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boost::filesystem::path - where are the attributes?
by Pete 19 Nov '04

19 Nov '04

I'm not sure if I'm missing something or not, but I couldn't find anything in the filesystem documentation that allows one to retrieve file/directory attributes such as: Date created/last accessed/last modified Hidden System Read Only Link Etc. I'm particularly interested in portable file date accessors (hoping to find methods in the path class returning boost::posix_time::ptime). Are there any known workarounds?

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function_traits of bind - functors possible?
by Roland Schwarz 19 Nov '04

19 Nov '04

Is it possible to use function_traits for functors that have been created with bind? I.e.: template<Function> foo (Function f) { typedef typename boost::function_traits<Function>::type fn_t; boost::signal<fn_t> sig; } .... foo(boost::bind(fobar, this, _1)); Apparently the above does not work, but I cannot figure out what I am missing. Roland

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FW: Leak when using boost threads under VC .NET using statically linked CRT
by alansa＠ati-uk.com 19 Nov '04

19 Nov '04

The following code leaks memory for each iteration of the loop for (;;) { boost::thread t(func); t.join(); } void func() { cout << "------" << endl; } If I replace func with func2 void func2() { try { throw 1; } catch {} } then it still leaks. But if I say fill up a vector with stuff or just return there is no leek. The interesting part is that it doesn't leak if use the version of threads built using the CRT as a .dll rather than static link. I also believe that the actual culprit is somewhere in boost.function since the code for boost.thread is so straight forward. I'm currently using boost 1.30 so it might have already been addressed in newer versions. Can anyone help?

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Signals & Slots
by Foster, Gareth 19 Nov '04

19 Nov '04

I think if you just follow through the different typical tasks you might undertake with the two libraries as Murray wrote: " 1. Create a signal 2. Connect a slot (callback function) to a signal. 2.2 For a member method. 2.3 For a non-member or static function. 3. Disconnect a slot. 4. Bind an extra parameter, so that e.g. a slot with 4 parameters can be used with a signal with 3 parameters. I don't personally find the more complex adaptors interesting. " Then write up a document where, in each case, the code needed for both libraries is given, and then I small discusion about any differences or similarities. Perhaps in each case, giving some approximate figure to indicate the similarity would be useful. Presumably, this could then end up in the appendix of, or being referenced by, a proposal for a standard signals/slots interface. I don't know what is involved to be honest. I suppose, it needn't be just the one person doing the comparison, there are four tasks in the list (and maybe a few more besides), so four people could spread the work load, and maybe a 5th could add final conclusions and draw together the others notes. Cheers all, Gaz -----Original Message----- From: libsigc-list-bounces(a)gnome.org [mailto:libsigc-list-bounces@gnome.org] On Behalf Of Carl Nygard Sent: 18 November 2004 19:20 To: Doug Gregor Cc: libsigc-list(a)gnome.org; boost-users(a)lists.boost.org; gtkmm-list(a)gnome.org Subject: Re: [sigc] Re: [Boost-users] Signals & Slots On Thu, 2004-11-18 at 14:09, Doug Gregor wrote: > On Nov 18, 2004, at 1:10 PM, Murray Cumming wrote: > I'm not in a position to do this at the moment, although possibly in > the future. It would be *wonderful* if someone went off and studied > both libraries in-depth to make this comparison, especially if that > person was not intimately familiar with either library beforehand. I'm in a reasonably sane position to do this, although only time will tell if what comes out is useful to anyone or not. Regards, Carl _______________________________________________ libsigc-list mailing list libsigc-list(a)gnome.org http://mail.gnome.org/mailman/listinfo/libsigc-list

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SV: [Boost-users] Manual in pdf?
by Daniel Lidström 19 Nov '04

19 Nov '04

) ) Daniel Lidström writes: ) > Hi, ) > ) > is the manual available in pdf or postscript? Or is there a way ) > to print it? The online manual is not very printer-friendly. ) ) Daniel, ) ) I assume you are talking about Boost-wide PDF (some of the Boost ) libraries/tools provide a standalone one on their own). In that case, ) it's not available for 1.31; we are working on making it available in ) the upcoming 1.32.0, which is due in a couple of days. ) How about the Spirit manual? Will it be available in printable format with 1.32.0? Thanks! -- Daniel

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Spirit help (again)
by Cory Nelson 19 Nov '04

19 Nov '04

Okay, I'm trying to learn Spirit and I've got the grammar down. I've tried looking at the documentation but still can not find out how to make a custom parser (that will let me use the [action] operator). Could someone give an example of a pascal string parser (one byte for length, string follows) to get me started? -- Cory Nelson http://www.int64.org

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MPL Library
by Edward Diener 18 Nov '04

18 Nov '04

I have bit the bullet and am attempting to get my head around the MPL library. I realize there is a book out by Messieurs Abrahams and Gurtovoy, I believe, but I thought I would tackle the boost documentation first. A few questions: 1) Is the documentation up to date ? 2) There are three separate documents to study, it seems, all giving information about the MPL library, a white paper circa 2002, a reference, and a mini-tutorial. Is the information in these in sync with each other ? The reason I ask is that the white paper/mini-tutorial mentions if_<> and apply_if<> but the reference does not mention them at all.Are they just understood intrinsic metafunctions that need no reference, or what ? If the former, are there more of these intrinsic metafunctions and, if co, what are they and what do they do ? 3) A number of the topics in the reference documentation mentioned in generalized overviews of the various sections have no specific links. Does this mean that they were never implemented ? Seems dubious in a number of cases. I would seriously like to figure out how MPL works and play around with it, but I feel stymied with what is in the boost docs.

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Key iterators
by Chris Goller 18 Nov '04

18 Nov '04

I'm just getting into boost and I really like it. I would like to iterate over keys of a multimap. so it would look like this: std::multimap<type, type>::key_iterator i = map.beginkey(); i != map.endkey(); i++ at each i++ it would move to the next key. -or- for_each(map.beginkey(), map.endkey(), whatever); Is this possible with the boost iterators? Thanks, Chris

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Re: [sigc] Re: [Boost-users] Signals & Slots
by Doug Gregor 18 Nov '04

18 Nov '04

On Nov 18, 2004, at 1:10 PM, Murray Cumming wrote: >> Very simple explanation here: my comments were about libsigc++ 1.2. > > It would be best for us to ignore them then. The differences are quite > large. Yes, please ignore them. >> I've glanced briefly at libstdc++ 2 > > For the record, Doug almost certainly means "libsigc++" instead of > "libstdc++". Correct. >> and was pleasantly surprised. I'd >> like to look into it further, but do not have the time now. I've been >> saying for a while that the Signals interface is not ready for >> standardization because we only had the one implementation (in Boost) >> and that it was not solid enough for standardization. However, with >> libstdc++ 2 adopting a similar interface, we might be able to converge >> on a single, solid interface for Signals & Slots within the C++ >> Standard Library. Library Technical Report 2 is open for submissions, >> and signals & slots have been on the wish list since the beginning... >> >> In any case, a thread titled "Boost Signals & Slots vs. libsigc++" is >> treading on dangerous territory :) > > I doubt that Boost Signals and libsigc++ 2 are significantly different. My cursory review of the libSIGc++ 2 reference documentation seems to indicate that the interfaces are similar. > A comparison should probably start by looking at the application code > needed to > 1. Create a signal > 2. Connect a slot (callback function) to a signal. > 2.2 For a member method. > 2.3 For a non-member or static function. > 3. Disconnect a slot. > 4. Bind an extra parameter, so that e.g. a slot with 4 parameters can > be > used with a signal with 3 parameters. I don't personally find the more > complex adaptors interesting. I'm not in a position to do this at the moment, although possibly in the future. It would be *wonderful* if someone went off and studied both libraries in-depth to make this comparison, especially if that person was not intimately familiar with either library beforehand. > Please do try to warn us if Boost Signals seems near to being > approved. We > would like to try porting gtkmm to it then. There is no current effort to write a proposal to bring the Boost.Signals interface to the C++ committee (that I know of). If this does happen, it will be _after_ we have a detailed comparison of both libraries and, of course, I will announce it on both the libSIGc++ and Boost mailing lists. Doug

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Re: [Boost-users] Signals & Slots
by Foster, Gareth 18 Nov '04

18 Nov '04

Doug, This is what murray had to say on the GTKmm list (future correspondance, if any, to be on the libsigc++ list), it's a very pleasing response I'm sure you will agree. Perhaps you could qualify you last statement though, that one seems to have murray a little stumped. Cheers! Gaz -----Original Message----- From: Murray Cumming [mailto:murrayc@murrayc.com] Sent: 18 November 2004 09:50 To: Foster, Gareth Cc: 'gtkmm-list(a)gnome.org'; libsigc-list(a)gnome.org Subject: Re: [Boost Signals & Slots] Vs [libsigc++] Questions comparing boost::signal to libsigc++ belong on the libsigc++ mailing list. I'm CCing it. boost::signal was developer in cooperation with Karl Nelson, the main original libsigc++ developer. Also, the libsigc++ 2 API was redesigned to be as much like boost::signal as possible, so that gtkmm can easily switch to boost::signal if it becomes an API-stable dependency or it is added to the C++ Standard Library. gtkmm has a long-standing policy of not reimplementing things when we can just reuse them. This part makes no sense to me. It would have to be explained properly before we could comment: " Basically, libsigc++ is a monolithic entity covering single and multiple-target callbacks, slots, and slot binding, Signals tackles only the multiple-target callbacks, relying on other Boost libraries (especially Function and Signals) to do most of the work, so it integrates cleanly with the rest of Boost. " Murray > Hello all, > > As you will see in the forward email below, I was chatting to a bloke who > works on boost::signal, I wondered how this stacked up against libsigc++, > and whether there was any chance it could be used in GTKmm and suchlike. A > GTKmm developer did pop up on the boost list and make the valid point that > API stability would be a major issue, nevertheless, I thought I'd send > this > out, and see what people here had to say. As I said on the boost list, I > am > thinking more ... > >> "hey, what do you think to this lads" than an outright "you should be > using Boost heathens!" > > I hope such discussion isn't offtopic. > > Thanks all! > > Gaz > > > -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Doug Gregor > Sent: 17 November 2004 15:49 > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Signals & Slots > > > On Nov 17, 2004, at 9:20 AM, Foster, Gareth wrote: >> I was just reading some mention of bugs in boost::signal, > > They weren't actually bugs :) > >> is this >> implementation in competition with libsigc++? i.e. does it aim to do >> the >> same job, but under a different license, or is there perhaps some >> fundamental design difference between the two? > > The Signals library aims to be much more flexible than libsigc++ and to > have an interface that is more comfortable for Boost. For instance, > slots are just function objects with similar signatures (like > Boost.Function, because Function is used in Signals), one can combine > the results of calling multiple slots into a single return value via an > arbitrary function object, and the lifetime of signals & slots is > automatically tied to "trackable" objects used in bind expressions to > build slots. > > Basically, libsigc++ is a monolithic entity covering single and > multiple-target callbacks, slots, and slot binding, Signals tackles > only the multiple-target callbacks, relying on other Boost libraries > (especially Function and Signals) to do most of the work, so it > integrates cleanly with the rest of Boost. > > Doug > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users > _______________________________________________ > gtkmm-list mailing list > gtkmm-list(a)gnome.org > http://mail.gnome.org/mailman/listinfo/gtkmm-list > Murray Cumming murrayc(a)murrayc.com www.murrayc.com www.openismus.com

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