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Proposal: Library to manage processes
by Julio M. Merino Vidal 22 Feb '05

22 Feb '05

Hi everyone, a while ago, I started to write a little utility that aims to interact with multiple VCS systems. I chose C++ (and I don't regret that decision at all), so I had to create multiple classes to interact with system internals and keep the "real" application code clean from such OS-specific calls. A few days ago, I decided to switch to use Boost in that project, basically because I was interested in the Filesystem library. Doing so, I have been able to remove some of my custom classes that dealt with files and directories (and which were quite ugly). Furthermore, this change has allowed me to use many other Boost goodies. Among the classes I wrote, there are some that provide an abstraction layer to launch other (child) processes. Once the process is launched, the code can access its standard input/output/error streams by using the standard iostreams framework. I'm willing to reorganize (well, mostly rewrite from scratch) such process-management classes to follow the Boost policies, aiming for future integration in Boost. But, before I start to do so, I would like to know if such library will be adequate to be integrated and/or if there is interest in it. FWIW, I've searched the mailing lists and found some people that said that they missed this functionality in Boost. Any comments? Thanks in advance, -- Julio M. Merino Vidal <jmmv84(a)gmail.com> http://www.livejournal.com/users/jmmv/ The NetBSD Project - http://www.NetBSD.org/

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Dynamic Exception Handlers [repost]
by David Abrahams 22 Feb '05

22 Feb '05

Can it really be two years ago that I talked about refactoring the mechanism in Boost.Python? http://aspn.activestate.com/ASPN/Mail/Message/boost/1537162 Well, I had to do it for a talk I'm giving, so here it is. It could easily be boost::detail-ized. Is there still interest? -- Dave Abrahams Boost Consulting www.boost-consulting.com

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Preprocessor question
by Arkadiy Vertleyb 22 Feb '05

22 Feb '05

Hi, Suppose I have the following macro: #define DO(x)\ BOOST_PP_CAT(STEP3, BOOST_PP_CAT(STEP2, BOOST_PP_EXPAND(STEP1 x))) #define STEP2STEP1 Now, DO(5) should IMO expand into STEP35. For some reason, VC71 expands it into STEP3 5. Where does the space come from? Can one CAT two tokens, and get a space between them? Is it a bug in VC71 or is it supposed to be like this? If I use BOOST_PP_SEQ_CAT outside, it does what I expect. Can anybody explain why? (the above exersize may not make sence out of context. I don't think the context is relevant, although I can provide it if necessary) Thanks in advance. Regards, Arkadiy

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Priority Queue in boost::graph::dijkstra_shortest_paths
by Lloyd J Lewins 21 Feb '05

21 Feb '05

Perhaps I am missing something, but I don't see how dijkstra_shortest_paths works currently. The priority queue (mutable_queue) in dijkstra_shortest_paths should order (gray) vertices by their distance from the source vertex. The ordering of the mutable_queue is achieved by the compare function, which therefore should order vertices by examining the distance map. However, the default compare function is simply std::less<D>(), where D is the value_type of the distance map. I.e., the compare simply orders the vertices by their vertex_descriptor, using less for the value_type (essentially a cast). I would think what is really needed is a less function which is bound to the distance map, and compares based off distance. For example: template<class Map> class less : public std::binary_function<typename boost::property_traits<Map>::value_type, typename boost::property_traits<Map>::value_type, bool> { typedef typename boost::property_traits<Map>::key_type key_type; typedef typename boost::property_traits<Map>::value_type value_type; public: explicit less(Map& m) : m(m) { } bool operator() (const key_type k1, const key_type k2) const { return m[k1] < m[k2]; } private: const Map& m; }; In which case the compare function would be somethink like: less<DistanceMap>(distance). Lloyd J. Lewins Fellow, Raytheon Co., llewins(a)raytheon.com +1 (310) 647-8832

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Apple GCC conditional in boost.python ??
by Marshall Clow 21 Feb '05

21 Feb '05

In boost/libs/python/src/converter/registry.cpp, I found: >#if defined(__APPLE__) && defined(__MACH__) && defined(__GNUC__) \ > && __GNUC__ == 3 && __GNUC_MINOR__ <= 4 && !defined(__APPLE_CC__) ># define BOOST_PYTHON_CONVERTER_REGISTRY_APPLE_MACH_WORKAROUND >#endif I have no idea what defining that big long symbol does, but I think that the conditionals are incorrect. <http://developer.apple.com/technotes/tn2002/tn2071.html> says: __APPLE__ This macro is defined in any Apple computer. __MACH__ This macro is defined if Mach system calls are supported. __APPLE_CC__ This macro is set to an integer that represents the version number of the compiler. This lets you distinguish, for example, between compilers based on the same version of GCC, but with different bug fixes or features. Larger values denote later compilers. I can't see any case where __APPLE__ and __GNUC__ are defined, and __APPLE_CC__ is not defined. Metrowerks? ==> No __GNUC__ Not on a Mac? ==> No __APPLE__ __APPLE_CC__ was defined for Apple-released versions of GCC, starting with 2.95.2 (so says Chris Espinosa at Apple). More historical info is at <http://developer.apple.com/releasenotes/DeveloperTools/GCC2.html> So, I think that that whole #if expression always evaluates to "false". -- -- Marshall Marshall Clow Idio Software <mailto:marshall@idio.com> It is by caffeine alone I set my mind in motion. It is by the beans of Java that thoughts acquire speed, the hands acquire shaking, the shaking becomes a warning. It is by caffeine alone I set my mind in motion.

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[boost::signals] connect/disconnect management suggestion
by kolach56＠yandex.ru 21 Feb '05

21 Feb '05

I used boost::signals in number of projects and found one thing inconvenient. I could easily connect anything to signal but sometimes it became hard to disconnect form it. It's ok if a connection time is bounded by a lifetime of trackable or connection objects. I used to use Group id for disconnection, but sometimes I needed it for call priority. ( In that case I would write a special GroupCompare function but it looked ugly. ) For experimental purposes, I constructed an alternative approach. For connection/disconnection management I used the following syntax: struct Test { void test( bool, int ); }; void f( bool ); signal<void (bool)> s; s.connect( &Test::test, t, _1, 5 ); s.disconnect( &Test::test, t, _1, 5 ); s.connect( &f, _1 ); s.disconnect( &f, _1 ); I just form a hash code from the arguments. It certainly makes the process longer, but in most cases I don't need something extremely fast there. In my projects, the performance is important in invocation process. It's only a variant, there might be a lot of other ways. So actually my suggestion is why not to have both approaches of connection/disconnection management? One for fast connection/disconnection and the other for extra control over it. -- Best regards, Nick mailto:kolach56@yandex.ru

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Review managers needed
by Tom Brinkman 21 Feb '05

21 Feb '05

The following libraries are scheduled to be reviewed in the coming weeks. Finite State Machine (FSM) Andreas Huber Review Manager - Pavel Vozenilek Policy Pointer David Held Fixed Strings Reece Dunn FOREACH Macro Eric Niebler typeof Arkadiy Vertleyb,Peder Holt If you are familiar with one of the these libraries and would like to volunteer to be the review manager, please contact me at reportbase(a)yahoo.com. Tom Brinkman Review Wizard __________________________________ Do you Yahoo!? Yahoo! Mail - Helps protect you from nasty viruses. http://promotions.yahoo.com/new_mail

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[Boost-bugs] [ boost-Bugs-1145183 ] Can't build on cygwin
by SourceForge.net 21 Feb '05

21 Feb '05

Bugs item #1145183, was opened at 2005-02-20 21:32 Message generated for change (Tracker Item Submitted) made by Item Submitter You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=107586&aid=1145183&group_… Category: None Group: None Status: Open Resolution: None Priority: 5 Submitted By: Nobody/Anonymous (nobody) Assigned to: Nobody/Anonymous (nobody) Summary: Can't build on cygwin Initial Comment: boost 1.32.0 from cvs while i'm trying to compile it under cygwin with: bjam -sTOOLS=gcc install i have an error: unknown target type for <@boost!libs!test! build>libboost_prg_exec_monitor. Anybody can help me? Thank you, diabolo(a)gcnet.ru ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=107586&aid=1145183&group_… ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click _______________________________________________ Boost-bugs mailing list Boost-bugs(a)lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/boost-bugs

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wave gcc "bits/c++config.h" invalid name
by Larry Evans 21 Feb '05

21 Feb '05

Getting: cd ~/prog_dev/boost-release/boost_1_32_0/lje/libs/fields_visitor/test/ wave -S/usr/include/c++/3.3 test_link.cpp #line 42 "/usr/include/c++/3.3/iostream" #pragma GCC system_header /usr/include/c++/3.3/iostream(42): exception caught: boost::filesystem::path: invalid name "c++config.h" in path: "bits/c++config.h" Should the criteria for valid name be changed?

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Two more typos
by Julio M. Merino Vidal 20 Feb '05

20 Feb '05

Hi again, another fix for two more typos is attached. Cheers, -- Julio M. Merino Vidal <jmmv84(a)gmail.com> http://www.livejournal.com/users/jmmv/ The NetBSD Project - http://www.NetBSD.org/

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