August 2005 - Boost - lists.preview.boost.org

weak_ptr, maybe empty
by Andy Thomas-Cramer 04 Aug '05

04 Aug '05

I have a weak_ptr that might be empty. If not empty, I'd like to make a smart pointer from it. But the code below throws in the shared_ptr constructor, and I don't see how to test whether a weak_ptr is empty. boost::weak_ptr<int> wp; boost::shared_ptr<int> sp(wp); if ( sp.get() ) { ... } Suggestions?

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[parameter] missing link in main page and libraries.htm?
by Joaquín Mª López Muñoz 03 Aug '05

03 Aug '05

Can't find links to Boost.Parameter docs from the main page or libraries.htm. Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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[Boost-bugs] [ boost-Bugs-1250901 ] polymorphic i/o archives and stl containers problem
by SourceForge.net 03 Aug '05

03 Aug '05

Bugs item #1250901, was opened at 2005-08-03 02:44 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=1250901&group_… Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: serialization Group: None Status: Open Resolution: None Priority: 5 Submitted By: Nobody/Anonymous (nobody) Assigned to: Robert Ramey (ramey) Summary: polymorphic i/o archives and stl containers problem Initial Comment: Hello, i downloaded 1.33.0 RC1 from http://www.osl.iu.edu/~dgregor/boost-1.33.0/ and tried to recompile some rather large projects with it (currently using 1.32.0). Using MS VC 7.1 and GCC 3.4.4 Doesnt work for boost::serialization: boost::archive::polymorphic_iarchive& ar boost::archive::polymorphic_oarchive& ar It bumps on STL containers now: boost\serialization\collections_load_imp.hpp(118) : error C2039: 'reset_object_address' : is not a member of 'boost::archive::polymorphic_iarchive' boost\archive\polymorphic_iarchive.hpp(52) : see declaration of 'boost::archive::polymorphic_iarchive' ---- snip "collections_load_imp.hpp" ---- // map input template<class Archive, class Container> struct archive_input_map { inline void operator()(Archive &ar, Container &s) { #if BOOST_WORKAROUND(BOOST_DINKUMWARE_STDLIB, == 1) typedef BOOST_DEDUCED_TYPENAME std::pair< BOOST_DEDUCED_TYPENAME Container::key_type, BOOST_DEDUCED_TYPENAME Container::referent_type > type; #else typedef BOOST_DEDUCED_TYPENAME std::pair< BOOST_DEDUCED_TYPENAME Container::key_type, BOOST_DEDUCED_TYPENAME Container::mapped_type > type; #endif stack_construct<Archive, type> t(ar); // borland fails silently w/o full namespace ar >> boost::serialization::make_nvp("item", t.reference()); std::pair<BOOST_DEDUCED_TYPENAME Container::const_iterator, bool> result = s.insert(t.reference()); assert(result.second); // make sure we inserted a new element ar.reset_object_address(& (* result.first), & t); } }; ---- snip "collections_load_imp.hpp" ---- "ar.reset_object_address(& (* result.first), & t);" is called but not implemeted for these "polymorphic" archive types? I only found it implemented in "basic_iarchive_impl" (and "basic_oarchive_impl" respective). What gives? It worked for 1.32 (because there was no "reset_object_address" there). Is there another (new) way to use polymorphic archive interfaces serializing stl containers? Regards, A. Focht ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=107586&aid=1250901&group_… ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click _______________________________________________ Boost-bugs mailing list Boost-bugs(a)lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/boost-bugs

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[1.33.0] Checklist for RC2
by Douglas Gregor 03 Aug '05

03 Aug '05

These are the issues we need to resolve before I can roll RC2, which is likely to become the final release: - Jonathan Turkanis needs a picture - Fix remaining broken links - iostreams: Document how to get bzip2/gzip iostreams to work in more/getting_started.html - regex: Decide what to do about std::equal bug in VC++ 8.0 beta (it *is* a beta, and it *is* a compiler bug) I expect that we can get all of these done for a release candidate tonight with a final release tomorrow. Doug

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Re: [boost] Interest for a perl6-like-junctions-class?
by Jan Hermelink 03 Aug '05

03 Aug '05

FlSt(a)gmx.de wrote: > BTW: Today I tried to install the > Perl 6 interpreter Pugs, but I didn't get it to work. I wanted to > analyze the Perl 6 implementation of junctions especially the behaivor > of comparisons, because I don't want to tell something wrong here. If you have Windows, try PXPerl (http://pixigreg.com/) It contains a ready-to-run pugs.exe. none, one, all and any seems to work... Jan

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Re: [boost] [mpl] as_sequence< X< Y > > instantiates typedefs in X<Y >
by Brian Braatz 03 Aug '05

03 Aug '05

I had run into a problem once where I had a forward declare of a type, and then the type was declared below a template- the template was trying to get to a type in the forward declared class, when I derived from the class, I was able to get it to compile. this was months ago and my memory could be wrong (I was also very tired when I wrote that). ----Original Message----- From: boost-bounces(a)lists.boost.org on behalf of Andreas Huber Sent: Tue 8/2/2005 11:36 AM To: boost(a)lists.boost.org Subject: Re: [boost] [mpl] as_sequence< X< Y > > instantiates typedefs in X<Y > --- Brian Braatz <brianb(a)rmtg.com> wrote: > Suggestion: > > is there some way in your design you can get away with deriving > from the > incomplete type to "de-incomplete" it? I don't understand. You can't inherit from an incomplete type. Regards, -- Andreas Huber When replying by private email, please remove the words spam and trap from the address shown in the header. _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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Re: [boost] weak_ptr, maybe empty
by Andy Thomas-Cramer 03 Aug '05

03 Aug '05

Thanks, that did it. It's not intuitive, and not obvious from the documentation. > -----Original Message----- > From: boost-bounces(a)lists.boost.org [mailto:boost-bounces@lists.boost.org] > On Behalf Of Michael B. Edwin Rickert > Sent: Wednesday, August 03, 2005 3:14 PM > To: boost(a)lists.boost.org > Subject: Re: [boost] weak_ptr, maybe empty > > Andy Thomas-Cramer wrote: > > I have a weak_ptr that might be empty. If not empty, I'd like to make a > > smart pointer from it. > > > > But the code below throws in the shared_ptr constructor, and I don't see > > how to test whether a weak_ptr is empty. > > > > boost::weak_ptr<int> wp; > > boost::shared_ptr<int> sp(wp); > > if ( sp.get() ) { > > ... > > } > > The documentation (http://boost.org/libs/smart_ptr/weak_ptr.htm) seems > to show a few options. The most similar to your situation would be: > > boost::weak_ptr< int > wp; > boost::shared_ptr< int > sp = wp.lock(); > if ( sp.get() ) { > ... > } > _______________________________________________ > Unsubscribe & other changes: > http://lists.boost.org/mailman/listinfo.cgi/boost

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[1.33.0] 300 broken links [repost]
by Jonathan Turkanis 03 Aug '05

03 Aug '05

Hi, I ran a shareware HTML link checker on release candidate 1, and found 334 broken links; I'm attaching the report. A few of them appear bogus ("Error: invalid syntax"), and some appear to reflect the temporary unavailability of news.gmane.org, but most appear legitimate. I'll volunteer to fix as many of them as I can, if it's not too late to make it into the release. Some I can't fix, because I don't know where they're supposed to point. Here are the affected areas of Boost: Libraries: - compatibility - conversion - crc - date_time - disjoint_sets - filesystem - format - function - graph - hash - iterator - math - minmax - multi_index - numeric/conversion - numeric/interval - numeric/ublas - parameter - preprocessor - property_map - ptr_container - python - random - range - rational - regex - serialization - smart_ptr - spirit - test - threads - timer - tuple - type_traits - utility - variant - wave Tools: - build (v1 + v2) - boostbook Misc: - index.htm - doc/html/index.html - doc/html/who_s_using_boost_.html - doc/html/who_s_using_boost_/open.html - more/discussion_policy.htm - more/mailing_lists.htm - more/test_policy.htm - more/background.html - more/bibliography.html - more/cpp_committee_meetings.html - more/error_handling.html - more/formal_review_schedule.html - more/generic_exception_safety.html - more/generic_programming.html - more/getting_started.html - more/regression.html - more/version_history.html - more/writingdoc/template/definitions.html - people/darin_adler.htm - people/dietmar_kuehl.htm - people/jonathan_turkanis.htm - people/mark_rodgers.htm - people/people.htm - people/ralf_w_grosse_kunstleve.htm - people/vesa_karvonen.htm Jonathan

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Boost regression notification (2005-08-03)
by Douglas Gregor 03 Aug '05

03 Aug '05

<html> <head> <meta http-equiv="refresh" content="1; url=issues-email.txt"> </head> <body> <p>Update in progress (building archive index, done in approximately 4 seconds), please wait...</p> </body> </html>

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[mpl] as_sequence< X< Y > > instantiates typedefs in X< Y >
by Andreas Huber 03 Aug '05

03 Aug '05

Hi there I'm trying to address a point raised by Jonathan Turkanis during the formal review of the statechart library. Basically, the problem boils down to the following: #include <boost/mpl/list.hpp> #include <boost/mpl/size.hpp> #include <boost/mpl/as_sequence.hpp> namespace mpl = boost::mpl; // InnerInitial is either an mpl sequence of types or a single type template< class InnerInitial > struct state { // stateArray_ must have a length equal to the number of types // in InnerInitial int stateArray_[ mpl::size< typename mpl::as_sequence< InnerInitial >::type >::type::value ]; }; // A is defined later, possibly in a different translation unit struct A; template< class X > struct B { typedef typename X::reactions reactions; }; int main() { // fine: instantiation with an incomplete type state< A > a; // fine: instantiation with an mpl sequence containing B< A > state< mpl::list< B< A > > > b; // error: mpl::as_sequence triggers the instantiation of B's member // typedef, which tries to access the member typedef of A. A compile- // time error results because A is still incomplete at this point. state< B< A > > c; // *** here *** return 0; } MSVC7.1 and GCC3.4 agree that the last state template instantiation is illegal (use of undefined type A). I'm wondering whether there is any way to make this legal (different as_sequence implementation, implement the state template differently, etc.)? Thanks & Regards, -- Andreas Huber When replying by private email, please remove the words spam and trap from the address shown in the header.

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[iostreams-1.33.0-RC1] documentation error?
by Russell Hind 03 Aug '05

03 Aug '05

2.1.1 states "Here io::stream<my_device> is a derived class of std::basic_streambuf, and io::stream<my_device> is a derived class of std::basic_istream, std::basic_ostream or std::basic_iostream depending on the mode of my_device, i.e., depending on which of the fundamental i/o operations read, write and seek it supports." Shouldn't the first part be "Here io::stream_buffer<my_device>"? Cheers Russell

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Re: [boost] [1.33.0] Checklist for RC2
by JOAQUIN LOPEZ MU?Z 03 Aug '05

03 Aug '05

----- Mensaje original ----- De: Douglas Gregor <doug.gregor(a)gmail.com> Fecha: Miércoles, Agosto 3, 2005 4:05 pm Asunto: [boost] [1.33.0] Checklist for RC2 > These are the issues we need to resolve before I can roll RC2, > which is > likely to become the final release: > > - Jonathan Turkanis needs a picture > - Fix remaining broken links > - iostreams: Document how to get bzip2/gzip iostreams to work > in > more/getting_started.html > - regex: Decide what to do about std::equal bug in VC++ 8.0 > beta (it > *is* a beta, and it *is* a compiler bug) > Hi, I posted about the following several times, but the message went unnoticed. Maybe it is a misunderstanding from my part, but the "getting started" page lists Boost.Serialization as not autolinkable and not dyanmically linkable. I think this is no longer true in Boost 1.33 (but I might be wrong.) I would have taken care of the problem myself, but currently I can't access the CVS, as I'm on vacation. I'd be greateful if someone can correct this bit. Thank you, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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Re: [boost] [1.33.0] User reports go live / feedback request
by Matt Doyle 03 Aug '05

03 Aug '05

> The draft version of user-centric regression reports is now > available at > http://engineering.meta-comm.com/boost-regression/CVS-RC_1_33_ > 0/user/summary_release.html > (http://tinyurl.com/bamym) If you'd like to comment on > usability/presentation of these before they go public with the > release, now it's time :). I liked the idea of having hyper-links to the details but I think the older 1.32 version was more readable. The first thing I did when I looked at it was print it out for reference. Without color the table is of no use. If you put text in each cell as before (OK, FAIL, ect...), in addition to the color, then it can be used in B/W or color. Scanned by Fortigate {X3BTB534}

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mailing list delays
by David Abrahams 03 Aug '05

03 Aug '05

The problem should be fixed now. Let's hear it for the OSL guys! From: Rob Henderson <robh(a)cs.indiana.edu> Date: July 26, 2005 8:50:35 AM MDT To: Jeff Squyres <jsquyres(a)osl.iu.edu> Cc: OSL Sysadmin <osl-sysadmin(a)osl.iu.edu>, Bruce Shei <shei(a)cs.indiana.edu> Subject: Re: boost mailing lists I wanted to let you know that I think I've figured out what is going on with the recent slowness with email to the mailman lists that was reported. The email address xxx@xxxx that is on the boost list appears to have some kind of anti-spam tarpit set up that is catching milliways. Email to this address is handled by mail.tapeinternational.no and it you telnet to port 25 on this host from milliways you will see that it is (I assume) deliberately slow. During the initial '220' response, it is sending characters at a rate of about one character per 30 seconds. This keeps the connection from milliways moving along at a rate sufficient to keep it from timing out but slow enough that delivery is taking hours. If you telnet to port 25 from any other CS/OSL host the response is very fast so it is clearly set up to catch milliways. I don't know why they have done this, but I'd say the options are to either remove that user from the list or contact them and try to get them to stop this. Please let me know if there is anything else I can do related to this issue. We have disabled delivery to the offending email address and notified its owner. -- Dave Abrahams Boost Consulting www.boost-consulting.com

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[1.33.0][iostreams][serialization]
by Jeff Flinn 03 Aug '05

03 Aug '05

I've spent the last several hours trying to update my project with 1.33.0.RC. The only changes were naming issues with iostreams, and the getting rid of the lovely :) asserts on serialization inclusions previous to archive inclusions. Also an issue with operator << and const_cast-ing appears below, and switching to the standard BOOST_SHARED_POINTER_EXPORT_GUID macro which now appears to handle pointers in namespaces properly. All compiles and links succesfully under VC7.1. Rudimentary xml serialization seems to save/load succesfully. I am having an problems when using iostreams/serialization together to support copy/paste/drag/drop under Windows MFC. Which all worked flawlessly using 1.32.0 along with pre-release iostreams. I'd appreciate it if anyone sees anything blatantly wrong with the code below. CSharedFileSink::write is not being called at all. This leads and assert in MFC's CSharedFile::Detach because the file has never been written to. The member CSafeDataSource::GlobalArchiveHdl instantiates a CSharedFileOStream and attempts to serialize it's mVal data member to a binary archive. Thanks in advance, Jeff namespace adi { namespace mfc { namespace clipboard { struct CSharedFileSink : public boost::iostreams::sink { CSharedFile& mSharedFile; CSharedFileSink( CSharedFile& aSharedFile ) : boost::iostreams::sink() , mSharedFile(aSharedFile) {} std::streamsize write( const char* s, std::streamsize n ) { mSharedFile.Write( s, n ); return n; } }; class CSharedFileOStream : private boost::base_from_member<CSharedFile> , public boost::iostreams::stream<CSharedFileSink> { typedef boost:: base_from_member<CSharedFile > tSharedFile; typedef boost::iostreams::stream<CSharedFileSink> tBase; public: CSharedFileOStream() : tSharedFile( GMEM_MOVEABLE|GMEM_DDESHARE|GMEM_ZEROINIT ) , tBase( CSharedFileSink( tSharedFile::member ) ) {} HGLOBAL Detach(){ return tSharedFile::member.Detach(); } }; template< class T > class CSafeDataSource : public COleDataSource { typedef T value_type; value_type mVal; HGLOBAL GlobalArchiveHdl() { CSharedFileOStream lOut; boost::archive::binary_oarchive oa( lOut ); // oa & mVal; // same result as below oa << const_cast<const value_type&>(mVal); //BOOST_1_33_0 return lOut.Detach(); } CSafeDataSource( const T& aVal ) : COleDataSource(),mVal(aVal){ DelayRenderData( NativeFormat() ); } friend void ToClipBoard<T>( const T& aVal ); friend void Drag<T>( const T& aVal , tDragImagePtr aDragImagePtr , DWORD aDropEffect ); public: static CLIPFORMAT NativeFormat(){ return RegisteredClipboardFormat<value_type>(); } virtual BOOL OnRenderGlobalData( LPFORMATETC lpFormatEtc, HGLOBAL* phGlobal ) { if( lpFormatEtc->cfFormat == NativeFormat() ) { return (*phGlobal = GlobalArchiveHdl())? TRUE : FALSE; } return FALSE; } }; } } }

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Boost Build V2 docs removed from cvs?
by John Maddock 03 Aug '05

03 Aug '05

All the links to the docs bbv2 docs from tools/build/v2/index.html seem to go nowhere. Has someone removed the docs from cvs? Thanks, John.

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[1.33.0] Final release schedule
by Douglas Gregor 03 Aug '05

03 Aug '05

The release is starting to shape up, and here is our final release schedule. We'll stick to it unless something goes horribly wrong. Code freeze - 11pm EST on Sunday, July 24 Total freeze (including documentation) - 11pm EST on Wednesday, July 27 Final release - Monday, August 1st Doug Gregor 1.33.0 Release Manager

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[date_time] and BCB
by Richard Jennings 03 Aug '05

03 Aug '05

The CVS head revision of date_time fails to compile with Borland C++ 5.6.4. This is because the run time libraries lack the re-entrant functions such as localtime_r. I added Borland to the list of compilers that do not support this in date_time/compiler_config.hpp and then the library compiles fine. Richard

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iterators::function_output_iterator is missing in boost_1_32_0
by Oleg Abrosimov 03 Aug '05

03 Aug '05

Hello boosters! I've just found that function_output_iterator, mentioned in boost_1_32_0/libs/iterator/doc/function_output_iterator.html is missing in the boost or boost/iterator directories both in my own copy and in sf.net CVS. Neither me nor my compiler could found it. Was it deprecated? or removed accidentally? Best, Oleg Abrosimov

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singleton design plan
by Jason Hise 03 Aug '05

03 Aug '05

This message is an in depth description of my current design plan for a new singleton library, which I hope to complete and schedule for review by boost in the coming year. I would appreciate any comments, questions, or suggestions regarding this plan before I begin work on the code. Specifically, I would like to know if there are any important issues that this design fails to address, or difficulties with the interface that would turn away potential users. (My old singleton library, which was not accepted by boost, is available at http://tinyurl.com/6qvrd. It was rejected primarily because it failed to adequately address concerns related to multi threading and dlls.) Thus far, my high level design plan looks like this: The creator_policy defines fundamental pointer, const_pointer, and reference types. These hold references to a creator policy instance which maintains the singleton internally, so that the pointer types can always see and access the state of the single instance. This way, pointers to the singleton instance are not invalidated when the state of the singleton changes. The creator_policy defines create, replace, and destroy methods, as well as methods to generate instances of the various pointer types. Create only creates the instance if it does not already exist, destroy only destroys the instance if it does exist, and replace makes sure any existing instance is destroyed before attempting creation. Thus far, I hope to support the following creators: -------------------------------------------------------------------------------- in_place_creator creates/destroys inside an aligned_storage POD interface: create ( [ctor params] ); replace ( [ctor params] ); destroy ( ); pros: no memory allocation/deallocation ever required constructor params can be easily specified cons: automatic creation, when it occurs, always uses the default constructor singleton cannot be created as a derived type useful for simple, user defined singleton classes -------------------------------------------------------------------------------- source_sink_creator owns fixed source and sink functors, specified with template parameters interface: create ( ); replace ( ); destroy ( ); pros: source can return a derived type automatic creation uses source rather than default construction cons: source and sink cannot be set or changed at runtime constructor arguments cannot be specified by calling code useful for singleton types provided by untouchable code, which may require calling special functions to get pointers to instances -------------------------------------------------------------------------------- dynamic_source_sink_creator owns dynamic source and sink functors interface: create ( [source[, sink]] ); replace ( [source[, sink]] ); destroy ( [source[, sink]] ); pros: source can return a derived type automatic creation uses source rather than default construction source and sink can optionally be changed at run time source and sink can change functor types when they are set (example: from function pointer to lambda expression) cons: specifying constructor parameters to pass is non-trivial dynamic memory allocation and virtual functions must be used to store the functors in order to allow for different functor types at runtime, thus creation is more expensive and can potentially fail useful for a singleton which needs to take the forms of unspecified derived types and is frequently destroyed and created via some type of factory -------------------------------------------------------------------------------- The lifetime_policy owns and wraps the creator policy, and provides pointer and reference types which wrap those belonging to the creator. It also provides functions to generate instances of the various pointer types, and provides a function to access the creator_policy instance. The unmanaged lifetime simply typedefs the underlying pointer and reference types, and thus results in no overhead. The longevity_lifetime and lifo_lifetime behave similarly, but handle scheduling of automated destruction when any of the pointer generation methods are called. The dependency_lifetime will wrap the internal pointer types to perform reference counting (the reference count itself will be stored in the lifetime_policy instance). The timeout_lifetime will manage a separate thread that releases the instance when it finishes counting down. It will also wrap the internal pointer types to reset the timer when a pointer is dereferenced, and reset and lock the timer while any references exist. The threading_policy owns and serializes access to the lifetime_policy. It also has a function to get access to the lifetime_policy instance, and provides pointer, const_pointer, and reference types which wrap and forward to the lifetime's corresponding types. For the single_threaded policy, these pointer types are simply typedefs of the lifetime's pointer types, resulting in no overhead, and the function through which the lifetime_policy instance is accessed just returns a raw pointer to it. For the multi_threaded policy, pointer types perform locking before forwarding to lifetime pointer types, and the reference type acts as a lock throughout it's existence. The mutex is stored inside the threading_policy instance. The function which returns a pointer to the lifetime_policy instance returns a smart pointer which serializes access. A storage_policy determines how instances of the threading_policy are stored (and because these instances contain instances of the other policies, this indirectly controls how all of the policy instances are stored). static_storage stores policy instances directly as global variables, which is fine for singletons that are not required to have a specific lifetime with regard to other singletons. These global variables will be set up in such a way that it will be guaranteed that any automatic destruction takes place before the policy bundle is destroyed. group_storage allows multiple singletons to have their policies stored in a master group. No policies in this group are destroyed until all automated destruction that will be performed by any members of the group has completed. This way, if destructors of some of the singletons in this group trigger re-creation of other singletons in the same group, the policies needed to recreate the singletons are guaranteed to still exist. dll_storage requires linking with singleton.dll, and stores instances in a special exported manager singleton to ensure unique singleton instances across dll boundaries. All policy instances of this type are guaranteed to be destroyed only after all automated destruction has taken place. A singleton class exists, which takes a singleton type and a name tag as template parameters. The name will have a default type called 'unnamed'. This name parameter enables using multiple singleton instances of the same type. Policies are traits of the name specified, so using the default name 'unnamed' results in using the default policies. Policies can be specified by declaring a name as an undefined struct, and then specializing the desired policy traits for that name. The singleton class contains three pointer types, which wrap those of the threading policy. These are strong_pointer, lazy_pointer, and weak_pointer. strong_pointer attempts automatic creation of the singleton instance if it does not exist when the pointer is first created, and also attempts automatic creation if needed any time it is dereferenced. lazy_pointer only attempts automatic creation when dereferenced, and weak_pointer will never create the instance automatically. For the lifo_lifetime, a strong_pointer can be used to specify a dependency of some singleton B on some singleton A by having B own a strong_pointer to A. This will ensure that A is created before B and destroyed after B. Const versions of these three pointer types will also exist. Creation, destruction, and non-const member functions will not be allowed to be called through these const pointer types. A single reference type will exist which will be the result of dereferencing any pointer type via the unary * operator. const_pointers return const qualified references. Pointers only perform temporary locking (if the threading policy supports locking) when a member function is called via the -> operator or when a create or destroy operation is invoked. References lock the singleton throughout their entire lifetime, and thus can be used to make a series of operations on the singleton instance atomic. A reference provides an implicit conversion to a raw reference of the singleton's type (which comes back const if the reference is const). Create and destroy can only be called on non-const references. Typical code will access a singleton instance by creating one of the above pointer types and calling member functions through it via the -> operator. Ex: singleton < MyType, SomeName >::lazy_pointer ptr; ptr->DoSomething ( ); -------------------------------------------------------------------------------- I plan to sneak an improved version of the null developed by Scott Meyers in with this code in a header called boost/null.hpp, and use it in the singleton's implementation. It will be defined as follows: namespace boost { const class { private: void operator & ( ) const; public: #ifndef BOOST_NO_MEMBER_TEMPLATES // provide conversion to any pointer type template < typename Class, typename Type > operator Type Class::* ( ) const { return 0; } template < typename Type > operator Type * ( ) const { return 0; } #else //provide conversion to int if member templates are not supported operator int ( ) const { return 0; } #endif//BOOST_NO_MEMBER_TEMPLATES } null; } #undef NULL #define NULL (::boost::null) -------------------------------------------------------------------------------- Any and all comments or suggestions on this plan are welcomed. Potential problems are much easier to address at design time than after the code is written. -Jason

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[signals] Signals 1.33 dylib crashes when used with Xcode
by Chiedo Acholonu 02 Aug '05

02 Aug '05

I'm using boost 1.33 and recently tried to build the signals dll using the darwin toolset. I then created a simple Xcode project called TestSignals to test it was working correctly. The project only contains the maximum.cpp example file (/boost-root/libs/signals/examples/maximum.cpp) linked against the signals dynamic library. The project builds just fine, but when I run the app, Xcode crashes with: "TestSignals has exited due to signal 10 (SIGBUS)." Here is a piece of the crash log (I can send the full log on request): --- Exception: EXC_BAD_ACCESS (0x0001) Codes: KERN_PROTECTION_FAILURE (0x0002) at 0x00000000 Thread 0 Crashed: 0 maximum.ob 0x0040c844 std::less<int>::operator()(int const&, int const&) const + 48 (stl_function.h:227) --- I tried using different example files, and they all crash. The library is built multithreaded and I do define BOOST_SIGNALS_DYN_LINK in my project. I'm running on Tiger 10.4.2 using Xcode 2.1. Has anyone tried this or run into a similar problem? Thanks, Chiedo

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singleton, dlls, and shared memory
by Jason Hise 02 Aug '05

02 Aug '05

I was researching how to ensure that a singleton has only one instance within a loaded dll and came up with this: http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dllproc/ba… The page has a lot of information, and while most of it makes a decent amount of sense, a good deal of it is still unfamiliar territory for me. So I have a few of questions. A) Security Attributes. How important are they? Is it ok to just use null for this parameter, or should I be researching this structure and its effects in depth? B) Size of shared memory. It appears that the 'pseudo file' being used as shared memory is fixed in size and thus I have to guess how much I might need at compile time. Is there a way to resize this file if need be? C) Allocating and deallocating the memory. Is there existing code out there that takes a buffer of memory like this and manages malloc/free like calls to it (possibly wrapping the functionality in a std allocator) or do I need to roll my own? -Jason

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[Boost-bugs] [ boost-Patches-1249809 ] Minor spell errors on lambda_functor_base.hpp header
by SourceForge.net 02 Aug '05

02 Aug '05

Patches item #1249809, was opened at 2005-08-01 22:57 Message generated for change (Settings changed) made by urzuga You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=307586&aid=1249809&group_… Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: None Group: None >Status: Closed Resolution: Fixed Priority: 5 Submitted By: Duilio J. Protti (dprotti) Assigned to: Nobody/Anonymous (nobody) Summary: Minor spell errors on lambda_functor_base.hpp header Initial Comment: Attached is the patch with the corresponding corrections. The patch is not just for /boost/lambda/detail/lambda_functor_base.hpp file, but also for lambda_fwd.hpp. Bye, Duilio Protti. ---------------------------------------------------------------------- Comment By: Jaakko Järvi (urzuga) Date: 2005-08-02 20:49 Message: Logged In: YES user_id=284669 Fixed ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=307586&aid=1249809&group_… ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click _______________________________________________ Boost-bugs mailing list Boost-bugs(a)lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/boost-bugs

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[Boost-bugs] [ boost-Patches-1249809 ] Minor spell errors on lambda_functor_base.hpp header
by SourceForge.net 02 Aug '05

02 Aug '05

Patches item #1249809, was opened at 2005-08-01 22:57 Message generated for change (Comment added) made by urzuga You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=307586&aid=1249809&group_… Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: None Group: None Status: Open >Resolution: Fixed Priority: 5 Submitted By: Duilio J. Protti (dprotti) Assigned to: Nobody/Anonymous (nobody) Summary: Minor spell errors on lambda_functor_base.hpp header Initial Comment: Attached is the patch with the corresponding corrections. The patch is not just for /boost/lambda/detail/lambda_functor_base.hpp file, but also for lambda_fwd.hpp. Bye, Duilio Protti. ---------------------------------------------------------------------- >Comment By: Jaakko Järvi (urzuga) Date: 2005-08-02 20:49 Message: Logged In: YES user_id=284669 Fixed ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=307586&aid=1249809&group_… ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_id=7477&alloc_id=16492&op=click _______________________________________________ Boost-bugs mailing list Boost-bugs(a)lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/boost-bugs

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[Announcement] LCSD'05 Call for papers, extended deadline
by jarvi 02 Aug '05

02 Aug '05

The following call for papers should be of interest to many in the Boost community. For more information, see http://lcsd05.cs.tamu.edu Posting the announcement has been approved by Boost moderators. Best, Jaakko Järvi ----------------------------------------------------------------------- LIBRARY-CENTRIC SOFTWARE DESIGN - LCSD'05 Workshop, on Sunday, October 16, 2005 at the Object-Oriented Programming, Systems, Languages and Applications (OOPSLA'05) conference in San Diego, California, October 16-20, 2005 ----------------------------------------------------------------------- CALL FOR PAPERS --- EXTENDED DEADLINE The deadline for submission has been extended to Aug 07, 2005. ----------------------------------------------------------------------- Libraries are central to all major scientific, engineering, and business areas, yet the design, implementation, and use of libraries are underdeveloped arts. This workshop is one of the first steps in the process of placing all aspects of libraries on a sound technical and scientific basis through research into fundamental issues and documentation of best practices. A software library is an organized collection of code with associated tools supporting programming in general or in specific domains, usually united by a specified set of principles and conventions. Most libraries are aimed at the use by several people and in different environments. The areas of software library research include * Design and implementation of libraries * Program and system design based on libraries * Libraries supporting specific application domains, such as biology and banking * Evolution, refactoring, and maintenance of libraries * Empirical studies of library use * Performance of libraries, including benchmarking and library-based optimizations * Design of language facilities and tools in support of library definition and use * Validation, debugging, and testing of libraries * Extensibility, parameterization, and customization * Distribution of libraries * Specification of libraries and their semantics * Usability for library users and developers * Assessing quality of libraries * Documentation and teaching of libraries * Creating and supporting communities of library users * Using several libraries in combination We invite the submission of extended abstracts on software library research, including, but not limited to, the above list of topics. The extended abstracts should address issues important to libraries as a field, i.e., describe ideas or techniques that can be reused for libraries across problem domains and/or languages; they should refrain from merely describing a particular library, no matter how novel the choice of domain. As an additional criterion, the extended abstracts are reviewed against suitability for a journal publication of the corresponding full paper. For uniformity, authors should use the latest ACM SIGS conference style file (option 1) at http://www.acm.org/sigs/pubs/proceed/template.html. Submissions should be limited to 10 pages in this style. Accepted extended abstracts will be posted on the workshop's Web site prior to the workshop, and collected in a proceedings published as a Rensselaer Polytechnic Institute tech report. Authors of selected papers will be invited to submit a full paper for a special issue of a journal, to be announced later. IMPORTANT DATES Aug 7 Submission of extended abstracts (extended from Jul 31) Sep 9 Notification of acceptance Oct 4 Final version posted on workshop Web site Oct 16 Workshop SUBMISSION PROCEDURE For details of the electronic submission procedure, see the workshop's Web site, http://lcsd05.cs.tamu.edu. ORGANIZERS * David Musser, Rensselaer Polytechnic Institute * Andrew Lumsdaine, Indiana University * Jaakko Jarvi, Texas A&M University * Sibylle Schupp, Chalmers University of Technology * Todd Veldhuizen, Indiana University * Jeremy Siek, Rice University Primarily, the email address lcsd05(a)cs.tamu.edu should be used for questions addressed to the organizers. PROGRAM COMMITTEE * Uwe Assmann, Technical University of Dresden * Matt Austern, Google Inc. * Herve Broennimann, Polytechnic University * Antonio Cisternino, University of Pisa * Jack Dongarra, University of Tennessee * Ulrich Eisenecker, University of Leipzig * Rob Fowler, HiPerSoft, Rice University * Calvin Lin, University of Texas at Austin * Anthony Simons, University of Sheffield * Alex Stepanov, Adobe Systems Inc. * Bjarne Stroustrup, Texas A&M and AT&T Labs * Don Syme, Microsoft Research * Frank Tip, IBM Research In addition, the organizers will serve as program committee members. WORKSHOP GOALS AND ACTIVITIES The workshop establishes a scientific forum for presenting original research in the design, implementation, and evaluation of software libraries. Other major activities include the identification of open questions specific to library research and the discussion of a strategic plan for establishing library research as a field. The outcome of the workshop is a combination of research contributions and specific next steps for improving the infrastructure for library research. Participants are expected to read the accepted submissions beforehand. The technical presentations, although based on the accepted papers, should not provide mere summaries of the papers. Instead, authors are encouraged to use their presentation slots (20 + 10 mins) to bring up topics for discussion. The technical presentations are mixed with scientific and organizational discussions. The discussions aim at furthering the topics of the presentations, thus their agenda will be publicly discussed among the participants and then posted on the website of the workshop. All participants are expected to come prepared with their tentative answers or thoughts. The full-day workshop starts with a keynote talk for the stimulation of discussion and concludes with a plenary discussion that decides the specific next steps for improving the infrastructure for library research. FOR MORE INFORMATION AND UPDATES please visit the workshop's Web site, http://lcsd05.cs.tamu.edu.

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