lambda::_1; class A { std::string s; public: A(std::string sIn):s(sIn){} void print_A() { std::cout<<"A="<<s<<std::endl; } bool isLong() { return s.length()>5; } }; int main() { std::string in; std::vector<A *> alist; std::vector<A *> longAList; while(in!="end") { in=""; std::getline(std::cin,in); alist.push_back(new A(in)); } std::for_each(alist.begin(),alist.end(), boost::lambda::if_then(bind(&A::isLong,_1),longAList.push_back(_1))); return 1; } -------------------------------------- main.cpp: In function `int main()': main.cpp:37: error: no matching function for call to `std::vector<A*, std::allocator<A*> >::push_back(const boost::lambda::lambda_functor<boost::lambda::placeholder<1> >&)' Suggestions? Thanks -- Thad

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Test Tools Linking Problem
by Merrill Cornish 26 Jul '05

26 Jul '05

I am an experienced programmer, but new to the Boost Libraries. I am using Boost 1.32.0 with MinGW under XP Pro. I have successfully compiled and link a program to the boost_regex-mgw-mt-1_32.dll Now I am trying use Boost test tools to write tests for it. When I compile and link, the compile passes without warnings, but the link fails with undefined reference to 'boost::test_tools::tt_detail::message_impl( boost::basic_wrap_stringstream<char>&, boost::unit_test::basic_cstring<char const>, unsigned int)' I initially set up to statically link with libboost_unit_test_framework-mgw-mt-1_32.lib. When I got the undefined reference, I added libboost_test_exec_monitor-mgw-mt-1_32.lib and libboost_prg_exec_monitor-mgw-mt-1_32.lib, "just in case." Still undefined. Eventually, I tried added in almost all of the static libraries PLUS copies all of the DLL into the program directory. Still undefined. At that point, I figured that something more than an incomplete makefile is the problem here. Anyone have any idea what I've missing? Merrill

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Re: [Boost-users] minimal spanning trees & Visual C++ 7.1
by Jasper, Alexander 26 Jul '05

26 Jul '05

> -----Ursprüngliche Nachricht----- > Von: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org]Im Auftrag von > Felipe Magno > de Almeida > Gesendet: Montag, 25. Juli 2005 22:04 > An: boost-users(a)lists.boost.org > Betreff: Re: [Boost-users] minimal spanning trees & Visual C++ 7.1 > > > On 7/25/05, Amit K. Jain <omlette(a)gmail.com> wrote: > > Thank you, it worked! That sounds good! > > > > It is bizarre behavior on the compiler's part, I hope they get it > > fixed eventually. > > > > -Amit > > > > > Hi! > > > > > > I suffered from ICEs using boost as well. They occured > using multi_index lib, though. Turning of "Minimal Rebuild" > helped for me. > > Minimal rebuild has given a lot of headache to me already. It has > introduced bugs in my applications when using boost(I think it > probably gets mistaken with its compilation depedancy and left some > files without compile, that in fact should have been recompiled... I > dont know...). Everyone seems to have the same problems. Often enough the strangest behavior has gone vanished after doing a "rebuild all". Some times it is saying "no relevant changes detected" ... in fact they weren't quite so irrelevant. Have you noticed this annoying bug of VC 7.1 debugger: create 2 (or more) files with the same name in different directories and build static libs from these directories. Put all projects in one solution file. The debugger is unable to distinguish between the 2 files. Every break is magically moved from one file to the other, when stepping code, the cursor moves in one file, but the code is executed in the other file. Annoying! I hope they fixed that with 8.0. > > > > > > > kind regards > > > > > > Alex > > > > _______________________________________________ > > Boost-users mailing list > > Boost-users(a)lists.boost.org > > http://lists.boost.org/mailman/listinfo.cgi/boost-users > > > > > -- > Felipe Magno de Almeida > Developer from synergy and Computer Science student from State > University of Campinas(UNICAMP). > Unicamp: http://www.ic.unicamp.br > Synergy: http://www.synergy.com.br > "There is no dark side of the moon really. Matter of fact > it's all dark." > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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SImple Boost Lambda problem using arguement as object.
by Thaddeus Olczyk 26 Jul '05

26 Jul '05

This piece of sample code demonstrates my problem quite well: #include <boost/lambda/lambda.hpp> #include <vector> #include <string> #include <iostream> using boost::lambda::_1; class A { std::string s; public: A(std::string sIn):s(sIn){} void print_A() { std::cout<<"A="<<s<<std::endl; } }; int main() { std::string in; std::vector<A *> alist; while(in!="end") { in=""; std::getline(std::cin,in); alist.push_back(new A(in)); } std::for_each(alist.begin(),alist.end(), _1->print_A()); // This is line 30 return 1; } ---- Using g++ ( 3.??) and the latest boost, I get this error: main.cpp: In function `int main()': main.cpp:30: error: base operand of `->' has non-pointer type `const boost::lambda::lambda_functor<boost::lambda::placeholder<1> >' Can anyone explain how to fix this? Thanks -- Thad

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