October 2004 - Boost-users - lists.preview.boost.org

dijkstra_shortest_paths and vertex_index
by Steve Buchko 16 Oct '04

16 Oct '04

I understand that when using listS to define vertices for a graph, I must also assign values to vertex_index before attempting to make use of dijkstra_shortest_paths. My question is, do the values assigned to vertex_index need to be sequential (i.e. 0 to n where n is the number of vertices in the graph), or can I assign any "random" integer to each vertex_index, as long as the values assigned are unique for each node? Does dijkstra_shortest_paths simply use the vertex_index as a unique identifier for the vertex, or is it using those indices to build an internal data structure such as an array or vector ... in which case using relatively large (or non-sequential) integers for vertex_index might be prohibitive from a memory or performance viewpoint? Thanks, steve

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RE: [Boost-users] boost::bind, MSVC7.1 and volatile-qualification
by Schalk_Cronje＠McAfee.com 15 Oct '04

15 Oct '04

> I wonder why gcc is able to compile it. :-) Well considering that the following also yields different results on MSVC7.1 and gcc 3.2/3.3 I would wonder if there is a problem with one of the compilers #include <iostream> #include <boost/bind.hpp> struct X { void f() {std::cout << "None" << std::endl;} void f() const {std::cout << "const" << std::endl;} }; template <typename T> void run( void (T::*f_)(), T& t_) {(t_.*f_)();} template <typename T> void run( void (T::*f_)() const, T const& t_) {(t_.*f_)();} int main() { X x; run(&X::f,x); boost::bind(&X::f,_1)(x); } >Do you really have a volatile member function somewhere? I thought that they >were "officially" worthless. Well, that is a different matter. If one might want to follow Andrei's suggestion of using volatile to encapsulate synchronisation then they are still worthwhile. (CUJ February 2001).

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RE: [Boost-users] Spirit
by Foster, Gareth 15 Oct '04

15 Oct '04

Thanks Ron, Joel, What i was after was the link Joel actually posted, but thats for the tip anyway Ron. Much appreiated both. Now i just have to get boost working with cygwin :) Regards, Gaz -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Ronald Garcia Sent: 14 October 2004 17:21 To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] Spirit Are you referring to code that translates C++ into an xml-ish parse tree, or code that makes c++ code look pretty as html? I am aware of an html pretty-printing program for c++ sources written using boost.regex, if that's what you seek. Cheers, Ron On Oct 14, 2004, at 8:24 AM, Foster, Gareth wrote: Hello all, I am trying to find some source code that uses spirit to parse C++ and convert it to HTML, i found some on google, but i misplaced it and i can't find it again. It looked like it could have been an example provided with the library, but i can't see it listed in the documentation. On a side note, anyone know the best way to use boost with cygwin? From source? Is there even another way? Thanks for any help! Gaz _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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for_each on container of any
by Frank Birbacher 15 Oct '04

15 Oct '04

Hello! I like the idea of containers (e.g. std::vector) of boost::any. But I'd like to execute some operation on each item of the sequence. Unfortenuately I would need to know the set of types in the container and check every one of them if I was going to use the std::for_each with a void(*)(boost::any&). That's not good at all. I'd like to pass a function object like: struct MyOperation { template<typename T> void operator() (T&) const; }; How can I do so? Is there any algorithm for doing so provided by boost? Frank

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max_element matrix
by Vicente Palazón González 15 Oct '04

15 Oct '04

Hello, sorry, I'm a beginner with uBLAS, and I think these are simple questions, is there a simple way to obtain the maximum element of an uBLAS matrix? is there an special iterator for ubLAS matrices to use with std::max_element? Vicente Palazón.

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BOOST_STATIC_ASSERT with intel compiler at class scope
by Thomas S. Urban 15 Oct '04

15 Oct '04

The BOOST_STATIC_ASSERT documentation indicates I can use it at template class scope (private recommended) - the assert shouldn't get triggered unless the class is instantiated. This seems to work ok with gcc-3.* but not with the intel compiler (8.1). // begin example program #include "boost/static_assert.hpp" template<class T> struct foo { foo (int) { } private: BOOST_STATIC_ASSERT (false); }; template <> struct foo<int> { foo (int i) { } }; int main () { foo<int> f (7); } // end example program I get the following error: foo.cpp(8): error: incomplete type is not allowed BOOST_STATIC_ASSERT (false); ^ compilation aborted for foo.cpp (code 2) Whether I provide the specialization for int or not, or whether I ever use struct foo in main or not. Is this a know issue? Do I have a build problem? I'm using boost version 1.30.2. Thanks Scott

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Spirit
by Foster, Gareth 14 Oct '04

14 Oct '04

Hello all, I am trying to find some source code that uses spirit to parse C++ and convert it to HTML, i found some on google, but i misplaced it and i can't find it again. It looked like it could have been an example provided with the library, but i can't see it listed in the documentation. On a side note, anyone know the best way to use boost with cygwin? From source? Is there even another way? Thanks for any help! Gaz

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boost::bind, MSVC7.1 and volatile-qualification
by Schalk_Cronje＠McAfee.com 14 Oct '04

14 Oct '04

Is there a known problem with boost::bind, volatile-qualified member functions and MSVC7.1? The following snippet of code happily compiles with various incantations of gcc, but fails with MSVC7.1. The same applies for 'const volatile'. #include <boost/function.hpp> #include <boost/bind.hpp> struct TEST { void gv0() volatile; void gvc0() volatile const; int gv2(int,int) volatile; int gvc2(int,int) volatile const; }; void instantiate() { TEST T; boost::function< void() > gv0 =boost::bind(&TEST::gv0,&T); // boost::function< int(int,int) > gv2 =boost::bind(&TEST::gv2,&T,_1,_2); // boost::function< void() > gcv0=boost::bind(&TEST::gvc0,&T); // boost::function< int(int,int) > gcv2=boost::bind(&TEST::gvc2,&T,_1,_2); } cl -c -TP -GS -GF -GR -vmv -vmg -EHsc -Zc:forScope -Zc:wchar_t -Op -Gm- -D_DEBUG -Od -Zi -Yd -MDd msvc71bind.cpp (Microsoft (R) 32-bit C/C++ Optimizing Compiler Version 13.10.3077 for 80x86) ******\boost\mem_fn.hpp(256) : warning C4180: qualifier applied to function type has no meaning; ignored ******\boost\bind\bind_template.hpp(156) : see reference to class template instantiation 'boost::_mfi::dm<R,T>' being compiled with [ R=void (void) volatile, T=TEST ] msvc71bind.cpp(21) : see reference to class template instantiation 'boost::_bi::bind_t<R,F,L>' being compiled with [ R=void (__thiscall &)(void) volatile, F=boost::_mfi::dm<void (void) volatile,TEST>, L=boost::_bi::list_av_1<TEST *>::type ] ******\boost\mem_fn.hpp(264) : warning C4180: qualifier applied to function type has no meaning; ignored ******\boost\mem_fn.hpp(274) : warning C4180: qualifier applied to function type has no meaning; ignored ******\boost\mem_fn.hpp(288) : warning C4180: qualifier applied to function type has no meaning; ignored ******\boost\mem_fn.hpp(293) : warning C4180: qualifier applied to function type has no meaning; ignored ******\boost\mem_fn.hpp(307) : warning C4180: qualifier applied to function type has no meaning; ignored ******\boost\bind.hpp(1572) : warning C4180: qualifier applied to function type has no meaning; ignored msvc71bind.cpp(21) : see reference to function template instantiation 'boost::_bi::bind_t<R,F,L> boost::bind<void(void) volatile,TEST,TEST*>(void (__thiscall TEST::* ),A1)' being compiled with [ R=void (__thiscall &)(void) volatile, F=boost::_mfi::dm<void (void) volatile,TEST>, L=boost::_bi::list_av_1<TEST *>::type, A1=TEST * ] ******\boost\mem_fn.hpp(286) : error C4716: 'boost::_mfi::dm<void __thiscall TEST::(void)volatile ,TEST>::operator()' : must return a value

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Re: Extending the boost::thread class
by arno.schaefer＠sqs.de 14 Oct '04

14 Oct '04

> For what it's worth, William Kempf began an implementation of thread > priorities and an exception-based thread cancellation scheme on the > thread_dev branch before he stopped working on Boost.Threads. If it's > completed enough (I haven't examined it closely enough yet to tell), > I hope to move it into the a Boost release after the upcoming 1.32. > That won't help you right now, however. I feel sorry about that, but perhaps it is possible to get a look to the actual state? Arno

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Boost & VC2005 (Whidbey)
by S.I.M. van Keulen 14 Oct '04

14 Oct '04

Hi all, recently I started 'porting' some projects to 64 bit Windows (AMD) using Visual Studio 2005. I noticed that the Compiler had trouble with Boost. Searching the net didn't provide much helpfull information. I wondered if any of you had tried anything with Boost and VC2005/Whidbey compilers. Or if any of you could direct me to some information source on the net. Thank you! Serge van Keulen

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