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

boost::shared_ptr and stl algorithms
by Bill Eidson 15 Apr '05

15 Apr '05

std::vector< boost::shared_ptr<T> > TVec; I want to write a function object to run std::for_each. to do somework against members of T and accumulate results in functor. My attempts have failed in VC7 with memory errors in my operator() method. struct fo { bool operator()( boost::shared_ptr<T>& t ) { return true; } }; Thanks in advance bille

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Will libraries built on WinNT run on Win98? (MinGW)
by Reed Hedges 31 Mar '05

31 Mar '05

I know that Win98 is not really supported, but is there any chance that libraries (specifically thread and regex) that were build on WinNT using MinGW work on Win98 (in MinGW)? My guess is no, but has anyone tried it? thanks reed

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BGL and reversing / moving edges
by joshrose 17 Dec '03

17 Dec '03

G'day, I was hoping someone might be able to tell me if they've run into any situations using BGL where they needed to move (or reverse (i.e. flip the source and target)) an edge within a graph implemented as an adjacency_list. I'm working on an implementation of an algorithm for max. weight bipartite matching ("the assignment problem"), and one of the assumptions in the algorithm is that non-matched edges are directed from one subgraph, A, to the other subgraph, B, and matched edges are directed the other way. Over the course of growing the matching, a simple way to add and remove edges from the candidate set is just to reverse the edge, thus the need for some way to reverse the edge within BGL. I don't think I can just remove and then re-add the edge in the other direction, primarily because doing so will (I believe) invalidate any edge_descriptors referring to that edge. In particular, there are property maps keeping track of the weight of edges, the predecessors of certain nodes, etc. that use edge descriptors as keys. I've spent a fair bit of time reading the documentation and looking through the implementation of adjacency_lists (incl. edge_list_impl), and I'm not really sure of a way to either move an edge directly within a graph, or even to create a new edge from another s.t. they have the same edge_descriptor (in general a bad thing, probably). Anyone have any thoughts on this? Thanks, -Josh

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Boost Software License: redistribute modified works?
by Steve M. Robbins 16 Dec '03

16 Dec '03

Hi, I've a question for the drafters of the Boost Software License - Version 1.0 - August 17th, 2003. Put yourself in the position of someone who wants to redistribute a modified version of Boost. For example, the linux distributors like Debian. The license begins with the permission grant: Permission is hereby granted, free of charge, to any person or organization obtaining a copy of the software and accompanying documentation covered by this license (the "Software") to use, reproduce, display, distribute, execute, and transmit the Software, and to prepare derivative works of the Software, and to permit third-parties to whom the Software is furnished to do so, all subject to the following: [... a restriction and a disclaimer paragraph ...] As I read this, "the Software" means "the unmodified tar or zip file obtained from boost.org". Is that correct? I'm permitted to "prepare derivative works of the Software", but the license doesn't specify what I may do with my derivative works. Clearly, I may distribute "the Software", but may I distribute the derivative work? Some licenses (e.g. the BSD and the GPL) make it clear that the terms apply to both the software and to derivative works. Shouldn't the boost license do likewise? -Steve

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[BGL] Using default_dfs_visitor on a graph with std::list as the vertex type
by sashan 25 Nov '03

25 Nov '03

I'm trying to use a vistitor class on a graph I have defined. The visitor class is very simple and inherits from default_dfs_visitor: class OpenGLVisitor : public boost::default_dfs_visitor { public: OpenGLVisitor(void); virtual ~OpenGLVisitor(void); }; My graph type is: typedef adjacency_list < vecS, listS, directedS > graph_t; The code to perform a dfs on the graph is as follows: graph_t g; depth_first_search(g, visitor(OGLVisitor)); However I get the compiler error (see attachment). If I change the typedef to typedef adjacency_list < vecS, vecS, directedS > graph_t; then there is no error. This seems odd since it should also work when the vertices of the graph use the std::list as their container class. I'm using VC++7.1.

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travelling salesman for BGL ?
by Philippe Guglielmetti 13 Nov '03

13 Nov '03

I'm looking for a free "travelling salesman problem" solver. Does anyone know if something exists for the Boost Graph Library ? I found nothing in the book... Is anybody interested in porting existing code, for example http://www.math.princeton.edu/tsp/concorde.html on BGL ? -- Philippe Guglielmetti - www.dynabits.com

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Is threads CodeWarrior project broken?
by Steve Folly 04 Nov '03

04 Nov '03

Hi, I'm trying to build the threads library on Codewarrior with the .mcp project supplied in libs/thread/build/ (using CW9, OS X 10.2.8), but Codewarrior says the file is not a project file. Is it broken? I could probably recreate it, but I'm not sure about about what source files to include for the Mac - there's all the extra stuff under src/mac/ and then what about the src/mac/msl_replacements/ stuff? Any help gratefully received. I'd like to do a multi-target project for Mac and Win32; tips for source files for Win32 would be helpful too. Thanks. Steve.

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RE: [Boost-users] [BLL] How to search in a list for an object comparing a data member?
by Ben Hutchings 01 Nov '03

01 Nov '03

Gianluca Silvestri <gianluca.silvestri(a)maior.it> wrote: > Hi all, > What I want to achieve is a code similar to this: > > struct Foo { int fDataMember;} > > int main() > { > std::vector<Foo> foos; > Foo fo; > std::find_if(foos.begin(), foos.end(), _1->fDataMember == > fo.fDataMember); //<-- won't compile; } Well, apart from the missing semi-colon, missing includes and missing closing brace, I imagine you're having trouble with "_1->fDataMember". This is a documented limitation of the lambda library - there is no way to defer lookup of member names (overloading -> just changes the type and value of the pointer used) so member access can't be done on a placeholder. > I know I could use a functor object but this is just an example for a > more general need. Sorry, you'll have to define functors. These template functor classes might be useful: template<typename C, typename V, const V C::* P> struct lookup_member_const { const V & operator()(const C & c) const { return c.*P; } }; template<typename C, typename V, V C::* P> struct lookup_member { V & operator()(C & c) const { return c.*P; } }; Mind you, there might be similar things in Boost already.

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Build+Install+/Zc:wchar_t in Visual studio builds
by John Maddock 01 Nov '03

01 Nov '03

Guys, Rene's new Install code is working very well for me now, but I have a question about how we're building with Visual Studio .NET. Currently the vc7 and vc7.1 toolsets turn on /Zc:wchar_t unconditionally when building, however this is not the default option in current versions of the IDE, and of course the two options produce binary-incompatible libraries (at least as far as regex is concerned). How should we handle this? At the very least I would like to see a bjam option to turn off /Zc:wchar_t, but how should we be building the libraries by default: turning native wchar_t support on is the standards conforming way, but not currently the default Visual Studio way, or the way many third party libraries (like ICU for example) are built. Does anyone know how this option interacts with MFC/ATL/VisualForms etc? We could of course create a new build variant to handle this, but with 8 regex lib/dll variants already I'm not keen to add another 8 (apart from anything else testing already takes too long). I'm cross posting this to the Boost.users group as well, since whatever resolution we take will affect them the most :-) Thanks, John.

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[newbie] creating a (complex?) C++ wrapper around a C function call...
by Jason House 31 Oct '03

31 Oct '03

I want to create a wrapper function template <class foo> op_pk_fd_set_class(packet *packet, int index, foo &value, int simulated_bits); around the following function... (in OPNET) op_pk_fd_set( packet* pkptr, // same as in wrapper int index, // same as in wrapper int some_constant, //OPC_TYPE_STRUCT void* value, int simulated_bits, // same as in wrapper void* (*copy_proc)(void* obj_to_copy,int alloc_size), void (dealloc_proc*)(void *obj), int alloc_size); I believe dealloc_proc can just be a function pointer to the destructor. I could very well be mistaken, but I believe that a normal constructor takes only one parameter. I also think alloc_size should be sizeof(foo). I do not know how to obtain function pointers for constructor and deconstructor member functions. Any assistance I could get would be appreciated.

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RE: [Boost-users] Re: Build+Install+/Zc:wchar_t in Visual studio builds
by Ben Hutchings 31 Oct '03

31 Oct '03

Edward Diener <eddielee(a)tropicsoft.com> wrote: > John Maddock wrote: > > Guys, > > > > We could of course create a new build variant to handle this, but > > with 8 regex lib/dll variants already I'm not keen to add another 8 > > (apart from anything else testing already takes too long). > > I think you have to do this John if you want to support both the C++ > wchar_t and the MS wchar_t in Boost libraries. Although there are > VC++ predefined macros, _WCHAR_T_DEFINED and _NATIVE_WCHAR_T_DEFINED, > which are defined when /Zc:wchar_t is used, they are also stupidly > defined, according to the documentation, when typedef unsigned short > wchar_t is used ( talk about idiotic MS decisions ). That appears to be a documentation bug. I checked this in VC++ 7.1 and _NATIVE_WCHAR_T_DEFINED is not defined by <cstddef>. There is no sign of a #define _NATIVE_WCHAR_T_DEFINED in the headers for version 7.0 or 7.1. > So Boost needs to use a macro which the end-programmer must define > which tells whether or not /Zc:wchar_t is being used or not, and > create another set of libraries accordingly. Even in the absence of a macro, this test works: #include <cstddef> #include <iostream> #include <ostream> #include "boost/type_traits.hpp" int main() { std::cout << "/Zc:wchar_t was "; if (!boost::is_same<wchar_t, __wchar_t>::value) std::cout << "not "; std::cout << "used\n"; }

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RE: [Boost-users] vc++
by Ben Hutchings 31 Oct '03

31 Oct '03

adel.essafi <adel.essafi(a)laposte.net> wrote: > is it possible to compile boost project directly with vc++ 6.0 without > using commande lines. if yes how? Yes - in the IDE, create a "makefile" project and enter the command lines and targets in the project settings. It would be nice to have project files included in the distributed source, but unfortunately the file format is different for every IDE and for every different version of the Visual C++ IDE so it would be difficult to keep them all up-to-date. Ben.

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[BLL] How to search in a list for an object comparing a data member?
by Gianluca Silvestri 31 Oct '03

31 Oct '03

Hi all, What I want to achieve is a code similar to this: struct Foo { int fDataMember;} int main() { std::vector<Foo> foos; Foo fo; std::find_if(foos.begin(), foos.end(), _1->fDataMember == fo.fDataMember); //<-- won't compile; } I know I could use a functor object but this is just an example for a more general need. Thanks, Gianluca

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vc++
by adel.essafi 30 Oct '03

30 Oct '03

hi list is it possible to compile boost project directly with vc++ 6.0 without using commande lines. if yes how? thanks Accédez au courrier électronique de La Poste : www.laposte.net ; 3615 LAPOSTENET (0,34/mn) ; tél : 08 92 68 13 50 (0,34/mn)

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Linker problem using boost::regex with VC6.5
by Sven Van Echelpoel 29 Oct '03

29 Oct '03

Hi, I'm having a strange problem when I try to include boost::regex in my project (VC6.5 on Win2K). I'm not using Build to build a separate regex dll but rather include the source files directly in the project (or rather in a small utility static library). I've defined BOOST_REGEX_STATIC_LINK to avoid __declspec( dllimport ) / __declspec( dllexport ). Although everything compiles just fine the linker complains that it cannot find the library boost_regex_vc6_mdsd.lib. Further investigation revealed that it is actuallty listed somewhere as an additional default library (the linker outputs this when you switch on link progress messages). Searching through the sourcecode for #pragma comment( lib, ... ) and #pragma comment( linker, ... ) directives came up empty as did a search for boost_regex_vc6_mdsd.lib in all sources and headers. I got it to link by letting the linker ignore boost_regex_vc6_mdsd.lib. Even so I still would like to know where this is comming from. Any ideas? Sven

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RE: [Boost-users] Linker problem using boost::regex with VC6.5
by Sven Van Echelpoel 29 Oct '03

29 Oct '03

Sven Van Echelpoel wrote: [...] > Are you sure that that's defined for all translation units that use or > implement Boost.Regex? Yep. Double checked it now and it is defined at the project level for every project [...] >> Searching through the sourcecode for >> #pragma comment( lib, ... ) and #pragma comment( linker, ... ) >> directives came up empty as did a search for boost_regex_vc6_mdsd.lib >> in all sources and headers. > > It's in "boost/regex/v3/regex_library_include.hpp". Found it. I can now see I need to define the guard macro BOOST_REGEX_NO_LIB to disable the auto-linking. Doing so makes everything build just fine. Thanks, Sven

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CEST timezone conversion, boost date_time
by Erik Thiele 29 Oct '03

29 Oct '03

hi. i am trying to convert between UTC and CEST/CET (Europe/Berlin) i don't find documentation or suitable functions in the Wiki, the examples or the documentation. also i don't understand the sourcecode of the time zone stuff. but i found that eu_dst_trait exists, but don't know what that is and how to use it. any ideas? cu & thx erik -- Erik Thiele

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Any thoughts on transparent marshalling?
by Hurd, Matthew 28 Oct '03

28 Oct '03

I wish to do some transparent marshalling... That is, via a policy, or some such, either call a function / functor returning a void or put stuff on a message queue for transportation. This is strictly asynch stuff, hence the void result or putting the message in the ether. The message queues I have in mind are tibrv, udp, tcp, shared mem, email, internal process queue... I see the serialization w.i.p. library will be useful here. Any tips on some useful boost libs / techniques to do this? Regards, Matt Hurd hurdm(a)sig.com +61.2.8226.5029

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Newbie uBLAS question
by J. Scott Pendergrass 28 Oct '03

28 Oct '03

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RE: [Boost-users] Linker problem using boost::regex with VC6.5
by Ben Hutchings 28 Oct '03

28 Oct '03

Sven Van Echelpoel wrote: > I'm having a strange problem when I try to include boost::regex in my > project (VC6.5 on Win2K). I'm not using Build to build a separate > regex dll but rather include the source files directly in the project > (or rather in a small utility static library). I've defined > BOOST_REGEX_STATIC_LINK to avoid __declspec( dllimport ) / __declspec( > dllexport ). Are you sure that that's defined for all translation units that use or implement Boost.Regex? > Although everything compiles just fine the linker complains that it > cannot find the library boost_regex_vc6_mdsd.lib. Further > investigation revealed that it is actuallty listed somewhere as an > additional default library (the linker outputs this when you switch > on link progress messages). Searching through the sourcecode for > #pragma comment( lib, ... ) and #pragma comment( linker, ... ) > directives came up empty as did a search for boost_regex_vc6_mdsd.lib > in all sources and headers. It's in "boost/regex/v3/regex_library_include.hpp". > I got it to link by letting the linker ignore > boost_regex_vc6_mdsd.lib. > Even so I still would like to know where this is comming from. Any > ideas? I know I had some kind of problem with the above-mentioned header generated the wrong library name when I first started using Boost.Regex so I disabled the header by defining its guard macro before including "boost/regex.hpp". However, I removed that just now and didn't have any problems. Have you created your own project definition which uses a different library name? It's probably easier just to use the makefile (vc6.mak) in Visual Studio. You can do this by selecting "Insert Project into Workspace", selecting "vc6.mak" from the build directory, and thus creating a project that calls nmake on the makefile. Then you just need to edit the project settings to specify what the target names are for each configuration.

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OpenBSD
by Adam Olsen 28 Oct '03

28 Oct '03

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Has anyone had any luck compiling boost_regex on OpenBSD 3.3? If so, how did you do it? Thanks, Adam Olsen -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.3 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQE/nDKyiTy1B31kxaoRAhhBAJ98+oS83jDY3kwgauPV0HN9HG5XOgCgwlpx JI8Bhk2EyKrgBn4fX72dBSk= =Owcv -----END PGP SIGNATURE-----

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[spirit][newbie] few questions
by GIE 27 Oct '03

27 Oct '03

Hello! What is "proper way" of implementing result value of parser, have i implement new parser or can (and how?) i use grammar construct with user defined result value that can be passed to attached action (for ex. matched GUID returning)? What is performance penalty for using vectors (they need realloc, don't they) in ast trees? And is there anyway to store scanner defined result in tree, besides using user-specified value in node_val_data and type casting it to specific type depending of node id? Thanks. -- With best regards, GIE.

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RE: [Boost-users] Boost Software License: redistribute modified works?
by Ben Hutchings 27 Oct '03

27 Oct '03

Steve M. Robbins <steven.robbins(a)videotron.ca> wrote: > I've a question for the drafters of the Boost Software > License - Version 1.0 - August 17th, 2003. I am not one of them, but I can give you some answers anyway. > Put yourself in the position of someone who wants to redistribute > a modified version of Boost. For example, the linux distributors > like Debian. > > The license begins with the permission grant: > > Permission is hereby granted, free of charge, to any person or > organization obtaining a copy of the software and accompanying > documentation covered by this license (the "Software") to use, > reproduce, display, distribute, execute, and transmit the > Software, and to prepare derivative works of the Software, and to > permit third-parties to whom the Software is furnished to do so, > all subject to the following: > > [... a restriction and a disclaimer paragraph ...] > > As I read this, "the Software" means "the unmodified tar or zip > file obtained from boost.org". Is that correct? No, it means whatever software says the licence applies to it. This licence does not (yet) apply to all of Boost. All parts of it are supposed to come with a licence that meets certain requirements, listed at <http://www.boost.org/more/lib_guide.htm#License>. The licence you are reading is supposed to be a standard licence that meets these requirements. There is a fuller explanation at <http://www.boost-consulting.com/boost/more/license_info.html>. > I'm permitted to "prepare derivative works of the Software", but the > license doesn't specify what I may do with my derivative works. > > Clearly, I may distribute "the Software", but may I distribute > the derivative work? I think that may be legally implicit, but I am not a lawyer. > Some licenses (e.g. the BSD and the GPL) make it clear that the terms > apply to both the software and to derivative works. Shouldn't the > boost license do likewise? Even if it is legally implicit, I can see that it would be a good idea to clarify it. Since it doesn't specify have a choice-of-law clause it could be interpreted according to any country's contract law and things that are implicit according to US law might not be so elsewhere. Ben.

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compiling as a framework
by Avram Aelony 27 Oct '03

27 Oct '03

This may be a naive question, but on Mac Os X one can compile other libraries as a "framework", for example I can use the OpenGL library by compiling as follows: % g++ mytest.cpp -framework OpenGL Is it possible to be able to do the same style compilation for Boost? Ideally, something like this would be nice... % g++ mytest.cpp -framework Boost Incidentally, although I have installed Boost with bjam, simply compiling a Hello World style program that uses a Boost function gives me errors... An example would be great. thanks, Avram

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directory_iterator TypeLoadException
by Sergey K. 26 Oct '03

26 Oct '03

Hello, I tried to run SimpleLs program, but got a TypeLoadException at the line below. I use boost-1.30.2, MSVC++7.0 Any idea what could be causing the problem? for ( fs::directory_iterator dir_itr( full_path ); dir_itr != end_iter; ++dir_itr ) // exception thrown here Output: In directory: C:\src\cpp Unhandled Exception: System.TypeLoadException: Could not load type boost.filesystem.dir_itr_imp from assembly Filesystem Demo, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null. at boost.==(shared_ptr<boost::filesystem::directory_iterator::dir_itr_imp>* a, shared_ptr<boost::filesystem::director y_iterator::dir_itr_imp>* b) at boost.filesystem.!=(directory_iterator* x, directory_iterator* y) in c:\lib\cpp\boost-1.30.2\boost\filesystem\oper ations.hpp:line 93 at main(Int32 argc, SByte** argv) in c:\src\cpp\boost\filesystemdemo\simplels.cpp:line 44

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