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BGL: Average path distance implementation
by P.Saffrey 22 Jul '05

22 Jul '05

I am writing a graph application using BGL where a key component is cycle detection. I need to know how long a cycle is. I can use breadth first search, but that gives me the shortest path. What I want is the average path length. I have an idea for an algorithm for this: basically do a breadth first search, disallowing any edge if it's been used before in this path and then take the mean of all the complete paths from the node to itself. Can anybody give me some clues as to how I can implement this? I would prefer to use the pucker event visitor approach, but I'm not sure whether I can use this to alter the search process. I'll need to cull a path from the search if it encounters a node with no outgoing edges that haven't been used already. I'm also not sure how to collect all the path lengths at the end. Peter -- P.Saffrey(a)ucl.ac.uk http://www.cs.ucl.ac.uk/staff/P.Saffrey/ Beacon Project http://www.grid.ucl.ac.uk/biobeacon/

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[bjam] How does one pass a compiler define
by Edward Diener 22 Jul '05

22 Jul '05

Is there a way to pass a compiler define when invoking bjam ? I want to build my libraries with by defining BOOST_ALL_DYN_LINK when linking to the dynamic run-time library. How do I do this ?

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compiler warnings using date_time library on VS.NET 2003
by Sean Rohead 22 Jul '05

22 Jul '05

I am using VS.NET 2003 and have a simple program which merely includes the Boost date_time library. When compiling, I get 4 warning messages about unsafe conversions. Is there some compiler setting that I can change to get rid of this warning? Shouldn't I be able to include a Boost library without getting warnings? Thanks! >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> // main.cpp #include "boost/date_time/posix_time/posix_time.hpp" void main() { } >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ------ Build started: Project: boost, Configuration: Debug Win32 ------ Compiling... main.cpp c:\lib\boost_1_32_0\boost\date_time\posix_time\conversion.hpp(27) : warning C4244: 'argument' : conversion from 'time_t' to 'long', possible loss of data c:\lib\boost_1_32_0\boost\date_time\time_system_counted.hpp(57) : warning C4244: 'initializing' : conversion from 'boost::date_time::counted_time_rep<config>::int_type' to 'boost::date_time::gregorian_calendar_base<ymd_type_,date_int_type_>::date_int_type', possible loss of data with [ config=boost::posix_time::millisec_posix_time_system_config ] and [ ymd_type_=boost::gregorian::greg_year_month_day, date_int_type_=boost::date_time::int_adapter<unsigned long>::int_type ] c:\lib\boost_1_32_0\boost\date_time\time_system_counted.hpp(52) : while compiling class-template member function 'boost::date_time::counted_time_rep<config>::date_type boost::date_time::counted_time_rep<config>::date(void) const' with [ config=boost::posix_time::millisec_posix_time_system_config ] c:\lib\boost_1_32_0\boost\date_time\time_system_counted.hpp(111) : see reference to class template instantiation 'boost::date_time::counted_time_rep<config>' being compiled with [ config=boost::posix_time::millisec_posix_time_system_config ] c:\lib\boost_1_32_0\boost\date_time\time.hpp(52) : see reference to class template instantiation 'boost::date_time::counted_time_system<time_rep>' being compiled with [ time_rep=boost::posix_time::int64_time_rep ] c:\lib\boost_1_32_0\boost\date_time\posix_time\ptime.hpp(32) : see reference to class template instantiation 'boost::date_time::base_time<T,time_system>' being compiled with [ T=boost::posix_time::ptime, time_system=boost::posix_time::posix_time_system ] c:\lib\boost_1_32_0\boost\date_time\time_parsing.hpp(81) : warning C4267: 'initializing' : conversion from 'size_t' to 'int', possible loss of data c:\lib\boost_1_32_0\boost\date_time\posix_time\time_parsers.hpp(27) : see reference to function template instantiation 'time_duration boost::date_time::parse_delimited_time_duration<boost::posix_time::time_duration>(const std::string &)' being compiled with [ time_duration=boost::posix_time::time_duration ] c:\lib\boost_1_32_0\boost\date_time\date_parsing.hpp(211) : warning C4244: 'argument' : conversion from 'std::allocator<_Ty>::value_type' to 'char', possible loss of data with [ _Ty=wchar_t ] c:\lib\boost_1_32_0\boost\date_time\date_parsing.hpp(253) : see reference to function template instantiation 'date_type boost::date_time::from_stream_type<date_type,std::basic_string<_Elem,_Traits,_Ax>::iterator>(iterator_type &,iterator_type &,wchar_t)' being compiled with [ date_type=boost::gregorian::date, _Elem=wchar_t, _Traits=std::char_traits<wchar_t>, _Ax=std::allocator<wchar_t>, iterator_type=std::basic_string<wchar_t,std::char_traits<wchar_t>,std::allocator<wchar_t>>::iterator ] c:\lib\boost_1_32_0\boost\date_time\gregorian\parsers.hpp(78) : see reference to function template instantiation 'boost::date_time::period<point_rep,duration_rep> boost::date_time::from_simple_string_type<boost::gregorian::date,wchar_t>(const std::basic_string<_Elem,_Traits,_Ax> &)' being compiled with [ point_rep=boost::gregorian::date, duration_rep=boost::gregorian::date_duration, _Elem=wchar_t, _Traits=std::char_traits<wchar_t>, _Ax=std::allocator<wchar_t> ]

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Re: [Boost-users] [bjam] How does one pass a compiler define
by Foster, Gareth 22 Jul '05

22 Jul '05

> Nobody -- other than that rhinoceros over there behind you -- > considers it adequate. > I hate to clutter the mailing list with redundant comments, but that really deserves a "lol". Lol. Gaz

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numeric::interval library an Alpha processor under OSF1
by Erwin 22 Jul '05

22 Jul '05

Hello, I would like to use the numeric::interval library on an Alpha EV 6.8 processor under the OSF1 operating system. My program runs fine under Linux on a Pentium 4, but on the Alpha machine, g++ tells me: boost/numeric/interval/hw_rounding.hpp:26:4: #error Boost.Numeric.Interval: Please specify rounding control mechanism. What has to be done? Where do I have to specifiy the rounding controls, how much do I need to know about processor internals etc? Which tests can and have to be done afterwards? Thanks for any advice! Best regards, Erwin

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Can't create time_duration with milliseconds on VS.NET 2003
by Sean Rohead 22 Jul '05

22 Jul '05

I am using VS.NET 2003 and attempting to create a time_duration using hours, minutes, seconds, and milliseconds. However, I get an error message regarding the 4th parameter (milliseconds). Here is my code and the error message: >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> // main.cpp #include "boost/date_time/posix_time/posix_time.hpp" using namespace boost::posix_time; void main() { time_duration t(8, 45, 00, milliseconds(100)); } >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ------ Build started: Project: boost, Configuration: Debug Win32 ------ Compiling... main.cpp c:\Documents and Settings\sean.rohead\My Documents\Visual Studio Projects\boost\main.cpp(13) : error C2664: 'boost::posix_time::time_duration::time_duration(boost::posix_time::time_duration::hour_type,boost::posix_time::time_duration::min_type,boost::posix_time::time_duration::sec_type,boost::posix_time::time_duration::fractional_seconds_type)' : cannot convert parameter 4 from 'boost::date_time::subsecond_duration<base_duration,frac_of_second>' to 'boost::posix_time::time_duration::fractional_seconds_type' with [ base_duration=boost::posix_time::time_duration, frac_of_second=1000 ] No user-defined-conversion operator available that can perform this conversion, or the operator cannot be called

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Re: [Boost-users] Newbie Question - Errors if i want to, compile using g++
by mix 21 Jul '05

21 Jul '05

Hi, Thanks for your reply, it works great :D I must use "-lboost_regex" mix -- Michael Weibel mailto:mix@openflex.net http://www.openflex.net

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[serialization] Building in 1.32 for Borland problem
by Edward Diener 21 Jul '05

21 Jul '05

I downloaded the standalone Spirit 1.62 and put it in a directory of my machine. I set SPIRIT_ROOT to that directory in my environment. I then used bjam to build my Boost libraries for Borland and Bcb6. The serialization build reports errors from the spirit/core/config.hpp in my Boost 1.32 directory tree that my compiler is not supported. Of course I was expecting it to pick up Spirit files from my SPIRIT_ROOT directory tree. Why is this not working correctly ?

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regex with multi-byte characters
by Ovanes Markarian 21 Jul '05

21 Jul '05

Hello all, I am using wide characters from the Xerces-C library. These are defined as always being a 2 bytes characters by: typedef short XMLCh; // can be also defined through the #define preprocessor directive I don't remember it I also saw a post http://lists.boost.org/boost-users/2003/09/5095.php where John answered that it is better to convert these character sequences on-the-fly to char. Somehow I don't like this approach, since I believe that with wrong encoding set on the system some information might get lost. Is it possible to use XMLCh as character traits in the regular expression if XMLCh* points to a null-terminated 2 bytes character sequence? -- With Kind Regards, Ovanes

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Fw: State machine framework with dynamic configurability
by Andreas Huber 21 Jul '05

21 Jul '05

Forwarded from comp.lang.c++.moderated for being OT there. Original thread: http://tinyurl.com/cmvud -- Andreas Huber When replying by private email, please remove the words spam and trap from the address shown in the header. "Dave" <pplppp(a)gmail.com> wrote in message news:<1120669819.949833.153720(a)g14g2000cwa.googlegroups.com>... > the FAQ illustrates how to modify the existing layout of an FSM, but I > doubt whether it would be possible to implement the main FSM in the > main exe and then dynamically load dlls to add inner/sub-states to > existing states; since the state transition/reactions have to be > specified as template parameters. > > >Out of curiosity: Would you care to describe what kind of application > >you need such a library for? > > This is probably off-topic for this ng but I'll provide my reasons so > you can decide if they're reasonable or not. > > The application I mentioned original post is a call control > application, in fact several of them. (Naturally each application is > maintained by a group of developers) Each of the applications has a > flat Fsm with many states. My goal is to design a framework that has a > main Fsm that is common to all the call control applications (with > points of customization pre-defined) and then dynamically load DLLs to > customize the behavior (by adding inner/sub-states) of the Fsm. The > obvious advantage of doing so would be code reuse. Another reason to > do > so is that if a customization for a specific customer is needed (say > add a few states to the fsm), only a few DLLs need to be > modified/added, whereas in the existing design the main application > has > to be modified and recompiled. In this way the customization may be > done by a developer who does not have full access to the source > code/statechart, all he/she needs to know is the interface of the > "point of customization". > > Dynamic configurabliity aside, the application I'm working on is a > call > control application, so I only need one instance of the state machine, > one instance of each state and use context objects to store state > information for each call. When I skimmed through the statechart > tutorial I see that the "Entry" and "Exit" functions are implemented > using the constructor and destructor of the simple_state class, so I > suppose that each state object is constructed when entered and > destructed when exited. I'm not sure.. if a state is entered and > exited > repeatedly, say in the stopwatch example, whether the object > construction/destruction incurs an unecessary cost. If I'm wrong, > please correct me. > > If there's a free Fsm libary (not licensed under GPL) that satisfies > my > requirements that would be great, but I would also consider commercial > products. Yet I'm under the impression that commerial Fsm libaries > usually come with graphical UML editors... right now I'm stuck with > Rational Rose 98 (old version), so the new tool would have to be able > to import UML diagrams drawn using Rational Rose 98. One good thing > about Rational Rose is that the saved files are pretty human readable > so I can just write a script to parse the state chart specifications > and generate code that uses some Fsm libarary (say boost statechart). > Of course another alternative would be rely on the UML editor to > generate frameowrk code for me but I would still have to make some > modifications to archive dynamic configurability. > > thanks > > Dave > - I'm a novice please be nice :-) > > > [ See http://www.gotw.ca/resources/clcm.htm for info about ] > [ comp.lang.c++.moderated. First time posters: Do this! ]

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