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[thread] All tests crashing...
by Christophe Galerne 26 Jul '02

26 Jul '02

Hi, OS: cygwin uptodate Boost: 1.28 C++ comp: g++ 2.95.3-5 After what appears like a warning | error free compilation of the thread library. I'm trying to compile the examples, like this: $ g++ -I/data/boost_1_28_0 -o monitor monitor.cpp /data/boost_1_28_ 0/libs/thread/build/bin/libboost_thread.lib/gcc/release/runtime-link- static/threading-multi/libboost_thread.lib Which compiles fine, however when trying to run the example, I get: $ ./monitor.exe Segmentation fault (core dumped) This happening with all the examples, I'm guessing that I must be doing something wrong... =:-D At the same time I'm doing not doing anything particularly wacky so if someone could point my obvious mistake. Do I need to link against boost_threadmon also? Tia, Christophe

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RE: [Boost-Users] XML
by schalk_cronje＠nai.com 26 Jul '02

26 Jul '02

> I'm writing an XML based project right now. I haven't been > able to find > any good, open source XML parser to incorporate into my > application, so I What's wrong with Xerces?

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Re: [Boost-Users] Re: [boost] Iterator Adaptor Poll
by David Abrahams 26 Jul '02

26 Jul '02

From: "Kresimir Fresl" <fresl(a)grad.hr> > > Jeremy Siek wrote: > > > On Fri, 26 Jul 2002, David Abrahams wrote: > > > dave> Don't you think people will find an iterator which traverses the > > dave> elements of a real sequence to be more-obvious? That's why I'm > > dave> suggesting the singly-linked list iterator. > > > The singly-linked list example was the second thing that popped into my > > mind... I like that a lot too. Perhaps we should do both :) > > What about `strided_iterator', i.e. iterator that with each > increment/decrement skips given number of elements in > a sequence? Testing for `end' can be interesting ;o) Yes, too interesting. We're looking for a simple "hello, world" example here. ----------------------------------------------------------- David Abrahams * Boost Consulting dave(a)boost-consulting.com * http://www.boost-consulting.com

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Re: [boost] Re: Iterator Adaptor Poll
by David Abrahams 26 Jul '02

26 Jul '02

From: "Gennadiy Rozental" <rogeeff(a)emailaccount.com> > BTW, you may consider CycleIteratorAdaptor or JoiningIteratorAdaptor. They > both really simple and illustrative. No simpler than the transform adaptor, though? As I've repeatedly posted, I think any introductory example ought to build a simple iterator, not an adaptor. -Dave ----------------------------------------------------------- David Abrahams * Boost Consulting dave(a)boost-consulting.com * http://www.boost-consulting.com

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RE: [Boost-Users] Re: [boost] Iterator Adaptor Poll
by Elliot Murphy 26 Jul '02

26 Jul '02

I really like that example iterator (I was just typing up an email to suggest it when I received this one). The example does something useful, and you can easily see the difference between reading lines of input without the iterator, and with the iterator. The comment on page 5 of that book really emphasizes just how much this example would benefit from using iterator_adaptor "Don't worry if you don't yet understand why everything in the line_iterator class is there; parts of it are only necessary for technical reasons." -elliot -----Original Message----- From: Jeremy Siek [mailto:jsiek@cs.indiana.edu] Sent: Friday, July 26, 2002 10:29 AM To: Boost-Users(a)yahoogroups.com Cc: boost(a)lists.boost.org Subject: Re: [Boost-Users] Re: [boost] Iterator Adaptor Poll Here's another idea for a "hello world" example. A rewrite of Matt Austern's line_iterator example from his Generic Programming and the STL book. The line_iterator call getline() and then return a std::string from operator*. On Fri, 26 Jul 2002, David Abrahams wrote: dave> dave> That's neat, but we already have the permutation adaptor, and I dave> don't think it's really a simple enough example. Beman's example dave> just makes a simple iterator, not an adaptor, and I think that's an dave> important feature for a "hello, world"-type introduction. dave> dave> -Dave ---------------------------------------------------------------------- Jeremy Siek http://php.indiana.edu/~jsiek/ Ph.D. Student, Indiana Univ. B'ton email: jsiek(a)osl.iu.edu C++ Booster (http://www.boost.org) office phone: (812) 855-3608 ---------------------------------------------------------------------- Yahoo! Groups Sponsor Click here to find your contact lenses! Info: <http://www.boost.org> Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service.

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RE: [Boost-Users] Fw: [boost] Iterator Adaptor Poll
by Hickman, Greg 26 Jul '02

26 Jul '02

> -----Original Message----- > From: David Abrahams [mailto:dave@boost-consulting.com] > Sent: Thursday, July 25, 2002 4:00 PM > To: Boost-Users(a)yahoogroups.com > Subject: [Boost-Users] Fw: [boost] Iterator Adaptor Poll > > > Hi Everyone, > > Have you tried to use iterator adaptors and found the documentation > wanting? I have recently updated the documentation in the CVS: > http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/*checkout*/boos > t/boost/libs/ > utility/iterator_adaptors.htm?rev=HEAD > > However, enough people have had problems approaching this > library that I > thought it would be useful to ask about what would make a gentle > introductory example. Beman recently sent me the enclosed, > but it seems to > define such an oddball toy iterator that I'm not sure it > would be a very > good motivating example. I'm asking for input, especially > from anyone who > has "gotten over the hump" so to speak, with iterator adaptors. I'm brand new to iterator_adaptors, and this is probably way too trivial an example, but I have several classes in my project which aggregate other polymorphic objects in part-whole relationships. I'd like clients who call 'the_aggregate.begin()' to be able to call non-const methods on the aggregate's Parts, but I'd like to prevent direct replacement of the underlying container element 'Part*' itself. Likewise, I'd like clients who call 'the_aggregate.begin() const' to be prevented from doing anything with the aggregate's Parts other than calling it's const methods. Of course, the STL container-supplied iterators aren't intended to work in this way. If this situation is common enough, and iterator_adaptor can be used to quickly generate iterators with the desired behavior (I haven't completely tested it as of yet, but it seems to work), then perhaps this is just one example of a reasonable "Hello, world" introduction to iterator_adaptors. Greg

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Regex matching quoted strings
by Poulson, Shawn 26 Jul '02

26 Jul '02

Hello all, I got Regex to compile and link into a project using MSVC6. My problem is in trying to implementing a command line parsing regexp that handles quoted strings. I have code that will selectively match quoted strings but somehow ignores non-quoted strings. The code fragment is below. I've read over Mastering Regular Expressions and some Perl Cookbook stuff but nothing works straight out of the book. Any tips? The code below finds all three parameters (in the spec var), but has no match for 'parm1'. Any help is certainly appreciated. Thanks. ----- 8< ----- 8< ----- boost::regex exp( "\"(?:(\\\\.|[^\"])*)\"[:space:]*" "|" "([^[:space:]]+)[:space:]*" ); std::string str = "parm1 \"parm2 parm3\" \"parm4 \\\"yo\\\"\""; std::string::const_iterator start = str.begin(), end = str.end(); boost::match_results<std::string::const_iterator> what; unsigned int flags = boost::match_default; while (boost::regex_search(start, end, what, exp, flags)) { std::string spec(what[0].first, what[0].second-what[0].first); std::string match(what[1].first, what[1].second-what[1].first); start = what[0].second; } ----- 8< ----- 8< ----- --- Shawn Poulson

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Re: [boost] Iterator Adaptor Poll
by Beman Dawes 26 Jul '02

26 Jul '02

At 04:46 PM 7/25/2002, David Abrahams wrote: >However, enough people have had problems approaching this library that I >thought it would be useful to ask about what would make a gentle >introductory example. Beman recently sent me the enclosed, but it seems to >define such an oddball toy iterator that I'm not sure it would be a very >good motivating example. ia_experiment.cpp is definitely oddball and definitely a toy. It was written to help me understand why I was getting compile errors from a real adaptor. Someone else can probably come up with an introductory example which is less oddball. But I'd like to defend the general principle of "toy" introductory examples. When someone knows nothing about a topic, a toy example is the best introduction. It is "known good", and can be used to verify that compilations using the library work as expected. It can be modified to see the effect of changes. Because it is a toy, it is totally non-threatening. It makes the reader feel superior, rather than like a dunce. The "C Programming Language" and "C++ Programming Language" books both started with a little "hello, world" program, very much a toy. Although simple, it starts the ball rolling with something that works and is understandable almost every reader. In the case of ia_experiment.cpp, it illustrates the relationship between the finished iterator, the Base class, and the Policies class with greater clarity IMO than documentation in any form other than C++ code. --Beman

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pass through buffer
by Tom Howard 26 Jul '02

26 Jul '02

Hi, I found some old emails about a pass through stream buffer, but I can't find it in the boost library. Am I going blind? Basically I'm in the middle of writing a gzstream class that compresses and decompresses data to and from a iostream and I thought this pass through buffer would be exactly what I need. Anyone know where it is or have any other pointers for me? Thanks in advance. Cheers, Tom Howard

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Fw: [boost] Iterator Adaptor Poll
by David Abrahams 25 Jul '02

25 Jul '02

Hi Everyone, Have you tried to use iterator adaptors and found the documentation wanting? I have recently updated the documentation in the CVS: http://cvs.sourceforge.net/cgi-bin/viewcvs.cgi/*checkout*/boost/boost/libs/ utility/iterator_adaptors.htm?rev=HEAD However, enough people have had problems approaching this library that I thought it would be useful to ask about what would make a gentle introductory example. Beman recently sent me the enclosed, but it seems to define such an oddball toy iterator that I'm not sure it would be a very good motivating example. I'm asking for input, especially from anyone who has "gotten over the hump" so to speak, with iterator adaptors. TIA, Dave --------------------------------- David Abrahams * Boost Consulting dave(a)boost-consulting.com * http://www.boost-consulting.com ----- Original Message ----- From: "Beman Dawes" <bdawes(a)acm.org> To: "Dave Abrahams" <david.abrahams(a)rcn.com> Cc: "Jeremy Siek" <jsiek(a)cs.indiana.edu> Sent: Thursday, July 25, 2002 3:21 PM Subject: Iterator adaptor example > Dave, > > Thanks for fixing the docs. I fixed and committed to CVS one more change > of BaseType -> Base. > > I found I needed an even more basic example than anything in the docs to > play with, particularly for creating an iterator from scratch, and put > together the attached. > > It is very simple, and does not demonstrate advanced features, but it > answered newbie questions I had in a way that only running code, modifying > it, and running again can do. (Not to mention fixing all the errors I made > before it would compile!) > > Feel free to include it in the distribution if you think it would help > others. Needs a better name of course. > > --Beman ---------- // Really dumb iterator_adaptor example program -----------------------------// // (C) Copyright Beman Dawes 2002. Permission to copy, use, modify, sell and // distribute this software is granted provided this copyright notice appears // in all copies. This software is provided "as is" without express or implied // warranty, and with no claim as to its suitability for any purpose. #include <boost/iterator_adaptors.hpp> #include <string> #include <iostream> class my_base { public: std::string name; my_base() : name( "foo" ) {} void operator++() { name = "bar"; } bool operator==( const my_base & rhs ) const { return name == rhs.name; } }; // if my_base had "const std::string & operator*() const { return name; }" // then custom policies would not be required. class my_policies : public boost::default_iterator_policies { public: template <class IteratorAdaptor> typename IteratorAdaptor::reference dereference(const IteratorAdaptor& x) const { return x.base().name; } }; typedef boost::iterator_adaptor< my_base, my_policies, // default_iterator_policies would do if my_base::op* were present const std::string, const std::string &, const std::string *, std::forward_iterator_tag, std::string::difference_type > my_iterator; int main() { my_iterator itr; my_iterator::value_type str( "hello, iterator\n" ); //verify value_type present std::cout << str; std::cout << *itr << std::endl; // foo std::cout << *++itr << std::endl; // bar std::cout << (itr == my_iterator() ? "bingo!" : "oops!" ) << std::endl; // oops std::cout << (itr == ++my_iterator() ? "bingo!" : "oops!" ) << std::endl; // bingo return 0; } [Non-text portions of this message have been removed]

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