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

boost::shared_ptr and stl algorithms
by Bill Eidson 15 Apr '05

15 Apr '05

std::vector< boost::shared_ptr<T> > TVec; I want to write a function object to run std::for_each. to do somework against members of T and accumulate results in functor. My attempts have failed in VC7 with memory errors in my operator() method. struct fo { bool operator()( boost::shared_ptr<T>& t ) { return true; } }; Thanks in advance bille

5 9

Will libraries built on WinNT run on Win98? (MinGW)
by Reed Hedges 31 Mar '05

31 Mar '05

I know that Win98 is not really supported, but is there any chance that libraries (specifically thread and regex) that were build on WinNT using MinGW work on Win98 (in MinGW)? My guess is no, but has anyone tried it? thanks reed

2 1

about license
by Marleny Rafferty 01 Apr '04

01 Apr '04

Hi- I am considering using boost in my applications, but I have a question about the boost license at http://www.boost.org/LICENSE_1_0.txt . It says (edited) "Permission is hereby granted, free of charge, to ... use [and] reproduce ... the Software". It also says that any derivative works must also have the same license grant. If my application uses boost libraries unchanged, is it considered a derivative work? If so, does that mean that if I distribute my compiled software, I must allow free of charge use and distribution? Thanks. -- Marleny

6 10

MultiArray questions
by Dr Mark H Phillips 24 Mar '04

24 Mar '04

Hi, I've recently found out about the existence of MultiArray and I am quite impressed! I was thinking of implementing something similar myself but now hopefully I don't have to! However I have a few questions that I'm hoping someone can answer. Question 1 ---------- In the user documentation there is an example which has some example code: for(index i = 0; i != 3; ++i) for(index j = 0; j != 4; ++j) for(index k = 0; k != 2; ++k) A[i][j][k] = values++; Why can't you change the != into <? Ie, do: for(index i = 0; i < 3; ++i) for(index j = 0; j < 4; ++j) for(index k = 0; k < 2; ++k) A[i][j][k] = values++; or can you? This would be more efficient I should think, and requiring that index types be ordered shouldn't be too onerous should it? Question 2 ---------- If I use the built-in "no-frills" C array type to represent a 2-dimensional array in row-major order, then I would access an element (i, j) by doing: a[ &a[0] + i*n + j ] where a is my m by n array. And if I wish to traverse a, in row-major order, I can do: for (int* ip=&(a[0]); ip<&(a[n*m]); ip+=n) { for (int* ijp=&(ip[0]); ijp<&(ip[n]); ++ijp) { visit(ijp); } } These are a very efficient ways of doing things, but it lacks somewhat in ease-of-generalization and in readbility. This is where the MultiArray library is useful. But do I lose in efficiency by going to MultiArray? Ie, in the simple case where base is 0, stride is 1, and when we traverse in row-major order, is the MultiArray library smart enough to do compile-time optimizations to generate code which is as efficient as the above? I am guessing that this sort of approach is what the Blitz++ library does?? Question 3 ---------- Is it possible to construct a new multi_array/multi_array_ref/const_multi_array_ref from an array_view by doing a deep copy of the view? A view is a nice way of looking at different parts of a MultiArray object in a readable way, but sometimes you might wish to turn this view into a more-efficiently represented object. Is this easy to do in the MultiArray library? Question 4 ---------- Sometimes you might have an object starts off being mostly accessed in row-major order, so you want a representation which works efficiently for this use. But down the track you might wish to change to mostly column-major access. Does MultiArray provide easy ways to transform from one underlying representation to another? Thanks, Mark Phillips.

3 2

Solaris and thread_resource_error
by Peter Jones 23 Mar '04

23 Mar '04

On Feb 1 of this year Baptiste Lepilleur posted a status report for Boost 1.31.0 Release candidate 2 on Solaris and AIX. It was mentioned that "boost.thread is now systematically failing with 'thread resource error'". I am experiencing the same thing on Solaris 8, with GCC 3.3.2 (GNU binutils) and Boost 1.31.0. Has anyone looked into this yet? If not, I am willing to track down what line in Boost.Threads is throwing thread_resource_error(). -- Peter Jones [unix;vi;crypto;c++;4wd] (http://pmade.org) PGP [5137 173E 5BFA 8C63 8982 F035 FDBB 1636 7D69 C63F]

2 3

Has mailing list 'from' address changed?
by Steve Folly 28 Feb '04

28 Feb '04

I'm not catch boost-users digest anymore with my mail rules? Vol 129 issue 3 from lists.boost.org, has a date stamp of 17:01:03. I've received a second copy from www.osl.ie.edu at 17:01:50. Is this a permanent change? -- Regards, Steve.

5 5

Re: Iterator adaptor interoperability
by Kris Braun 28 Feb '04

28 Feb '04

Dave Abrahams wrote: > Your best bet is to write an type generator: > template <class Iterator> > struct simple_iterator > { > typedef boost::transform_iterator< > do_nothing< typename Iterator::value_type > > , Iterator > > type; > }; Thank you for the quick and clear reply! I'm now having a very similar problem with a slightly more complicated example (that builds on the first): template< class Iterator > struct harder_iterator { typedef simple_iterator< Iterator >::type inner_type; typedef boost::indirect_iterator< inner_type > type; static type Create( const Iterator& iter ) { return type( inner_type( iter ) ); } }; This "composite" iterator not only has problems with comparison, but assignment from non-const to const as well. Is there a way to handle this case? Thanks, Kris __________________________________ Do you Yahoo!? Yahoo! Mail SpamGuard - Read only the mail you want. http://antispam.yahoo.com/tools

2 3

building boost 1.31.0
by Greg Silverman 27 Feb '04

27 Feb '04

Hi, I have not been able to build version 1.31.0. I run bjam -sTOOLS=gcc-nocygwin Basically, I get a lot of undefined references from the linker. The linker cannot find "cpp_main", "init_unit_test_suite", and, so on. It seems to be a problem with the testing, regression testing, unit testing, etc. Greg Silverman Northrop Grumman San Jose, CA

1 0

lambda / boost usage questions
by Luis De la Parra 26 Feb '04

26 Feb '04

hello, I don't have much experience with boost, so I'm having problems getting boost lambda to work...hope someone here can point me in the right direction. I have: class Song {public: string artist( ) const { return m_artist } string title( ) const { return m_title } private: string m_artist, m_title; } typedef boost::shared_ptr<Song> pSong; vector<pSong> c; and I am trying to use lambda to find a song in c which matches a certain artist and title...something like iterator it = find_if( c.begin(), c.end(), something ) but I havn't figured out what "something" should look like I've tried find_if(begin(),end(), (_1->artist() == "a1" && _1->title = "t1" ) ); but the compiler -- or I =) -- doesn't seem to know the type of _1 --> error: base operand of `->' has non-pointer type `const boost::lambda::lambda_functor<boost::lambda::placeholder<1> >' If I try it = find_if(begin(),end(), boost::bind(&Song::artist,_1) == "a1" ); it fails because "_1" is ambiguos (defined as lambda/placeholder and boost/arg ) using boost::lambda::bind (and not including the "normal" bind ) gives a bunch cryptic errors... I've tried several other variants with lambda / lambda::bind / boost::bind but I havn't figured it out... can anyone help me out? I'd also like to know what's the difference between boost::bind and boost::lambda::bind ? Also... is there a way to know when a lambda object is going to be constructed?, it's probably just that I don't know much about the BLL, but in cases where you have several nested lambdas and binds, I'm not sure which lambda objects will get constructed. regards, luis

3 4

bug in numeric_cast<unsigned long>, <unsigned char>, and <unsigne d int> in gcc 3.3.2
by King, William D 26 Feb '04

26 Feb '04

Hello, I am seeing a bug that the regression tests miss for numeric_cast<unsigned long> with gcc 3.3.2. Specifically, the following code is throwing an exception: double small_value = 1.25; unsigned long l=0; l = numeric_cast<unsigned long>(small_value); // throws exception! unsinged char c=0; c = numeric_cast<unsigned char>(small_value); // throws exception! I am under the impression that numeric_cast is supposed to accept losses of precision (by truncating the fractional values), and to throw exceptions only if there is a range or sign error. Is this so? This error happens only when I try to cast a value with a non-zero fraction; i.e. 1.25 breaks but 1.0 is fine. It only occurs for unsigned types -- signed int, char, and long appear to work correctly. I have found the same incorrect behavior with gcc 3.3.2 on both solaris and linux. Using sunpro on solaris, the same code runs correctly. The regression tests don't catch this, since they only test numeric_cast with integral values 1 and LONG_MAX. Any ideas? It looks like a compiler problem to me. Davis King william.d.king(a)bankofamerica.com

2 1

Boost.Test and Threads
by p.klotz＠icoserve.com 26 Feb '04

26 Feb '04

Hi After our migration from Boost 1.30.2 to Boost 1.31.0 several multithreaded tests no longer work stable. We tracked it down to the macros BOOST_UT_LOG_BEGIN and BOOST_UT_LOG_END. When one protects this macro calls with a mutex, the tests work stable again. After the investigation we found 'Support for the testing of multithreaded programs.' on the open issues list of Boost.Test. Does this mean that Boost.Test is not thread-safe at all? Do we misuse Boost.Test by calling things like BOOST_CHECK_EQUAL, BOOST_CHECK and BOOST_REQUIRE concurrently from different threads? Any clarification on this topic is welcome. Best regards, Peter.

2 1

newbie doubts in compilation process
by Gustavo Sánchez 26 Feb '04

26 Feb '04

Hi all, I am newbie in Boost libraries, and I'm specially interested in Graph Library (BGL). I'm working with VC++ 6.0 and I have a couple of questions about usign the library under this SDK. Of course I've read the Boost documentation and I know VC++ 6 doesn't pass the regresion test but I'm doubty about the compilation process. Those are the steps I followed: 1.- I did the outlined comands in getting started cd boost_1_31_0 bjam "-sTOOLS=msvc" install As result I obtained in drive C: a boost dir with "include" and "libs" subdirs and boost_date_time-vc6-mt-1_31.dll boost_date_time-vc6-mt-gd-1_31.dll boost_filesystem-vc6-mt-1_31.dll boost_filesystem-vc6-mt-gd-1_31.dll boost_regex-vc6-mt-1_31.dll boost_regex-vc6-mt-gd-1_31.dll boost_signals-vc6-mt-1_31.dll boost_signals-vc6-mt-gd-1_31.dll boost_thread-vc6-mt-gd-1_31.dll and the related .lib files. Why aren't there any .dll file of the others libraries(graph, math, type_traits...)??? 2.- I executed bjam in directory: BOOST_ROOT\libs\graph\test and what I obtained was empty directories like BOOST_ROOT\bin\boost\libs\graph\test\vector_graph_cc.test\msvc\debug just one for every test source. I supose that is due to VC++ 6.0 is not able to compile the BGL, is that the reason??? I get something similar if I executed bjam in directory: BOOST_ROOT\libs\graph\examples 3. I did that ---> A full set of tests and status tables can be run thusly on a Windows system: cd %BOOST_ROOT%\status bjam --dump-tests test >bjam.log 2>&1 start notepad bjam.log (this is just a cut of the full file ilustrating the output related to graph library) boost-test(COMPILE) "property_iter" : "libs\graph\test\property_iter.cpp" boost-test(COMPILE) "copy" : "libs\graph\test\copy.cpp" boost-test(COMPILE) "vector_graph_cc" : "libs\graph\test\vector_graph_cc.cpp" boost-test(RUN) "isomorphism" : "libs\graph\test\isomorphism.cpp" boost-test(RUN) "subgraph" : "libs\graph\test\subgraph.cpp" boost-test(COMPILE) "reverse_graph_cc" : "libs\graph\test\reverse_graph_cc.cpp" boost-test(COMPILE) "graph_concepts" : "libs\graph\test\graph_concepts.cpp" boost-test(RUN) "graph" : "libs\graph\test\graph.cpp" boost-test(COMPILE) "filtered_graph_cc" : "libs\graph\test\filtered_graph_cc.cpp" boost-test(COMPILE) "edge_list_cc" : "libs\graph\test\edge_list_cc.cpp" boost-test(COMPILE) "dijkstra_cc" : "libs\graph\test\dijkstra_cc.cpp" boost-test(COMPILE) "dfs_cc" : "libs\graph\test\dfs_cc.cpp" boost-test(RUN) "dfs" : "libs\graph\test\dfs.cpp" boost-test(COMPILE) "bfs_cc" : "libs\graph\test\bfs_cc.cpp" boost-test(RUN) "bfs" : "libs\graph\test\bfs.cpp" boost-test(COMPILE) "adj_matrix_cc" : "libs\graph\test\adj_matrix_cc.cpp" boost-test(COMPILE) "adj_list_cc" : "libs\graph\test\adj_list_cc.cpp" boost-test(RUN) "transitive_closure_test" : "libs\graph\test\transitive_closure_test.cpp" What is quite surprising to me because it's suposed VC++ can't compile all BGL, http://boost.sourceforge.net/regression-logs/cs-win32.html. Some explanation about this ??? Thanks a lot ...(I continue diving in ) --------------------------------- Antivirus Filtros antispam 6 MB gratis ¿Todavía no tienes un correo inteligente?

2 1

boost::lambda and MinGW on Windows
by Vladimir Suhoy 26 Feb '04

26 Feb '04

I have troubles compiling boost::lambda with MinGW on windows MinGW: 2.0.0-3 (yeah, I know its old) gcc: 3.2 (mingw special 20020817-1) The compiler thinks that types in boost/lambda/construct.hpp in boost::detail::destructor are undefined.. However when I put #include <boost/type_traits/remove_cv.hpp> #include <boost/type_traits/is_pointer.hpp> lines in boost/lambda/construct.hpp - then it works. _________________________________________________________________ Add photos to your messages with MSN 8. Get 2 months FREE*. http://join.msn.com/?page=features/featuredemail

1 0

RE: [Boost-users] newbie doubts in compilation process
by Ben Hutchings 26 Feb '04

26 Feb '04

Gustavo Sánchez <gustsanc(a)yahoo.es> wrote: [snip] 1.- I did the outlined comands in getting started cd boost_1_31_0 bjam "-sTOOLS=msvc" install As result I obtained in drive C: a boost dir with "include" and "libs" subdirs and [snip list of DLLs] and the related .lib files. Why aren't there any .dll file of the others libraries(graph, math, type_traits...)??? All their source code is included in header files as inline functions or function templates. Whatever code you use from them will automatically be compiled into your executable. I can't answer your other questions. Ben.

1 0

RE: [Boost-users] Re: about license
by Ben Hutchings 26 Feb '04

26 Feb '04

Darryl Green <Darryl.Green(a)unitab.com.au> wrote: > Cross posted from boost-users... > > > -----Original Message----- > > From: David Abrahams [mailto:dave@boost-consulting.com] > > Sent: Wednesday, 25 February 2004 11:43 AM > > Marleny Rafferty <marleny(a)rafferty.net> writes: > > > > > Hi- > > > > > > I am considering using boost in my applications, but I have a > > > question about the boost license at > > > http://www.boost.org/LICENSE_1_0.txt . It says (edited) > > > "Permission is hereby granted, free of charge, to ... use [and] > > > reproduce ... the Software". > > > > > > It also says that any derivative works must also have the same > > > license grant. > > > > > > If my application uses boost libraries unchanged, is it > > > considered a derivative work? > > > > Yes. > > Really? The ligitimacy of this stance seems questionable (but ianal > etc). Further I did not see it as being part of the objectives for the > license. Quite the opposite in fact. (Disclaimer: IANAL, and any reputable lawyer would take plenty of time to provide you with considered advice.) My understanding is that executable or object code is a derivative work of all the source code that it is built from. So any executable that uses a library is a derivative work of that library. (There is a question as to whether this applies to header files that only define named constants and structure layouts, but little question that it applies to inline and statically-linked function definitions. The FSF asserts that using dynamically-linked function definitions also creates a derivative work.) Your source code, however, does not become a derivative work of a library that it depends on, unless you copy part or all of the library's source code into it.

1 0

shared_ptr/shared_array Question
by voodoo4 26 Feb '04

26 Feb '04

I downloaded yesterday the boost libraries (mainly for the memory libs) and to tell the truth i'm impressed with pool and smart pointers. Especially the boost smart pointers will save me from months of coding! However i have a question about smart pointers. Let's say i have these objects(the code is just an example): class Slave { Slave(); ~Slave(); }; class Master { Master(); Master(int size); ~Master(); Slave *sl; }; I want "sl" to be an array of Slaves on the free store but the sized will be determined in the constructor. With normal pointers i would write: Master::Master(int val) { sl=new Slave[val]; } Master::~Master() { delete sl; } How can i achieve the same with boost smart pointers? I've read the manual three or four times but i still don't get how to work this out. Does this have something to do with the empty ptr? I believe solution is in front of my eyes but i'm too blind(as usual) to see it...

3 5

Boost regex_replace vc6 ATL LNK1120
by Robert McKinnon 26 Feb '04

26 Feb '04

All, I am trying to incorporate the boost::regex into an ATL project that I am working on. Everything seems to work well until I try to use the regex_replace function. When I compile I get the following error: ===== Creating library Debug/yetan.lib and object Debug/yetan.exp test.obj : error LNK2001: unresolved external symbol "void __cdecl boost::throw_exception(class exception const &)" (?throw_exception@boost@@YAXABVexception@@@Z) Debug/yetan.dll : fatal error LNK1120: 1 unresolved externals Error executing link.exe. ====== I have created Non-ATL projects and everything seems to work fine. Any guidance or suggestions would be appreciated. Thanks, Rob

3 2

disabling the building of debug libraries
by Philipp Thomas 26 Feb '04

26 Feb '04

For a Linux build, I would like to only build the static and shared libraries and omit the debug versions. What's the easiest way to achieve this? Philipp -- Philipp Thomas <pth(a)suse.de> SUSE LINUX AG, Maxfeldstr. 5, D-90409 Nuremberg, Germany

1 0

Re: [Boost-users] shared_ptr/shared_array Question
by cyril.godart＠bnpparibas.com 26 Feb '04

26 Feb '04

Hi, I suggest the following code: class Master { typedef boost::smart_ptr<Slave> slave_ptr_t; typedef boost::smart_ptr<const Slave> slave_cst_ptr_t; typedef std::vector<slave_ptr_t> vec_slaves_t; typedef std::vector<slave_cst_ptr_t> vec_cst_slaves_t;//defining this one is good practice as you'll see later Master(); Master(size_t i) { slaves_.resize(i);// assume slave has an empty ctor defined. } vec_cst_slaves_t slaves() //something like const vec_cst_slaves_t& slaves() const should work { return slaves_; //nice casting that I failed to notice until someone in this list mentioned it to me }; vec_slaves_t slaves_; }; As you rightly guessed, a big advantage of this approach is that the plumbing of copy-assigment dtor and so on reduces drastically. I find it extremely convenient, even though there is a performance hit. Regards, Cyril Godart. Internet goochrules@hotmail.com@lists.boost.org - 25/02/2004 21:09 Please respond to boost-users(a)lists.boost.org Sent by: boost-users-bounces(a)lists.boost.org To: boost-users cc: Subject: Re: [Boost-users] shared_ptr/shared_array Question On Feb 25, 2004, at 12:27 PM, voodoo4 wrote: > I downloaded yesterday the boost libraries (mainly for the memory > libs) and > to tell the truth i'm impressed with pool and smart pointers. > Especially the boost smart pointers will save me from months of coding! > However i have a question about smart pointers. > > Let's say i have these objects(the code is just an example): > > class Slave > { > Slave(); > ~Slave(); > }; > > class Master > { > Master(); > Master(int size); > ~Master(); > > Slave *sl; > }; > > I want "sl" to be an array of Slaves on the free store but the sized > will be > determined in the constructor. > > With normal pointers i would write: > > Master::Master(int val) > { > sl=new Slave[val]; > } > > Master::~Master() > { > delete sl; > } > > > How can i achieve the same with boost smart pointers? I have no idea (see below). > I've read the manual three or four times but i still don't get how to > work > this out. > Does this have something to do with the empty ptr? > I believe solution is in front of my eyes but i'm too blind(as usual) > to see > it... > I don't think you're using the right tool for the job. From what I know, smart pointers should be used when you have one object, here you (potentially) have many. I think what you really want to do here is to use a container class like stl::list or stl::vector to contain your slave objects. If you still want to use smart pointers, I guess you could use a list of smart pointers, but there's really no point for that if your slave class is properly coded (for instance, has a ctor, copy ctor, virtual dtor, and operator=). --MP _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users This message and any attachments (the "message") is intended solely for the addressees and is confidential. If you receive this message in error, please delete it and immediately notify the sender. Any use not in accord with its purpose, any dissemination or disclosure, either whole or partial, is prohibited except formal approval. The internet can not guarantee the integrity of this message. BNP PARIBAS (and its subsidiaries) shall (will) not therefore be liable for the message if modified. --------------------------------------------- Ce message et toutes les pieces jointes (ci-apres le "message") sont etablis a l'intention exclusive de ses destinataires et sont confidentiels. Si vous recevez ce message par erreur, merci de le detruire et d'en avertir immediatement l'expediteur. Toute utilisation de ce message non conforme a sa destination, toute diffusion ou toute publication, totale ou partielle, est interdite, sauf autorisation expresse. L'internet ne permettant pas d'assurer l'integrite de ce message, BNP PARIBAS (et ses filiales) decline(nt) toute responsabilite au titre de ce message, dans l'hypothese ou il aurait ete modifie.

2 1

RE: [Boost-users] Re: about license
by Darryl Green 26 Feb '04

26 Feb '04

Cross posted from boost-users... > -----Original Message----- > From: David Abrahams [mailto:dave@boost-consulting.com] > Sent: Wednesday, 25 February 2004 11:43 AM > Marleny Rafferty <marleny(a)rafferty.net> writes: > > > Hi- > > > > I am considering using boost in my applications, but I have > a question > > about the boost license at > http://www.boost.org/LICENSE_1_0.txt . It > > says (edited) > "Permission is hereby granted, free of charge, to ... > > use [and] reproduce ... the Software". > > > > It also says that any derivative works must also have the > same license > > grant. > > > > If my application uses boost libraries unchanged, is it considered a > > derivative work? > > Yes. Really? The ligitimacy of this stance seems questionable (but ianal etc). Further I did not see it as being part of the objectives for the license. Quite the opposite in fact. > > > If so, does that mean that if I distribute my compiled software, I > > must allow free of charge use and distribution? > > No, the license gives an explicit exemption for compiled code > (emphasis mine): [let me just re-insert some additioanl context here] ! The copyright notices in the Software and this entire statement ! ... ! must be included in all copies of the Software, in whole or in part, and > > all derivative works of the Software, UNLESS SUCH COPIES OR DERIVATIVE > WORKS ARE SOLELY IN THE FORM OF MACHINE-EXECUTABLE OBJECT > CODE GENERATED BY > A SOURCE LANGUAGE PROCESSOR. > I took this to mean that nobody can delete/change the copyright/license in the sources if they copy or produce a derivative work but that there is no need to include the license in a binary distribution. It did not occur to me that leaving the license in place somehow forms a viral attachment to other source in a source distribution. It potentially makes this license incompatible with the intent of other (open and closed) source licenses eg. // some_gpled_source_file.cpp // this file is distributed under the gpl // changed some stuff so we use boost libs #include <some_boost_lib> // oops - now it is some boost/gpl hybrid?????? I thought avoiding this sort of thing was precisely why the boost license was developed. I also thought this interpretation of "derived work" was somewhat contentious anyway. In a commercial context, this interpretation appears to make this license hopeless - anyone obtaining a copy of source code which uses boost (which you appear to be claiming is automatically a derivative work), appears to be free to do what they like with it. It is hardly reasonable that this occur if a company distributes source code with some particular intent/license for its use. That is even without considering the issue of copies obtained without the company/authors permission, whether the copy was obtained accidentally or criminally, and then redistributed. I'm keen to stop people copying my commercial executables, but I'm a lot more keen to stop them running off with the source code! A bit of digging through the archives finds http://aspn.activestate.com/ASPN/Mail/Message/boost/1686928 Which seems to explain why I thought the intent was what I understood it to be. Whatever the conclusion I think this needs to be in the FAQ. Regards Darryl Green. ########################################################################## This e-mail is for the use of the intended recipient(s) only. If you have received this e-mail in error, please notify the sender immediately and then delete it. If you are not the intended recipient, you must not use, disclose or distribute this e-mail without the author's prior permission. We have taken precautions to minimise the risk of transmitting software viruses, but we advise you to carry out your own virus checks on any attachment to this message. We cannot accept liability for any loss or damage caused by software viruses. ##########################################################################

2 1

Dynamically resize matrix when inserting more elements
by Lars Schouw 26 Feb '04

26 Feb '04

Guys I want to use the boost matrix and found out that I have to know the size of the matrix when I construct it. (except from resizing and loosing my data). Is there any way I can add more information to a matrix and in the samt time resize it on the fly when more memory is needed? Regards Lars Schouw Tokyo --------------------------------- Do you Yahoo!? Get better spam protection with Yahoo! Mail

1 0

RE: [Boost-users] shared_ptr/shared_array Question
by Mark Storer 26 Feb '04

26 Feb '04

I'd go with scoped_array<> by default, and only go with shared_array<> if you need to share OWNERSHIP of that array. This master/slave example doesn't give enough context to make the choice apparent. PS: There's a bug in your original code: > Master::~Master() > { > delete sl; > } If you use the [] version of new, you should use the [] version of delete: Master::~Master() { delete[] sl; } Otherwise, many implementations of 'delete' will only call the destructor of the first element in the array, and may or may not free up the entire block of memory. Some implementations may actually clean everything up properly, but I wouldn't count on it if I were you. --Mark Storer Software Engineer Cardiff Software #include <disclaimer> typdef std::disclaimer<Cardiff> Discard;

1 0

Host IP changing Thursday
by Beman Dawes 26 Feb '04

26 Feb '04

The system administrators at Indiana University are planning to change the Boost mailing lists to a new host IP address Thursday. Although the changeover itself will happen very quickly, it will take some time for the DNS change to propagate. Boost's DNS usually specifies 6 hour refreshes and 12 hour "Time to Live". We will cut that to 1 hour each from now until it is clear the change is working well. So you should see no more than a two hour outage. The last time we did something like this it went pretty smoothly, but a few people had trouble with cached copies of the IP address for a few days. Anyhow, be aware that change is coming Thursday, and that mailing list response time will be longer than usual during the changeover. Thanks, --Beman

1 0

Re: [Boost-users] boost::bind placeholders and MSVC .NET 2003 and .pch
by Vladimir Suhoy 25 Feb '04

25 Feb '04

>Could you please remove the " && BOOST_MSVC <= 1300" version check from >line >41 of boost/bind/placeholders.hpp and tell us whether this fixes the >problem? Yes, it does. Everything works right even with .pch turned on. _________________________________________________________________ Tired of spam? Get advanced junk mail protection with MSN 8. http://join.msn.com/?page=features/junkmail

2 1

Re: [Boost-users] Counting matches with Regex V4
by john.wismar＠autozone.com 25 Feb '04

25 Feb '04

Earlier, I wrote: > > <Using VC7.0> > > I'm converting to V4 of Regex, and I thought I might be able to > count regex matches using this snippet: <snip> > boost::sregex_iterator itBegin(first, last, e); > boost::sregex_iterator itEnd; > ptrdiff_t pd = std::distance(itBegin, itEnd); > > I get these errors: > > xutility(312) : error C2665: 'std::_Iter_cat' : none of the 12 overloads > can convert parameter 1 from type 'boost::sregex_iterator' <snip different _Iter_cat overloads taking integral types> > Anyone have any thoughts? Is it a VC7.0 issue? Is there a better or > different way of doing the same thing? I should have mentioned that I'm using boost 1.31.0. After some further research, I found that this DOES appear to be a VC7.0-only problem. It doesn't happen in VC7.1, notably. The problem seems to be with VC7.0's implementation of the standard library. In particular, there's another overload of std::_Iter_cat that takes a std::iterator as a parameter; this overload wasn't considered by the compiler when it generated the error message above. It looks like instead of relying on iterators to define typedefs for iterator_category, value_type, et al., the library assumes that an iterator must actually derive from std::iterator. This assumption has been removed from the library implementation in VC7.1. Given all of this, it seems like my options are to modify my copy of regex_iterator.hpp, modify my copy of <xutility>, or hope that someone has a third option. (Upgrading to vc7.1 is not an option this week. :-) -------------------------------- John Wismar jwismar(a)midsouth.rr.com ------------------------------------------------------------------------ The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer.

2 2