- Boost - lists.boost.org

Re: GNU GPL
by Alexander Terekhov 04 Apr '05

04 Apr '05

David Abrahams wrote: > > Uzytkownik <uzytkownik2(a)poczta.onet.pl> writes: > > > Simple answer: yes or no? > > I understand yes, but I'm not sure and, for me, details doesn't matter > > for me. > > If you really want a simple answer, the only responsible thing for any > of us to say is "ask a lawyer." None of us are lawyers and we can > only describe our amateur understanding of the legal issues. You don't need to be a lawyer*** to realize that, apart from Law History, Mr. Moglen is Professor of GNU Copyright Law, not Copyright under Berne Convention and its US "codification", so to speak. All distributions of publicly available [L]GPL'd works (including distribution of derivative works under copyright law) fall under 17 USC 109 (nonexistent in the GNU Republic), not [L]GPL. As for "combinations", software is protected as literary works by definition, and "combination" of multiple works is protected as "compilation", not "derivative work." < Forward Online > -------- Original Message -------- Message-ID: <423FFBFC.5993610A(a)web.de> Newsgroups: gnu.misc.discuss Subject: Re: using GPL api to be used in a properietary software References: ...<slrnd3hm9n.8ci.isaac(a)latveria.castledoom.org> < for the sake of linking-back in future > Isaac wrote: > > On Mon, 14 Mar 2005 12:12:29 +0100, Martin Dickopp > <expires-2005-04-30(a)zero-based.org> wrote: > > > > That depends on how the program has been created and other details. If a > > program uses the ISO-standardized C library API, and uses no components > > of a particular C library while it is being created, then a derivative > > work of the program and a particular C library is created the moment the > > program is run (and therefore linked with the library). But I can also > > imagine different circumstances under which a derivative work is already > > created when the programm is written. > > Taking two works and pasting them together does not create a derivative > work, but instead creates some kind of compilation, most likely > a collective work. If there is no recasting, transforming or adaptation > of the original work, then I don't think the result fits the statutory > definition. > > However a collective work is separate combinations collected into a > whole which seems to accurately describe linking to a library for at > least some linking technologies. > > For static linked works, the diference between a derivative work and > a collective work is usually meaningless because distribution requires the > distributing the library. But the difference is critical if the two > joined works are to be distributed separately. Distribution under "first sale" aside for a moment, here's a nice explanation highlighting some other differences regarding compilations and derivative works. ---- HOUSE REPORT NO. 94-1476 Section 103 complements section 102: A compilation or derivative work is copyrightable if it represents an ''original work of authorship'' and falls within one or more of the categories listed in section 102. Read together, the two sections make plain that the criteria of copyrightable subject matter stated in section 102 apply with full force to works that are entirely original and to those containing preexisting material. Section 103(b) is also intended to define, more sharply and clearly than does section 7 of the present law (section 7 of former title 17), the important interrelationship and correlation between protection of preexisting and of ''new'' material in a particular work. The most important point here is one that is commonly misunderstood today: copyright in a ''new version'' covers only the material added by the later author, and has no effect one way or the other on the copyright or public domain status of the preexisting material. Between them the terms ''compilations'' and ''derivative works'' which are defined in section 101 comprehend every copyrightable work that employs preexisting material or data of any kind. There is necessarily some overlapping between the two, but they basically represent different concepts. A ''compilation'' results from a process of selecting, bringing together, organizing, and arranging previously existing material of all kinds, regardless of whether the individual items in the material have been or ever could have been subject to copyright. A ''derivative work,'' on the other hand, requires a process of recasting, transforming, or adapting ''one or more preexisting works''; the ''preexisting work'' must come within the general subject matter of copyright set forth in section 102, regardless of whether it is or was ever copyrighted. The second part of the sentence that makes up section 103(a) deals with the status of a compilation or derivative work unlawfully employing preexisting copyrighted material. In providing that protection does not extend to ''any part of the work in which such material has been used unlawfully,'' the bill prevents an infringer from benefiting, through copyright protection, from committing an unlawful act, but preserves protection for those parts of the work that do not employ the preexisting work. Thus, an unauthorized translation of a novel could not be copyrighted at all, but the owner of copyright in an anthology of poetry could sue someone who infringed the whole anthology, even though the infringer proves that publication of one of the poems was unauthorized. ---- regards, alexander. ***) http://www.google.de/groups?selm=42374045.B468A838%40web.de

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[1.33 release] proposal: a little art for the ack section
by Joaquín Mª López Muñoz 04 Apr '05

04 Apr '05

Hi all, Continuing with our short-lived tradition of adorning the release ack section with a not so serious picture, I'm taking the liberty of proposing the attached bit. It can be seen in action in http://195.235.93.150/boost.html The guy at the computer is a medieval representation of our valiant release manager Mr. Gregor. If this is felt unappropriate or plain ugly, please say so, I won't have any kind of hard feeling against opposition to the idea: it is just that last Saturday it was ranining in Madrid and I had some vacant time to try my drawing skills. Best, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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testing
by David Abrahams 04 Apr '05

04 Apr '05

please ignore this -- Dave Abrahams Boost Consulting www.boost-consulting.com

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GMane posting slow?
by David Abrahams 04 Apr '05

04 Apr '05

In the past few days I've noticed that most of my posts through GMane incur a long delay before going out. Is anyone else seeing the same symptoms? This wouldn't be a problem for me if posts happened in the background, but since I'm using Emacs message-mode, I can't do much else until the messages get sent. -- Dave Abrahams Boost Consulting www.boost-consulting.com

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[Thomas Barket] Bug still in new (1.32.0) version of boost library
by David Abrahams 04 Apr '05

04 Apr '05

FYI -- Dave Abrahams Boost Consulting www.boost-consulting.com

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[errorinfo] A proposal for better error handling
by Don G 04 Apr '05

04 Apr '05

A technique I have used and evolved over the past few years is a more powerful way to handle errors, derived from std::exception. Following are the motivations and some details. I am curious to hear if others find this a useful facility. The current std::exception class suffers from several problems that limit its use: 1. It cannot be polymorphically copied for storage. 2. It has no virtual "rethrow" method. 3. Instances cannot be extended with extra details. 4. Underlying system error codes are lost. Either of the first two problems would prevent effective marshalling of an instance, as would be needed in an asynchronous environment. The 3rd problem greatly reduces the ability to capture pertinent information during the unwinding process. Example 1 - Capturing an error for later use class StateMachine { private: errorinfo::ptr error_; void called_on_error (const errorinfo & err) { error_ = err.clone(); } }; There are two mechanisms for adding error information: Extending and Chaining. The simpler case is extending an errorinfo object. The reason to extend an errorinfo is that the caller will have more details about the context of the failure than the thrower. Typically a lower level method may encounter a problem and throw an exception, but doesn't know _why_ it was called. The caller, however, knows more about the "why" and can add those details before letting the exception unwind further. Example 2 - Extending the description of an error try { do_something(); do_something_else(); do_something_more(); } catch (const error::logic & x) { x.extend("Failed to achieve my goal").raise(); } The idea behind chaining is similar to that of extending. When extending an errorinfo, only the description (reported by the what() method) is changed. The type of errorinfo is unchanged. There are times that what the caller may be doing would change the kind of failure reported upwards. For example, a method that searches for something might throw error_not_found. The caller might decide that this would be an inappropriate type to throw to his caller and so would want to catch error_not_found and throw some other exception. To preserve the original error_not_found, we can chain it with the newly created exception. Example 3 - Chaining errors try { find_something(); } catch (const error::not_found & x) { throw error_whatever(x.clone(), "Failed in some way"); } I have posted errorinfo.zip on the Yahoo files section for those wanting more detail. __________________________________ Do you Yahoo!? Take Yahoo! Mail with you! Get it on your mobile phone. http://mobile.yahoo.com/maildemo

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[signals] Performance
by Jody Hagins 04 Apr '05

04 Apr '05

Are there any docs which describe the performance of the signal/slot library? I was about to embark on a performance study because I want to use it in a very high performance critical code path, but I thought I'd ask if anyone else may have already done some work in this area. Thanks!

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Re: Asynchronicity (long)
by Don G 03 Apr '05

03 Apr '05

Hi Boris, No problem on the delay. I sometimes have long spells of silence due to work/family/church/life-in-general. :) My answers / opinions are below... --- Boris <boris(a)gtemail.net> wrote: > Hi Don, > > sorry for my late answer but work caught me again. At least > it's good to see others jumping in and keeping the > discussion alive. :) > > > [...] > > ------ Sketch -------- > > [...] > > It reminds me of I/O completion ports - several ports each > of them handling several events? Is your idea similar to this? It is similar, but the channel concept has no analogy. Then again, most async mechanisms are similar, it's just in the details that they diverge<g>. QueueUserAPC + SleepEx(ALERTABLE) is also similar, but again lacking the channel notion. The closest analogy in Windows is the USER thread message queue, an HWND and Get/DispatchMessage + PostMessage. I believe one can find nearly a one-to-one correspondence with that model. > > ------ Pseudo-code -------- > > > > class nexus > > The concept of the class really reminds me of a I/O > completion port. The only difference is that there is no > invisible background thread being responsible for a > nexus object - the application has to make sure that > there is one thread controlling a nexus object? Essentially, yes. Nothing is hidden with the possible exception of how does some body of code know the proper nexus object to which a channel should be connected. This can be explicit, but a thread-specific data item is also compelling. > > [...] > > class channel > > AFAICS you use this class to communicate with a nexus object. > The owner thread does the multiplexing (waiting for different > events in a nexus object) and other threads communicate with > this nexus object through channels which are responsible for > synchronizing? Is this correct? If I understand you correctly, Yes. The channel objects are the means by which the user enqueues events to a nexus object and a different piece of user code calls the nexus object to dispatch/dequeue the messages. > So the difference between your approach and I/O completion > ports in Windows is ... hm, I think in Windows a completion > port is a combination of your nexus and channel, isn't it? It is basically that, yes. The channel class, however, I believe to be a very important concept. Merging it with the nexus class would create dangerous situations where one would have to ask at the point a message is enqueued: "will it be OK to deliver this message regardless of what might happen between now and the time of delivery?" The key impulse that can make this answer always NO is "delete foo". The delete operation is synchronous. Without a channel to serve as a way to cancel pending messages to that object, we would have dangling pointers in the queue (a bad thing). Best, Don __________________________________ Do you Yahoo!? Yahoo! Small Business - Try our new resources site! http://smallbusiness.yahoo.com/resources/

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Re: [1.33.0] Release schedule suggestion
by Dave Gomboc 03 Apr '05

03 Apr '05

> I'll agree again. The changes I check in when we are in release mode (have a > release branch active) _always_ go to both the trunk and the branch. The > branch doesn't help me in any way. > > Apr 15: feature freeze > Release "when it's done" If "when it's done" is short enough, e.g. 2-3 weeks, then it's not even worth branching. Better to just concentrate on getting kinks out for the release. Is this at all realistic? Dave

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Re: Proposal: intrusive containers
by Jaap Suter 03 Apr '05

03 Apr '05

> 1. Instead of providing the two options of deriving and embedding, let > the user provide ADL-style 'next' and 'prev' lookup functions that for a > given type provide hooks to the intrusive containers. "I'm not sure about this, most of the difficulty is involved in manipulating the links" Yes, the access provided to the links should obviously be referential so the containers can freely manipulate them. " - iterator adaptor or facade can be used to easily create iterators for types with their own next and prev pointers." It's not the iterators I'm worried about. It's being able to provide uniform STL-ish access to all my current intrusive containes. Inserting and removing elements from such containers becomes a lot more consistent, I believe. "If there was a check that a node wasn't in a container on insertion wouldn't these problems disappear?" Yes, but I don't always want to pay for this check if my own program logic dictates that I cannot possibly be inserting an item that already exists. In my own code, we have an 'insert' and a 'safe_insert'. However, occasional refactoring turns an 'insert' using piece of code into something that should be using 'safe_insert'. I'd like to be able to temporarily turn on invariant checking for a list when I'm working on the code around it, so I can make sure my changes didn't violate any conditions. Regards, Jaap Suter

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