June 2004 - Boost - lists.boost.org

libs/iterator/doc/iterator_concepts.pdf not marked as binary
by Peter Dimov 14 Jul '04

14 Jul '04

libs/iterator/doc/iterator_concepts.pdf is not marked as binary in the CVS. The result is that it apparently has been scrambled at commit time, as neither a Windows nor a Linux check out a readable PDF. In addition, Windows always shows it as locally modified; my cvs commit just committed a new revision of iterator_concepts, but I didn't touch the file. I can't fix it because I don't have the original PDF, and cvs can't check out a working version. -- Peter Dimov http://www.pdimov.com

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Math functions for statistics - a draft TR2 proposal.
by Paul A Bristow 13 Jul '04

13 Jul '04

As promised recently, I am presenting a draft of proposals for math functions which are needed for even most elementary statistics. I have been encouraged to submit this to both the C and C++ Standard Library groups at the same time. (They seem to speaking more than in the past). These are additions to the list drawn up by Walter Brown accepted into TR-1. The style and format follows his closely even though there were some opposition to them from the C++ community. However I think we have to accept that C and C++ compatibility are valued more than C++ 'ideality', and not try to re-open this area of dissent. The draft has been uploaded to the files area in a new folder Math Functions as "More Mathematical Functions.pdf" 220 kb. I'd be grateful if some CVS whizz would copy it to the sandbox as I know that many are unable to access the fiels section. It would be useful to have comments on 1 Typographical mistakes. 2 Mathematical mistakes (prepared by someone with seriously rusty math!). 3 The choice of functions espcially if there are any your feel strongly are missing, or are not needed (say why). 4 The choice of names. Clarity is preferred to curtness. 5 The choice of names for derivatives like the inverse and complement. I have added suffixes _inc and _c (or _com?). ( for C there will be suffixes f and l for the float and long double versions). Thanks. Paul PS I am on holiday for two weeks and will not respond to your observations until July. Paul A Bristow Prizet Farmhouse, Kendal, Cumbria UK LA8 8AB +44 1539 561830 +44 7714 330204 mailto: pbristow(a)hetp.u-net.com

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boost::function code size
by Vladimir Prus 11 Jul '04

11 Jul '04

Hello, I've became interested in how efficient code-size-wise boost::function is, so I wrote a small script which generates a function which calls boost::function object N times and finds the size of the generated function. The results are somewhat interesting and somewhat alarming (to me). On gcc 3.3 with -Os, each call to boost::function costs 147 bytes of code size. With -O3 it's about 166 bytes. On gcc 3.4 calls cost 203 bytes with -Os and between 220 and 240 with -O3. However, when boost::function is called 15 times, the inliner heuristics kick in and calls are no longer inlined -- meaning each call costs about 14 bytes. This is a good thing for 3.4, but still: 1. For 3.3 boost::function causes a serious code bloat. 2. Even for 3.4, I'm not sure how it will perform if calls are done in several modules. Or how the heuristics will work on non-trivial cases: if they use the % of size increase then on large modules boost::function inlining can cost much more. Given that, IIUC, boost::function has to do indirect call somewhere anyway, I'm not sure inlining is such a good idea. Maybe some of the methods should be declared out-of-line, so that compiler don't try to inline them? - Volodya

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[filesystem + iterator] directory iterator problem
by Vladimir Prus 08 Jul '04

08 Jul '04

There's a bug report on sourceforge: https://sourceforge.net/tracker/index.php?func=detail&aid=937606&group_id=7… which boils down to the fact that directory_iterator it(...); path p = *it++; does not work correctly. The exact problem is that the above line return a copy of the iterator, and increments 'it', but both iterators have shared_ptr to the same internal structure, so by time user deferences the copy, it gets the next file in the directory. The filesystem lib sources contain the following comment: The *r++ requirement doesn't appear to apply to the new single_pass_traversal category Thus I'm leaving the proxy out pending confirmation from the N1477 authors I'm not sure I understand that. It seems that *r++ should work, since signle pass iterator requires that r++ should work and return object of type X (call it r2), and the reabable iterator requires that *r2 should work. Am I wrong? And BTW, don't the above requirements mean r++ cannot return a proxy object, but only a real copy of the iterator? - Volodya

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Boost Mathematicians
by Tom Brinkman 07 Jul '04

07 Jul '04

What is the current status of all Boost mathmatical, statistical and econometric libraries currently in development? The collection of boost math libraries that are currently included in the library are world-class and provide a wonderful foundation to build-upon. However, many areas of advanced statistical and mathmatical inference are not currently being addressed by any of the boost libraries. Is there currently a way for those boost developers with a background in mathmatics to coordinate their efforts. If not, why not? Lets get such a discussion started. A continued and regular dialog of mathmatics as it relates to boost library development would be of great use, primaryily to avoid overaping our efforts. If your a mathmetician and agree with me that boost is a great foundation to build-upon, let the group/me know. Points for Discussion: 1) We should keep a seperate list of boost::math libraries that are currently under development and provide a forum for advanced discussions. How can we do this? 2) We need a way to attract the best mathmaticians in the world. How can we make the boost libraries an even more attractive development platform for the mathemiticians? 3) We should create a list of mathmatical algorithims and libraries that are needed. 4) We need some very basic boost specific math-tutorials for our future mathemiticans and potential library writers. 5) We need to advertise to the development community about how strong of a foundation boost is for mathmatical library development. In short, lets tell the world that this is the premiere place for advanced mathmatical library development, as I believe that it could be. Comments? Regards, Tom Brinkman __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Re:Re: [boost] Re: 1.32 release preparation
by Robert Ramey 06 Jul '04

06 Jul '04

Johannes Brunen wrote: >> And if there are a large >> number of new things left out by that approach then we should plan >> another release sooner rather than waiting 4 months. >However, then you need new volunteers which have to spend the time for the >whole procedure again. The release procedure is too onerous. This isn't the problem, it's a symptom of a more subtle problem. If the source of this difficulty can be found can corrected, then releases can occur more frequently. My personal view is that it's a symptom of a development process that couples otherwise independent/orthogonal efforts. This is due to the fact that we're all working against a development tree that has experimental code in it. So minor issues ripple across all efforts. >I could think of a review process which accepts a library only after the >list of requested changes has been made. > I would prefere a review process which leads to final > acceptance only after a library is 'CVS' compatible i.e. does not yield to > any (known) regressions of the existing pool libraries and is equipted > with a working testing facility. The review process qualifies submissions for inclusion into boost. I don't think there are any libraries that have been accepted then suffered changes which made them unacceptable. It's not fair to ask a submitter to require that that he totally "finish" the package before submission when it cannot be guaranteed that it will be accepted. The review process isn't the problem, its working quite well. It's just that there is more effort than first meets the eye between the time a library is deemed acceptable and the time it is ready for inclusion into boost. The serialization library including code, headers, tests, html, jamfiles, *.bat, and shell scripts is has passed 25,0000 lines. This takes time and no changes in the review or release procedure can change that. There is the review package which seems to work pretty well. But I would be reluctant to check it in as it doesn't match the review acceptance conditions and I'm concerned about trying to maintain a package which I have now moved beyond. Robert Ramey

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Re:Re: [boost] Re: 1.32 release preparation
by Robert Ramey 06 Jul '04

06 Jul '04

Message: 16 Date: Sun, 27 Jun 2004 22:25:47 -0500 From: "Aaron W. LaFramboise" <aaronrabiddog51(a)aaronwl.com> Subject: Re: [boost] Re: 1.32 release preparation To: boost(a)lists.boost.org Message-ID: <40DF8FBB.4040408(a)aaronwl.com> Content-Type: text/plain; charset=us-ascii Aaron W. LaFramboise wrote: >Robert Ramey wrote: >> Dave Abrahams wrote: >> >> >>>I'd like to know the reasons for "all the sudden rush". We did >>>announce a schedule long ago, and it has already been delayed by three >>>weeks. I'm not asking in order to point fingers; I just want to know >>>how to avoid the "sudden rush" next time. >> >> >> Here is the current scenario. >> >> a) The announcement gets posted - release 1.32 scheduled for date x. >> b) Each developer decides - uh oh I better get in my changes before date x. >> c) Of course these changes take longer >> d) and break some other things >> e) which takes longer still >> >> Personally I think the concept of scheduling a release fundamentally flawed. >> I would suggest another idea. >As an observer, I'm fairly impressed with GCC's release methodology. >http://gcc.gnu.org/develop.html >A critical component is a schedule that includes several stages during >which certain sorts of changes are unacceptable. >There's still rush, but most of the rush for major features or other >destabilizing elements happens long before the release comes around. I found this to be very interesting. I had never seen this before. It basically implements my view that the "Main Line" should be code that is always works and is ready to be used, tested and potentially released. As far as I'm concerned it's totally consistent with my proposal which I thought was un-orthodox but now see that is used at least by GCC. So, my view would be - stick to the original 28 June date, require that new libraries be added to branches and merge to main as appropriate. I realize its not THAT easy - but it would address the concerns that I have about the whole process and allow all libraries to proceed on independent schedules. New libraries would be tested against the "known good tree" independently of one another. Take as a small example changes in MPL. The current method is to check in a new version of MPL and see what happens. Presumable some issues will arise and now we have a broken system which inhibits development of other libraries until the issues are resolved. Under the proposed method, the new MPL would be check in under its own branch and issues would be detected on all libraries before they affect other developers. Anyway - my 2 cents. Robert Ramey

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Administrative Requests
by David Abrahams 05 Jul '04

05 Jul '04

Just a reminder -- I'm not the only moderator. Please post all administrative requests to boost-owner(a)lists.boost.org so that the workload of responding to them is distributed across everyone who can handle them. Thanks, -- Dave Abrahams Boost Consulting http://www.boost-consulting.com

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codewarrior 8.0 problem
by Pavol Droba 04 Jul '04

04 Jul '04

Hi, Regression tests show that codewarrior 8.0 have some problems with string algo lib. Report is here: http://tinyurl.com/35asy It seems, that compiler cannot find std::locale class. Can somebody with an access to this compiler help here. Thanks in advance. Regards, Pavol

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Proposal: Addition to boost::integer_traits
by Jeffrey C. Jacobs 04 Jul '04

04 Jul '04

A while ago I proposed adding a signed_traits class and then after receiving some input decided it better this be a property of some existing traits object, ideally "integer_traits" since only integer can be signed. I tried to contact some people to whom I'd been referred about changing integer_traits.hpp but never heard back. Otherwise I have received no negative feedback from this proposal. The idea is simple, as with the min and max constants associated with boost::integer_traits, there would be: boost::integer_traits<x>::unsigned_type boost::integer_traits<x>::signed_type I also proposed a boost::integer_traits<x>::type But that would be x and so wouldn't be very useful. With these additions, one would be able to get the signed or unsigned form of a type without knowing the type detail. In other words, one can apply "signed" or "unsigned" to any specialized integral type that supports it. (Obviously bool would not be supported, nor would any non-integral types.) OTOH, a user-defined pseudo-integral type could provide its own specialization which would be a way of converting between signed and unsigned Abstract Integral Types (AITs) in a generic way: template <> class integer_traits<my_signed_type> : public std::numeric_limits<my_signed_type>, public detail::signed_integer_traits_base<my_signed_type, my_unsigned_type> { BOOST_STATIC_CONSTANT(bool, is_integral = true); }; Note: here I do not use the boost::detail::integer_traits_base helper because my_signed_type does not have a min or max value and even if it did, it is not possible to do in-class initialization with abstract data types. I would also be providing a specialization of std::numeric_limits. Note also because of these orthagonal properties, I provide a separate base class for signed_integer_traits_base, rather than adding to integer_traits_base. The idea would then be to have a new type in the boost::details namespace: template <class ST, class UT> class signed_integer_traits_base { public: typedef ST signed_type; typedef UT unsigned_type; }; And define each integral type correspondingly, e.g.: template<> class integer_traits<bool> : public std::numeric_limits<bool>, public detail::integer_traits_base<bool, false, true>, public detail::signed_integer_traits_base<bool, bool> { }; template<> class integer_traits<char> : public std::numeric_limits<char>, public detail::integer_traits_base<char, CHAR_MIN, CHAR_MAX>, public detail::signed_integer_traits_base<signed char, unsigned char> { }; // ... template<> class integer_traits<int> : public std::numeric_limits<int>, public detail::integer_traits_base<int, INT_MIN, INT_MAX>, public detail::signed_integer_traits_base<signed int, unsigned int> { }; template<> class integer_traits<unsigned int> : public std::numeric_limits<unsigned int>, public detail::integer_traits_base<unsigned int, 0, UINT_MAX>, public detail::signed_integer_traits_base<signed int, unsigned int> { }; // ... The one problem with this as I see is cv-qualification. Clearly, this will only provide the cv-unqualified types input as if I read ISOC++ 14.1.5 correctly, and I may not be, the top-level cv-qualification of the integral type template parameter would be dropped. E.g.: boost::integer_traits<const int>::signed_type would be [signed] int, NOT const [signed] int. In general, this is what you want because it saves you from writing specialization for each cv-qualification, but it then looses information about the source type, namely how it was cv-qualified. For the other traits, where static functions or constants are provided, the cv-qualification does not matter; it is only in the manifestation of the typedef that causes this inconvenience. However, I think this approach better than none though suggestions and corrections are welcome. Jeffrey.

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