February 2012 - Boost-users - lists.preview.boost.org

[interprocess] Determine size of managed_shared_memory
by Kai Benndorf 12 Oct '19

12 Oct '19

Hi all, I want to create a managed_shared_memory in exactly the size I needed. Therefore I do something like this: size = sizeof( common_managed_shared_memory ); size += sizeof( MyClassInSharedMem ); managed_shared_memory segment(create_only, "name", size ); MyClassInSharedMem allocates itself some memory by segment->allocate(). I added this also to the size, but get a boost::interprocess::bad_alloc exception on allocating this additional memory. Are there some magic bytes I forgot to add? Many thanks in advance Kai

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[statechart] Passing parameters from event to State Local Storage
by Christophe Bourez 16 Nov '16

16 Nov '16

I need to maintain a parameter into the state local storage. This parameter is initially contained in the event that causes the transition to the target state. I give hereafter a small illustrative example. typename sc = boost::statechart; class EvTest : public sc::event<EvTest> { public: EvTest(std::size_t val) : value(val) {} std::size_t getValue() const { return this->value; } private: std::size_t value; }; class MyStateMachine; class StSource; class StTarget; class StSource : public sc::simple_state<StSource, MyStateMachine> { public: typedef sc::custom_reaction<EvTest> reactions; sc::result react(const EvTest &event) { // How to pass event.getValue() to the target state ? transit<StTarget>(); } }; class StTarget : public sc::simple_state<StTarget, MyStateMachine> { public: StTarget(std::size_t val) : val(value) {} private: std::size_t value; }; Thanks, Christophe

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Statechart serialization
by mbrodeur65 04 Mar '15

04 Mar '15

Hi, I'm looking for a solution to serialize boost::statechart objects. I'm aware that this feature is on the statechart library todo list but was wondering if there are any workaround to achieve this with the latest boost release (1.34) ? thanks for your help ! mbrodeur65 -- View this message in context: http://www.nabble.com/Statechart-serialization-tf4131326.html#a11749139 Sent from the Boost - Users mailing list archive at Nabble.com.

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[Thread] Read-write locks
by lfrfly＠icqmail.com 18 Sep '14

18 Sep '14

I'm trying to create a standard read/write lock using Boost Threads, and I'm having a bit of difficulty mapping the Boost concepts onto the usual ones. A read/write lock should have several states: Locked for reading (multiple threads may lock at once), locked for writing (only one thread may lock, and no threads may be locked for reading at the same time), and unlocked. Ideally it would be nice if an RWL which is locked for reading may temporarily upgrade to locked for writing, then return to the locked for reading state. Boost supports several relevant notions of locking: shared locking, upgrade locking, and exclusive locking. This to me is a confusing distinction. In particular, a shared_mutex seems appropriate as the basis for a RWL, but is lock_upgrade() the equivalent of a write lock and lock_shared the equivalent of a read lock? This is unclear. If "upgrade locking" is not the same as "exclusive locking", then is an upgrade lock actually exclusive? Could someone please clarify this.

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[Statechart] How to decide between post_event and process_event atrun time ?
by Philippe DAVID 22 Jul '14

22 Jul '14

Hi, I have a method in which I want to post/process an event. The thing is, this method can be called from outside the state machine (so I need to call process_event), or indirectly by a reaction of the state machine (in this case I must call post_event since process_event is not reentrant). I don't want to write 2 distinct methods to do this (one that calls post, and the other process), I would much rather prefer adding a 'if' in my method that tells me if I have to call process_event or post_event (if I'm being called indirectly by the state machine or not). Is there a way to do this with statechart ? regards, Philippe

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[asio] resolver::cancel() problem
by Matthew Edwards 14 Mar '14

14 Mar '14

In my application (and a separate test program) it seems as though the cancel() function on the resolver does not work as intended. For async resolves, the cancel functionality should abort them immediately and pass an 'operation aborted' error code to the callback handler. In my tests, I will resolve an invalid domain (this causes the resolve to take a few seconds, to demonstrate the problem), sleep for 100ms, then call cancel on the resolver object. No cancelling actually occurs, and the callback is simply triggered after a few seconds with a "No host found" error code, not the expected operation aborted. Has anyone experienced this before, or know how I might be using the resolver incorrectly?

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[BGL] Having a cost function as weight map
by Maxime van Noppen 06 Sep '13

06 Sep '13

Hi, I can't find how to do this pretty basic thing : having a function instead of a field to compute the cost of edges for various path finding algorithms. I couldn't find the answer in the documentation and Google was of no help. Did I miss something obvious ? Example : ------------------- #include <boost/graph/dijkstra_shortest_paths.hpp> #include <boost/graph/graph_traits.hpp> #include <boost/graph/adjacency_list.hpp> struct my_edge { double cost() const { return cost_ * 2; } double cost_; }; struct my_node { }; int main() { typedef boost::adjacency_list< boost::vecS, boost::vecS, boost::directedS, my_node, my_edge > graph_t; typedef boost::graph_traits<graph_t>::vertex_descriptor vertex_t; graph_t graph; vertex_t v /*= ... */; using boost::weight_map; // Works : boost::dijkstra_shortest_paths(graph, v, weight_map(boost::get(&my_edge::cost_, graph))); // Doesn't compile : //boost::dijkstra_shortest_paths(graph, v, // weight_map(boost::get(&my_edge::cost, graph))); } ------------------- Thanks ! -- Maxime

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Identify cycles in a undirected graph
by NsPx 20 Aug '13

20 Aug '13

Hi all, I use undirected_dfs to detect all cycles in a undirected graph. I detect a cycle with DFSVisitor.back_edge(e,g) but how can I get the list of vertices defining this cycle ? Thanks by advance

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can't get first example in boost tutorial to work
by 7stud 11 Mar '13

11 Mar '13

I'm trying to install boost on mac osx 10.4.7. I followed the tutorial "Getting Started on Unix Variants" found here: http://www.boost.org/doc/libs/1_35_0/ more/getting_started/unix-variants.html Following the instructions in the tutorial, I installed boost in /usr/local as instructed, so my directory structure is: /usr/local/boost_1_34_1/boost But when I run the first example in the tutorial: #include <boost/lambda/lambda.hpp> #include <iostream> #include <iterator> #include <algorithm> int main() { using namespace boost::lambda; typedef std::istream_iterator<int> in; std::for_each(in(std::cin), in(), std::cout << (_1 * 3) << " " ); } I get the error(among others): error: boost/lambda/lambda.hpp: No such file or directory If I change the include path to: #include </user/local/boost_1_34_1/boost/lambda/lambda.hpp> I get the error(among others): error: boost/lambda/core.hpp: No such file or directory But core.hpp is in the lambda directory: /usr/local/boost_1_34_1/boost/lambda$ ls algorithm.hpp control_structures.hpp lambda.hpp bind.hpp core.hpp loops.hpp casts.hpp detail numeric.hpp closures.hpp exceptions.hpp switch.hpp construct.hpp if.hpp I'm using the Xcode 2.4 IDE to run my C++ programs. I also tried to execute the program from the command line with the original include path: #include <boost/lambda/lambda.hpp> but I get the same error: ~/2testing/dir1$ g++ prog1.cpp prog1.cpp:1:35: error: boost/lambda/lambda.hpp: No such file or directory prog1.cpp: In function 'int main()': prog1.cpp:8: error: 'boost' has not been declared prog1.cpp:8: error: expected namespace-name before ';' token prog1.cpp:8: error: '<type error>' is not a namespace prog1.cpp:11: error: '_1' was not declared in this scope I get the same errors again with the full include path: #include </user/local/boost_1_34_1/boost/lambda/lambda.hpp> $ g++ prog1.cpp In file included from prog1.cpp:1: /usr/local/boost_1_34_1/boost/lambda/lambda.hpp:14:33: error: boost/lambda/core.hpp: No such file or directory /usr/local/boost_1_34_1/boost/lambda/lambda.hpp:21:52: error: boost/lambda/detail/operator_actions.hpp: No such file or directory /usr/local/boost_1_34_1/boost/lambda/lambda.hpp:22:61: error: boost/lambda/detail/operator_lambda_func_base.hpp: No such file or directory /usr/local/boost_1_34_1/boost/lambda/lambda.hpp:23:63: error: boost/lambda/detail/operator_return_type_traits.hpp: No such file or directory /usr/local/boost_1_34_1/boost/lambda/lambda.hpp:26:45: error: boost/lambda/detail/operators.hpp: No such file or directory /usr/local/boost_1_34_1/boost/lambda/lambda.hpp:30:46: error: boost/lambda/detail/member_ptr.hpp: No such file or directory prog1.cpp: In function 'int main()': prog1.cpp:8: error: 'boost' has not been declared prog1.cpp:8: error: expected namespace-name before ';' token prog1.cpp:8: error: '<type error>' is not a namespace prog1.cpp:11: error: '_1' was not declared in this scope What path should I be using? Or, should I set an environment variable somewhere?

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Asio and ZeroMQ
by Matthias Vallentin 11 Oct '12

11 Oct '12

A while ago, Maciej Gajewski started an effort to use Asio to observe a ZeroMQ socket [1]. Based on his code, I put together a thin library that wraps the implementation details. Since other have requested a working example, here it is now at github: https://github.com/mavam/bmq Any feedback is highly appreciated. A basic usage example looks like this: #include <boost/asio/io_service.hpp> #include <bmq.h> int main() { boost::asio::io_service io; bmq::context ctx(1); bmq::component c(ctx, io); auto sink = c.add_sink(ZMQ_PAIR, "inproc://x"); c.subscribe(sink, [](bmq::message&& msg) { std::string str(static_cast<char*>(msg.data()), msg.size()); std::cout << str << std::endl; }); auto source = c.add_source(ZMQ_PAIR, "inproc://x"); bmq::message msg(const_cast<char*>("foo"), 3, nullptr); source->send(msg); // Execute message handler. io.poll(); return 0; } At this point, the library is really thin and only provides very rudimentary wrapping of ZeroMQ. In the future, I plan to extend it in order to facilitate applications that build on message-passing. The dataflow abstraction I envision is essentially a directed graph, where nodes represent components and edges communication links. 0mq provides the edges and the Asio handles asynchronous event processing at the component level. The motiviation is that this model lends itself well for scaling out distributed systems over large clusters. Matthias [1] http://permalink.gmane.org/gmane.network.zeromq.devel/9538

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[Sandbox - endian] Why is endian still in sandbox?
by Nathaniel J Fries 07 Oct '12

07 Oct '12

A fairly novel (at least when put up against more intricate labours like asio, filesystem, and their like) project which appears to be finished and would be a very useful companion to existing libraries sits in the sandbox. Is there a reason for this?

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[Range] insert algorithm fails if target is a map
by Robert Jones 11 Sep '12

11 Sep '12

The title says it all really. The failure occurs because the insert algorithm expects the container to provide a 3-arg insert of the form container.insert( position, begin, end ); whereas map's, multimap's and set's insert method only takes two arguments... map.insert( begin, end ); Is this limitation by design? It would be easy to provide specialisations for maps, mmaps and sets, but that would not be a completely general solution. - Rob.

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[Graph] compilation error under Windows but not under Linux
by Gaël de Chalendar 29 Aug '12

29 Aug '12

Hello, I have a compilation error under Windows (Visual C++ 2008) with a code that works well under Linux (gcc 4.6.1 and before). The compilation error is: =========== /FsaAccess16.tcc(833) : error C2784: 'std::pair<graph_traits<G>::in_edge_iterator,graph_traits<G>::in_edge_iterator> boost::in_edges(graph_traits<G>::vertex_descriptor,const boost::subgraph<Graph> &)'ÿ: impossible de d‚duire l'argument modŠle pour 'const boost::subgraph<Graph> &' … partir de 'FrCeaLic2m::Common::FsaAccess::selected_graph_types16::spareGraphType' C:\PROGRA~1\boost\BOOST_~1\boost/graph/subgraph.hpp(432)ÿ: voir la d‚claration de 'boost::in_edges' Z: \Projets\MoteurMultimedia\mm_common\src\common/FsaAccess/FsaAccess16.tcc(778)ÿ: lors de la compilation de la fonction membre '<Inconnu>' de la classe <Inconnu> z: \projets\moteurmultimedia\mm_common\src\common\fsaaccess\FsaAccessReader16.h(118)ÿ: voir la r‚f‚rence … l'instanciation de la classe modŠle 'FrCeaLic2m::Common::FsaAccess::FsaAccess16<graphType>' en cours de compilation with [ graphType=FrCeaLic2m::Common::FsaAccess::selected_graph_types16::spareGraphType ] z: \projets\moteurmultimedia\mm_common\src\common\fsaaccess\FsaAccessSpare16.h(35)ÿ: voir la r‚f‚rence … l'instanciation de la classe modŠle 'FrCeaLic2m::Common::FsaAccess::FsaAccessReader16<graphType>' en cours de compilation with [ graphType=FrCeaLic2m::Common::FsaAccess::selected_graph_types16::spareGraphType ] =========== The line that does not compile is boost::tie(iei,ie_end) = boost::in_edges(commonTarget,m_graph); The function being compiled is declared like that: template <typename graphType > std::pair< const typename boost::graph_traits<graphType>::vertex_descriptor, bool > FsaAccess16<graphType>::findEquivalentInRegister( dicoVertexType tempState ){ ... And here graphType, the type of m_graph is spareGraphType defined by: struct selected_graph_types16 { ... typedef boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, dicoVertexCountProperty> spareGraphType; ... This is a cmake based project that I compile using qtcreator. I'm a Linux developer and I'm a little bit lost with VC outputs and tools under Windows... Regards, Gaêl -- Gael de Chalendar CEA LIST Centre de Fontenay-aux-Roses Laboratoire Vision et Ingénierie des Contenus (Vision and Content Engineering Laboratory) Bat. 38-2 ; 18, rue du Panorama ; BP 6 92265 Fontenay aux Roses Cedex ; France Tél.:01.46.54.80.18 ; Fax.:01.46.54.75.80 Email : Gael.D.O.T.de-Chalendar.A(a)T.cea.D.O.T.fr

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Re: [Boost-users] asio HTTP Server 3 example memory leak
by admin＠thefireflyproject.us 25 Aug '12

25 Aug '12

2 1

accumulator operations
by Olaf Peter 04 Jun '12

04 Jun '12

Hi, I like to collects some stats. There are several data slices where I can partially/separated collect them (each of them). Finaly I like to combine these stats to a single one to get summarized informations. How to? May this work: accumulator_set<..> acc1; accumulator_set<..> acc2; ... accumulator_set<..> acc_all; ... acc1(42); ... acc_all += acc1; ... acc_all += acc2; Because did not found informations about. The same problem woulde be probably for a threaded implementation too. Thanks, Olaf

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[multi_array] operator= requires resize - why?
by Markus Werle 04 Jun '12

04 Jun '12

Hi! IMHO the behaviour of operator= for multi_array is a little bit broken. A lot of preconditions required: template <typename ConstMultiArray> multi_array_ref& operator=(const ConstMultiArray& other) { [...] // make sure the dimensions agree assert(other.num_dimensions() == this->num_dimensions()); assert(std::equal(other.shape(),other.shape()+this->num_dimensions(), this->shape())); Besides the fact that I get mad about asserts instead of exceptions (please change this to a way users may choose) why do we have such an odd behaviour here? >From page 1, line 3 of the docs I cite: "The interface design is in line with the precedent set by the C++ Standard Library containers" - this is not true for operator=, since std::<container>::operator= works fine for me all the time _without_ any resize. Could we please change the behaviour of multi_array::operator= to take care of resize where in need to? IMHO operator= should result in a true copy ignoring previous state. Markus

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offlist - Re: [iterator] Problems with iterator_facade and const-qualification
by Neil Groves 24 May '12

24 May '12

On Sat, May 7, 2011 at 5:52 PM, Dave Abrahams <dave(a)boostpro.com> wrote: > On Fri, May 6, 2011 at 1:51 PM, Evan Driscoll <driscoll(a)cs.wisc.edu> > wrote: > > On 05/06/2011 11:59 AM, Jeff Flinn wrote: > >> > >> You might google any_iterator, and see how other authors have addressed > >> similar problems. > > > > Great! I tried to find someone who had done something similar, figuring I > > couldn't have been the first, but all the search terms I tried were too > > generic. > > > > Thanks, > > Evan > > You can find one in the ASL that's built on iterator_facade. > http://stlab.adobe.com/classadobe_1_1any__iterator.html > > The underlying Boost.Range implementation implements an any_iterator that I believe to be similar to the one in ASL in terms of functionality. I believe that the small-buffer optimization implementation is superior to forcing the definition of a closed-set of possible type as suggested in a TODO within the ASL documentation. During my performance testing I had considerably superior performance than the ASL implementation. I wondered if you disliked my implementation, or had any feedback. Additionally I wondered what you thought about moving the Boost.Range internal any_iterator implementation into Boost.Iterator. I can't honestly imagine a good use-case for using any_iterator in preference to any_range, hence I haven't suggested this previously. This could easily be due to my lack of imagination! Can you think of a time when using an any_iterator on any interface would be superior to using an any_range? Your opinions and guidance would be much appreciated. HTH, > > -- > Dave Abrahams > BoostPro Computing > http://www.boostpro.com Regards, Neil Groves

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Recommended mock framework to use with Boost?
by doug livesey 15 Mar '12

15 Mar '12

Hi -- I'm trying to learn to develop properly with C++ and Boost, and to that end am learning along with Boost.Test, as I'm a BDD coder in another language (Ruby) in my day job. I'm at the point, now, where my tests could really benefit from a mocking framework. There doesn't appear to be one in Boost (not documented, at least), so I wondered if anyone on the list could recommend a mocking framework that they use that works well with Boost.Test? Any and all advice gratefully received, Doug.

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Boost.Generic sources?
by Nathan Ridge 05 Mar '12

05 Mar '12

I just read about the Boost.Generic library at https://github.com/boostcon/2011_presentations/raw/master/thu/Boost.Generic…. It looks amazing! I understand it's not fully complete, but are the sources available somewhere? Thanks, Nate.

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Problem building boost MPI with Visual Studio 2010
by k m 05 Mar '12

05 Mar '12

Hi All I have installed openmpi in C:\Program Files\OpenMPI_v1.5.4-win32\ in an XP box and want to compile boost to produce graph-parallel library. But got the following error: The system cannot find the path specified. The system cannot find the path specified. The system cannot find the path specified. The system cannot find the path specified. MPI auto-detection failed: unknown wrapper compiler C:/Program Files/OpenMPI_v1. 5.4-win32/bin/mpic++.exe Please report this error to the Boost mailing list: http://www.boost.org You will need to manually configure MPI support. MPI launcher: mpirun -np when I ran in a Visual Studio 2010 command prompt: b2 --toolset=msvc-10.0 --build-type=complete architecture=x86 address-model=32 stage --debug-configuration I added the MPI config in boost_1_48_0\tools\build\v2\user-config.jam as below: using mpi : "C:/Program Files/OpenMPI_v1.5.4-win32/bin/mpic++.exe" ; Could anyone help on this? Gary

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Boost.Interprocess containers question
by Davidson, Josh 02 Mar '12

02 Mar '12

I have an object that I'm storing in shared memory that contains a map data member whose values are lists. The processes that interact with this object don't have direct access to the map data structure. Instead, the object is accessed and modified through its public interface. The issue I am running into is how to handle new key, value insertions. I would prefer to leave the fact that the object is in shared memory an implementation detail, but in order to construct a new list to insert in the map, the list needs to be initialized with an allocator using the segment manger. Unless I pass that segment manager into every method that might add a new list to the map, I'm struggling how to get it working. I can't simply store a pointer to the managed shared memory or segment manager within the class since the address would only be valid in the process that constructed it. The only possible implementations I can think of would be to require passing in the segment manager into all of the methods and then create a simple wrapper class that contains a pointer to this object along with a pointer to the segment manager. The wrapper class would essentially "duplicate" each of the methods in the wrapped class but drop the segement manager parameter since it has it as a member. Processes that "find" this object in shared memory would then be responsible for wrapping it in an object of the wrapper class. The other possible implementation would be to always open the shared memory segment by name before modifying the map. Josh

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Graph: writing graph properties to graphml file
by Juerg Tschirren 01 Mar '12

01 Mar '12

I wrote the code below to construct a directed graph with internal properties (for vertices, edges, and the graph itself) and write everything to a graphml file. The code compiles and works as it is, but my two questions are: 1. What dynamic property do I have to add to write the graph properties out to the graphml file as well? So far I could only figure out how to write vertex and edge properties. 2. Does everything else look good? Specifically, is it O.K. to define the properties the way I did in the first typedef line (without using boost::property<>), and is it O.K. to access the properties the way I do it? Juerg //--- start of example code typedef boost::adjacency_list<boost::listS, boost::vecS, boost::directedS, std::string, std::string, std::string> Graph; typedef boost::graph_traits<Graph>::vertex_descriptor vertex_t; typedef boost::graph_traits<Graph>::edge_descriptor edge_t; Graph g; vertex_t u = boost::add_vertex(g); vertex_t v = boost::add_vertex(g); edge_t e; bool b; boost::tie(e,b) = boost::add_edge(u,v,g); g[u] = "a_vertex_name"; g[v] = "an_other_vertex_name"; g[e] = "an_edge_name"; boost::get_property(g) = "the_graph"; boost::dynamic_properties dp; dp.property("vertex_data", boost::get(boost::vertex_bundle, g)); dp.property("edge_data", boost::get(boost::edge_bundle, g)); std::ofstream graphmlOutFile("graph.xml"); boost::write_graphml(graphmlOutFile, g, dp, true); graphmlOutFile.close();

2 1

zip_iterator.hpp / boost::tuple requires a using namespace std!
by mark pashley 01 Mar '12

01 Mar '12

Hi, I have been using zip iterators with a BOOST::Test to check that maps contain expected values. After moving some templated code to a header file I found that the code would not compie unless I place a *'using namespace std;' * declaration within one of functions. The compiler is gcc 4.6.2 and 4.4.2. The version of boost is 1.47 and 1.49 The minimum code snippet is as follows: * using namespace std; // without this the next line does not compile!* The error from gcc is: -- View this message in context: http://boost.2283326.n4.nabble.com/zip-iterator-hpp-boost-tuple-requires-a-… Sent from the Boost - Users mailing list archive at Nabble.com.

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embedding
by Andreas Fabri 01 Mar '12

01 Mar '12

Hello I am wondering if there is ongoing work around the notion of embeddings of the Boost Graph Library. In the CGAL project which deals with geometric data structures we have written specializations of the graph_traits for the polyhedral surface, the halfedge datastructure, 2D triangulations, and arrangements. This allows to run BGL algorithms directly on CGAL data structures. http://www.cgal.org/Pkg/BGL. As these graphs are always embedded, that is as there is a circular order of edges we introduced a HalfedgeGraph concept http://www.cgal.org/Manual/latest/doc_html/cgal_manual/BGL_ref/Concept_Half… where one has global functions in order to walk along the border of a face, and go from an outgoing edge via the opposite incoming edge to a neighbor face. Would any of these ideas be interesting for the maintainers of the BGL. best regards, andreas -- Andreas Fabri, PhD Chief Officer, GeometryFactory Editor, The CGAL Project phone: +33.492.954.912 skype: andreas.fabri

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[PREDEF] Review for the Boost.Predef library by Rene Riviera
by Joel Falcou 29 Feb '12

29 Feb '12

The review of BOOST.PREDEF by Rene Riviera is scheduled between Monday, February 20th to February 29th. ================ Contents & Scope ================ BOOST.PREDEF defines a set of compiler, architecture, operating system, and library version numbers from the information it can gather of C++ predefined macros or those defined in generally available headers. The idea for this library grew out of a proposal to extend the Boost Config library to provide more, and consistent, information than the feature definitions it supports. What follows is an edited version of that brief proposal. =============== How to get it ? =============== Sources and documentation can be retrieved from http://tinyurl.com/73n6a3k ================ Writing a Review ================ The reviews and all comments should be submitted to the developers list, and the email should have "[PREDEF] Review" at the beginning of the subject line to make sure it's not missed. Please explicitly state in your review whether the library should be accepted. The general review checklist: - 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? And finally, every review should answer this question: - Do you think the library should be accepted as a Boost library? Be sure to say this explicitly so that your other comments don't obscure your overall opinion.

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PP: commas issues
by MM 29 Feb '12

29 Feb '12

Hi, I am trying to generate a list of instances of the same template with different pairs of args, to populate a mpl container, with PP so, mpl::vector< tmpl<A::x,A::y>, tmpl<B::x,B::y>, tmpl<C::x, C::y> > i'm having trouble with the commas. I successfully generate the pp sequence (tmpl<A::x,A::y>)(tmpl<B::x,B::y>) (tmpl<C::x, C::y>) but from this to get the enumeration, it's impossible using SEQ_ENUM, because the sequence contains commas MM

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[multi_array] How to specify degenerate at runtime?
by Anton Daneyko 29 Feb '12

29 Feb '12

Greetings to Boosters, I have a 3D multi_array and I would like to make 2D slices using dimensions specified at runtime. I know the index of degenerate dimension and an index of slice, that I want to extract in that degenerate dimension. Currently the ugly workaround looks like that: if (0 == degenerate_dimension) { Slice slice = input_array[boost::indices[slice_index][range()][range()]]; } else if (1 == degenerate_dimension) { Slice slice = input_array[boost::indices[range()][slice_index][range()]]; } else if (2 == degenerate_dimension) { Slice slice = input_array[boost::indices[range()][range()][slice_index]]; } Is there a more beautiful way to construct index_gen object? Something like that: var slicer; for(int i = 0; i < 3; ++i) { if (degenerate_dimension == i) slicer = boost::indices[slice_index]; else slicer = boost::indices[range()]; } Slice slice = input_array[slicer]; It seems each subsequent call to boost::indices::operator[] returns a different type depending on the dimensionality, so there's no way to use a single variable, that can hold the temporary index_gen object.

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iterator_facade with incomplete type as Value argument
by Philipp Moeller 29 Feb '12

29 Feb '12

I've tried writing an iterator with iterator_facade that returns itself as the result of dereference, but the Value template argument requires a complete type because it tries to make a difference between returning by value or reference if Value is_pod (as far as I understand). #include <boost/iterator/iterator_facade.hpp> class iter : public boost::iterator_facade< iter, iter, boost::forward_traversal_tag > { public: void fancy_non_iterator_member(); private: friend class boost::iterator_core_access; void increment() { } bool equal(iter const& other) const { return true; } iter& dereference() const { return const_cast<Derived&>(static_cast<const Derived&>(*this)); } }; Is this the intended behavior of iterator_facade? Is there some workaround? Would such an iterator actually be conforming? -- Philipp Moeller GeometryFactory

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boost python & context manager/with statement
by Avi Bahra 29 Feb '12

29 Feb '12

Does boost python support context management using the with statement? In my case I need to manage __enter__/__exit__ on the c++ side. Could not find any examples for this in the documentation. Any help appreciated. Best regards, Ta, Avi

3 2

Using boost with PathScale v4.x under Linux
by Roberto Fichera 29 Feb '12

29 Feb '12

Hi there, I've compiled the last boost v1.49 against PathScale v4.x compiler under 64bit linux distribution, but when compiling certain library that uses the boost/numeric/interval/rounded_transc.hpp include file, I end up on getting some error regarding asinh(), acosh() and atanh() which were searched in the std namespace. Compiling the same library against g++ or MSVC goes pretty straight without problems. /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp: In member function 'T boost::numeric::interval_lib::rounded_transc_exact<T, Rounding>::asinh_down(const T&)': /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp:42: error: 'std::asinh' has not been declared /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp: In member function 'T boost::numeric::interval_lib::rounded_transc_exact<T, Rounding>::asinh_up(const T&)': /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp:42: error: 'std::asinh' has not been declared /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp: In member function 'T boost::numeric::interval_lib::rounded_transc_exact<T, Rounding>::acosh_down(const T&)': /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp:43: error: 'std::acosh' has not been declared /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp: In member function 'T boost::numeric::interval_lib::rounded_transc_exact<T, Rounding>::acosh_up(const T&)': /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp:43: error: 'std::acosh' has not been declared /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp: In member function 'T boost::numeric::interval_lib::rounded_transc_exact<T, Rounding>::atanh_down(const T&)': /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp:44: error: 'std::atanh' has not been declared /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp: In member function 'T boost::numeric::interval_lib::rounded_transc_exact<T, Rounding>::atanh_up(const T&)': /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp:44: error: 'std::atanh' has not been declared /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp: In member function 'T boost::numeric::interval_lib::rounded_transc_std<T, Rounding>::asinh_down(const T&)': /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp:77: error: 'std::asinh' has not been declared /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp: In member function 'T boost::numeric::interval_lib::rounded_transc_std<T, Rounding>::asinh_up(const T&)': /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp:77: error: 'std::asinh' has not been declared /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp: In member function 'T boost::numeric::interval_lib::rounded_transc_std<T, Rounding>::acosh_down(const T&)': /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp:78: error: 'std::acosh' has not been declared /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp: In member function 'T boost::numeric::interval_lib::rounded_transc_std<T, Rounding>::acosh_up(const T&)': /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp:78: error: 'std::acosh' has not been declared /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp: In member function 'T boost::numeric::interval_lib::rounded_transc_std<T, Rounding>::atanh_down(const T&)': /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp:79: error: 'std::atanh' has not been declared /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp: In member function 'T boost::numeric::interval_lib::rounded_transc_std<T, Rounding>::atanh_up(const T&)': /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp:79: error: 'std::atanh' has not been declared /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp: In member function 'T boost::numeric::interval_lib::rounded_transc_opp<T, Rounding>::asinh_down(const T&)': /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp:122: error: 'std::asinh' has not been declared /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp: In member function 'T boost::numeric::interval_lib::rounded_transc_opp<T, Rounding>::asinh_up(const T&)': /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp:122: error: 'std::asinh' has not been declared /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp: In member function 'T boost::numeric::interval_lib::rounded_transc_opp<T, Rounding>::atanh_down(const T&)': /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp:123: error: 'std::atanh' has not been declared /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp: In member function 'T boost::numeric::interval_lib::rounded_transc_opp<T, Rounding>::atanh_up(const T&)': /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp:123: error: 'std::atanh' has not been declared /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp: In member function 'T boost::numeric::interval_lib::rounded_transc_opp<T, Rounding>::acosh_down(const T&)': /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp:132: error: 'std::acosh' has not been declared /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp: In member function 'T boost::numeric::interval_lib::rounded_transc_opp<T, Rounding>::acosh_up(const T&)': /TempData/boost_1_49_0_pathscale/boost/numeric/interval/rounded_transc.hpp:132: error: 'std::acosh' has not been declared Thus, I had a look in the boost include file boost/numeric/interval/detail/bugs.hpp and look like that apply the patch below fixes the compilation error: --- numeric/interval/detail/bugs.hpp.orig 2012-02-29 10:44:06.876597264 +0100 +++ numeric/interval/detail/bugs.hpp 2012-02-29 10:18:42.831581398 +0100 @@ -25,7 +25,7 @@ #else # define BOOST_NUMERIC_INTERVAL_using_math(a) using std::a # if defined(BOOST_HAS_INV_HYPERBOLIC) -# if defined(__GLIBCPP__) || defined(__GLIBCXX__) +# if defined(__GLIBCPP__) || defined(__GLIBCXX__) || defined(__GLIBC__) # define BOOST_NUMERIC_INTERVAL_using_ahyp(a) using ::a # else # define BOOST_NUMERIC_INTERVAL_using_ahyp(a) using std::a does anyone can comment? Thanks in advance, Roberto Fichera.

1 0

[PREDEF] Review ends today
by Joel Falcou 29 Feb '12

29 Feb '12

The review of Boost.PRedef by Rene Rivera is ending today, February 29th. I recall to all people wanting to submit a formal review to do so. Regards

1 0

Metaprogramming Question
by John M. Dlugosz 28 Feb '12

28 Feb '12

I've not had much opportunity to do much template metaprogramming in my work, but I've kept up with my reading. So, might I get some advice on how to approach this problem? I'm thinking of an assert-like statement that follows the syntax of Boost.Format, thus avoiding the variadic argument list. MY_FANCY_ASSERT (cond, "format string") % arg % arg; works if the macro expands to an unnamed temporary, whose destructor does the interesting work if the first argument is false. my_assert_formatter_type (cond, "cond", __FILE__, __LINE__, "format string") This is easy to do, simply deriving from boost::formatter, I would think. But, I want to avoid doing any work except on failure. This means remembering the arguments including the following %arg stuff, and passing everything through to Boost.Format based on the condition. So I'm thinking that template metaprogramming can let me collect all the arguments (any number of them) into one object, efficiently at compile time. So, what approach should I use? Plain MPL and classic metaprogramming? Fusion? Phoenix? and any concrete suggestions on how to proceed, or pointers to similar works? Thanks, —John

6 16

boost::python handles boost::shared_ptr specially...
by Neal Becker 28 Feb '12

28 Feb '12

Will it just work if I use std::shared_ptr instead?

2 1

WIN64 vs _WIN64
by Roberto Fichera 28 Feb '12

28 Feb '12

Hi All, I got a compilation error while compiling a library under Win64 arch that includes the boost/numeric/interval/msvc_rounding_control.hpp c:\boost_1.48\include\boost/numeric/interval/detail/msvc_rounding_control.hpp(33) : error C4235: nonstandard extension used : '_asm' keyword not supported on this architecture c:\boost_1.48\include\boost/numeric/interval/detail/msvc_rounding_control.hpp(33) : error C2065: 'FLD' : undeclared identifier c:\boost_1.48\include\boost/numeric/interval/detail/msvc_rounding_control.hpp(34) : error C4235: nonstandard extension used : '_asm' keyword not supported on this architecture So I checked the code under boost/numeric/interval/detail/msvc_rounding_control.hpp and it seems that it does a preprocessor check against WIN64 instead of _WIN64 namespace boost { namespace numeric { namespace interval_lib { namespace detail { #if BOOST_MSVC < 1400 || *defined(WIN64)* extern "C" { double rint(double); } #else inline double rint(double x) { _asm FLD [x] ; _asm FRNDINT ; //_asm RET ; } #endif Is there any reason why do not check against _WIN64 instead of WIN64 since the boost does always check against _WIN64? _WIN64 is also already pre-defined as normal MSVC definition when targeting x86_64 archs. [roberto@roberto include]$ grep -R WIN64 * boost/serialization/force_include.hpp:#elif ! defined(_WIN32) && ! defined(_WIN64) boost/detail/win/synchronization.hpp: #if defined(_WIN64) boost/detail/win/basic_types.hpp:# ifdef _WIN64 boost/intrusive/detail/mpl.hpp:#if defined(_MSC_EXTENSIONS) && !defined(__BORLAND__) && !defined(_WIN64) boost/python/converter/builtin_converters.hpp:# if defined(_MSC_VER) && defined(_WIN64) && PY_VERSION_HEX < 0x03000000 boost/xpressive/xpressive_fwd.hpp:# if (defined(_WIN32) || defined(_WIN64) || defined(_WINCE)) \ boost/thread/win32/thread_primitives.hpp:# ifdef _WIN64 boost/regex/config.hpp:# if(defined(_WIN32) || defined(_WIN64) || defined(_WINCE)) \ boost/signals2/detail/lwm_win32_cs.hpp:#if defined(_WIN64) boost/config/compiler/intel.hpp:#if (!(defined(_WIN32) || defined(_WIN64)) && defined(__STDC_HOSTED__) && (__STDC_HOSTED__ && (BOOST_INTEL_CXX_VERSION <= 1200))) || defined(__GXX_EXPERIMENTAL_CPP0X__) boost/config/compiler/intel.hpp:#if defined(_WIN32) || defined(_WIN64) boost/smart_ptr/detail/lwm_win32_cs.hpp:#if defined(_WIN64) *boost/numeric/interval/detail/msvc_rounding_control.hpp:#if BOOST_MSVC < 1400 || defined(WIN64)*

2 2

C++ guru required!
by Robert Ramey 27 Feb '12

27 Feb '12

I've got a really dumb question. My question is illustrated by the following code snippit. template<class T, class U> T inline operator%(const T & lhs, const U & rhs) { if(0 == rhs) throw std::domain_error("Divide by zero"); if(boost::is_same<T, boost::uintmax_t>::value && boost::numeric::is_signed<U>::value ){ if(1 == rhs || -1 == rhs) // is this dropped? overflow("unsigned type can hold this result"); } return lhs % rhs; } I would like to think that the second if is always dropped from the compile for a particular pair of types since this can be evaluated at compile time. If I'm correct, I can replace some tedious template metaprogramming for some straightforward and transparent code inserted in a convenient code inserted in the most convenient place. Andre Alex... gave a talk at "Going Native" proposing a "static if" for this case. But I don't see the necessity for for this since I would assume that the compiler just optimises away the "dead" code. I've compiled the above and it seems to do what I want but still I wonder. Basically I see lots of applications of variations on this idea to get the benefits of tmp without the attendent pain. Am I missing anything here? Robert Ramey

8 20

[quickbook] how to use
by Nathan Ridge 27 Feb '12

27 Feb '12

Hello, I am trying to use QuickBook to write documentation for a project (that's not a Boost library), and I have a basic question about how to use it. So far I've followed the setup instructions on this page, built the quickbook executable by running bjam in BOOST_ROOT\tools\quickbook, written a .qbk file in QuickBook format, and ran the quickbook executable on my .qbk file to produce an XML file which looks like BoostBook XML. Now how do I go about generating HTML or PDF from that BoostBook XML file? Thanks, Nate

2 1

[build] Is there any interest in a configure auto generator for boost-build?
by Tianjiao Yin 27 Feb '12

27 Feb '12

Hello all: Boost build configure (site-config.jam) is not easy to write for me, especially when I install some new compilers or tools. So I wrote a script to generate the configure in "/etc/site-config.jam" automatically for myself. You can get the whole source code here: http://ideone.com/kkI2G When I run this script by using argument "--setup", it will generate a new configure in "/etc/site-config.jam" like this: http://ideone.com/4yWyI I am using archlinux, not tested in any other platform. For archers, this script is part of boost-build-nightly in AUR, it works for me. BTW, boost-build 2.0_m12 is in the archlinux official repository. But this version is too outdated to build many examples in the boost 1.48.0. When m13 release? Regards, Tianjiao

1 0

[Container] comment on slist/forward_list documentation
by Brian Wood 26 Feb '12

26 Feb '12

Iiuc, Boost.Container implements slist but not forward_list. I'd like to suggest tweaking the following sentence. *"Boost.Container* updates the classic slist container with C++11 features like move semantics and placement insertion and implements it a bit differently for the standard C++11 forward_list." ^^ It might be better to say "and implements it a bit differently than the standard C++ forward_list." ? I wondered if you had both an slist and a forward_list implementation for a while and did some other checking to figure out what was in the library. http://www.boost.org/doc/libs/1_49_0/doc/html/container/non_standard_contai… Shalom Brian Wood Ebenezer Enterprises http://webEbenezer.net

2 1

[Iterators] How to implement proxy iterators?
by Oswin Krause 26 Feb '12

26 Feb '12

Hi Everybody, I'm trying to implement a proxy_iterator for ublas::matrix which should behave as an iterator over the matrix rows. My "obvious" solution does not seem to work: typedef boost::numeric::ublas::matrix<double> Matrix; typedef boost::numeric::ublas::matrix_row<Matrix> MatrixRow; typedef boost::numeric::ublas::vector<double> Vector; struct MatrixIterator: public boost::iterator_facade< MatrixIterator, Vector,//the semantic value type is a Vector boost::random_access_traversal_tag, MatrixRow//reference is a row of a matrix >{ //snip constructors private: friend class boost::iterator_core_access; //snip iterating stuff //fun part MatrixRow dereference() const { return row(*m_matrix,m_element); } std::size_t m_element; Matrix* m_matrix; }; which reuslts in an error that MatrixRow can't be implicitely casted to Vector. Which is correct. At the moment I'm using a 90% hacked workaround which changes the ValueType of the Iterator to MatrixRow. This seems to work as long as I don't use algorithms which rely on the actual value_type of the iterator (for example iter_swap as implemented in the gnu libstdc++ will fail miserably even though a correct swap is implemented for the MatrixRow...different story ) Since I need std::random_shuffle I am out of luck. I tried to find the actual requirements of iterator_facade with respect to ValueType/ReferenceType in the documentation, but was not able to find them. Does someone now a solution to this problem which works and results in an iterator which can safely be used in random_shuffle? Or can point me to the correct requirements? Greetings from Germany, Oswin Krause

2 5

Linking problem
by Johan Råde 26 Feb '12

26 Feb '12

I built Boost with the command b2 toolset=msvc-10.0 address-model=32 link=static runtime-link=shared threading=multi stage I'm linking statically with Boost and dynamically with the CRT (compiler option /MD). I get the error message LINK : fatal error LNK1104: cannot open file 'libboost_iostreams-vc100-mt-1_49.lib' What might the problem be?

3 4

any progress on the logger?
by Victor Whiskey Yankee 25 Feb '12

25 Feb '12

Hello, Any progress on getting the logger into an official release? Thanks, Vic

2 1

[phoenix] Extending actors
by paul Fultz 25 Feb '12

25 Feb '12

Hi all, I am wanting to extend actors to access a member variable from the class. In the examples they show extending an acotr by using a lazy function to call the function. I was thinking I could use a lazy function to access the member, something like this: template <typename Expr> struct point_actor : actor<Expr> { typedef actor<Expr> base_type; typedef point_actor<Expr> that_type; point_actor( base_type const& base ) : base_type( base ) {} typename expression::function<x_impl, that_type>::type x; typename expression::function<y_impl, that_type>::type y; }; Where x_impl and y_impl are lazy functions that access the x and y variable. Would this work as member variables, rather than member functions? Also, why wouldnt the second parameter to expression::function take just actor instead of just point_actor<Expr>? Does that make sense? The reason I ask is I would like to control the actor that is returned and do something like this(using the above actor): template <typename Expr> struct rect_actor : actor<Expr> { typedef actor<Expr> base_type; typedef rect_actor<Expr> that_type; rect_actor( base_type const& base ) : base_type( base ) {} typename expression::function<top_impl, point_actor >::type top; typename expression::function<bottom_impl, point_actor >::type bottom; }; expression::terminal<phoenix::argument<1>, rect_actor > arg1; (cout << arg1.top.x)(my_rect()); Does that make sense? I can't seem to find any reference on the predefined expressions, and I also can't find the header file for expression::function. Finally, the is_actor trait doesn't seem work for extended actors.Is there a workaround for that? Thanks, Paul

2 4

Boost 1.49.0 release notice
by Beman Dawes 24 Feb '12

24 Feb '12

Release 1.49.0 of the Boost C++ Libraries is now available. These open-source libraries work well with the C++ Standard Library, and are usable across a broad spectrum of applications. The Boost license encourages both commercial and non-commercial use. This release contains one new library (Heap) and numerous enhancements and bug fixes for existing libraries. For details, including download links, see http://www.boost.org/users/news/version_1_49_0 You can also download directly from SourceForge: http://sourceforge.net/projects/boost/files/boost/1.49.0/ To install this release on your system, see http://www.boost.org/doc/libs/release/more/getting_started/index.html Thanks, --The Boost release team Beman Dawes Daniel James Eric Niebler Rene Rivera Vladimir Prus

3 2

Detecting file encoding
by norulez＠me.com 24 Feb '12

24 Feb '12

Hi, is there a way in boost to detect the encoding of a file? Thanks in advance Best Regards NoRulez

1 0

iterator_adaptor: making dereference of adapted tree node* return node value
by Rob Desbois 24 Feb '12

24 Feb '12

I have the following iterator_adaptor type: template< class NODE > struct node_iterator: public boost::iterator_adaptor< node_iterator<NODE>, // Derived NODE*, // Base typename NODE::value_type // Value > { typename NODE::value_type dereference() const { return this->base_reference()->data(); } }; // and later: typedef detail::node_iterator<node_type> iterator; typedef detail::node_iterator<const node_type> const_iterator; This throws up the issue that in const_iterator, Value is not const, producing the following error: /usr/include/boost/iterator/iterator_facade.hpp:517:32: error: invalid initialization of non-const reference of type ‘container::detail::node_iterator<const container::detail::node<long unsigned int> >::reference {aka long unsigned int&}’ from an rvalue of type ‘container::detail::node<long unsigned int>::value_type {aka long unsigned int}’ I could do some type traits magic with is_same, is_const and add_const to add the constness to Value if present on NODE, but is this the right way to do it? I've also thought about indirect_iterator - but adding operator*() to the node type seems not quite right. Perhaps transform_iterator...or is there some different method that might be more suitable? TIA, --rob -- Rob Desbois Blog: http://theotherbranch.wordpress.com/ "I disapprove of what you say, but I’ll defend to the death your right to say it", Voltaire

3 5

[posix_time] from_time_t bug
by Matthew Jenks 24 Feb '12

24 Feb '12

Hello, I am running into a problem with boost::posix_time::from_time_t() on a PC with, windows xp, visual studio 2010. When I input a number larger than the decimal equivalent of 0x7FFFFFFF (maximum posssible int32) into the function it returns a ptime with a date of 1902 or something close to. I assume the UNIX equivalent of time_t is a int32 and that is why I am having this problem, but I know a time_t is the equivalent to __int64 in windows xp. Is there is a MACRO define I am missing or is this a bug that needs to be fixed with this function so that it can accept the windows equivalent of time_t? Shouldn't this function accept and convert larger intigers thank int32 to a ptime or do I have to write my own? Thanks, Matt

2 1

Getting Mac address once ip address
by radha bhavani 24 Feb '12

24 Feb '12

Hi, Is there any api available in boost library to get mac addess of the device if ip address is know. Regards, Bhavani

2 1

[MultiIndex] how to rebuild index
by Igor R 24 Feb '12

24 Feb '12

Hello, What's the most simple way to rebuild an index? If elements change without notifying the container, would iterating from begin to end and calling modify() with no-op - do the job? (I remember there already was such a question, but can't find it.) Thanks.

3 3

[asio] Issue with resolver query for 64-bit browsers (IE)
by Jacques, Keiko 23 Feb '12

23 Feb '12

I am writing a browser plugin which needs to get the size of a file using the HTTP HEAD request. In order to send the request I am using the boost socket and the boost::asio::ip::tcp::resolver::query to get the ip address and service port. I am basically using code from the asio sync_client sample provided with Boost 1.48.0. using boost::asio::ip::tcp; boost::asio::io_service io_service; tcp::resolver resolver(io_service); tcp::resolver::query query(hostname, "http"); tcp::resolver::iterator endpoint_iterator = resolver.resolve(query); tcp::resolver::iterator end; This works fine when I run this on a Windows platform (Windows 7) using 32-bit browsers such as Firefox, Chrome, and IE. This also works fine when I run this as a desktop application through a test driver on a Windows (Vista , Windows7)64-bit platform. However, when I run this as a browser plugin on the Windows Vista 64-bit platform using IE (64-bit) it seems to crash on the line: tcp::resolver resolver(io_service); I'm not sure if this is a Boost issue or an IE issue, so I was wondering if anyone knows of any incompatibility issues and/or limitations with Boost and IE (64-bit) which could cause this to happen. Thanks Keiko ________________________________ This e-mail and any attachments may contain confidential material for the sole use of the intended recipient. If you are not the intended recipient, please be aware that any disclosure, copying, distribution or use of this e-mail or any attachment is prohibited. If you have received this e-mail in error, please contact the sender and delete all copies. Thank you for your cooperation.

1 0

REGEX Don't understand the matching behavior: regex_search vs. regex_match
by Andy Falanga (afalanga) 23 Feb '12

23 Feb '12

Hi, I understand enough that regex_match() searches for matches based on the entire input string and apparently regex_search() allows for matches of the expression within the input string (i.e. the expression need not match the entire input string). However, I'm not understanding why the following happened: const char* pInput("Loc info: Channel 2, Target 0, Lun 0"); boost::cmatch found; boost::regex expression(".*Channel ([[:digit:]]{1,3})); // looking for the channel number only if(boost::regex_match(pInput, found, expression, boost::regex_constants::match_partial)) { std::cout << "Matched: " << std::atoi(found[1].first) << std::endl; } When using the above, with regex_match(), the match succeeded but the output string was: "Matched: 0". What?!? If the expression was matched, why did the capture group 1 contain 0? How should the expression have been made? That's what I don't understand. I've found that what I want is accomplished with altering the above thusly: const char* pInput("Loc info: Channel 2, Target 0, Lun 0"); boost::cmatch found; boost::regex expression("Channel ([[:digit:]]{1,3})); // looking for the channel number only if(boost::regex_search(pInput, found, expression)) { std::cout << "Matched: " << std::atoi(found[1].first) << std::endl; } This gives me: "Matched: 2." Which is what I'm looking for. I'd like to understand why regex_match() wasn't giving me what I wanted. Thanks everyone, Andy

2 2