March 2008 - Boost-users - lists.preview.boost.org

Egg Review starts today March 31st
by dan marsden 31 Mar '08

31 Mar '08

The review of the Egg library by Shunsuke Sogame starts today.The library is concerned with the implementation and adaptation of function objects. As function objects are everywhere in Boost and C++, I hope to see plenty of discussion and votes during the review. Introduction: It is not so easy to define Function Objects especially if you want to support Boost.ResultOf and Boost.Lambda. Therefore, as Boost provides iterator_facade and iterator adaptors, Egg provides function_facade and function adaptors. Egg provides the following features: * Workaround for the Forwarding Problem http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2002/n1385.htm * Helpers to build Function Objects: * egg::function and egg::function_facade provides the way to build Function Objects which supports Boost.ResultOf and Lambda. * Function Objects Adaptors(in other words, higher-order functions): * egg::curryN supports the currying. * egg::pipable emulates extension methods(C#). * egg::fuse/unfuse emulates variadic functions. * egg::nestN represents nested lambda expressions. * etc... The documentation is on line: http://p-stade.sourceforge.net/boost/libs/egg/ The zipped source code is in Vault/FunctionObjects: http://tinyurl.com/34lgda Tested under: Boost Development Trunk and Boost Version1.34.1. --------------------------------------------------- Please always state in your review, whether you think the library should be accepted as a Boost library! Additionally please consider giving feedback on the following general topics: - What is your evaluation of the design? - What is your evaluation of the implementation? - What is your evaluation of the documentation? - What is your evaluation of the potential usefulness of the library? - Did you try to use the library? With what compiler? Did you have any problems? - How much effort did you put into your evaluation? A glance? A quick reading? In-depth study? - Are you knowledgeable about the problem domain? Thanks Dan Marsden Review Manager ___________________________________________________________ Yahoo! For Good helps you make a difference http://uk.promotions.yahoo.com/forgood/

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matlab & boost
by elviin 31 Mar '08

31 Mar '08

Hi, I have found that Matlab uses Boost libraries and maybe headers also. It's surprising since people often compare their legacy Matlab code and new C++ boostified code. There is no reference from Mathworks on "Who's using Boost". boost_date_time-vc80-mt-1_33_1.dll boost_filesystem-vc80-mt-1_33_1.dll boost_regex-vc80-mt-1_33_1.dll boost_serialization-vc80-mt-1_33_1.dll boost_signals-vc80-mt-1_33_1.dll boost_thread-vc80-mt-1_33_1.dll boost_wserialization-vc80-mt-1_33_1.dll See the directory MATLAB\R2007b\bin\win64. Elviin

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Boost 1.35.0 released
by Beman Dawes 31 Mar '08

31 Mar '08

Boost is pleased to announce the availability of release 1.35.0. This is a major release that includes 12 new libraries, and coincides with an upgrade and reorganization of the www.boost.org web site. The new libraries are: * Asio: Portable networking, including sockets, timers, hostname resolution and socket iostreams, from Chris Kohlhoff. * Bimap: Boost.Bimap is a bidirectional maps library for C++. With Boost.Bimap you can create associative containers in which both types can be used as key, from Matias Capeletto. * Circular Buffer: STL compliant container also known as ring or cyclic buffer, from Jan Gaspar. * Function Types: Boost.FunctionTypes provides functionality to classify, decompose and synthesize function, function pointer, function reference and pointer to member types. From Tobias Schwinger. * Fusion: Library for working with tuples, including various containers, algorithms, etc. From Joel de Guzman, Dan Marsden and Tobias Schwinger. * GIL: Generic Image Library, from Lubomir Bourdev and Hailin Jin. * Interprocess: Shared memory, memory mapped files, process-shared mutexes, condition variables, containers and allocators, from Ion Gaztañaga. * Intrusive: Intrusive containers and algorithms, from Ion Gaztañaga. * Math/Special Functions: A wide selection of mathematical special functions from John Maddock, Paul Bristow, Hubert Holin and Xiaogang Zhang. * Math/Statistical Distributions: A wide selection of univariate statistical distributions and functions that operate on them from John Maddock and Paul Bristow. * MPI: Message Passing Interface library, for use in distributed-memory parallel application programming, from Douglas Gregor and Matthias Troyer. * System: Operating system support, including the diagnostics support that will be part of the C++0x standard library, from Beman Dawes. Among existing libraries, Boost.Threads has been upgraded to reflect changes made by the C++ committee in the process of including Boost.Threads in C++0x. Dozens of people contribute to each Boost release. Rene Rivera, Daniel James, and John Maddock were instrumental in readying this release. It wouldn't have happened without them. --Beman Dawes, Release Manager

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Gzip filters with concatenated buffers
by David White 30 Mar '08

30 Mar '08

Hi everyone, I'm using gzip_decompressor in a manner similar to the example program found at the bottom of http://boost.org/doc/libs/1_35_0/libs/iostreams/doc/classes/gzip.html . It mostly works well, however there is a feature of the standard Unix gzip(1) program that it doesn't seem to emulate: gzip allows one to concatenate gzipped files together, and when one uncompresses the resulting file it will be identical to if the two uncompressed files had been concatenated. That is to say, one can do this: $ echo "abc" > a $ echo "def" > b $ gzip a $ gzip b $ cat a.gz b.gz > c.gz $ gunzip -c c.gz abc def $ However, using this Boost code: ifstream file("c.gz", ios_base::in | ios_base::binary); filtering_streambuf<input> in; in.push(gzip_decompressor()); in.push(file); boost::iostreams::copy(in, cout); Will result only in the first line, "abc" being output. Is there any easy way to emulate the behavior of gzip(1) in this regard? Any help is appreciated. David

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Re: [Boost-users] [boost] [Graph] need help on remove_vertex ....
by Bernhard Lippmann 30 Mar '08

30 Mar '08

-->http://lists.boost.org/boost-users/2008/03/34808.php Hello Aaron, you assumption is corrrect, I used a vecS: typedef adjacency_list<listS, vecS, undirectedS, // Vertex properties property <vertex_name_t, std::string >, // Edge properties property <edge_weight_t, float, property <edge_index_t, std::size_t, property <edge_name_t, std::string >>>> TGraph; I may change now to typedef adjacency_list<listS, listS, .....>, is there any sample code how to add_edges for listS and how to update the property maps, once I removed a single vertex or more .... Best Bernhard -----Ursprüngliche Nachricht----- Von: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org]Im Auftrag von Aaron Windsor Gesendet: Mittwoch, 26. März 2008 14:06 An: boost-users(a)lists.boost.org Betreff: Re: [Boost-users] [boost] [Graph] need help on remove_vertex .... On Sun, Mar 23, 2008 at 6:21 PM, Bernhard Lippmann wrote: > > Hi, > > > I need some help on the remove_edge, remove_vertex functions. > What is wrong with my two functions, removing edges or vertex from a graph > with a given name in the coressponding property map. > pls. see code snippet > after calling my function a second time I get a run time error. > I did the code as shown under > http://www.boost.org/libs/graph/doc/adjacency_list.html > but I feel the rebuild of the vectors did not work, > any input is welcome > > Best > > Bernhard > > > > > > this is the code in the main program: > > // ok > MyElementList.RemoveVertexByName("vss!",g, VertexNamesMap); > // now the run time error ... > MyElementList.RemoveVertexByName("vss!s",g, VertexNamesMap); > > > > this is the called sub routine: > > > > /*$ > **************************************************************************** > ** > Method Name RemoveVertexByName ()... > Parameters std::string AE_Name > Return long , Index in Map > Description remove vertex with a given name > see > http://www.boost.org/libs/graph/doc/adjacency_list.html > for troubles > **************************************************************************** > ****** */ > void TElementList::RemoveVertexByName(std::string elementname, TGraph &g, > TVertexNameMap &VertexNamesMap) > { > Tvertex_iter vi, vi_end, next; > tie(vi, vi_end) = vertices(g); > for (next = vi; vi != vi_end; vi = next) { > ++next; > if (VertexNamesMap[*vi] == elementname) { > remove_vertex(*vi, g); } > } > > } Hi Bernhard, Your RemoveVertexByName function will work only if the vertices in your graph are stored in a list, but your email seems to suggest that you have them stored in a vector. If your vertices are stored in a vector, you're not going to be able to remove them in a single loop like this because you'll invalidate the underlying std::vector iterators you're using when you remove vertices. If you are using a list to store your vertices, this code should work as long as VertexNamesMap is populated with all of the vertices in your original graph. Regards, Aaron _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users No virus found in this incoming message. Checked by AVG. Version: 7.5.519 / Virus Database: 269.22.0/1343 - Release Date: 25.03.2008 19:17 No virus found in this outgoing message. Checked by AVG. Version: 7.5.519 / Virus Database: 269.22.0/1343 - Release Date: 25.03.2008 19:17 No virus found in this outgoing message. Checked by AVG. Version: 7.5.519 / Virus Database: 269.22.1/1348 - Release Date: 28.03.2008 10:58

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[Review][Proto] Review finished
by Hartmut Kaiser 30 Mar '08

30 Mar '08

Hi all, the review of Eric Nieblers Proto Library has finished. Even if I still need to prepare the review summary over the next couple of days I'm convinced we had a very productive and very active review period - we received 16 votes, which is way more than the average. Thanks to all who prepared a review or who simply took part in the vibrant discussions. Regards Hartmut Review Manager

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Boost Thread Examples
by Andrew Maclean 30 Mar '08

30 Mar '08

In previous versions, Boost Thread used to have a series of examples. I looked in the current release documentation but I can't seem to find them. Does anyone know where they are? They were useful to quickly illustrate the thread features. Andrew -- ___________________________________________ Andrew J. P. Maclean Centre for Autonomous Systems The Rose Street Building J04 The University of Sydney 2006 NSW AUSTRALIA Ph: +61 2 9351 3283 Fax: +61 2 9351 7474 URL: http://www.acfr.usyd.edu.au/ ___________________________________________

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[bimap] as relationship container
by Neil Hunt 30 Mar '08

30 Mar '08

Firstly, I think the bimap library is great. What would suit my situation is to use a container type of relation that allowed storage of some information with each relationship. Effectively: map_of_relation< UserDefineValueType, KeyComp > (and related multimap, unordered_map, etc). As a usage example, in database terms, TableA references TableB. Attached to the TableA->TableB relationship, would be a bimap of rows in TableA that reference rows in TableB. So... typedef bimap< set_of<Rows:iterator>, set_of<Rows:iterator>, map_of< RelationshipDescription > > RowRelationships; typedef bimap< multiset_of<Table::Ptr>, multiset_of<Table::Ptr>, map_of_relation< shared_ptr<RowRelationships> > > TableRelationships; Is this easy to add with the current bimap architecture? Neil

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templated operator<<() problems
by Olaf Peter 30 Mar '08

30 Mar '08

Hello, for formatting output I wrote the following classes: ---8<--- namespace /* anonymous */ { namespace mpl = ::boost::mpl; using ::boost::enable_if; using ::boost::xpressive::sregex; using ::boost::xpressive::as_xpr; template<typename StringT> struct is_string : mpl::false_ { }; template<> struct is_string<std::string> : mpl::true_ { }; template <typename Tp, typename Enable = void> struct formatter { formatter( const Tp& data ) : output( data ) { } std::ostream& write_on( std::ostream& os ) const { os << output; return os; } private: const Tp& output; }; template <typename Tp> struct formatter<Tp, typename enable_if< is_string<Tp> >::type> { formatter( const Tp& data ) : output( data ), re( as_xpr("\r") ), format("\n") { } std::ostream& write_on( std::ostream& os ) const { using ::boost::xpressive::regex_replace; std::ostream_iterator<std::ostream::char_type> out_iter( os ); regex_replace( out_iter, output.begin(), output.end(), re, format ); return os; } private: const Tp& output; const sregex re; const std::string format; }; } --->8--- Mainly, this replaces all '\r' by '\n' in all string in the given data, e.g.: ---8<--- template<typename DataT> void foo::write_key_data_pair( std::ostream& os, const std::string& key, const DataT& data ) const { os << "[" << key << "]" << " " ; formatter<DataT>( data ).write_on( os ); os << std::endl ; } --->8--- Anyway, overloading global operator<<() as template<typename T> static inline std::ostream& operator<<( std::ostream& os, const T& rhs ) { return rhs.write_on( os ); } would force all to have a write_on member function, isn't it. Is there a way around and even use operator<<() notation ?? Thanks, Olaf

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Using Boost with c++ builder from rad studio 2007
by Sean Farrow 30 Mar '08

30 Mar '08

Hi: I use boost with visual studio 2005 most of the time but ned to also use boost with c++ builde from rad studio 2007. Does the bjam system support this c++ builder version if so what would the command line be? Any help apreciated. Sean

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