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sparse bitset
by Anuj Garg 28 May '09

28 May '09

my application requires sparse bitsets. Type requirements: *Block *is an unsigned integer type how hard would it be to replace this with a custom structure. basically instead of storing them as a Array or uint's i would like to store them as a link-list of uint or hash-map.

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Spirit Not Parsing
by Aston 28 May '09

28 May '09

Hello, I am evaluating Boot.Spirit for parsing a custom format. I have presented the code below and config file as well. I expect numUsers to be 2 but it is zero, indicating that integer_action() was not call at all. I tried with assign_d as well, it also didn't help. I guess I am missing something, and I cannot figure out that since parse() returns 0. can anybody point that out ? thanks, Aston ============ src file begin ============ #include <iostream> #include <fstream> #include <string> #include <boost/spirit.hpp> using namespace boost::spirit; int numUsers = 0; void integer_action( const int& var) { numUsers = var; }; int parse_conf_file( char* buffer) { rule<> l_root = str_p("FakeRC") >> *blank_p >> *alpha_p >> eol_p; rule<> l_params = *blank_p >> *alpha_p >> *blank_p >> str_p("Integer") >> *blank_p >> *int_p[&integer_action] >> eol_p; rule<> l_end = str_p("end") >> eol_p; rule<> conf_lines = l_root | *l_params | l_end; return parse( buffer, conf_lines).full; } int main( int argc, char** argv) { std::ifstream conf(".fakerc", std::ios::binary); conf.seekg( 0, std::ios::beg); int start = conf.tellg(); conf.seekg( 0, std::ios::end); int end = conf.tellg(); int size = end - start; conf.seekg( 0, std::ios::beg); char* buffer = new char[size]; std::fill( buffer, buffer + size, 0); conf.read( buffer, size); buffer[size - 1] = 0; int err_code = parse_conf_file( buffer); std::cout << ( err_code == 0 ? "success" : "failed"); std::cout << ": " << err_code << std::endl; std::cout << "numUsers: " << numUsers << std::endl; delete[] buffer; conf.close(); return 0; } ============ src file end ============ ============ .fakerc contents ============ FakeRC FakeRC_Name Users Integer 2 end ============ end .fakerc ============ Explore and discover exciting holidays and getaways with Yahoo! India Travel http://in.travel.yahoo.com/

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G++ hack/challenge?
by David Abrahams 27 May '09

27 May '09

Hi all, In preparation for BoostCon, I'm looking for a workaround for the problems described in http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2009/n2855.html. In particular I need a way to detect whether a type "has a move constructor" (without causing a compiler error, of course) in GCC 4.4. Ideally, "has a move constructor" would mean - when constructed from an rvalue of the same type, a copy constructor with signature T(T const&) is not used. though I would settle for - has a constructor with the signature T(T&&) I'm willing to use G++-specific hackery if necessary. I strongly suspect it's impossible, but if you can think of any way to do it, I'd really appreciate knowing about it. You'll be my hero forever ;-) TIA, -- Dave Abrahams BoostPro Computing http://www.boostpro.com

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Review request: gil::io
by Christian Henning 26 May '09

26 May '09

Hi to all, the new gil::io extension is ready for review. The release candidate is available from the link below containing the header files, tests, and documentation. There are jamfiles available to run the tests and to compile the documentation. http://gil-contributions.googlecode.com/files/rc2.zip This file is almost 9 MB due to the amount of test images I'm using for testing. If that's a problem I can certainly create a slimmer release candidate. A lot of things have changed for this extension but also a lot of things haven't. The interface is more or less the same. But the list of features has been grown by a lot. For instance, all formats support now in-memory read and write. The tiff extension supports a lot more formats to be read and written. n-bit images are now supported for all formats that include those. etc. etc. Right now the lib is called gil::io_new but once it's accepted it will be renamed to gil::io. Of course, I'm open for all kinds of input, critiques, and insights. Thanks a lot to all people who have helped me on this release! Regards, Christian

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Using boost with visual studio 2010
by Sean Farrow 26 May '09

26 May '09

Hi: I am looking at using boost with the beta 1 of visual studio 2010. If this compiler isn't detected automatically, what files will I need to alter? Any help Appreciated Sean. __________ Information from ESET NOD32 Antivirus, version of virus signature database 4102 (20090525) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com

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The Boost Bug Sprint is coming!!
by Marshall Clow 26 May '09

26 May '09

The boost bug sprint is coming! It starts next Friday, May 28th, and runs through Sunday June 7th. The goal is to address a large number of open bugs/patches/feature requests in the trac system at <http://svn.boost.org>. There are currently 795 open tickets; we'd like to knock that number down _a lot_. What can you do? 1) You can fix bugs. * If you are a library author, you can commit your fixes. ;-) * If you are not a library author, you can fix a problem on your local machine (and test it!!), and then attach your fix as a patch to the Trac ticket for the library author to commit. If you do this, please provide a test case that exercises the problem; i.e, one that fails w/o your patch, and succeeds afterwards. 2) You can characterize bugs. * You can attempt to replicate the bug on your system(s), and attach information that you discover to the Trac ticket. This will make it easier for other people to solve the problem, even if you cannot. * You can write test cases demonstrating the problem, and attach them to the Trac ticket. * You can determine if the bug still exists; sometimes they get fixed, and the ticket never gets closed. 3) You can test patches. * Some of the tickets in the trac system contain patches - some are quite old. You can install these patches on your system, and determine if they (a) build, and (b) work. * You can write test cases for the patches, and attach them to the ticket. 4) You can help implement new features. * There are a whole set of "feature requests" in the Trac system. If you have an idea about one of these, you can add comments to the trac system. You can attempt to implement these new features, and attach the patch to the ticket. (Don't forget the test cases!!). Every day during the bug sprint, I'll post the # of tickets modified/closed/opened on the previous day, as well as the total number of open tickets. --------- Sign-up sheet -------- The following people have committed to participate in the bug sprint. Please add you name here, along with what you can do. 1) Marshall Clow (coordination, Mac OS X characterization) 2) Beman Dawes (filesystem, system, timer) 3) Doug Gregor (function, graph, logic, mpi, numeric, property_map, signals) -- -- Marshall Marshall Clow Idio Software <mailto:marshall@idio.com> It is by caffeine alone I set my mind in motion. It is by the beans of Java that thoughts acquire speed, the hands acquire shaking, the shaking becomes a warning. It is by caffeine alone I set my mind in motion.

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[multi_array] Bug in rbegin(), rend()?
by John Reid 25 May '09

25 May '09

I'm having some trouble iterating over a 2-dimensional multi_array in reverse order. I'm using boost 1.38 with gcc-4.2.4 and the following code won't compile with the error given below: #include <boost/multi_array.hpp> template< typename It > void iterate_over( It begin, It end ) { while( end != begin ) { begin->end() - begin->begin(); ++begin; } } void test() { boost::multi_array< double, 2 > m; iterate_over( m.begin(), m.end() ); // works fine iterate_over( m.rbegin(), m.rend() ); // causes error } This looks to me like a bug in the implementation of the reverse iterator for multi_array. Am I wrong? John. /home/john/Dev/ThirdParty/boost/boost_1_38_0/boost/iterator/iterator_facade.hpp: In static member function ‘static typename boost::mpl::if_<boost::is_reference<Reference>, Pointer, boost::detail::operator_arrow_proxy<ValueType> >::type boost::detail::operator_arrow_result<ValueType, Reference, Pointer>::make(Reference) [with ValueType = boost::multi_array<double, 1ul, std::allocator<double> >, Reference = boost::detail::multi_array::sub_array<double, 1ul>, Pointer = boost::multi_array<double, 1ul, std::allocator<double> >*]’: /home/john/Dev/ThirdParty/boost/boost_1_38_0/boost/iterator/iterator_facade.hpp:648: instantiated from ‘typename boost::detail::operator_arrow_result<typename boost::detail::iterator_facade_types<Value, CategoryOrTraversal, Reference, Difference>::value_type, Reference, typename boost::detail::iterator_facade_types<Value, CategoryOrTraversal, Reference, Difference>::pointer>::type boost::iterator_facade<I, V, TC, R, D>::operator->() const [with Derived = boost::reverse_iterator<boost::detail::multi_array::array_iterator<double, double*, mpl_::size_t<2ul>, boost::detail::multi_array::sub_array<double, 1ul> > >, Value = boost::multi_array<double, 1ul, std::allocator<double> >, CategoryOrTraversal = boost::detail::iterator_category_with_traversal<std::input_iterator_tag, boost::random_access_traversal_tag>, Reference = boost::detail::multi_array::sub_array<double, 1ul>, Difference = long int]’ src/sandbox/seqan_sandbox.cpp:12: instantiated from ‘void iterate_over(It, It) [with It = boost::reverse_iterator<boost::detail::multi_array::array_iterator<double, double*, mpl_::size_t<2ul>, boost::detail::multi_array::sub_array<double, 1ul> > >]’ src/sandbox/seqan_sandbox.cpp:22: instantiated from here /home/john/Dev/ThirdParty/boost/boost_1_38_0/boost/iterator/iterator_facade.hpp:326: error: no matching function for call to ‘implicit_cast(boost::detail::multi_array::sub_array<double, 1ul>*)’

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XML character escaping
by Jeremiah Willcock 25 May '09

25 May '09

There is a function encode_char_entities() in boost/property_tree/detail/xml_parser_utils.hpp; is that safe to use from other Boost libraries? Boost.Graph's GraphML writer currently generates its own XML, and I just changed it to escape strings using that function. Should that be moved to someplace more public? -- Jeremiah Willcock

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gsoc access to sandbox
by Michael Lopez 25 May '09

25 May '09

Hello, I'm a boost gsocer (relations graph proposal) and I was wondering if it might be possible for me to store my work in the sandbox. If not, is there any particular location where I ought to store my files? Michael

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[BCP] Script for global renaming Boost Namespace
by Artyom 25 May '09

25 May '09

Hello, Today Boost does not provide any backward binary compatibility. This makes big problems in shipping 3rd part libraries that depend on Boost because library user must use the same version of Boost as that 3rd part library was compiled with. The problem is become even more critical for ELF platforms (UNIXes) where all symbols are exported by default. I had written a small Python script that switches boost namespace to other, allowing 3rd part project include it without collisions with primary Boost namespace. The script passes over the source tree of boost and changes each include path from <boost/foo/bar.hpp> too <newnamespace/foo/bar.hpp> and renames all macros and identifiers from some_BOOST_something to some_NEWNAMESPACE_something and some_boost_something to some_newnamespace_something. It does not touch comments (copyright) and strings unless the string is in form "boost/.*" which is usually some reference for include. I've run this script on the 1.39 version of boost and successfully build full boost release and run some of regression tests like Boost.Asio, Boost.Regex, Boost.Function and others, The source code is available at: http://art-blog.no-ip.info/files/rename.py You run it as: ./rename /path/to/boost/source new_namespace_name It renames all macros and namespaces to new namespace, and renames main include directory to new_namespace_na,e. Few points: 1. It is only alpha version script, I just want to see feedback and proposals 2. I do not update build scripts. I assume that each library that tryes to import its own version of Boost would provide its own build system. 3. The build scripts should be updated differently because they have different syntax and grammar. The required changes are to fix different build defines Please, give feedback proposal. If there someone who is familiar with Boost.Build systems can actually help, this would be very good. Today there is a big problem with working with different versions of Boost. It should be solved. I think this script may be a valuable addition to Boost.BCP utility that allows extracting a subset of boost for integration in 3rd part tools and libraries. Thanks, Artyom

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