November 2006 - Boost-users

Re: [Boost-users] Boost ROCKS !!!!!
by Nindi Singh 01 Nov '06

01 Nov '06

Cool ! Actualy I am now working another factory implementation. In the new implementation, the Base Class will hold a typedef for a Boost Variant, and then the derived objects can be instantiated by the factory by being given a std::map of the variants and stripping out the values to make a call to the constructor of the derived class. The ONLY intrusion on the classes would be a typelist in the Base class to type the appropriate Boost::Variant and a typelist in the derived class identifing the signature of the constructor to be called by the factory, similar to the factory i have posted previously. The MPL really is VERY cool, and I think I have JUST touched the surface !!!. In fact I put my order in for 'C++ Template Metaprogramming: Concepts, Tools, and Techniques from Boost and Beyond' at Amazon this afternoon !!!! ----- Original Message ---- From: Sohail Somani <s.somani(a)fincad.com> To: boost-users(a)lists.boost.org Sent: Wednesday, 1 November, 2006 8:46:28 PM Subject: Re: [Boost-users] Boost ROCKS !!!!! > -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Nindi Singh > > For the past few months I have been making more and more use > of Boost, in fact I would say becoming more and more reliant > on Boost, every so often introducing myslef to a new library. > But discovering the MPL, well that was awsome. The first time > I applied it was to implement a factory. I would NEVR have > though of doing it this way WITHOUT the MPL. Any comments on > my use ( or indeed abuse !) of Boost would be more than apprieciated. [snip code] Actually, I've been thinking of doing something similar and I am also interested in what people say! PS: Boost does rock _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users ___________________________________________________________ The all-new Yahoo! Mail goes wherever you go - free your email address from your Internet provider. http://uk.docs.yahoo.com/nowyoucan.html

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Re: [Boost-users] Boost ROCKS !!!!!
by Sohail Somani 01 Nov '06

01 Nov '06

> -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Nindi Singh > > For the past few months I have been making more and more use > of Boost, in fact I would say becoming more and more reliant > on Boost, every so often introducing myslef to a new library. > But discovering the MPL, well that was awsome. The first time > I applied it was to implement a factory. I would NEVR have > though of doing it this way WITHOUT the MPL. Any comments on > my use ( or indeed abuse !) of Boost would be more than apprieciated. [snip code] Actually, I've been thinking of doing something similar and I am also interested in what people say! PS: Boost does rock

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Lambda probs
by Noah Roberts 01 Nov '06

01 Nov '06

My statement: T::iterator it = std::find_if(container.begin(), container.end(), l::bind(&typename T::value_type::GetName, l::_1) != l::constant(0) && !l::bind(stricmp, l::bind(&typename T::value_type::GetName, l::_1), l::var(name))); GetName() returns a char*. I get errors about there being no != or ! for const boost::lambda::lambda_functor<T> I also tried == 0 and == constant(0) for the second part. More detailed error follows: 1>c:\documents and settings\nroberts\my documents\visual studio 2005\projects\pipeflo refactor\code\clist_util.h(60) : error C2678: binary '!=' : no operator found which takes a left-hand operand of type 'const boost::lambda::lambda_functor<T>' (or there is no acceptable conversion) 1> with 1> [ 1> T=boost::lambda::lambda_functor_base<boost::lambda::action<2,boost::lambda::function_action<2>>,boost::tuples::tuple<char *(__thiscall NamedObject::* const )(void),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,boost::lambda::detail::bind_traits<boost::tuples::null_type>::type>> 1> ] 1> c:\program files\microsoft visual studio 8\vc\platformsdk\include\guiddef.h(197): could be 'int operator !=(const GUID &,const GUID &)' 1> while trying to match the argument list '(const boost::lambda::lambda_functor<T>, boost::lambda::lambda_functor<T>)' 1> with 1> [ 1> T=boost::lambda::lambda_functor_base<boost::lambda::action<2,boost::lambda::function_action<2>>,boost::tuples::tuple<char *(__thiscall NamedObject::* const )(void),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,boost::lambda::detail::bind_traits<boost::tuples::null_type>::type>> 1> ] 1> and 1> [ 1> T=boost::lambda::identity<const int> 1> ] 1> c:\documents and settings\nroberts\my documents\visual studio 2005\projects\pipeflo refactor\code\clist.h(358) : see reference to function template instantiation 'bool NameInUse<CList_tmpl<VALUE_TYPE>>(T &,const char *,DLinkObject *,HWND)' being compiled 1> with 1> [ 1> VALUE_TYPE=DLinkObject, 1> T=CList_tmpl<DLinkObject> 1> ] 1> c:\documents and settings\nroberts\my documents\visual studio 2005\projects\pipeflo refactor\code\clist.h(357) : while compiling class template member function 'bool CList_tmpl<VALUE_TYPE>::NameInUse(char *,VALUE_TYPE *,HWND)' 1> with 1> [ 1> VALUE_TYPE=DLinkObject 1> ] 1> c:\documents and settings\nroberts\my documents\visual studio 2005\projects\pipeflo refactor\code\lineupchangeable.h(13) : see reference to class template instantiation 'CList_tmpl<VALUE_TYPE>' being compiled 1> with 1> [ 1> VALUE_TYPE=DLinkObject 1> ]

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microsec_clock not recognized in VC8
by Cheng, Victor S 01 Nov '06

01 Nov '06

> I'm using 1.33.1 date_time library, but ran into a problem with > microsec_clock. It's not recognized in VC8: > > error C2653: 'microsec_clock' : is not a class or namespace name > > If I change it to second_clock, then it's fine. Is this a known > problem for VC8? > ---- Here is my test code -------- #include "boost/date_time/posix_time/posix_time.hpp" #include <iostream> int main() { using namespace boost::posix_time; using namespace boost::gregorian; ptime now = microsec_clock::local_time(); //second_clock::local_time(); ... } ----- Here is how I built the library ---- "C:\Program Files\Microsoft Visual Studio 8"\vc\bin\vcvars32.bat c: cd \dev\boost_1_33_1 bjam -sTOOLS=vc-8_0 --prefix=C:\Dev\Boost --without-python --builddir=build install ------------------------------------------------------------------------------ This message is intended only for the personal and confidential use of the designated recipient(s) named above. If you are not the intended recipient of this message you are hereby notified that any review, dissemination, distribution or copying of this message is strictly prohibited. This communication is for information purposes only and should not be regarded as an offer to sell or as a solicitation of an offer to buy any financial product, an official confirmation of any transaction, or as an official statement of Lehman Brothers. Email transmission cannot be guaranteed to be secure or error-free. Therefore, we do not represent that this information is complete or accurate and it should not be relied upon as such. All information is subject to change without notice. -------- IRS Circular 230 Disclosure: Please be advised that any discussion of U.S. tax matters contained within this communication (including any attachments) is not intended or written to be used and cannot be used for the purpose of (i) avoiding U.S. tax related penalties or (ii) promoting, marketing or recommending to another party any transaction or matter addressed herein.

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Re: [Boost-users] [boost.serialization] serialization crash
by RIVASSEAU Jean Noel 01 Nov '06

01 Nov '06

I've had the same problems. The problem is with the bool field. Code restoring the archive crashes if the bool stored in the archive is not equal to 0 or 1. But since you did not write a constructor in the Obj class, the boolean will actually be initialized with anything( eg, read 14675002 for example), and will be serialized that way in the archive since it seems the serialization code does not check if the bool is equal to 0 or 1 (only the restoration code). So, the solution is to initialize your boolean correctly and be very careful whenever you use booleans. However, I think the Serialization code should be fixed (remove the check for 0 or 1, it probably does more bad than good. Jean-Noël ________________________________ De : boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] De la part de Pavlo Korzhyk Envoyé : jeudi 26 octobre 2006 16:09 À : boost-users(a)lists.boost.org Objet : [Boost-users] [boost.serialization] serialization crash The following code crashes under cygwin+boost1.33 and under mingw+boost1.33 I create text archive in a file, and then serialization crashes when restoring object from that archive. The problem seem to be with bool field, if I replace bool x; with int x; in the class Obj implementation, everything runs fine. Is this a bug in serialization code? #include <iostream> #include <sstream> #include <fstream> #include <vector> #include <map> using namespace std; #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> #include <boost/serialization/vector.hpp> #include <boost/serialization/map.hpp> using namespace boost; using namespace boost::serialization; class Obj { friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & x; } public: bool x; }; class Item; class Cheq : public Obj{ friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & boost::serialization::base_object<Obj>(*this); ar & v; ar & id; } public: vector<Item> v; int id; Cheq(){} }; class Item{ friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & a; ar & s; } public: int a; string s; }; class Row{ friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & m1; ar & m2; } public: map<string,string> m1,m2; }; class Data{ friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & a; ar & m; ar & cheque; } public: int a; map<string,string> m; map<int,Cheq> cheque; }; BOOST_CLASS_TRACKING(Data, boost::serialization::track_never) #include "boost/serialization/export.hpp" BOOST_CLASS_EXPORT(Data); BOOST_CLASS_EXPORT(Cheq); BOOST_CLASS_EXPORT(Item); int main(int argc, char** argv) { Data d; d.cheque[0]=Cheq(); //if(argc>1 && argv[1][0]=='1') { ofstream os("datfile"); boost::archive::text_oarchive oar(os); oar << d; } //if(argc>1 && argv[1][0]=='2') { ifstream is("datfile"); boost::archive::text_iarchive iar(is); iar >> d; } cout << "without crash\n"; return 0; } -- WBR, Pavlo Korzhyk ICQ#155870780

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boost filesystem
by Aubrey, Jason 01 Nov '06

01 Nov '06

Hi, When I run the following program it runs successfully but throws an exception during shutdown. I don't know why, but it seems that the call to boost::filesystem::file_size() is corrupting memory somehow. This example only shows the call to file_size() but I think I've seen similar trouble with other calls within boost::filesystem. Am I doing something wrong here or is this a bug? Regards, Jason Aubrey ---------------------- Environment: OS: Win2k Compiler: VS7.1 Boost: v1.33.1 ---------------------- #include <boost/filesystem/operations.hpp> #include <fstream> int main(int, char**) { // Create a file using namespace std; const string fileName("/temp/test.txt"); ofstream file; file.open(fileName.c_str()); const string message("this is a test"); file << message; file.close(); const boost::intmax_t fileSize = boost::filesystem::file_size(fileName); if( fileSize != message.size() ) throw std::exception("Bad result"); return 0; } ---------------------- The following pop-up occurs during program completion: Window Title="Microsoft Visual C++ Debug Library" Window Icon=Critical Error Window Text=" Debug Assertion Failed! Program: .... File: dbgdel.cpp Line: 52 Expression: _BLOCK_TYPE_IS_VALID(pHead->nBlockUse) For information on how your program can cause an assertion failure, see the Visual C++ documentation on asserts. (Press Retry to debug the application)" Buttons=[Abort] [Retry] [Ignore]

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Error when build boost using GCC on AIX, "stdint.h not exist"
by kongko kongko 01 Nov '06

01 Nov '06

Hi,I want to install boost 1.33.1 on PowerPC AIX 5.1,my complier is GCC 4.0.1. This error occure: "/boost_1_33_1/boost/cstdint.hpp:42:23: error: stdint.h: A file or directory in the path name does not exist." I have can't find stdint.h in my system,Does anybody has the same problem?How can i solve it ? Thanks a lot. _________________________________________________________________ 免费下载 MSN Explorer: http://explorer.msn.com/lccn/

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Re: [Boost-users] [Boost.Parameter] How to Use Named Parameters in a Class Hierarchy?
by james.jones＠firstinvestors.com 31 Oct '06

31 Oct '06

From: "Wu Yinghui, Freddie" <yhwu(a)volumeinteractions.com> > To use the class hierarchy, my program loads the DLL requested by user > using LoadLibrary() (We're using Windows, but it should be similar to > Linux, I suppose), and makes use of the Derived1/Derived2 classes via a > pointer to the Base class. > > Since I have no information about the derived classes when building my > main executable (only Base class is known then), I cannot make direct > use of Derived1/Derived2 types in my main program. -- Yet, I need a way > to provide some arbitrary set of arguments to the derived classes. > > Hope my explanation clears your doubts. Do you have any suggestion or > alternative design in mind? Try a single boost::any parameter. Then pass structures as needed. This is essentially equivalent to the void* method everyone used in the bad old pre-Boost days, but it's type-safe. - James Jones Administrative Data Mgmt. Webmaster 375 Raritan Center Pkwy, Suite A Data Architect Edison, NJ 08837

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