June 2010 - Boost-users - lists.preview.boost.org

General C++: Unresolved reference to operator overloads
by Etienne Philip Pretorius 19 Jun '10

19 Jun '10

Hello List, I please be kind, as I know this is not boost related. Inside the header file I define the following: /* Operator + */ std::vector<std::uint8_t> operator+( const std::vector<std::uint8_t>& x, const std::vector<std::uint8_t>& y ); /* Operator - */ std::vector<std::uint8_t> operator-( const std::vector<std::uint8_t>& x, const std::vector<std::uint8_t>& y ); And then inside the implementation CPP file I do the following: /* Operator + */ std::vector<std::uint8_t> operator+( const std::vector<std::uint8_t>& x, const std::vector<std::uint8_t>& y ) { *obmitted for brievity* }; /* Operator - */ std::vector<std::uint8_t> operator-( const std::vector<std::uint8_t>& x, const std::vector<std::uint8_t>& y ) { *obmitted for brievity* }; Yet when I compile I keep on getting : undefined reference to `operator+(std::vector<unsigned char, std::allocator<unsigned char> > const&, std::vector<unsigned char, std::allocator<unsigned char> > const&)' Is there something that I am missing? Kind Regards, Etienne Pretorius

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[MPI] Test fails
by Miguel Ángel Vázquez 19 Jun '10

19 Jun '10

Dear all, I already installed Boost MPI library and I tested like you suggest in the tutorial (executing bjam in /libs/mpi/test). Unfortunately, it doesn't pass all the tests and I don't know whether they are important or not or what to do to try to fix them. I enclose you the output, hope someone can help me somehow. Cheers, Miguel

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Re: [Boost-users] building the boost documentation for reading off-line
by Steven Watanabe 19 Jun '10

19 Jun '10

AMDG Sean Farrow wrote: > Is there any way I can build the boost documentation to allow me to read > this on a machine that is (90) percent of the time not connected to the > internet. > The packaged releases include compiled documentation. If you're working off svn, please see https://svn.boost.org/trac/boost/wiki/BoostDocs/GettingStarted In Christ, Steven Watanabe

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boost serialization compile warnings
by Barry Haddow 19 Jun '10

19 Jun '10

Hi Does anyone know what these compiler warnings mean? I get them when I try to serialize a non-constant object. If I copy my object into a const, and then serialize, the warnings go away. I also get them from the demo. I looked at check.hpp, and it refers you to the rationale, but I see no explanation of 'object tracking' there. /mnt/saxnot3/bhaddow/boost/include/boost/mpl/print.hpp: In instantiation of ‘boost::mpl::print<boost::serialization::BOOST_SERIALIZATION_STATIC_WARNING_LINE<98> >’: /mnt/saxnot3/bhaddow/boost/include/boost/serialization/static_warning.hpp:92: instantiated from ‘boost::serialization::static_warning_test<false, 98>’ /mnt/saxnot3/bhaddow/boost/include/boost/archive/detail/check.hpp:98: instantiated from ‘void boost::archive::detail::check_object_tracking() [with T = Josiah::FVector]’ regards Barry

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building the boost documentation for reading off-line
by Sean Farrow 19 Jun '10

19 Jun '10

Hi: Is there any way I can build the boost documentation to allow me to read this on a machine that is (90) percent of the time not connected to the internet. Regards Sean.

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Serialize a boost function (actually a member function pointer)
by Fabian Fritz 18 Jun '10

18 Jun '10

Hi, I want to use boost serialization to serialize a boost function. In other places I learned that I need to use non-intrusive serialization and the target<>() method, but I still don't get it to work: #include <vector> #include <iostream> #include <fstream> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <boost/function.hpp> class A { public: void func1() { std::cout << "Hello World"; } }; typedef void (A::*fPointerType)(); class FuncPointerWrapper { boost::function<void (A*)> f; friend class boost::serialization::access; template<typename Archive>void serialize(Archive & ar, const unsigned int version) { ar & f; } public: FuncPointerWrapper() {} FuncPointerWrapper(fPointerType fun) { f = fun; } boost::function<void (A*)> getFuncPointer() {return f;} }; //non-intrusive namespace boost { namespace serialization { template<typename Archive>void serialize(Archive & ar,boost::function<void (A*)> & f, const unsigned int version) { ar & (f.template target<fPointerType>()); //error: no match for 'operator&' in 'ar & ((boost::function_base*)(+f))->boost::function_base::target [with Functor = void (A::*)()]()'| // but how do I have to use it then? } } } int main() { FuncPointerWrapper fpw(&A::func1); std::ofstream ofs("filename"); { boost::archive::text_oarchive oa(ofs); // write class instance to archive oa << fpw; // archive and stream closed when destructors are called } A a; fpw.getFuncPointer()(&a); // Some other place, some other time: FuncPointerWrapper fpw2; { std::ifstream ifs("filename"); boost::archive::text_iarchive ia(ifs); ia >> fpw2; } A b; fpw2.getFuncPointer()(&b); }

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What is boost::copy?
by John Dlugosz 18 Jun '10

18 Jun '10

In other threads, I see mentions of boost::copy. I'd like to find out about it. Which library is it in? How is it different from std::copy? (Once I know what it's part of, I'll just read the docs) --John TradeStation Group, Inc. is a publicly-traded holding company (NASDAQ GS: TRAD) of three operating subsidiaries, TradeStation Securities, Inc. (Member NYSE, FINRA, SIPC and NFA), TradeStation Technologies, Inc., a trading software and subscription company, and TradeStation Europe Limited, a United Kingdom, FSA-authorized introducing brokerage firm. None of these companies provides trading or investment advice, recommendations or endorsements of any kind. The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer.

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[lambda] make lambda play well with std::complex, imag, real, abs, etc.
by alfC 18 Jun '10

18 Jun '10

Hi, I need some complex arithmetic in lambda expressions, for that I implemented this to make some std::complex functions work with Boost.Lambda. namespace boost{ namespace lambda{ #define BOOST_LAMBDA_COMPLEX_IMPL(function_name) \ template<typename Arg> \ lambda_functor<lambda_functor_base< \ action<2, function_action<2> >, \ boost::tuples::tuple< \ const double& (* const)(const std::complex<double>&), \ const lambda_functor<Arg> \ > \ > > function_name(const lambda_functor<Arg>& f){ \ return boost::lambda::bind(static_cast<double const&(*) (std::complex<double> const&)>(&std::function_name<double>), f); \ } BOOST_LAMBDA_COMPLEX_IMPL(real) BOOST_LAMBDA_COMPLEX_IMPL(imag) BOOST_LAMBDA_COMPLEX_IMPL(abs) BOOST_LAMBDA_COMPLEX_IMPL(norm) } } use as boost::function<double(complex)> f = imag(_1) + real(_1) + abs(_1+2.); I have two questions about it: 1) Is this something that is implemented in some other way already? 2) it seem imposible to generalized to other template overloads of imag<T>, real<T> (i.e. something that can be used for std::complex<T>) because the template parameter Arg doesn't have information about the actual type. is it so? (comments on the code and alternatives also accepted) Thank you, Alfredo

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[type_traits] Checking for same class template
by Edward Diener 18 Jun '10

18 Jun '10

The type_trait is_same<T,T> can be used to check if two types are the same. Is there a type_trait to check if two templates are the same ? A template class I am developing takes as a template parameter a template rather than a class and I would like to check, to be used in MPL, whether the template being passed as a template parameter is the same as another template.

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Re: [Boost-users] Can't compile with date time
by André Santee 18 Jun '10

18 Jun '10

According to the doc, date_time is one of the libs which the build is not necessary (but optional). Am I misinterpreting it or is it wrong? Here's the link: http://www.boost.org/doc/libs/1_41_0/more/getting_started/windows.html#head… André. Date: Thu, 17 Jun 2010 18:55:43 -0400 > From: Brett Gmoser <bgmoser(a)codexterous.com> > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Can't compile with date time > Message-ID: <4C1AA7EF.4080506(a)codexterous.com> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > On 6/17/2010 6:42 PM, Andr? Santee wrote: > > Why is my Visual C++ Express giving me the following error message? > > > > LINK : fatal error LNK1104: cannot open file > > 'libboost_date_time-vc90-mt- > gd-1_41.lib' > > > > The boost documentation says that the date_time library is > > header-only. Why is it trying to find binaries? > > > > Andre. > > > > I'm not sure where you read that date_time is header only, but it isn't. > :) You'll need to build boost to use it. Make sure MSVC knows where to > find the binaries you want it to link with. >

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