- Boost-users - lists.boost.org

[boost-users][boost foreach, iterating]
by chun ping wang 03 Dec '07

03 Dec '07

hi, is their anyway where i can use boost foreach to iterate through two different containers at once. Like I have two vector of float and i want to iterate through them parallell.. (not using indexing.. since it doesn't work with all types). Thanks. Something that is equalivent to python, for x,y in xArray, yArray: # do some awesome stuff. print x, y

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Re: [Boost-users] [type_traits] checking if some type is copyconstructible or assignable
by Ovanes Markarian 03 Dec '07

03 Dec '07

I don't believe it as well, since I tried to implement it over the weekend, but I got always stuck, so I thought may be the boost gurus know how to do it ;) Thanks for your answer! Best Regards, Ovanes On 12/3/07, John Maddock <john(a)johnmaddock.co.uk> wrote: > > > > Ovanes Markarian wrote: > > >> Hello all! > > >> > > >> I am wondering, why the type_traits do not have a construct to check > > >> if some type is copy constructible (I mean if the copy constructor > > >> is available (public) or not). > > >> > > >> > > >> May be it can be implemented via calculating at compile time if some > > >> type can be copied or not... May be it is not possible at all. > > > > We don't believe that it's possible in the current language, sorry. Of > > course if you can prove us wrong..... > > > > Regards, John. <http://lists.boost.org/mailman/listinfo.cgi/boost-users> > >

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[type_traits] checking if some type is copy constructible or assignable
by Ovanes Markarian 03 Dec '07

03 Dec '07

Hello all! I am wondering, why the type_traits do not have a construct to check if some type is copy constructible (I mean if the copy constructor is available (public) or not). May be it can be implemented via calculating at compile time if some type can be copied or not... May be it is not possible at all. With Kind Regards, Ovanes

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build boost.python tutorial "hello world" without bjam
by damny＠web.de 03 Dec '07

03 Dec '07

hi there, for some days i try to build the boost.python tutorial "hello world" without bjam on winxp by using mingw. so i wrote a *.bat-file: // --- snip ----------------------------------------------------------------------------- @echo off SETLOCAL SET DIR_MINGW=c:\development_compiler\mingw\ SET DIR_BOOST=c:\development_compiler\_boost\ SET DIR_PYTHN=c:\development_compiler\python25\ SET DIR_PRJCT=%~dp0 SET NME_PRJCT=hello SET CC=c:\development_compiler\mingw\bin\g++.exe SET INCL=-I%DIR_BOOST%include\boost-1_34_1 -I%DIR_PYTHN%include -I%DIR_MINGW%include SET LIBS=-L%DIR_BOOST%lib -L%DIR_PYTHN%libs -L%DIR_MINGW%lib %CC% -O0 -shared %INCL% %LIBS% -lboost_python-mgw34-s-1_34_1 -lpython25 %DIR_PRJCT%%NME_PRJCT%.cpp -o %NME_PRJCT%.pyd ENDLOCAL // --- snip ----------------------------------------------------------------------------- this works fine. but nevertheless it produces errors. // --- snip ----------------------------------------------------------------------------- D:\Temp\boost_test>c:\development_compiler\mingw\bin\g++.exe -O0 - shared -Ic:\development_compiler\_boost\include\boost-1_34_1 -Ic:\development_compiler\python25\include -Ic:\development_compiler\mingw\include -Lc:\development_compiler\_boost\lib -Lc:\development_compiler\python25\libs -Lc:\development_compiler\mingw\lib -lboost_python-mgw34-mt-s-1_34_1 -lpython25 D:\Temp\boost_test\hello.cpp -o hello.pyd C:\DOKUME~1\DBlock\LOKALE~1\Temp/cciAbaaa.o:hello.cpp:(.text+0x11e): undefined reference to `_imp___ZN5boost6python6detail11init_moduleEPKcPFvvE' C:\DOKUME~1\DBlock\LOKALE~1\Temp/cciAbaaa.o:hello.cpp:(.text$_ZN5boost6python3de fIPFPKcvEEEvS3_T_[void boost::python::def<char const* (*)()>(char const*, char const* (*)())]+0x6e): undefined reference to `_imp___ZN5boost6python6detail17scope_setattr_docEPKcRKNS0_3api6objectES3_' C:\DOKUME~1\DBlock\LOKALE~1\Temp/cciAbaaa.o:hello.cpp:(.text$_ZN5boost6python6detail17make_function_auxIPFPKcvENS0_21default_call_policiesENS_3mpl7vector1IS4_EE EENS0_3api6objectET_RKT0_RKT1_[boost::python::api::objectboost::python::detail: :make_function_aux<char const* (*)(), boost::python::default_call_policies, boost::mpl::vector1<char const*> >(char const* (*)(), boost::python::default_call_policies const&, boost::mpl::vector1<char const*> const&)]+0x73): undefined refere nce to `_imp___ZN5boost6python7objects15function_objectERKNS1_11py_functionE' C:\DOKUME~1\DBlock\LOKALE~1\Temp/cciAbaaa.o:hello.cpp:(.text$_ZN5boost6python7objects21py_function_impl_baseC2Ev[boost::python::objects::py_function_impl_base:: py_function_impl_base()]+0x7): undefined reference to `_imp___ZTVN5boost6python7objects21py_function_impl_baseE' C:\DOKUME~1\DBlock\LOKALE~1\Temp/cciAbaaa.o:hello.cpp:(.rdata$_ZTVN5boost6python7objects23caller_py_function_implINS0_6detail6callerIPFPKcvENS0_21default_call_p oliciesENS_3mpl7vector1IS6_EEEEEE[vtable for boost::python::objects::caller_py_function_impl<boost::python::detail::caller<char const* (*)(), boost::python::def ault_call_policies, boost::mpl::vector1<char const*> > >]+0x18): undefined reference to 'boost::python::objects::py_function_impl_base::max_arity() const' C:\DOKUME~1\DBlock\LOKALE~1\Temp/cciAbaaa.o:hello.cpp:(.text$_ZN5boost6python3api6objectC2Ev[boost::python::api::object::object()]+0x7): undefined reference to `_imp___Py_NoneStruct' C:\DOKUME~1\DBlock\LOKALE~1\Temp/cciAbaaa.o:hello.cpp:(.text$_ZN5boost6python7objects23caller_py_function_implINS0_6detail6callerIPFPKcvENS0_21default_call_poli ciesENS_3mpl7vector1IS6_EEEEED1Ev[boost::python::objects::caller_py_function_impl<boost::python::detail::caller<char const* (*)(), boost::python::default_call_policies, boost::mpl::vector1<char const*> > >::~caller_py_function_impl()]+0x16) : undefined reference to `_imp___ZN5boost6python7objects21py_function_impl_baseD2Ev' C:\DOKUME~1\DBlock\LOKALE~1\Temp/cciAbaaa.o:hello.cpp:(.text$_ZN5boost6python7objects23caller_py_function_implINS0_6detail6callerIPFPKcvENS0_21default_call_poli ciesENS_3mpl7vector1IS6_EEEEED0Ev[boost::python::objects::caller_py_function_impl<boost::python::detail::caller<char const* (*)(), boost::python::default_call_policies, boost::mpl::vector1<char const*> > >::~caller_py_function_impl()]+0x16) : undefined reference to `_imp___ZN5boost6python7objects21py_function_impl_baseD2Ev' C:\DOKUME~1\DBlock\LOKALE~1\Temp/cciAbaaa.o:hello.cpp:(.text$_ZNK5boost6python15to_python_valueIRKPKcEclES5_[boost::python::to_python_value<char const* const&>::operator()(char const* const&) const]+0xf): undefined reference to `_imp___ZN5boost6python9converter19do_return_to_pythonEPKc' C:\DOKUME~1\DBlock\LOKALE~1\Temp/cciAbaaa.o:hello.cpp:(.text$_ZNK5boost6python9type_info4nameEv[boost::python::type_info::name() const]+0x15): undefined reference to `_imp___ZN5boost6python6detail12gcc_demangleEPKc' collect2: ld returned 1 exit status // --- snip ----------------------------------------------------------------------------- any ideas what's wrong? any ideas how to fix that? many, many thnx daniel PS: i build boost.python by doing this ... // --- snip ----------------------------------------------------------------------------- @echo off SETLOCAL SET path=%path%;C:\Development_Compiler\MinGW\Bin bjam.exe -a "-sTOOLS=mingw" "-sGCC_ROOT_DIRECTORY=C:\Development_Compiler\MinGW" "-sPYTHON_VERSION=2.5" "-sPYTHON_ROOT=C:\Development_Compiler\Python25" --build-dir=C:\Temp --toolset=gcc --with-python install ENDLOCAL // --- snip ----------------------------------------------------------------------------- _____________________________________________________________________ Der WEB.DE SmartSurfer hilft bis zu 70% Ihrer Onlinekosten zu sparen! http://smartsurfer.web.de/?mc=100071&distributionid=000000000066

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Simple Linking Error
by Daniel 03 Dec '07

03 Dec '07

I wrote a simple "Hello, world!" program to test if boost/asio was working correctly: #include <iostream> #include <boost/date_time/posix_time/posix_time.hpp> int main() { std::cout << "Hello, world!\n"; return 0; } But, I get this: (GCC C++ 4.1.2/Linux version 2.6.22-gentoo-r8) test.cpp:(.text+0x10b): undefined reference to `boost::system::get_system_category()' test.cpp:(.text+0x115): undefined reference to `boost::system::get_posix_category()' test.cpp:(.text+0x11f): undefined reference to `boost::system::get_posix_category()' test.cpp:(.text+0x129): undefined reference to `boost::system::get_system_category()' This happens when I used '#include <boost/date_time/posix_time/posix_time.hpp>' I can't figure out what I'm missing

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serialization of vector of pointers
by Stathis 03 Dec '07

03 Dec '07

Hi, What is the right way to serialize/deserialize a container of pointers, e.g. std::vector< int* > ? I want to store the values, not the addresses in this case. Should I just flatten my data and store it in a different fashion, then read the flat data and build my objects with a builder? I ended up storing the size of the container in a separate variable before the data, when serializing. Then when deserializing, I use this size value to scale the container, create new ints, read their individual values via the deserialized data values and finally store them back to the new object. Can you give an example of how to do this better? cheers, --stathis

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[serialization] Can binary-objects be trackable ?
by Youhei Murakami 03 Dec '07

03 Dec '07

Hello everyone. I found a description pasted below in boost/serialization/binary_object.hpp. Does this description means that binary-objects can't track ? [ in binary_object.hpp ] // don't track binary objects - usually they will be created on the stack // and tracking algorithm (which uses the object address) might get // confused. note that these address will likely be members of some // other structure which itself is tracked, so as a practical matter // suppressing tracking shouldn't cause any redundancy. BOOST_CLASS_TRACKING(binary_object, boost::serialization::track_never) #endif // BOOST_SERIALIZATION_BINARY_OBJECT_HPP

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Copying types from a mpl vector to a fusion vector
by Germán Diago 02 Dec '07

02 Dec '07

Hello. I'm trying to build a library and I'm doing heavy use of boost mpl and fusion libraries. I'd like to know a way to fill a boost::fusion::vector<> with the types contained in a boost::mpl::vector. Anyone knows how to do this? The code I have so far: template <class T1, class T2, class T3, class T4, class T5, class T6, class T7, class T8, class T9, class T10> struct Func { //This is the initial sequence typedef typename boost::mpl::vector<T1, T2, T3, T4, T5, T6, T7, T8, T9, T10> sequence; //The sequence without NullTypes typedef typename boost::mpl::filter_view<sequence, boost::mpl::not_<boost::is_same<NullType, boost::mpl::_1> > >::type validsequence; //The vector I want to fill with validsequence. Note that this is a fusion vector, not a mpl vector typedef boost::fusion::vector<> voidvector; /***************PROBLEM HERE*******************/ //I want to copy validsequence types into voidvector typedef typename somewaytocopy::type type; }; Thanks in advance.

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[regex] problem with regular expression
by John Kiopela 02 Dec '07

02 Dec '07

Hi all, I am having some troubles with making a regular expression to parse a file of financial data. First, the file looks like this (simplified): BEGIN FINANCIAL INFORMATION 0 4 John (the name is mentioned somewhere between the two tags) 6 3 8 END FINANCIAL INFORMATION BEGIN FINANCIAL INFORMATION 0 David 6 8 END FINANCIAL INFORMATION BEGIN FINANCIAL INFORMATION 2 4 7 4 0 3 John 6 8 END FINANCIAL INFORMATION I want to create a regular expression which gives me all financial informations of John. My first try was: "BEGIN FINANCIAL INFORMATION.*?John.*?END FINANCIAL INFORMATION" The problem here is that the second ".*?" also matches "END FINANCIAL INFORMATION", which means that the following substring is also a match: BEGIN FINANCIAL INFORMATION 0 David 6 8 END FINANCIAL INFORMATION BEGIN FINANCIAL INFORMATION 2 4 7 4 0 3 John 6 8 END FINANCIAL INFORMATION Can somebody please help me with this regular expression? I'm trying to find out how I can type "any character except the string 'END FINANCIAL INFORMATION'", but without succes so far. Thanks in advance. Kind regards, John

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boost-users [boost lambda, boost foreach]
by chun ping wang 02 Dec '07

02 Dec '07

Hi, lets say i have two arbitary container of any stl type. template < class T, template <typename ELEM, typename = std::allocator<ELEM> > class CONT > typename boost::enable_if<boost::is_floating_point<T>, T>::type getManhattanDistance(const CONT<T>& ObjectX, const CONT<T>& ObjectY) I want to be able to iterate through both containers to get the euclidean distance.. i.e. sqrt of sum of each item in ObjectX - ObjectY square. Psuedocode looks like this.. /*********************************************** * getManhattanDistance(ObjectX, ObjectY) * * overAllSum <-- 0 * * for i <-- 0 to sizeof (ObjectX) * * Xn <-- ObjectX[i] * * Yn <-- ObjectY[i] * * difference <-- (Xn - Yn) * -1 * * overAllSum <-- overAllSum + difference * ***********************************************/ but i want to make it as abstract (allowing nonindexable containers) but also clear as possible without losing speed. Whats the best way to do this using boost library.

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