July 2008 - Boost-users - lists.preview.boost.org

Interest in yet another properties library?
by Sergey Sadovnikov 11 Jul '08

11 Jul '08

Hello All, Would there be any interest in another C++ properties implementation? I know that boost sandbox already contains properties library. But I could offer yet another implementation of such library with some advantages like this: - Simple properties set initialization. Only one call from the constructor: class SomeClass { public: //... SomeClass() : properties__(this) {/*...*/} //... }; - Many kins of properties. Now implemented: Simple properties similar to datamembers. Properties bindable to getter/setter methods of container class. Properties bindable to arbitrary methods. Index properties with up to three levels of indirection. - Properties could be "abstract" and need implementation in derived classes - In-place initialization of simple properties. For example: PROPERTY_I(int, ContainerSize, 10) - Generic runtime access to the properties via names: SomeClassWithProps c; int val; c.properties__.invoke_get("ContainerSize", var(val) = boost::lambda::_1); c.properties__.invoke_set("ContainerSize", 20); - Runtime enumeration of properties: // Property visitor function template<typename P> void PropertyEnumerator(const std::string& propertyName, P SomeClassWithProps::* propInfo) { //... ] // Properties enumeration: SomeClassWithProps::properties__::enum_s(PropertyEnumerator); - Simple serialization of properties: template<typename Ar> void serialize(Ar& ar, const unsigned int ver) { ar & properties__; } - Quite simple definition in class. A piece of code from real project: // Example of abstract properties definition in the base class: class IPlayerCraft : public IAirObject { public: IPlayerCraft() : properties__(this) {;} virtual ~IPlayerCraft(){} // Craft status enum ECRAFTSTATUS { csREADY =0, csFLYING, csREPAIRING, csREFUELING, csREARMING, csTRANSFERING, csMAXCOUNT }; PROPERTIES(IPlayerCraft, // Craft name ABSTRACT_RW_PROPERTY(std::wstring, Name) // Static craft info ABSTRACT_RO_PROPERTY(SCraftInfo const*, Info) // Craft home base ABSTRACT_RO_PROPERTY(IBase const*, HomeBase) // Is craft on the base? ABSTRACT_RO_PROPERTY(bool, IsOnTheBase) // Craft status ABSTRACT_RO_PROPERTY(ECRAFTSTATUS, Status) // Current craft speed ABSTRACT_RO_PROPERTY(TPARAM, Speed) // Craft weapon ABSTRACT_INDEX_PROPERTY(IItem*, CraftWeapon, 1, (CraftSlotCoord)) // Craft weapon ammo ABSTRACT_RO_INDEX_PROPERTY(TPARAM, CraftWeaponAmmo, 1, (CraftSlotCoord)) ); //... }; // Implementation class class PlayerCraft : public IPlayerCraft { public: PlayerCraft(SCraftInfo const*, Player* player); ~PlayerCraft(); PROPERTIES(PlayerCraft, IMPLEMENT_PROPERTY(IPlayerCraft, PROPERTY(std::wstring, Name)) IMPLEMENT_PROPERTY(IPlayerCraft, PROPERTY(SCraftInfo const*, Info)) IMPLEMENT_PROPERTY(IPlayerCraft, RO_PROPERTY(IBase const*, HomeBase, GetHomeBase)) IMPLEMENT_PROPERTY(IPlayerCraft, PROPERTY(bool, IsOnTheBase)) IMPLEMENT_PROPERTY(IPlayerCraft, PROPERTY_I(ECRAFTSTATUS, Status, csTRANSFERING)) IMPLEMENT_PROPERTY(IPlayerCraft, PROPERTY_I(TPARAM, Speed, 0)) IMPLEMENT_PROPERTY(IPlayerCraft, INDEX_PROPERTY(IItem*, CraftWeapon, 1, (CraftSlotCoord), GetCraftWeapon, SetCraftWeapon)) IMPLEMENT_PROPERTY(IPlayerCraft, RO_INDEX_PROPERTY(TPARAM, CraftWeaponAmmo, 1, (CraftSlotCoord), GetCraftWeaponAmmo)) ); // ... IBase const* GetHomeBase() const {return m_HomeBase;} private: // ... IItem* GetCraftWeapon(int slotId) const; void SetCraftWeapon(int slotId, IItem* weapon); TPARAM GetCraftWeaponAmmo(int slotId) const; }; As you can see, properties definition based on boost::preprocessor. It allows to implement quite complex background (with many special abilities) for quite simple front-end. It is assumed what access to the properties in many cases is same as access to the datamember: PlayerCraft craft; std::string craft_name = craft.Name; //... IItem* weapon = craft.CraftWeapon[1]; And there is special access form needs in some cases: craft.Name(); or craft.Name.get(); If there is an interest in such properties implementation I could start prepare code for formal library review. -- Best Regards, Sergey mailto:flex_ferrum@artberg.ru

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[general] boost and embedded applications
by damny＠web.de 11 Jul '08

11 Jul '08

hi, does anyone of you have experiences with using boost in embedded applications (real time os task (no linux), memory management, ...)? thnx daniel ____________________________________________________________________ Ihre Messenger, Communities und E-Mails jetzt in einem Programm! WEB.DE MultiMessenger http://www.produkte.web.de/messenger/?did=3071

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[BGL] get_property does not seem to return a reference
by Torsten Sadowski 11 Jul '08

11 Jul '08

Hi, I use an additional map as a graph property. The manual says get_property returns a reference: template <class GraphProperties, class GraphPropertyTag> const typename graph_property<adjacency_list, GraphPropertyTag>::type& get_property(const adjacency_list& g, GraphPropertyTag); so I would expect I could simply change the map but and forget about it. This does not work and I have to use set_property after my changes which means I have been working with a copy. Any ideas why this happens? Cheers, Torsten

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by davidcravey＠verizon.net 11 Jul '08

11 Jul '08

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Variable-length template argument lists in C++03?
by Robert Dailey 11 Jul '08

11 Jul '08

Hi, Is there a way that I can provide variable length template argument lists in C++03 using boost? An example of what I want to achieve is below: template< typename t1, typename t2, ..., typename tN > void MyFunction( t1 param1, t2 param2, ..., tN paramN ) { boost::tuple<t1, t2, ..., tN> myTuple; AnotherFunction( param1, param2, ..., paramN ); } Right now to do this I have to create several class specializations which gets very nasty. Help is appreciated. Thanks.

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Boost::asio segfault
by Campbell Morrison 11 Jul '08

11 Jul '08

Hi, I am running an asynchronous server, and an asynchronous client with asio. I wanted to get an understanding of how the buffering worked with asio, so I performed the following test: Created an asynchronous server that output an incrementing counter every 1ms. Created a asynchronous client that received the counter, but would pause for 1 second in the handler (I.e. my server is publishing information mush faster than the client could receive it) I found that the client would not miss out on any information, i.e. the recieved counter would only ever increment by the amount the server was incrementing by. I found that after sometime though, the server segfaults (possibly a buffer getting overrun??) So my question is, can anyone point me in the direction of information that will tell me how to adjust the buffer asio is using internally (if it is, I have looked in the doco but couldn't find anything)? Also, what gaurentees does asio provide for delivery of a message, if any? regards, campbell.

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How to convert a vector of base classes to template based code?
by Peng Yu 11 Jul '08

11 Jul '08

Hi, The following program uses virtual functions. Essentially I need to go through all the pairs in 'v'. Since I have already know what are in v at compile time. I would like to convert the dynamic polymorphism to template. Therefore, the runtime would be better. I think this should be done with the help of boost::mpl. But I'm not sure how to do it. Would you please help me? Thanks, Peng #include <iostream> #include <vector> #include <boost/shared_ptr.hpp> struct shape { virtual void show_me() const = 0; virtual ~shape() { } }; struct square : public shape { void show_me() const { std::cout << "square"; } }; struct circle : public shape { void show_me() const { std::cout << "circle"; } }; struct triangle : public shape { void show_me() const { std::cout << "triangle"; } }; int main() { std::vector<boost::shared_ptr<shape> > v; { boost::shared_ptr<shape> s(new square); v.push_back(s); } { boost::shared_ptr<shape> s(new circle); v.push_back(s); } { boost::shared_ptr<shape> s(new square); v.push_back(s); } { boost::shared_ptr<shape> s(new triangle); v.push_back(s); } for(std::vector<boost::shared_ptr<shape> >::const_iterator it = v.begin(); it != v.end(); ++ it) { for(std::vector<boost::shared_ptr<shape> >::const_iterator it2 = it + 1; it2 != v.end(); ++ it2) { (*it)->show_me(); std::cout << " vs. "; (*it2)->show_me(); std::cout << std::endl; } } }

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library naming of boost 1.35.0
by Daniel Bauer 11 Jul '08

11 Jul '08

hi, i try to compile boost 1.35.0 with mingw 3.4.5, bjam 3.1.16 and winxp sp2. so i created a *.BAT-file like follows: @echo off SETLOCAL SET MINGW=C:\Development_Compiler\MinGW SET PYTHN=C:\Development_Compiler\Python25 SET BUILD=C:\Development_Libs\Boost_v1.35.0 SET path=C:\WINDOWS;C:\WINDOWS\system32;%MINGW%\Bin cls bjam.exe -a "-sTOOLS=mingw" "-sGCC_ROOT_DIRECTORY=%MINGW%" "-sPYTHON_ROOT=%PYTHN%" "-sPYTHON_VERSION=2.5" --link=static --runtime-link=static --threading=single --optimization=on --toolset=gcc --build-dir=%BUILD% --build-type=complete install ENDLOCAL for builing boost 1.34.1 (bjam 3.1.15) this works well and i get a bunch of *.A-files (*). but with combination named above i get no *.A-files, but *.LIBs. is there a different library naming than described in http://www.boost.org/doc/libs/1_35_0/more/getting_started/windows.html#libr… ? regardless of "--threading=single" i also get many "libboost...mt...lib"-files. why ("--build-type=complete" covers "--threading=single"?) ? thank you, daniel (*) i didn't tested it over again, but the BAT-file is always the same

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Re: [Boost-users] [preporcessor]Can we use BOOST_PP_SEQ_FOLD_LEFT on sequences with one element?
by JOAQUIN M. LOPEZ MUÑOZ 11 Jul '08

11 Jul '08

________________________________________ De: boost-users-bounces(a)lists.boost.org [boost-users-bounces(a)lists.boost.org] En nombre de vicente.botet [vicente.botet(a)wanadoo.fr] Enviado el: jueves, 10 de julio de 2008 23:59 Para: boost-users(a)lists.boost.org Asunto: [Boost-users] [preporcessor]Can we use BOOST_PP_SEQ_FOLD_LEFT onsequences with one element? > Hello, > > I'm a beginer with the preprocessor library. My goal is to generate from a > sequence (a)(b)(c) => a::b::c and from (a) => a > [...] > BOOST_PP_SEQ_FOLD_LEFT(NAME, BOOST_PP_SEQ_HEAD((a)), > BOOST_PP_SEQ_TAIL((a))) Here lies the problem: (a) does not have a tail (there is no such thing as an empty PP sequence, unfortunately). I'm afraid you'll have to treat sequences of size 1 separately from the general case. Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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booser::serialization compilation times
by Andreas Sæbjørnsen 10 Jul '08

10 Jul '08

We are a team that develops a C/C++/Fortran/Binary compiler project called ROSE and we want to serialize the Abstract Syntax Tree (AST). This AST has 436 different custom class types and uses maps, sets, vectors, lists and hash maps. These classes have about 1229 different variables. For convenience reasons we wanted to serialize the AST using boost::serialize, but we have some compiler performance problems. Currently the compilation takes (GCC 4.1.2) -48 minutes to compile and link a program that takes seconds to compile without serialization -The resulting binary goes from <1MB to 122 MB in size. -The compilation uses 2 GB of RAM -The object file contains 98075 symbols with serialization and 41 without If the templates for loading the AST is not instantiated the instantiated templates for saving the AST takes about - 19 minutes to compile and link - The resulting binary goes from <1MB to 77MB - The compilation uses 1.1GB of RAM We have our own custom serialization mechanism that is not that easy to support, but it does not visibly increa My machine is a 2.66 Ghz Quad Core Xeon 5355, 16 GB RAM and 2 TB of striped storage. Is there any trick I can use to reduce the compilation time? When the compilation time is 48 minutes boost::serialization is unfortunately not an option for us although it is a great tool at runtime. thanks, Andreas

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