August 2003 - Boost-users - lists.preview.boost.org

RE: [Boost-Users] Re: Re: boost::intrusive_ptr and Managed C++?
by Ferdinand Prantl 22 Aug '03

22 Aug '03

Hi Holger, > -----Original Message----- > From: Holger Grund [mailto:yg-boost-users@gmane.org] > Sent: Thursday, August 21, 2003 14:50 > To: boost-users(a)yahoogroups.com > Subject: [Boost-Users] Re: Re: boost::intrusive_ptr and Managed C++? > > > "Ferdinand Prantl" <ferdinand.prantl(a)ixos.de> wrote > > > The second option (as Holger says) is to make a simple facade to the > c++ > > library (all you might use), which will not have templates (here > smart > > pointers) on the interface, and to use this facade instead. > > > Did I say that? Anyway, I absolutely agree. Oops, sorry, I thought a bit further... :-) > > I just want to point out that IMHO the best solution is to > _not_ export instrusive_ptr_add_ref and _release. If you do > new and delete are called from different modules which works > only if the same CRT instance is used. And that works only if > both link against the exact same version of the CRT dll (that > is both linking against a static CRT still yields to > instances => two heaps => error). The generally safest solution yes, but not always the simpliest and most understandable. With a pile of C++ libraries with templates and STL on interface to use, I would not be very keen on writing facades for each and every... Every such a wrapper also increases the complexity of the solution. > > While we're at it, it's almost always a bad thing to export > classes or functions that rely on classes from a DLL. DLLs > are a run time concept. They don't have any clue which > version of the compiler a consumer is built with. > > E.g. say you export a function > void foo( std::string& s ) > { > s = "Hello World!"; > } Oh yeah, that's terrible constraint - if releasing binary library, one must support more compilers and also create different binary names (e.g. boost_regex). It is not needed if you release sources of the library (not the case of commercial APIs). If STL is widely used in the dependency tree of libraries, it is a pity to abandon it from their interfaces, building special marshalling structures or serializing into streams or return pointers. In this situation I broke the general recommendation (no templates on iface), preferred simplier solution and went on with STL on interfaces. It is cheaper and runs faster too. I moved the task of creating a facade without STL to the person, who needs it. As long as everybody are happy with usage of the same STL on interface, such a facade does not need to be borned (for managed .net assemblies it is also not necessary)... > > The DLL is built with the version A of the compiler and STL > and the consuming application is built with version B. There > is no guarantee for a binary compatibility between the two > version. And indeed the code above will break if version 6 & > 7 of VC are used (The former used a COW scheme while the > second uses a short string optimization). This must not happen. It is responsibility of the build configuration to use the belonging import libraries. It can be checked and forced by pragmas in msvc. Ferda > > Also, do note that the DLL CRT now supports side by side sharing. > > While I am in rant mode the catch(...) thing is also a very > bad idea in VC. This currently catches (this will be fixed in > 8.0) structured exception that are not C++ exception. That > way serious error conditions are silently ignored. > > -hg > > > > > ------------------------ Yahoo! Groups Sponsor > ---------------------~--> Buy Ink Cartridges or Refill Kits > for Your HP, Epson, Canon or Lexmark Printer at Myinks.com. > Free s/h on orders $50 or more to the US & Canada. > http://www.c1tracking.com/l.asp?cid=5511 > http://us.click.yahoo.com/l.m7sD/LIdGAA/qnsNAA/EbFolB/TM ---------------------------------------------------------------------~-> Info: <http://www.boost.org> Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

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boost::python - double vs. int - unexpected behavior
by cavok＠filibusta.crema.unimi.it 21 Aug '03

21 Aug '03

hi, i attached a simple example that shows the following behavior: $ python Python 2.2.3+ (#1, Aug 10 2003, 10:11:23) [GCC 3.3.1 (Debian)] on linux2 Type "help", "copyright", "credits" or "license" for more information. >>> import test >>> a=test.A() >>> a.f(3) double >>> a.f(3.8) double >>> a.f(int(3)) double >>> $ well, doesn't it look weird? any idea on how i can get the correct c++ method called? cheers dom -----[ Domenico Andreoli, aka cavok --[ http://filibusta.crema.unimi.it/~cavok/gpgkey.asc ---[ 3A0F 2F80 F79C 678A 8936 4FEE 0677 9033 A20E BC50 [Non-text portions of this message have been removed]

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[BGL] How to destroy a subgraph?
by Stefan Slapeta 21 Aug '03

21 Aug '03

Hi, is it possible to destroy a subgraph child? I didn't find nothing on this in the documentation. Is there any other way to free the subgraph's resources? Thanks, Stefan

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RE: [Boost-Users] Re: boost::intrusive_ptr and Managed C++?
by Ferdinand Prantl 21 Aug '03

21 Aug '03

Hello Drew, I implement managed assembly in mc++. I use c++ library with smart pointers and stlport on the interface to implement a functionality in unmanaged c++, even if it is exposed to .net through managed classes. So this scenario in general works. Holger has already answered you, I see also the problem in different heaps/runtime versions. You must ensure the same versions of the runtime (not only debug/release but also version of msvs - 6, 7, 7.1) and of the templated libraries used (in my case stlport for 6, 7, 7.1, which also must use the same runtime). I use msvcrt/msvcrtd everywhere and link everything automatically using pragmas to prevent strange errors from manual configuration. It can look complex but in reality it is pretty simple. The second option (as Holger says) is to make a simple facade to the c++ library (all you might use), which will not have templates (here smart pointers) on the interface, and to use this facade instead. Good Luck, Ferda P.S. with the first option you will come to problems if you register the assembly for CCW but that's another story... -----Original Message----- From: Holger Grund [mailto:yg-boost-users@gmane.org] Sent: Wednesday, August 20, 2003 18:18 To: boost-users(a)yahoogroups.com Subject: [Boost-Users] Re: boost::intrusive_ptr and Managed C++? "Drew" <drewtenn(a)yahoo.com>, > I originally posted this to microsoft.public.dotnet.languages.vc, > but they referred me back to here. > > Has anyone used boost's intrusive_ptr with Managed C++ extensions? > Mmh, not really. And it actually doesn't (currently ?) sound like a very compelling idea to me. > I have a small project where the executable (managed) is linked to a > native C++ dll. > > The code looks like: > > int _tmain() > { > boost::intrusive_ptr<Unmanaged> pUn = __nogc new Unmanaged(); > > return 0; > } > > when I exit out of main, boost::intrusive_ptr_release() throws an > exception. The last known method called is: > > UnmanagedLib.dll!_CrtIsValidHeapPointer(...) Line 1807 > This probably is not related to the managed extensions. It's more likely that intrusive_ptr's dtor calls into the DLL to free the pointer which is only possible if both modules use the DLL version of the CRT. The message indicates that the pointer to be freed is bogus or more likely from another heap. This is caused by a mismatch of the CRTs used by the main program and the DLL. You could use the /MD[d] option for both projects, so that both modules share a common CRT heap. I'd prefer to move intrusive_ptr_add_ref/release functions to the program that uses the instrusive_ptr. Don't export these functions from the DLL. Rather include these functions at build time. That way you ensure, that operator delete is called from the same module as operator new and everything should be fine. > Unmanaged* pUm = new Unmanaged(); > delete pUm; > Yep. Same module. No problem. hth -hg ------------------------ Yahoo! Groups Sponsor ---------------------~--> Buy Ink Cartridges or Refill Kits for Your HP, Epson, Canon or Lexmark Printer at Myinks.com. Free s/h on orders $50 or more to the US & Canada. http://www.c1tracking.com/l.asp?cid=5511 http://us.click.yahoo.com/l.m7sD/LIdGAA/qnsNAA/EbFolB/TM ---------------------------------------------------------------------~-> Info: <http://www.boost.org> Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/

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[BGL] single pair problem with bfs
by Jérémie Leguay 21 Aug '03

21 Aug '03

Hi everybody! I really need to perform the single-pair problem. I have begin to implement it as it is written in some mail of the mailing list. I do a breadth first search and I want to use both a visitor recor_distances and a visito of my own which throws an exception to stop the algorithm when the destination is found. My problem is that I did'nt found the way to mix theses two visitors. Can you help me? regards, Jérémie ___________________________________________________________ Do You Yahoo!? -- Une adresse @yahoo.fr gratuite et en français ! Yahoo! Mail : http://fr.mail.yahoo.com

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boost::intrusive_ptr and Managed C++?
by Drew 20 Aug '03

20 Aug '03

I originally posted this to microsoft.public.dotnet.languages.vc, but they referred me back to here. Has anyone used boost's intrusive_ptr with Managed C++ extensions? I have a small project where the executable (managed) is linked to a native C++ dll. The code looks like: int _tmain() { boost::intrusive_ptr<Unmanaged> pUn = __nogc new Unmanaged(); return 0; } when I exit out of main, boost::intrusive_ptr_release() throws an exception. The last known method called is: UnmanagedLib.dll!_CrtIsValidHeapPointer(...) Line 1807 but when I replace my code with: Unmanaged* pUm = new Unmanaged(); delete pUm; no exception is thrown. Please help! -Drew

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lambda&MSVC7.0 problem
by GIE 20 Aug '03

20 Aug '03

Hello! While trying to compile empty test prog (only #include "boost/lambda/lambda.hpp" and main) i've got following errors: ...\lambda\detail\arity_code.hpp(66) : error C2065: 'T' : undeclared identifier ...\boost\lambda\detail\arity_code.hpp(66) : error C2687: cannot define a nested UDT of a template class out of line ...\boost\lambda\detail\arity_code.hpp(66) : fatal error C1903: unable to recover from previous error(s); stopping compilation Can this be helped? (boots version 1.30.0) -- With best regards, GIE.

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[bgl] question to induced subgraphs
by Stephan Höfer 20 Aug '03

20 Aug '03

Hello, I use an induced subgraph of a graph with additional user defined properties like coordinates and so on. Do I have access to this properties via the get and put functions using the indices of the subgraph or do I have to access these properties via the parent (if it is the root) resp. root of the subgraph? I tried both without the demanded success. Using the second way the results were a little bit more accurate than using the first way, but they were wrong in either case. I created the subgraph as Graph& tSubgraph = g.create_subgraph; where g is a before initialized graph. Maybe it works copying the properties to the subgraph, but that wouldn't be efficient in my opinion. Thanks in advance for your answers, Stephan

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PC-Lint reports errors for VC6-specific implementation in is_same.hpp
by stefan_felkel2000 20 Aug '03

20 Aug '03

Hi all, Since I have included boost\dynamic_bitset.hpp in my project, PC-Lint reports many thousands of redefinitions of symbol 'is_same_part_1<<1>>::part_2<<1>> for the following code in type_traits\is_same.hpp. #ifdef BOOST_MSVC // the following VC6 specific implementation is *NOT* legal // C++, but has the advantage that it works for incomplete // types. template< typename T1 > struct is_same_part_1 { template<typename T2> struct part_2 { enum { value = false }; }; template<> struct part_2<T1> { enum { value = true }; }; }; If I replace #ifdef BOOST_MSVC with #if (defined BOOST_MSVC) && (BOOST_MSVC < 1300) The code compiles with Visual Studio .NET 2003 and PC-Lint doesn't report any error. Stefan Felkel

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ClearCase and Boost
by Matt Trentini 20 Aug '03

20 Aug '03

Heya Everyone, We use Rationals ClearCase for our source code control here at work and I'm trying to figure out how to best integrate Boost into the ClearCase VOB's. I understand that this probably isn't the ideal forum but I felt certain that someone else out there has a similar configuration! My issue has to do with the different versions of boost. I don't need to maintain a complete source history (don't need every change to every file, just regular releases) but I do want to have multiple versions located at the same place (ie ie want there to be only one boost directory, not boost_1_30, boost_1_30_2 etc) with labels to specify the version. This way our build environment can always look at the one place in the VOB's and we use our config spec to specify which version we're using. Should be simple. ;) Now, I can download a version of boost, extract the files, export them (with clearexport_ffile) then import (clearimport) to the VOB. Then I can label those files. Unfortunately, if any files (or directories) have been deleted I won't know about it - they'll just remain there. I had a quick scan through the attic files and it seems like deleting files is not particularly uncommon. I don't want those old files (which could have been deprecated or buggy or whatever) just lying around waiting for bugs to creep in. So does anyone know of a better way? How are other people doing this? Cheers, Matt PS I've thought of 'hacky' solutions, like telling clearexport_ffile to create a unique branch for every new version of boost and just leaving each new version on the branch...or creating a branch and then running a script over everything, determining if anything needs removing. But, as I said, these are hacky! :)

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