February 2004 - Boost-users - lists.preview.boost.org

[BGL] adjacency_list: OutEdgeList and EdgeList
by Ded Panas 11 Feb '04

11 Feb '04

I'm somewhat unclear about the difference between OutEdgeListS and EdgeListS selectors of adjacency_list. My questions is: 1. Why EdgeListS defaults to listS, while OutEdgeListS to vecS (BTW, doc says that EdgeListS defaults to vecS also) ? 2. In the docs ("Choosing the Edgelist and VertexList"), what is Edgelist: OutEdgeListS or EdgeListS? It is unclear (seems it is OutEdgeListS). TIA dedpanas

2 1

RE: [Boost-users] Re: Re: Thread creation state
by Kutch, Patrick G 11 Feb '04

11 Feb '04

Looking at the code, by 1st guess would be that you have a race condition. tObj->runthread() is getting executed before tObj->createthead() has finished its business and the worker thread has actually entered the mutex. Meaning that tObj->runthread() calls the notify_one() BEFORE the actual worker thread does a wait. Thus when your threadproc does a lock and then a wait, it will wait forever because nothing will do the notify_one() again. Race conditions are funny things, may work perfectly on one box forever, then change one line of code, or take it to another system and bad things happen. May also behave differently under different OS's - mutexes are a prime examle of this, under Windows they seem to be recursive by default, but not under LINUX. A down and dirty way to see if my theory is correct, put in a delay between the tObj->createthread() and tObj->runthread() lines. Hope this helps - if it does praise me with thanx, if it doesn't it was a crackpot theory or I haven't had sufficient coffee yet to make an intelligent analysis - you pick. :-) good luck, - Patrick -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of Michael Glassford Sent: Wednesday, February 11, 2004 7:40 AM To: Boost Users mailing list Subject: [Boost-users] Re: Re: Thread creation state What I meant was, can you post a complete sample that you have actually compiled and run and that has actually demonstrated the problem? That obviously isn't the case with the code you posted because it contains syntax errors and the main() function in your second post doesn't match the definition of the testCommand class in your first post. Having said that, I fixed the errors the best I could and don't see the problem. It would help if you could: 1) Tell me what compiler and compiler version you're using. 2) Tell me what Boost version you're using. 3) Post a complete code sample that demonstrates the problem. 4) Specify what compile and link options you're using (perhaps you could attach a make file or project file?) Sorry; I'm trying to help, but if you want me to be able to figure out the problem you'll have to help me out. Mike ----- Original Message ----- From: <janardhan.guptha(a)efi.com> Newsgroups: gmane.comp.lib.boost.user Sent: Tuesday, February 10, 2004 11:32 PM Subject: RE: Re: Thread creation state > > The rest of the applicatin is just creating the object and preparing it > for execution. I am using Win32 version of boost.Thread implementation. > > The creation code snipet is > > void main() { > testCommand *tObj = new testCommand(11); > tObj->createthread(); > tObj->runthread(); > } > > > -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org]On Behalf Of Michael > Glassford > Sent: Wednesday, February 11, 2004 12:17 AM > To: boost-users(a)lists.boost.org > Subject: [Boost-users] Re: Thread creation state > > > It would be a lot easier to help if you could post a complete, > compilable example that demonstrates the problem. Also, it would be > useful to know whether you are using the Win32, pthread, or Mac > implementation of Boost.Thread. > > Thanks, > > Mike > > > <janardhan.guptha(a)efi.com> wrote in message > news:433CFA26BCA852438922F929E3D07955AE53A7@blraddc02.efi.internal... > > I am creating a boost thread, how to know in which state it is > created. > > I have a code snippet that is waiting always in the thread creatin > functon > > istelf. Where as i tried with some boost samples, they are working > amazingly > > perfect. This is how my code snippet looks like > > > > typedef boost::mutex::scoped_lock lock; > > class testCommand { > > static void threadfunc() { > > testCommand *testObj = mMapCommand[mObjID]; > > testObj->processthread(); > > }; > > > > static map< int mObjID, testCommand*> mMapCommand; > > private: > > void createthread() { > > mThread = new boost::thread(&testCommand::threadfunc); > > } > > void processthread() { > > lock lk(mMutex); > > mCondition.wait(lk); > > //// Some Action > > }; > > > > void runthread() { > > lock lk(mMutex); > > mCondition.notify_one(); > > }; > > > > public: > > static int mObjID; > > boost::thread *mThread; > > boost::condition mCondition; > > boost::mutex mMutex; > > }; > > > > > > The newly created thread is waiting at the following location > forever, by > > the time > > i get a chance to execute the new thread is greatly delayed. > > > > NTDLL! 77f8856e() > > boost::detail::thread::lock_ops<boost::mutex>::unlock(boost::mutex & > {...}) > > line 49 > > boost::detail::thread::scoped_lock<boost::mutex>::unlock() line 85 + > 11 > > bytes > > > boost::detail::thread::scoped_lock<boost::mutex>::~scoped_lock<boost:: > mutex> > > () line 74 > > `anonymous namespace'::thread_param::started() line 47 + 15 bytes > > thread_proxy(void * 0x0012fd74) line 71 > > _threadstartex(void * 0x00961040) line 212 + 13 bytes > > KERNEL32! 7c57b382() > > > > It sounds like i am missing something here. The queries here are > > 1. why it is waiting at the above specified line forever ? > > 2. Where can i get few worth thread samples done using boost::thread > > > > Regards > > Janardhan > > > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

1 0

RE: [Boost-users] Re: Conversions between shared_ptr<Base>andshared_ptr<Derived>
by Ben Hutchings 11 Feb '04

11 Feb '04

Konstantin Baumann <boost(a)ks-baumann.de> wrote: > For performance reasons I would like to see something like the > following conversion operators in shared_ptr<T>: > > template<class T> > class shared_ptr { > public: > ... > template<class S> > operator shared_ptr<S>&() throw() { > BOOST_STATIC_ASSERT(T* is convertible to S*); > return reinterpret_cast<shared_ptr<S>&>(*this); > } > > template<class S> > operator const shared_ptr<S>&() throw() const { > BOOST_STATIC_ASSERT(T* is convertible to S*); > return reinterpret_cast<const shared_ptr<S>&>(*this); > } > > }; // class shared_ptr<T> > > This would mimic the standard conversion from T* to S* without any > performance penalty for shared_ptr<T>. <snip> Don't sacrifice correctness for performance. First, the reinterpret_cast results in undefined behaviour. If you think you know that the actual behaviour is OK, you are wrong. If S is a base class of T then the conversion of T* to S* generally requires changing the bits of the pointer, unless S is the first non-virtual base. Second, if we can create a reference of type shared_ptr<S> to an object of type shared_ptr<T>, then we can also modify that object to contain a pointer of type S* which may not be convertible to T*.

1 0

RE: [Boost-users] Re: Thread creation state
by janardhan.guptha＠efi.com 11 Feb '04

11 Feb '04

The rest of the applicatin is just creating the object and preparing it for execution. I am using Win32 version of boost.Thread implementation. The creation code snipet is void main() { testCommand *tObj = new testCommand(11); tObj->createthread(); tObj->runthread(); } -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org]On Behalf Of Michael Glassford Sent: Wednesday, February 11, 2004 12:17 AM To: boost-users(a)lists.boost.org Subject: [Boost-users] Re: Thread creation state It would be a lot easier to help if you could post a complete, compilable example that demonstrates the problem. Also, it would be useful to know whether you are using the Win32, pthread, or Mac implementation of Boost.Thread. Thanks, Mike <janardhan.guptha(a)efi.com> wrote in message news:433CFA26BCA852438922F929E3D07955AE53A7@blraddc02.efi.internal... > I am creating a boost thread, how to know in which state it is created. > I have a code snippet that is waiting always in the thread creatin functon > istelf. Where as i tried with some boost samples, they are working amazingly > perfect. This is how my code snippet looks like > > typedef boost::mutex::scoped_lock lock; > class testCommand { > static void threadfunc() { > testCommand *testObj = mMapCommand[mObjID]; > testObj->processthread(); > }; > > static map< int mObjID, testCommand*> mMapCommand; > private: > void createthread() { > mThread = new boost::thread(&testCommand::threadfunc); > } > void processthread() { > lock lk(mMutex); > mCondition.wait(lk); > //// Some Action > }; > > void runthread() { > lock lk(mMutex); > mCondition.notify_one(); > }; > > public: > static int mObjID; > boost::thread *mThread; > boost::condition mCondition; > boost::mutex mMutex; > }; > > > The newly created thread is waiting at the following location forever, by > the time > i get a chance to execute the new thread is greatly delayed. > > NTDLL! 77f8856e() > boost::detail::thread::lock_ops<boost::mutex>::unlock(boost::mutex & {...}) > line 49 > boost::detail::thread::scoped_lock<boost::mutex>::unlock() line 85 + 11 > bytes > boost::detail::thread::scoped_lock<boost::mutex>::~scoped_lock<boost:: mutex> > () line 74 > `anonymous namespace'::thread_param::started() line 47 + 15 bytes > thread_proxy(void * 0x0012fd74) line 71 > _threadstartex(void * 0x00961040) line 212 + 13 bytes > KERNEL32! 7c57b382() > > It sounds like i am missing something here. The queries here are > 1. why it is waiting at the above specified line forever ? > 2. Where can i get few worth thread samples done using boost::thread > > Regards > Janardhan _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

2 1

RE: [Boost-users] long compilation time of variant over long typelist with gcc
by Ben Hutchings 11 Feb '04

11 Feb '04

Graeme Lufkin <gwl(a)u.washington.edu> wrote: <snip> > When I compile code that declares a variable of this variant > type, the compilation takes unreasonably long (like, 1.5 hours on a > 2Ghz machine). For fewer types it goes much quicker, the transition > to unreasonably long happens around 14 types in the mpl::vector. <snip> > Something else I've noticed: the Intel compiler doesn't have the > compilation problem! I've attached sample case code that uses 16 > types, which takes less than 5 seconds to compile with Intel 8.0 and > almost 200 with GCC 3.2.2 (both on linux). > When I try the full 20 types I need, GCC chugs for several > hours, which is unacceptable for my project. Is there anything I can > do, or is this a GCC shortcoming that I need to wait for? I suggest you try newer versions of GCC (3.3 and 3.4 beta); if those still have the problem then report this as a bug at <http://gcc.gnu.org/bugs.html> with the keyword "compile-time-hog". Also check whether the poor performance is due to swapping, which indicates excessive use of memory and not necessarily excessive use of CPU time.

1 0

Spirit: pt_parse doesn't compile when using phrase_scanner_t for rules
by Steve Folly 11 Feb '04

11 Feb '04

Hi, I've read FAQ question number one about the free parse() function not compiling when and I've managed to get that to work by using rule<phrase_scanner_t> as suggested. However, I need to use the pt_parse method to create a parse tree. I'm obviously missing something really obvious because now pt_parse wont compile, even though I'm using a phrase_scanner_t because of the space_p skip parser. Any pointers most welcome. Thanks. Steve.

2 2

long compilation time of variant over long typelist with gcc
by Graeme Lufkin 10 Feb '04

10 Feb '04

I've recently become excited by the variant class and the apply_visitor technique. I've got a list of about 20 types that I want to handle in my variant (they're all related, so I won't need to supply 20 operator() to my visitors!). So I create a mpl::vector of the types, and then use make_variant_over to create my particular variant type. All this works fine (modulo a few days struggling to learn mpl stuff). When I compile code that declares a variable of this variant type, the compilation takes unreasonably long (like, 1.5 hours on a 2Ghz machine). For fewer types it goes much quicker, the transition to unreasonably long happens around 14 types in the mpl::vector. Side question: I finally found the macros BOOST_MPL_USE_PREPROCESSED_HEADERS and BOOST_MPL_LIMIT_VECTOR_SIZE that I had to suitably define to use such large mpl::vector-s. Are these documented anywhere, or am I missing the "suggested" way to do this? Something else I've noticed: the Intel compiler doesn't have the compilation problem! I've attached sample case code that uses 16 types, which takes less than 5 seconds to compile with Intel 8.0 and almost 200 with GCC 3.2.2 (both on linux). When I try the full 20 types I need, GCC chugs for several hours, which is unacceptable for my project. Is there anything I can do, or is this a GCC shortcoming that I need to wait for? -- - Graeme gwl(a)u.washington.edu "This sentence contains exactly threee erors."

1 0

Re: building boost with sunpro compilers
by King, William D 10 Feb '04

10 Feb '04

Thanks for your comments. The list sort problem is in the binary_search_test. binary_search_test.cpp in the utility library fails for sunpro 5.5 and 5.4, so sun needs to use the same workaround that begins in line 120 for DINKUMWARE and VC6. I will check my notes to find where the member template friends were an issue. It was something I found in 1.30.0, so, I am not sure if it will also be an issue in 1.31.0. So far, compiling 1.31.0 with sunpro is giving me much more trouble than either 1.30.0 or 1.30.2; sunpro doesn't like some of the iterator_facade code, which causes the filesystem library and several other tests to fail to compile. Davis King william.d.king(a)bankofamerica.com -----Original Message----- >From: boost-users-request(a)lists.boost.org >Message: 7 >Date: Tue, 10 Feb 2004 11:52:13 -0500 >From: Christopher Currie <christopher(a)currie.com> >Subject: [Boost-users] Re: building boost with sunpro compilers >To: boost-users(a)lists.boost.org >Message-ID: <c0b27u$luu$1(a)sea.gmane.org> >Content-Type: text/plain; charset=us-ascii; format=flowed >> The main fixes I have found so far is that for 5.5 and 5.4, >> BOOST_NO_LIST_SORT and BOOST_NO_MEMBER_TEMPLATE_FRIENDS need to be defined. >Can you point up which tests lead you to this conclusion? >Sun is supposed to be releasing an Early Access version of their next >compiler in the near future; I'll be focusing regressions and bugfixes >on that version once it's available. >Christopher ------------------------------

1 0

Thread creation state
by janardhan.guptha＠efi.com 10 Feb '04

10 Feb '04

I am creating a boost thread, how to know in which state it is created. I have a code snippet that is waiting always in the thread creatin functon istelf. Where as i tried with some boost samples, they are working amazingly perfect. This is how my code snippet looks like typedef boost::mutex::scoped_lock lock; class testCommand { static void threadfunc() { testCommand *testObj = mMapCommand[mObjID]; testObj->processthread(); }; static map< int mObjID, testCommand*> mMapCommand; private: void createthread() { mThread = new boost::thread(&testCommand::threadfunc); } void processthread() { lock lk(mMutex); mCondition.wait(lk); //// Some Action }; void runthread() { lock lk(mMutex); mCondition.notify_one(); }; public: static int mObjID; boost::thread *mThread; boost::condition mCondition; boost::mutex mMutex; }; The newly created thread is waiting at the following location forever, by the time i get a chance to execute the new thread is greatly delayed. NTDLL! 77f8856e() boost::detail::thread::lock_ops<boost::mutex>::unlock(boost::mutex & {...}) line 49 boost::detail::thread::scoped_lock<boost::mutex>::unlock() line 85 + 11 bytes boost::detail::thread::scoped_lock<boost::mutex>::~scoped_lock<boost::mutex> () line 74 `anonymous namespace'::thread_param::started() line 47 + 15 bytes thread_proxy(void * 0x0012fd74) line 71 _threadstartex(void * 0x00961040) line 212 + 13 bytes KERNEL32! 7c57b382() It sounds like i am missing something here. The queries here are 1. why it is waiting at the above specified line forever ? 2. Where can i get few worth thread samples done using boost::thread Regards Janardhan

2 1

How to export arrays from C(++) to python using boost
by Shukla, Nitin (Export) 10 Feb '04

10 Feb '04

I want to export an array of int and floats from C(++) to python using Boost but don't know how? Can anyone help me out? Is there any tutorials specifically on C(++)/Python interfacing using the Boost tool? I also want to export the BOOL type of C(++) to Python. How can I do that? --Nitin

2 1

building boost with sunpro compilers
by King, William D 10 Feb '04

10 Feb '04

Hello, I've been wondering if anyone else is trying to build boost on Solaris with recent sunpro compilers. In 1.31.0, the config files warn if you use any version later than 5.3, while the regression tests are running on 5.4, and Sun's latest release is 5.5. The main fixes I have found so far is that for 5.5 and 5.4, BOOST_NO_LIST_SORT and BOOST_NO_MEMBER_TEMPLATE_FRIENDS need to be defined. I would be interested in comparing notes and fixes with anyone else using Sunpro 5.5 (0x550). Thanks, Davis King william.d.king(a)bankofamerica.com

2 1

Re: [Boost-users] Problems with boost build setup
by Michael Buksas 10 Feb '04

10 Feb '04

On Sat, 31 Jan 2004 07:55:27 -0700, Jeff Garland wrote > First off, what version of bjam and boost are you using? I'm going to > assume version 1.30.2 of boost. It looks like boost-jam 3.1.7 from the rpm, and boost 1.30.2. > I think that bjam isn't that great at compiling outside of the boost > directory tree in the 1.30.2 version (I'm sure someone will correct me > if I'm offbase here :). This is a surprise. I had just assumed that the boost-jam would work the same way on user projects as in the library itself. Well, you know what they say about assuming... I'll ask about the install option at the jamboost list. Thanks for the pointer. In the meantime, is copying the libraries and using makefiles for application code typically what people do to link against boost libraries currently? Thanks again, Mike -- Michael Buksas <mb1(a)buksas.net>

1 0

how to expose the func like "print( char * str, ... )" ?
by iceryeah 09 Feb '04

09 Feb '04

hello, problem 1: i can expose the function like void a( void ) def( "a", a ); but there is anthor function like this: void DebugMessage( char *msg,... ); i don't know how to expose this function. problem 2: module test int num = 0; void set( int a ) { num = a; } then i expose set func , and do this in script: import test test.set( 10 ) and then in host app, i check the var num, it is not 10,why? thanks very much.

2 1

Spirit: a skip parser that counts newlines?
by Steve Folly 09 Feb '04

09 Feb '04

Hi, Before I launch into it, does anybody have an example of a parser that can count newlines. I would have thought this would be quite common, so I'm surprised to see it's not standard within Spirit? (Or maybe I didn't look hard enough?) I'm writing a parser which will parse multi-line files. I'd like to report an error along with a line number. I realise the error can't be detailed - e.g. what the parser expected, rather, just 'an error' - which why I'd like the line number to at least give the user a fighting chance. I assume the parser simply stops at the point where parsing failed, and thus I'd know the line number? I'm guessing I'd have to supply this as a custom skip parser to the parse method? Thanks for any clues. -- Regards, Steve.

2 1

RE: [Boost-users] configuring boost on MS Visual Studio 6 where the installation drive isn't C:
by Ben Hutchings 09 Feb '04

09 Feb '04

Someone using the wrong account to write email <Administrator(a)sbcltd.com> wrote: > Wayne, > > There might still be conflicts if the compiler can't place everything > into it's proper namespace. In addition, some sdk's force > everything into std namespace Really? That would be truly evil. > or into the global namespace. If you use "using namespace boost;", > you're basically doing the same thing. > > There are a couple of options that could be used separately. <snip> > 2. The second is wrap the offending sdk in it's own namespace. Here > is what I have come up with. I have three files here. c.h is the > original function. b.h wraps it in it's own namespace, and main.cpp > can only use it with the new namespace. Simple example, but hopefully > it illustrates what I'm trying to get across. <snip> That's all very well for inline code, but how about external code that's linked in later, that has been compiled without using the namespace? By the way, possessive "its" has no apostrophe.

1 0

[BGL] Removing vertices and internal properties
by Frédéric Mayot 09 Feb '04

09 Feb '04

Hi, I have a graph in the form of an adjacency_list with an internal property. I'm using vecS for both vertices and edges (and I don't want to use listS). When I remove a vertex with remove_vertex(), it seems that my property map is invalidated. Can I remove the property (from the map) which corresponds to the deleted vertex ? Is there any solution ? Thanks. Fred

2 1

Dynamic Multi Array Library
by RGProlog＠aol.com 09 Feb '04

09 Feb '04

Is anyone interested in dynamic_multi_array template library that offers user intuitive convenience of use as well as capacity to hone in upon any specific subset of a multi-dimensional array? As an example of usage, a dynamic_multi_array object can be constructed and then resized and then reshaped like this: size_t arrayShape = { 3, 7, 15}; dynamic_multi_array<double, 3> A(arrayShape); boost::array<size_t, 3> anotherArrayShape = {{ 5, 4, 22}}; A.resize(anotherArrayShape); boost::array<size_t, 5> yetAnotherArrayShape = {{ 440, 1, 1, 0, 0}} ; A.reshape(yetAnotherArrayShape); size_t stillAnotherArrayShape[4] = { 22, 10, 2, 11}; A.reshape(stillAnotherArrayShape); The library’s design owes a lot to Andrei Alexandrescu’s ideas. It is based on the data_table helper class template defined as follows: template<typename X> class data_table { … protected: std::vector<X> data_table_ ;}; template<> <value_type> class data_table { … protected: value_type* data_table_ ;}; Then, a sequence of the table class instantiation types is recursively defined and then given a name that is shared in different dimensional contexts as follows: typedef data_table<value_type> data_table_01; ……………………………………………. typedef data_table< data_table_49 > data_table_50 ; class Int2Type<int> { typedef data_table_01 data_table; } …………………………………………… class Int2Type<> <50> { typedef data_table_50 data_table; } Being a recursive template class, the data_table is implemented in a concise code that is mostly about stating a few recursive rules and implementing some access operators and is totally dimension independent. This is the central feature of the design since the user level wrapper class template by virtue of exporting a dimension appropriate data_table instantiation that uses its shared name template <T, size_t i, Allocator> class dynamic_multi_array { ………………………………………. typedef …. class Int2Type <i>::data_table; } is also implemented in a way that hides all the implementation details, is concise and dimension independent, thus providing user with a great deal of flexibility, syntax safety, and, in case of a new user, a flat learning curve. This is a std::vector based design. The dynamic_multi_array template class, the library’s main component, extends, where appropriate, std::vector capacities, replicates its exception safety guarantees and has std::vector as its back end storage device. The library’s code, documentation that includes a short tutorial and a few key tests and will be posted in Dynamic Multi Array Folder on boost Files once the issue of available space will be resolved.

1 0

(no subject)
by RGProlog＠aol.com 09 Feb '04

09 Feb '04

Is anyone interested in dynamic_multi_array template library that offers user intuitive convenience of use as well as capacity to hone in upon any specific subset of a multi-dimensional array? As an example of usage, a dynamic_multi_array object can be constructed and then resized and then reshaped like this: size_t arrayShape = { 3, 7, 15}; dynamic_multi_array<double, 3> A(arrayShape); boost::array<size_t, 3> anotherArrayShape = {{ 5, 4, 22}}; A.resize(anotherArrayShape); boost::array<size_t, 5> yetAnotherArrayShape = {{ 440, 1, 1, 0, 0}} ; A.reshape(yetAnotherArrayShape); size_t stillAnotherArrayShape[4] = { 22, 10, 2, 11}; A.reshape(stillAnotherArrayShape); The library’s design owes a lot to Andrei Alexandrescu’s ideas. It is based on the data_table helper class template defined as follows: template<typename X> class data_table { … protected: std::vector<X> data_table_ ;}; template<> <value_type> class data_table { … protected: value_type* data_table_ ;}; Then, a sequence of the table class instantiation types is recursively defined and then given a name that is shared in different dimensional contexts as follows: typedef data_table<value_type> data_table_01; ……………………………………………. typedef data_table< data_table_49 > data_table_50 ; class Int2Type<int> { typedef data_table_01 data_table; } …………………………………………… class Int2Type<> <50> { typedef data_table_50 data_table; } Being a recursive template class, the data_table is implemented in a concise code that is mostly about stating a few recursive rules and implementing some access operators and is totally dimension independent. This is the central feature of the design since the user level wrapper class template by virtue of exporting a dimension appropriate data_table instantiation that uses its shared name template <T, size_t i, Allocator> class dynamic_multi_array { ………………………………………. typedef …. class Int2Type <i>::data_table; } is also implemented in a way that hides all the implementation details, is concise and dimension independent, thus providing user with a great deal of flexibility, syntax safety, and, in case of a new user, a flat learning curve. This is a std::vector based design. The dynamic_multi_array template class, the library’s main component, extends, where appropriate, std::vector capacities, replicates its exception safety guarantees and has std::vector as its back end storage device. The library’s code, documentation that includes a short tutorial and a few key tests and will be posted in Dynamic Multi Array Folder on boost Files once the issue of available space will be resolved. P.S. The space issue is that I freed the space I previously occupied on boost Files and still cannot post the message. Need help here.

1 0

RE: [Boost-users] configuring boost on MS Visual Studio 6 where the installation drive isn't C:
by Dernoncourt, Wayne CTR NAVAIR 3184, ,10 09 Feb '04

09 Feb '04

Thanks much. I think the folks here have sent a message (I leave here a little after 1:30 on Friday and discussion sometimes takes a while) to the other SDK developers asking if they could put their SDK in a namespace and do this the "right" way instead of this round-about method. But yes this could work as well. Thanks much. -----Original Message----- From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org]On Behalf Of Administrator Sent: Friday, February 06, 2004 12:57 To: 'Boost Users mailing list' Subject: RE: [Boost-users] configuring boost on MS Visual Studio 6 where the installation drive isn't C: Wayne, There might still be conflicts if the compiler can't place everything into it's proper namespace. In addition, some sdk's force everything into std namespace or into the global namespace. If you use "using namespace boost;", you're basically doing the same thing. There are a couple of options that could be used separately. 1. One is to not use "using namespace". Preface everything used from there with boost:: or std::. More typing, less pain, less chance for conflict. 2. The second is wrap the offending sdk in it's own namespace. Here is what I have come up with. I have three files here. c.h is the original function. b.h wraps it in it's own namespace, and main.cpp can only use it with the new namespace. Simple example, but hopefully it illustrates what I'm trying to get across. -------------------------------------------------- c.h ------------------------------------------------- #ifndef _C_H #define _C_H inline int garbage_method() { return 0; } #endif // -------------------------------------------------- b.h -------------------------------------------------- #ifndef _B_H #define _B_H namespace garbage_namespace { #include "c.h" } #endif // -------------------------------------------------- main.cpp -------------------------------------------------- #include "b.h" int main() { return garbage_namespace::garbage_method(); }

1 0

suspend/cancel thread
by janardhan.guptha＠efi.com 09 Feb '04

09 Feb '04

Hi, i working on an application using boost::thread. The application cretaes a thread, then put in wait state. Based on the user input i want the thread eitjer to move it to run state or cancel the thread. As i am newbie to boost thread, i couldn't find any documentation or working example that satisfies my requiremnt. So someone can help me out?? Rgds, Janardhan

3 2

std::map problem.
by Joshua Little 08 Feb '04

08 Feb '04

I'm working on making a factory class but have run into a problem. I think I'm trying to get the shared pointer out the wrong way. std::map<std::string, boost::shared_ptr<Logger> > LoggerFactory::loggers; boost::shared_ptr<Logger> LoggerFactory::getInstance(std::string& logger) { boost::shared_ptr<Logger> TheLogger; LoggerMap::iterator i = loggers.find(logger); if (!(*i).second.get()) { TheLogger.reset(new Logger()); loggers[logger] = TheLogger; } else { TheLogger = (*i).second; } return TheLogger; } I thought that the TheLogger = (*i).second line was the correct way to get any logger within the map but when I run it I get this segfault: Program received signal SIGSEGV, Segmentation fault. LoggerFactory::getInstance(std::string&) (logger=@0x22ff58) at e:/boost-1.30.2/boost/detail/shared_count.hpp:123 123 if(use_count_ == 0 && weak_count_ != 0) boost::throw_exception(boost::bad_weak_ptr()); if I comment out the 'TheLogger = (*i).second;' line everything seems to fine. Any ideas? Joshua.

2 2

Help with shared_ptrs please
by Steve Folly 08 Feb '04

08 Feb '04

Hi, I'd like some help trying to crack a problem I've got. Now, I am using shared pointers at the moment, and that might be part of my problem, or it might not, but I'll describe the situation and you can tell to go elsewhere if you like! :) Part of my application involves scripting - allowing the user to write file based scripts to execute within the context of an application. I've designed it so it also gives the ability for the application writer to create some 'scripts' by creating classes directly in the C++ code. The script has the ability to run in the main thread of the app, but some statements could potentially block, so each statement is run from a 'timer' event which gets scheduled immediately. Those that block wait for an event and continue on that event. This part is working well. The statements are classes constructed in a hierarchical manner with things like a block class (a statement itself) which has a list of statements in it, an if statement class - which has an expression evaluator, a statement for the 'then' part, and an optional statement for the 'else' part. You get the idea? After looking at boost::lambda I thought it would be nice if I could construct my script similar to how lambda does these sorts of control statements - the if_, switch_, for_ constructs. The idea I have is like: expression exp = ... If_statement s1 = if_( expr)->then_( s2 )->else_( s3 ); while_statement ws = while_( expr ).do_( s1 ); One of the things I decided early on was to use shared_ptrs. The while_ and if_ constructs are functions returning a shared pointer to the real if statement object. Now my problem: given the example above. The do_ method of a while_statement takes a shared pointer to a statement so I don't have to worry about deallocation. Constructing the if_ statement on it's own is no problem, but if I was to construct one directly within the do_ part of the while statement it wont compile: while_( expr ).do_( if_(expr)->then_(s2)->else_(s3) ); The problem is to be able to chain then_ and else_ together, I have to return a plain pointer because the if_ statement itself doesn't know about it's shared pointer. So now, the compiler complains that can't implicitly convert a plain if_statement pointer into a shared pointer. And even if it could, I don't have the original shared pointer to hand. Now, I hope you're all still listening at the back! :) My first thought was to somehow get the object to look after the shared pointer, but surely if the object has a reference to itself, the ref count of the shared pointer could never reach zero? As I said right at the beginning, I think is a problem I have with shared pointers, whether it be a misunderstanding about them or maybe I'm using them the wrong way? I could always go for scrapping the shared pointers all together, and make the classes responsible for their own (de)allocation, but I was rather hoping to avoid that. Any tips and suggestions on ways forward will be much appreciated. (Even if to say - "ha! it'll never work", or "try a another newsgroup"! :) TIA. -- Regards, Steve.

2 5

PreProcessor Library and Class Constructors
by Paul Grenyer 07 Feb '04

07 Feb '04

Hi All I fear I may be trying to get a square peg in a round hole, but here goes anyway... I'm trying to use the boost PreProcessor library to generate constructors with varying numbers of parameters. I've tried the following: #include <boost/preprocessor/arithmetic/inc.hpp> #include <boost/preprocessor/punctuation/comma_if.hpp> #include <boost/preprocessor/repetition.hpp> #ifndef MAX_CONCRETE_CONSTRUCTOR_PARAMS #define MAX_CONCRETE_CONSTRUCTOR_PARAMS 3 #endif #define CONCRETE_CONSTRUCTOR(Z, N, _) \ template<class R BOOST_PP_COMMA_IF(N) BOOST_PP_ENUM_PARAMS(N, class A)> \ explicit Concrete( BOOST_PP_ENUM_PARAMS(N, A) ) \ { } class Concrete { public: BOOST_PP_REPEAT(BOOST_PP_INC(MAX_CONCRETE_CONSTRUCTOR_PARAMS), CONCRETE_CONSTRUCTOR, _) }; int main() { Concrete a( 1, 2 ); return EXIT_SUCCESS; } But this gives me the following error: error C2660: 'Concrete::Concrete' : function does not take 2 arguments I have feeling I'm doing something very wrong or that can't be done. Regards Paul Paul Grenyer Email: paul(a)paulgrenyer.co.uk Web: http://www.paulgrenyer.co.uk Have you met Aeryn: http://www.paulgrenyer.co.uk/aeryn/? Version 0.3.0 beta now ready for download

1 0

RE: [Boost-users] How to export arrays from C(++) to python using boost
by Shukla, Nitin (Export) 06 Feb '04

06 Feb '04

Hi, I working on an application where an array of ints and floats are to exported from C++ to Python using boost::python. As I am newbie to boost python, I couldn't find any documentation or working example that satisfies the above requirement. Can someone help me out?? Nitin. -----Original Message----- From: Shukla, Nitin (Export) [mailto:nitin.shukla@pw.utc.com] Sent: Thursday, February 05, 2004 3:19 PM To: 'boost-users(a)lists.boost.org' Subject: [Boost-users] How to export arrays from C(++) to python using boost I want to export an array of int and floats from C(++) to python using Boost but don't know how? Can anyone help me out? Is there any tutorials specifically on C(++)/Python interfacing using the Boost tool? I also want to export the BOOL type of C(++) to Python. How can I do that? --Nitin _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

1 0

RE: [Boost-users] configuring boost on MS Visual Studio 6 where t he installation drive isn't C:
by Administrator 06 Feb '04

06 Feb '04

Wayne, There might still be conflicts if the compiler can't place everything into it's proper namespace. In addition, some sdk's force everything into std namespace or into the global namespace. If you use "using namespace boost;", you're basically doing the same thing. There are a couple of options that could be used separately. 1. One is to not use "using namespace". Preface everything used from there with boost:: or std::. More typing, less pain, less chance for conflict. 2. The second is wrap the offending sdk in it's own namespace. Here is what I have come up with. I have three files here. c.h is the original function. b.h wraps it in it's own namespace, and main.cpp can only use it with the new namespace. Simple example, but hopefully it illustrates what I'm trying to get across. -------------------------------------------------- c.h ------------------------------------------------- #ifndef _C_H #define _C_H inline int garbage_method() { return 0; } #endif // -------------------------------------------------- b.h -------------------------------------------------- #ifndef _B_H #define _B_H namespace garbage_namespace { #include "c.h" } #endif // -------------------------------------------------- main.cpp -------------------------------------------------- #include "b.h" int main() { return garbage_namespace::garbage_method(); } -----Original Message----- From: Dernoncourt, Wayne CTR NAVAIR 3184, ,10 [mailto:wayne.dernoncourt@navy.mil] Sent: Friday, February 06, 2004 5:43 AM To: Boost Users mailing list Subject: RE: [Boost-users] configuring boost on MS Visual Studio 6 where the installation drive isn't C: Well that worked much better as far as it went (747 updated files out of 747 targets wth no skipped files and no failures). The version of the bjam binary was a little larger (~5k) than the one I compiled<scratches head>, but using this produced no errors. Unfortunately we still have at least a few problems. As I described originally we are using a highly specialized third party SDK. Part of this SDK redefines reverse_iterator (as well as min & max) evidently the MS Visual C++ reverse iterator is broken in some way. From a cursory examination of the two implementations, it appears that both the two are very similiar in functionality if not implementation. The issue with min/max could be eliminated by commenting out line 59 of boost/config/stllib/dinkumware.hpp (line defines BOOST_NO_STD_MIN_MAX). There doesn't appear to be a similiar line for the reverse iterator. One of the issues appears to be that this third party SDK doesn't seem to use namespaces for the SDK. From my limited understanding, for namespaces to be used effectively, the different libraries/SDK's would need to be in their own namespaces. If Boost had theirs and the third party used the global namespaces, there could still be conflicts. Is my understanding correct?

1 0