August 2007 - Boost-users - lists.preview.boost.org

Program_options : option couples and order
by Patrick Sizun 30 Aug '07

30 Aug '07

Hi, I would like to know if it's possible, with program_options, to handle the order in which several values of the same options are entered. E.g. : when entering prog -f file1.txt -n 2 -f file2.txt -n 3 I need to get the (f,n) couples right, and the use of the -n option should be mandatory for each file. How is it possible to enforce that? or does it all belong to the post-processing of the options ? Regards, Patrick

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Re: [Boost-users] Program_options assertion failure
by Fletcher, Matthew (Information Technology) 29 Aug '07

29 Aug '07

Well I presume you've already tried turning off the unicode option but I would try recompiling with the setting 'Use Multi-Byte Character Set' and also have 'Treat wchar_t as Built-in Type' set to No. The unicode setting doesn't affect the char *'s, but could certainly affect what happens when you create a std::string from one without explicitly setting a size/allocator. I agree with James that a mismatch between these settings is a very likely cause. Matt -- This e-mail is confidential and the information contained in it may be privileged. It should not be read, copied or used by anyone other than the intended recipient. If you have received it in error, please contact the sender immediately by telephoning +44 (0)20 7623 8000 or by return email, and delete the e-mail and do not disclose its contents to any person. We believe, but do not warrant, that this e-mail and any attachments are virus free, but you must take full responsibility for virus checking. Please refer to http://www.dresdnerkleinwort.com/disc/email/ and read our e-mail disclaimer statement and monitoring policy. Dresdner Kleinwort is the trading name of the investment banking division of Dresdner Bank AG, and operates through Dresdner Bank AG, Dresdner Kleinwort Limited, Dresdner Kleinwort Securities Limited and their affiliated or associated companies. Dresdner Bank AG is a company incorporated in Germany with limited liability and registered in England (registered no. FC007638, place of business 30 Gresham Street, London EC2V 7PG), and is authorised by the German Federal Financial Supervisory Authority and by the Financial Services Authority ('FSA') and regulated by the FSA for the conduct of designated business in the UK. Dresdner Kleinwort Limited is a company incorporated in England (registered no. 551334, registered office 30 Gresham Street, London EC2V 7PG), and is authorised and regulated by the FSA. Dresdner Kleinwort Securities Limited is a company incorporated in England (registered no. 1767419, registered office 30 Gresham Street, London EC2V 7PG), and is authorised and regulated by the FSA.

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metaclass must be exactly Boost.Python.class, not a subclass?
by william.r.chesters＠jpmorgan.com 29 Aug '07

29 Aug '07

Hi, I'd like to create a metaclass M which I can use to construct new Python classes C inheriting from a C++ base class B. B's metaclass is of course "Boost.Python.class", so I inherit M from that. It's not quite working for me though, because when I try to pass an instance of one of the C's back to C++, I get a "TypeError: No registered converter was able to extract a C++ pointer to type B from this Python object of type C". It seems that BP is testing for "type(type(obj)) is Boost.Python.class" rather than "isinstance(Boost.Python.class, type(type(obj))". Is this an easy issue to fix or work around? Many thanks, William This communication is for informational purposes only. It is not intended as an offer or solicitation for the purchase or sale of any financial instrument or as an official confirmation of any transaction. All market prices, data and other information are not warranted as to completeness or accuracy and are subject to change without notice. Any comments or statements made herein do not necessarily reflect those of JPMorgan Chase & Co., its subsidiaries and affiliates. This transmission may contain information that is privileged, confidential, legally privileged, and/or exempt from disclosure under applicable law. If you are not the intended recipient, you are hereby notified that any disclosure, copying, distribution, or use of the information contained herein (including any reliance thereon) is STRICTLY PROHIBITED. Although this transmission and any attachments are believed to be free of any virus or other defect that might affect any computer system into which it is received and opened, it is the responsibility of the recipient to ensure that it is virus free and no responsibility is accepted by JPMorgan Chase & Co., its subsidiaries and affiliates, as applicable, for any loss or damage arising in any way from its use. If you received this transmission in error, please immediately contact the sender and destroy the material in its entirety, whether in electronic or hard copy format. Thank you. Please refer to http://www.jpmorgan.com/pages/disclosures for disclosures relating to UK legal entities.

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serialization lib, const data, documentation
by Robbie Morrison 29 Aug '07

29 Aug '07

Hello all Regarding the Boost.Serialization library. Archiving to XML requires the use of name-value-pairs for all serialized objects, be they stand-alone or encapsulated. I wanted to confirm the following is correct. In reference to the online and bundled HTML documentation: http://www.boost.org/libs/serialization/doc/serialization.html#const file:///.../boost_1_34_1/libs/serialization/doc/serialization.html#const It would appear that the code block which reads: ar & const_cast<T &>(t); should also mention that, in the case of XML serialization: using boost::serialization::make_nvp; // for convenience ar & make_nvp("t", const_cast<T &>(t)); // cast used on load Moreover, this code could be a candidate for a macro, something like (or would this create its own can of worms?): ar & BOOST_SERIALIZATION_NVP_CONSTDATA(T, t); ar & BOOST_SERIALIZATION_CONSTDATA_NVP(T, t); --- On that note, a new page describing user Boost.Serialization macros and their usage might be helpful. For instance I have created the following list (readers should note that my comments may well be incorrect): BOOST_CLASS_EXPORT_GUID(SubClass, "MySC") // GUID is "globally unique id" BOOST_CLASS_EXPORT(SubClass) // shortcut if class name is acceptable BOOST_CLASS_VERSION(Class, 2) // reset class version, the default is zero BOOST_IS_ABSTRACT(AbstractClass) // only some compilers [which ones ?] BOOST_SERIALIZATION_NVP(data) // shortcut if object name acceptable [1] BOOST_SERIALIZATION_BASE_OBJECT_NVP(Base) // shortcut if object name acceptable [2] BOOST_SERIALIZATION_SPLIT_MEMBER() // 'serialize' to 'save'/'load' BOOST_SERIALIZATION_SHARED_PTR(Class) // depreciated [3] BOOST_CLASS_TRACKING(MyVirtualBaseClass, boost::serialization::track_always) BOOST_SHARED_POINTER_EXPORT(T) // depreciated from Boost version 1.32 BOOST_SHARED_POINTER_EXPORT_GUID(T, K) // depreciated from Boost version 1.32 BOOST_SERIALIZATION_LIBRARY_VERSION // yields a "release" number [4] [1] boost::serialization::make_nvp("data", data); [2] requires #include <boost/serialization/base_object.hpp> [3] more specifically, for types without tracking set, that is using boost::serialization::track_never also under 1.34.1 this generates code only for particular Metrowerks and Borland compilers [4] requires #include <boost/serialization/serialization.hpp> (but doesn't appear to be maintained) I don't mind drafting out such a page. Could it be part of the official web documentation or would I be better to add it to the boost wiki as an informal contribution. many thanks in advance Robbie --- Robbie Morrison PhD student -- policy-oriented energy system simulation Institute for Energy Engineering (IET) Technical University of Berlin (TU-Berlin), Germany [from IMAP client]

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Program_options assertion failure
by Johnathan Bunn 29 Aug '07

29 Aug '07

im having an issue with a project using visual studio pro 2005 if it makes a difference the librarys im using are Qt, pdflib, boost, and some crystal com stuff thorugh activex my problem is that when I build in release my command line args are parsed fine and my application behaves as expected. when I build in debug mode, I get an asertion failure as follows Assertion failed: n == name.size()-2, file libs\program_options\src\options_description.cpp, line 122 the relevent code is as follows // process command line args.. po::options_description desc( "TEST" ); desc.add_options( ) ("help", "produce help message" ); ("hideSplash", "hide splash message" ) ("report", po::value<int>( ), "show requested report and quit" ) ; po::variables_map vm; po::store( po::parse_command_line( argc, argv, desc ), vm ); po::notify( vm ); if( vm.count( "help" ) ){ Log::Info::out( ) << "Help Message requested"; // show help window return true; } there is more blocks the same as the last if block that look for my other messages they are commented out now for testing though I am completely stumped and sought help on the #boost irc channel volodya and others on that channel were stumped as well if anyone has any insight into this issue I thank you in advance for your help :-D -- To follow the Path, Look to the master, Walk with the master, See through the master, Become the master

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Boost Parameter Question.
by Surya Kiran Gullapalli 29 Aug '07

29 Aug '07

Hello all, I'm a newbie to boost parameter library. I had no problem in using BOOST_PARAMETER_MEMBER_FUNCTION as long as the function is non static. what is the macro to use for static member function. I gave BOOST_PARAMTER_MEMBER_FUNCTION ( (static void), ... ) But i was getting warning messages with MSVC 8.0 compiler, with boost-1.34.1 warning C4042: 'unnamed-parameter': has bad storage class. I do not know whether these are harmless or not. Please help. Thanks, Surya

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[boost::format] How to not display 0 integer?
by tomasz2k＠poczta.onet.pl 29 Aug '07

29 Aug '07

Hello group I'm using boost::format heavily to format my output for user. I've run into a problem that I cannot resolve for now. I use this format: int i = 4; cout << format ("(%|1$+2|)") % i; // -> (+4) i = -4; cout << format ("(%|1$+2|)") % i; // -> (-4) That's fine and expected. But my question for the one below: int i = 0; cout << format ("(%|1$+2|)") % i; // -> ( 0) // -> ( ) how? How to avoid printing 0? I want formatter to print values in plus or in minus only. When there's value 0 - display only spaces to width. My problem is that I cannot create wrapper over that integer, I must feed formatter with int for various reasons. Does anyone know how to achive this? Maybe I override some parts of library or parsing method? Maybe some of you added your own formatts to formatter and want to share? Any hint or example would be valuable. Thanks in advance, Tomasz Kalkosiñski

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warning C4180 in VS 2005 for bind.hpp
by Adam Badura 29 Aug '07

29 Aug '07

I have a large project at work. We use Visual Studio 2005 with SP 1 and Boost 1.34.0. When we use boost::bind in algorithms on collections we very often get following warning (at level 3): J:\ThirdParty\boost_1_34_0\boost/bind.hpp(1575) : warning C4180: qualifier applied to function type has no meaning; ignored the detailed message is following (just an example extract from compilation log, sadly I was unable to produce a simple stand-alone example - but if it is required then I will give some more work into finding one): J:\ThirdParty\boost_1_34_0\boost/bind.hpp(1575) : warning C4180: qualifier applied to function type has no meaning; ignored J:\ThirdParty\boost_1_34_0\boost/bind.hpp(1609) : see reference to class template instantiation 'boost::_bi::add_cref<Pm,I>' being compiled with [ Pm=boost::shared_ptr<nle::views::ScrollEventListener> , I=1 ] j:\sources\Common/Helpers/Observable.h(128) : see reference to class template instantiation 'boost::_bi::dm_result<Pm,A1>' being compiled with [ Pm=boost::shared_ptr<nle::views::ScrollEventListener> (__thiscall boost::weak_ptr<nle::views::ScrollEventListener>::* )(void), A1=boost::arg<1> ] j:\sources\Common/Helpers/Observable.h(120) : while compiling class template member function 'void common::helpers::Observable<T>::registerListener(const boost::weak_ptr<T> &) const' with [ T=nle::views::ScrollEventListener ] j:\sources\NLE/Views/ScrollInfo.h(65) : see reference to class template instantiation 'common::helpers::Observable<T>' being compiled with [ T=nle::views::ScrollEventListener ] One of my colleagues found a "solution" to this problem. If the modifier "const" is removed in one of typedef's the no warning are generated. However we would like a better solution since modifying the library doesn't seem a good one. What to do? Adam Badura

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Graph: "extra" edge processing during BFS
by Eric Fowler 29 Aug '07

29 Aug '07

I have an algorithm that just screams breadth first search. After some thrashing around in the graph library I am confident in about 90% of the implementation. However there is one little snag: When I examine a grey vertex, I want to do some basic logic on the vertex and the "candidate" next edge to see if what I want to do with this edge and this vertex is "legitimate", according to my own definition of legitimacy(*). If the edge is good, I use it, perhaps relaxing it, if not, I just pass on it and go on to the next one. I would like to do this without tweaking or rewriting the BFS algo. Can this be done with just visitors and the various template parameters or must I write my own BFS variant (not that hard to do of course)? Eric * My idea of "legitimate" is to check to see if a path to a given vertex already contains a certain vertex. The path is built as I run the algorithm. "Parent" vertices are stored as the algorithm runs so I can follow a chain up from the examined vertex back to the root. So the basic logic is: Vertex u = Q.top(); Q.pop(); vis.examine_vertex(u, g); //this is already in BFS if(has_certain_property(u, g)) add_to_tree(u, g); else do_not_add(u, g); .... etc.

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Different functions based on type of iterator?
by HighCommander4 29 Aug '07

29 Aug '07

Let's say I had a function template <typename Iterator> void function(Iterator first, Iterator last); and I want it to call two different functions based on if Iterator is a random access iterator or just a forward iterator. Essentially, I want two versions of this function: template <typename RandomAccessIterator> void function(RandomAccessIterator first, RandomAccessIterator last); template <typename ForwardIterator> void function(ForwardIterator first, ForwardIterator last); I want a function call to function(a, b) to translate to the first one if a and b are random access iterators, and the second one if they are not. I'm thinking of somehow combining enable_if and concept checking, I'm just not sure how... -- View this message in context: http://www.nabble.com/Different-functions-based-on-type-of-iterator--tf4345… Sent from the Boost - Users mailing list archive at Nabble.com.

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