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Properties and boost::any / boost::program_options
by Dirk Gregorius 27 Dec '04

27 Dec '04

Dear group, I have a text file which defines several properties. For example: // Properties.txt "Position" "1.0 2.0 3.0" "Color" "1.0 0.0 0.0" "Intensity" "500" I wonder if it is possible to use the Property structure like defined in the boost::any example: // Property from boost::any help file struct Property { Property(); Property( const char* ) // Convinence c'tor for easy use with std::find Property( const std::string&, const boost::any& ); std::string Key; boost::any Value; } typedef std::vector<Property> Properties_t; // Operators for sorting and finding bool operator==( const Property& lhs, const Property& rhs ) { return lhs. Key == rhs.Key; } bool operator<( const Property& lhs, const Property& rhs ) { return lhs. Key < rhs.Key; } I want to do two things. First I like to parse through my text file and simply push_back() the parsed properties as pairs of strings: // The parse function - basically void ParseProperties( std::ifstream& is, Properties_t& properties ) { std::string key, value; while( is ) { is >> key >> value; properties.push_back( Property( key, value ) ); } std::sort( properties.begin(), properties.end() ); } Then later I would like to be able to process the properties like this: // Process the parsed properties... void ProcessProperties( const Properties_t& properties ) { typedef Properties_t::iterator PIter; PIter pos = find( properties.begin(), properties.end(), "Position" ); // Here we need the const char* c'tor if ( pos != properties.end() ) Vector3 position = any_cast<Vector3>( pos->Value ); } 1. Is it possible to use boost::any in this way? If yes - where and how do I have to implement the conversions? 2. If this is not possible could I use boost::programm_options instead for the value type? How and where do I have to implement the conversion here. 3. Would you suggest to define a simple Value class like this when I can not use any boost classes: class Value { public: Value(); Value( const std::string& ) template<typename T> T As(void ) const; private: std::string m_Value; } Are there any rules how to implement such a class? I have very, very few experience with template code. So do I need a traits class to look up the conversions in the As() function or how should a simple class like this be implemented in order to be nicely extendable by a client? I wish you all a nice christmas and a happy new year! Regards, -Dirk

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[boost][regex] Bug in regex 1.32 ?
by Jan Hermelink 27 Dec '04

27 Dec '04

Hello, I think there is a bug in Boost.Regex 1.32.0 with regex_constants::icase. std::string s("xx"); boost::regex re("x", boost::regex_constants::icase); boost::regex_replace(s, re, "a"); The replace yields "axa"; should be "aa" I think. Without the icase flag the replace yields "aa". Thank you Jan

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Re: [boost] Re: thoughts on a GUI component library
by brangdon＠cix.compulink.co.uk 27 Dec '04

27 Dec '04

In-Reply-To: <cqcjii$hs0$1(a)sea.gmane.org> dave(a)boost-consulting.com (David Abrahams) wrote (abridged): > That's okay for simple things, but for any serious printing work you > need to know you're talking to a printer. For example, you may need to > embed postscript in your output stream. Not all printers support postscript, so you'd need to know not just that you were printing, but what kind of printer it was. Although there probably needs to be some kind of abstraction-busting pass-through mechanism, I see it as the exception rather than the rule. Another issue is transparency. My employer's drawing framework supports semi-transparency in the form of an alpha channel. This is used by us for things like anti-aliasing, and by users for subtle colour blends. Some printers can support transparency directly and some cannot. We found we needed a relatively elaborate architecture to hide that detail from application drawing code. I'm a bit concerned about the scope of this boost project. Our drawing framework is pretty huge. -- Dave Harris, Nottingham, UK

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automatic garbage collecting algorithm and its implementation in c++
by yilin yang 27 Dec '04

27 Dec '04

hi, everybody i've just designed and coded a garbage collecting infrastructure named u_canforget. it was uploaded onto the news group at boost.yahoo. the main idea is that we count the reference to track the life-cycle of the given object. as the new operator was overloaded to statisfy this requirement. the other important concept was the reference object. with the syntax represented by the redefined macros, the codes may be written in a very simple way with relationships automatically constructed, objects are freed without delete operater can be realized as well. i would keep tracking this thread, if there are any thought about this algorithm. thx for your advices. your's yilin. --------------------------------- Do You Yahoo!? 150万曲MP3疯狂搜，带您闯入音乐殿堂美女明星应有尽有，搜遍美图、艳图和酷图 1G就是1000兆，雅虎电邮自助扩容！

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Re: [boost] [gui] Shoulders of Giants
by brangdon＠cix.compulink.co.uk 26 Dec '04

26 Dec '04

In-Reply-To: <20041222211651.GD2616(a)maribor.izzy.net> alan-boost(a)engrm.com (Alan Gutierrez) wrote (abridged): > I'd like to take some time and study what has gone before. > [...] > I've advocated the use of a CSS layout component to render > the View-Controller aspect [...] Are you aware of the variations on MVC, in particular Model-View-Presenter? MVP has been so successful in Smalltalk that I consider MVC obsolete. Taligent's whitepaper is here: http://www.carfield.com.hk/document/software_design/MVP.pdf and there is more material at Object Art's Smalltalk site: http://www.object-arts.com/EducationCentre/Overviews/ModelViewPresenter.ht m -- Dave Harris, Nottingham, UK

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spirit fileiterator always uses std_iterator on posix
by dieMumiee＠gmx.de 26 Dec '04

26 Dec '04

Hi, Found that code in boost/spirit/iterator/file_iterator.hpp template < typename CharT = char, typename BaseIterator = #ifndef BOOST_SPIRIT_FILEITERATOR_WINDOWS fileiter_impl::std_file_iterator<CharT> #else fileiter_impl::mmap_file_iterator<CharT> #endif > class file_iterator; BOOST_SPIRIT_FILEITERATOR_POSIX which is defined a few lines above is never used. Are there any issues with the posix-mmap code? It "worked" here, I modified the code to : template < typename CharT = char, typename BaseIterator = #if defined(BOOST_SPIRIT_FILEITERATOR_WINDOWS) || defined(BOOST_SPIRIT_FILEITERATOR_POSIX) fileiter_impl::mmap_file_iterator<CharT> #else fileiter_impl::std_file_iterator<CharT> #endif > class file_iterator; Regards, Andreas Pokorny -- +++ Sparen Sie mit GMX DSL +++ http://www.gmx.net/de/go/dsl AKTION f�r Wechsler: DSL-Tarife ab 3,99 EUR/Monat + Startguthaben

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[Boost-bugs] [ boost-Support Requests-1091153 ] ublas extendability 2
by SourceForge.net 25 Dec '04

25 Dec '04

Support Requests item #1091153, was opened at 2004-12-25 10:21 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=207586&aid=1091153&group_… Category: None Group: None Status: Open Resolution: None Priority: 5 Submitted By: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: ublas extendability 2 Initial Comment: Hi. I want to multiplicate ublas matrices with custom (non- ublas) vectors. Is there some possibility ? Please see attached files and compilation messages. It seems that the job can be done with more knowledge of ublas tunning. Thank you. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=207586&aid=1091153&group_… ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/ _______________________________________________ Boost-bugs mailing list Boost-bugs(a)lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/boost-bugs

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[Boost-bugs] [ boost-Support Requests-1091151 ] ublas extendability1
by SourceForge.net 25 Dec '04

25 Dec '04

Support Requests item #1091151, was opened at 2004-12-25 10:18 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=207586&aid=1091151&group_… Category: None Group: None Status: Open Resolution: None Priority: 5 Submitted By: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: ublas extendability1 Initial Comment: Hi. I am using ublas with types other then built in scalars (like "double" or "int"). Typical jobs: prod(matrix<double>,vector<v3d<double> >) or triangular_solve(matrix<double>,vector<v3d<double> >). In order to be able to do it, I have made partial specialization of "promote_traits" template in namespace "boost::numeric::ublas" for my classes. This works. Is this technique good ? Or uBLAS intended only for built in types ? See attached files. Is it good to intervene to ublas namespace, like done in file "vnd.h" at the end. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=207586&aid=1091151&group_… ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://productguide.itmanagersjournal.com/ _______________________________________________ Boost-bugs mailing list Boost-bugs(a)lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/boost-bugs

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Lambda Question
by Brian Braatz 24 Dec '04

24 Dec '04

Is is possible to, given a functor generated as a result of a lambda bind expression, pull the return type from the lambda functor? (still digging through the lambda bind code and have not found the answer to this yet. I sent a previous post with sample code that shows what I am trying to do) Any help or direction would be greatly appreciated. Thanks Brian

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RE: [boost] Re: Lambda Question
by Brian Braatz 24 Dec '04

24 Dec '04

> -----Original Message----- > On Behalf Of Arkadiy Vertleyb > "Brian Braatz" <brianb(a)rmtg.com> wrote > > > Is is possible to, given a functor generated as a result of a lambda > > bind expression, pull the return type from the lambda functor? > > I am wondering if "result_of" may be something that you are looking for. > OTOH, I don't really know what the status of this library is. > > Regards Thank you for your thoughts- result_of looks like what I want - but I am having difficultly figuring out what the lamda factor LOOKS like after it is compile time generated. (I am (very very) slowly dissecting lambda bind to try to figure this out). IF ANYONE knows the answer to how you would GET TO result_of syntax wise help would be appreciated. (previous mail with sample code below) -----Original Message----- From: boost-bounces(a)lists.boost.org [mailto:boost-bounces@lists.boost.org] On Behalf Of Brian Braatz Sent: Wednesday, December 22, 2004 8:03 AM To: boost(a)lists.boost.org Subject: [boost] Help \ Advice requested on getting the return type from aLambda fctor I wrote up the simple example that shows what I am trying to figure out Basically, I am trying to pull the deduced return type (or explicitly passed as a template param in lambda bind()) in my template. If I have a function that is receiving a functor, I would like to be able to take that functor and pull the RETURN TYPE out of it. Lets say I have a function that returns a string: std::string ReturnAString() { return "this is a string"; } And then here is my template function (code below does not compile) template < typename TFUNCTOR> TFUNCTOR::result_type CallFctorDeduceRet( TFUNCTOR & functor) { return functor(); } Now here is my bind call std::cout << ( bind<std::string>(&ReturnAString)); Is there a way to GET to the return type in the Lambda fctor that was generated with a BIND call? I would like to be able to pull the <std::string> from the bind call and use it in the template function. It is not a problem for my template function to be dependant upon lambda bind. I have been going through the lambda code. And while it is brilliant, I am having a bit of difficulty figuring out what I am looking at (grin). Any help or direction is greatly appreciated FULL SAMPLE CODE HERE: template <typename CURRIEDTYPE> // Id class for currying type without creating the object class Id { public: typedef CURRIEDTYPE TYPE; }; // Explictly pass IN a return type template < typename TFUNCTOR, typename TRET> TRET CallFctorPassInRet ( TFUNCTOR & functor, Id<TRET> & ) { Id<TRET>::TYPE TRet; TRet = functor(); return TRet; } std::string ReturnAString() { return "this is a string"; } // try to get return type from the lambda fctor // Below does not compile- but it is along the lines of what I // WANT to do- note that I am trying to get from the Lambda functor the deduced return type template < typename TFUNCTOR> TFUNCTOR::result_type CallFctorDeduceRet( TFUNCTOR & functor) { return functor(); } void Test_LambdaRetDeduction() { std::cout << "CallFctorPassInRet returns [" << CallFctorPassInRet( bind(&ReturnAString), Id<std::string>()) << "]" << std::endl; // below is what I want to make work std::cout << "CallFctorDeduceRet returns [" << CallFctorDeduceRet( bind<std::string>(&ReturnAString)) << "]" << std::endl; }

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