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[multi_index] How to use a class instead of a struct with the boost:multi_index_container? (addendum)
by jamaj 15 Nov '10

15 Nov '10

Hi All, Since I posted the previous message, I made some experiments. First, I changed the employee from struct to class: From struct employee { int id; std::string name; int age; employee(int id_,std::string name_,int age_):id(id_),name(name_),age(age_){} friend std::ostream& operator<<(std::ostream& os,const employee& e) { os<<e.id<<" "<<e.name<<" "<<e.age<<std::endl; return os; } }; to class employee { int id; std::string name; int age; employee(int id_,std::string name_,int age_):id(id_),name(name_),age(age_){} friend std::ostream& operator<<(std::ostream& os,const employee& e) { os<<e.id<<" "<<e.name<<" "<<e.age<<std::endl; return os; } }; I got some errors /home/jamaj/src/wxTestes/multiindexsample/main.cpp|31|error: ‘int employee::id’ is private /home/jamaj/src/wxTestes/multiindexsample/main.cpp|69|error: within this context| typedef multi_index_container< employee, indexed_by< ordered_unique< tag<id>, BOOST_MULTI_INDEX_MEMBER(employee,int,id)>, ordered_non_unique< tag<name>,BOOST_MULTI_INDEX_MEMBER(employee,std::string,name)>, ordered_non_unique< tag<age>, BOOST_MULTI_INDEX_MEMBER(employee,int,age)> > > employee_set; So, I had to change the scope of index class members to public, and it worked: class employee { public: int id; std::string name; int age; employee(int id_,std::string name_,int age_):id(id_),name(name_),age(age_){} friend std::ostream& operator<<(std::ostream& os,const employee& e) { os<<e.id<<" "<<e.name<<" "<<e.age<<std::endl; return os; } }; The question is: is there any other way to do it without exposing all class members? Thanks in advance. Best Regards. José Augusto Jr. jamaj

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[multi_index] How to use a class instead of a struct with the boost:multi_index_container?
by jamaj 14 Nov '10

14 Nov '10

Dear All, I want to use a class instead of a struct to create a multi_index container. But the example that comes with the documention (basic.cpp) uses a struct. Which changes (if there are any) must I make in order to use this container with a class of objects, instead of with structs? Thanks in advance. Best Regards, José Augusto Jr. (jamaj)

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Doubt about using boost:multiindex containers with classes
by José Augusto Jr. 14 Nov '10

14 Nov '10

Dear All, I've written a set of classes. Suppose I have a class called WorkCenter and another called Machine. I created a smart pointer to each Machine object. Each Workcenter has one or more Machines. I could create a vector of MachineSmartPointers. But I will need to search for Machines by some different index keys, like by the unique ID (an Int) or by Tag (a String). I could not find any example like that. In the Boost documentation the example is made with a struct. I know that a class, in C++, is very similar to a Struct. But I dont know how to write this code. Could someone give me a light on this? Thanks in advance. -- sds. Written by - Escrito por: José Augusto M. Andrade Jr. - JamaJ

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Re: [Boost-users] Boost.Random multithreading
by Steven Watanabe 14 Nov '10

14 Nov '10

AMDG On 11/14/2010 7:03 AM, Juan Antonio Farré Basurte wrote: > Are random number generators thread safe? Can I use a random number > generator by multiple threads without explicit locking? No. > I guess the answer is no... Then I wonder if every thread could use a > different instance of the same random number generator without interference > between the different generators. > > I guess the answer is yes for pseudorandom generators. But what about > real random generators? If I have different instances of one, they all have > to access the same source of randomness (maybe hardware). Will they > synchronize transparently? random_device reads from /dev/urandom. I assume that this is safe. In Christ, Steven Watanabe

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boost::asio::buffer exception
by Lloyd Kanakkassery 14 Nov '10

14 Nov '10

Hi, I want to write some data using boost::asio::write(). write() has two arguments, one is the stream to which the data to be written and the other is the data buffer. The data buffer can be created using boost::asio::buffer() function. When I use it this way it works. Then, I have tried to wrap boost::asio::bufffer() in my custom function like this boost::asio::const_buffers_1 MyBuffer(string msg) { return boost::asio::const_buffers_1(boost::asio::const_buffer(msg.c_str(),msg.length())); } The I use this in my asio::write() as booost::asio::write(mySocket, MyBuffer("hai")); This program compiles and runs but it throws an exception called "The system detected an invalid pointer address in attempting to use a pointer argument in a call". I understand that, it is associated with the MyBuffer() function. I have checked it with the buffer() function available in "buffer.hpp". Both are written in the same way, but my function is throwing exception. Could you give some hint? Thanks and Regards, Lloyd

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[fusion] named parameter technique with fusion::map
by alfC 13 Nov '10

13 Nov '10

Hi, After I discovered Boost.Fusion I realize that I can define proper named functions with Boost.Fusion. Named in the sense of instrospection (not in the sense of default user parameters). It was something that is easy to achieve but it was very verbose. I simplified a little bit the syntax but at the end I got stuck just before achieving something useful with this ideas. I need a little help towards the end. using namespace boost::fusion; double H(double p, double q){ // original function for reference return p*p + q*q; } struct p{}; struct q{}; double H(map<pair<p, double>, pair<q, double> > const& args){ return H(at_key(args), at_key<q>(args)); } int main(){ cout << H( map<pair<p, double>, pair<q, double> >( make_pair(1.), make_pair<q>(2.) ) ); return 0; } One question: Why I can not interchange the order of p and q in the last call, after all it is a map at the library could in principle differentiate the pairs? making it possible to call an unordered named parameter. e.g. cout << H( map<pair<p, double>, pair<q, double> >( make_pair<q>(2.), // was p make_pair(1.) // was q ) ); Is it possible to interchange the order to give more flexibility to the user? After a little playing I gladly found that the make_pair is not stricly necesary cout << H( map<pair<p, double>, pair<q, double> >(1.,2.) ); which is a nice improvement. It seems that still there is some redundancy, so I tried cout << H(make_map<p, q>(1.,2.)); and worked! On the side of the function definition I can have an alternative syntax which may be shorter but more difficult to interpret: double H(result_of::make_map<p, q, double, double>::type const& args) { ... } although it is not a great improvement. Second question: Does it occur to anyone how simplify things further? This is nice because *in principle* I can distinguish between the two parameters (strictly speaking is all one big parameter) at compile time via templates. Third question: I say in principle because I am stuck here. For example how can I implement a named parameter bind? It seems to me that I am close to achieving this but I don't know exactly how. What I want is some kind of "bind<H, q>(3.0)" which is a function object that effectively evaluates to H( pvalue, 3.0) or to H(make_map(pvariable), 3.0) when calling bind<H, q>(3.0)(pvalue) or bind<H, q>(3.0)(make_map(pvalue)). Note that the most general case is something that defines partial parameters by a map //if H had four parameters: auto b = my::bind<H, set<q1, q2> >( make_map<q1, q2>(3.0, 4.0) ) ; // or my::make_bind<H>( make_map<q1, q2>(3.0, 4.0) ) // and then use it as b(make_map<p1, p2>(5.0,6.0)); I think this seems to be promising although I need a little push to finish the technique I hope it is useful for someone (if I am not reinventing the wheel) and that we can round up the idea. or just wanted to know some opinions. Thank you, Alfredo (Note, named parameter boost library is not the proper way to go here because the of the level of instrospection I need in the functions, and because the use of named parameters is not to omit passing parameters but to recognize 'externally' certain parameters).

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Re: [Boost-users] Boost.Random Generator ignores seed
by Alex Hagen-Zanker 13 Nov '10

13 Nov '10

> I'm using mt19937 random number generator, belonging to Boost.Random >library, and it looks to ignore my call to seed. > I show relevant code. > > static mt19937 gen; > static MiniUni cien(1, 100); > static variate_generator d100(gen, cien); > > int main() { > { > struct timeval time; > gettimeofday( > gen.seed(time.tv_usec); > } > > And it generates the same sequence over and over. I've double-checked >that time.tv_usec really changes. Could it be that variate_generator d100(gen, cien) defaults to variate_generator<mt19937, MiniUni> d100(gen,cien) whereas you really need variate_generator<mt19937&, MiniUni> d100(gen,cien)? The constructor of the variate_generator now makes a copy of gen and changing the seed of gen afterwards does not affect the variate_generator. Solution: explicitly use variate_generator<mt19937&, MiniUni>(gen,cien). Kind regards, Alex

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Re: [Boost-users] Boost.Random Generator ignores seed
by alfC 13 Nov '10

13 Nov '10

On Nov 13, 2:09 pm, Juan Antonio Farré Basurte <j...(a)tinet.org> wrote: > Hello, > > I'm using mt19937 random number generator, belonging to Boost.Random > library, and it looks to ignore my call to seed. > I show relevant code. > > static mt19937 gen; > static MiniUni cien(1, 100); > static variate_generator d100(gen, cien); > > ..... > > int main() { > { > struct timeval time; > gettimeofday( > gen.seed(time.tv_usec); > } > > .... > > And it generates the same sequence over and over. I've double-checked > that time.tv_usec really changes. > Any help would be appreciated. > Thanks, Try with a negative seed. gen.seed( - time.tv_usec); -- Alfredo

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[serialization][thread] possible regressions? (was: [1.45.0] Beta 1 available from SourceForge)
by Eric Niebler 13 Nov '10

13 Nov '10

I don't know whether this is a serialization issue or a thread issue. Robert, Anthony, can you two weigh in? Eric On 11/11/2010 6:32 AM, Ruediger Berlich wrote: > Hi again, > > here is an update: I have now also tested the behaviour below ("pure virtual > method called; terminate called without an active exception" -> related to > Boost.Serialization) with Boost 1.44 and see the same problem. This does not > happen with 1.43. > > Anyway, I thought it might be important to know that whatever causes this > wasn't introduced with 1.45 but 1.44 (and of course I might be doing > something wrong which only triggers now due to 1.44's changes in the > serialization library). > > Thanks and Best Regards, > Ruediger > > > Ruediger Berlich wrote: >> Dear all, >> here are a few experiences with the beta: >> >> Beman Dawes wrote: >> [...] >>> Please download the beta, give it a try, and report any problems you >>> encounter. >> >> Platform: >> ========= >> Kubuntu 10.10 64 bit, g++ 4.4.5 >> >> Compilation: >> ============ >> Runs mostly smoothely, albeit with many warnings of the type: >> >> [...] >> libs/program_options/src/parsers.cpp:233: instantiated from here >> ./boost/function/function_base.hpp:321: warning: dereferencing type-punned >> pointer will break strict-aliasing rules >> ./boost/function/function_base.hpp:325: warning: dereferencing type-punned >> pointer will break strict-aliasing rules >> [...] >> >> This is not a new situation and has been there with many prior versions. >> It happens in different components. >> >> Compiling a complex application >> =============================== >> (The Geneva library's trunk version, close to version 0.85, see >> http://launchpad.net/geneva ; depends on probably a dozen different boost >> libraries) >> >> In order to get it to compile I hat to make a single change: >> I had to add "#include <boost/serialization/nvp.hpp>" prior to the >> inclusion of the date_time libraries in a single file (out of some 65 >> headers, some of which also include date_time), or else I would get >> messages of the type >> >> /opt/boost145/include/boost/date_time/gregorian/greg_serialize.hpp: In >> function ‘void boost::serialization::save(Archive&, const >> boost::gregorian::date&, unsigned int)’: >> /opt/boost145/include/boost/date_time/gregorian/greg_serialize.hpp:58: >> error: there are no arguments to ‘make_nvp’ that depend on a template >> parameter, so a declaration of ‘make_nvp’ must be available >> >> I _do_ serialize date_time objects in my application. This is new with >> Boost 1.45 (compared with 1.43). >> >> Running the application >> ======================= >> >> When running the application in serial. multithreaded or networked mode >> (Geneva does distributed parametric optimization, but also allows >> multithreaded optimization and has a serial mode for debugging), I get the >> error: >> >> [...] >> 1000: 4.99999977648258e-05 >> End of optimization reached >> Done ... >> pure virtual method called >> terminate called without an active exception >> Aborted >> >> "Done" is printed at the end of main(), so there are only some singletons >> left to clean up, one of which stems from the Boost.Serialization library, >> AFAIK. >> >> Running the application in gdb yields: >> >> /********************************************************/ >> (gdb) up >> #1 0x00007ffff40726b0 in abort () at abort.c:92 >> 92 abort.c: No such file or directory. >> in abort.c >> (gdb) up >> #2 0x00007ffff49126bd in __gnu_cxx::__verbose_terminate_handler() () from >> /usr/lib/libstdc++.so.6 >> (gdb) up >> #3 0x00007ffff4910906 in ?? () from /usr/lib/libstdc++.so.6 >> (gdb) up >> #4 0x00007ffff4910933 in std::terminate() () from /usr/lib/libstdc++.so.6 >> (gdb) up >> #5 0x00007ffff491128f in __cxa_pure_virtual () from >> #/usr/lib/libstdc++.so.6 >> (gdb) up >> #6 0x00007ffff4fc1f16 in >> > boost::serialization::void_cast_detail::void_caster::operator<(boost::serialization::void_cast_detail::void_caster >> const&) const () from /opt/boost145/lib/libboost_serialization.so.1.45.0 >> (gdb) up >> #7 0x00007ffff4fc282d in >> > boost::serialization::void_cast_detail::void_caster::recursive_unregister() >> const >> () from /opt/boost145/lib/libboost_serialization.so.1.45.0 >> (gdb) up >> #8 0x00007ffff4fc2f27 in >> > boost::serialization::void_cast_detail::void_caster_shortcut::~void_caster_shortcut() >> () from /opt/boost145/lib/libboost_serialization.so.1.45.0 >> (gdb) up >> #9 0x00007ffff4fc289f in >> > boost::serialization::void_cast_detail::void_caster::recursive_unregister() >> const >> () from /opt/boost145/lib/libboost_serialization.so.1.45.0 >> (gdb) up >> #10 0x00007ffff72ad64f in >> > boost::serialization::void_cast_detail::void_caster_primitive<Gem::Geneva::GPersonalityTraits, >> Gem::Geneva::GObject>::~void_caster_primitive (this=0x7ffff7bb7e80, >> __in_chrg=<value optimized out>) at >> /opt/boost145/include/boost/serialization/void_cast.hpp:198 >> 198 recursive_unregister(); >> (gdb) up >> #11 0x00007ffff72ad7be in >> > boost::serialization::detail::singleton_wrapper<boost::serialization::void_cast_detail::void_caster_primitive<Gem::Geneva::GPersonalityTraits, >> Gem::Geneva::GObject> >::~singleton_wrapper ( >> this=0x7ffff7bb7e80, __in_chrg=<value optimized out>) >> at /opt/boost145/include/boost/serialization/singleton.hpp:111 >> 111 m_is_destroyed = true; >> (gdb) up >> #12 0x00007ffff40748c0 in __cxa_finalize (d=0x7ffff7baa2d0) at >> cxa_finalize.c:56 >> 56 cxa_finalize.c: No such file or directory. >> in cxa_finalize.c >> (gdb) up >> #13 0x00007ffff7016366 in __do_global_dtors_aux () >> from >> /home/rberlich/geneva-build/src/geneva/libgemfony-geneva.so.0.8.5rc0 >> (gdb) up >> #14 0x0000000000000000 in ?? () >> (gdb) up >> Initial frame selected; you cannot go up. >> /********************************************************/ >> >> Gem::Geneva::GPersonalityTraits is a purely virtual class, marked as such >> with the following code: >> "BOOST_SERIALIZATION_ASSUME_ABSTRACT(Gem::Geneva::GPersonalityTraits)" . >> GObject is the base class of all optimization-related classes. >> >> The exact same code compiles and runs fine with Boost 1.43, the last >> version I have been using excessively. I cannot really comment on Boost >> 1.44 , but would be happy to try if it helps. >> >> Note that the above problem does not seem to have any influence on the >> results of the program. The problems only appear at the very end of the >> execution, when various singletons get destroyed. >> >> Best Regards, >> Ruediger -- Eric Niebler BoostPro Computing http://www.boostpro.com

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Boost::shared_ptr and CPP_UNIT
by Barry79 13 Nov '10

13 Nov '10

Hi there, In my unit test I do something like this - void setup() { m_a = ptr_t(new A()); m_b = ptr_t(new B(m_a)); m_c = ptr_t(new C()); m_b->Register(m_c); } void tearDown() { } I was wondering if I should be implementing anything in tearDown (like calling reset on these shared pointers) where I would normally call delete, and if so, why? Thanks, Barry -- View this message in context: http://boost.2283326.n4.nabble.com/Boost-shared-ptr-and-CPP-UNIT-tp3040738p… Sent from the Boost - Users mailing list archive at Nabble.com.

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bug in date time library? local_microsec_clock::local_time() gives compilation error
by dobrov 12 Nov '10

12 Nov '10

hello Just simple call: boost::local_time::local_microsec_clock::local_time(). gives compilation error in boost header: /usr/include/boost/date_time/microsec_time_clock.hpp:116: error: no matching function for call to 'boost::local_time::local_date_time_base<boost::posix_time::ptime, boost::date_time::time_zone_base<boost::posix_time::ptime, char> >::local_date_time_base(boost::gregorian::date&, boost::posix_time::time_duration&)' I use boost 1.42 and gcc 4.4.5 I have information, that the same problem occurs with boost 1.44 and Sisual Studio. Is it a bug in library? best regards ---------------------------------------------------------------------- Najlepsza wyszukiwarka tanich lotĂłw! SprawdĹź >>> http://linkint.pl/f284a

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Converting between two different enumerations
by John Dlugosz 12 Nov '10

12 Nov '10

I'm looking at a lot of boilerplate code where two different enumerations are used for the same semantic meaning, and a pair of functions (a bit switch statement) converts one to the other. In this case, all the values are #define constants, not typed enumerations. But there are lots of such pairs. I'm wondering if there is a simple "bi-map" class that can take a list of pairs and produce the effect of both functions. If one of the lists of values is consecutive it should be especially easy to initialize. - TradeStation Group, Inc. is a publicly-traded holding company (NASDAQ GS: TRAD) of three operating subsidiaries, TradeStation Securities, Inc. (Member NYSE, FINRA, SIPC and NFA), TradeStation Technologies, Inc., a trading software and subscription company, and TradeStation Europe Limited, a United Kingdom, FSA-authorized introducing brokerage firm. None of these companies provides trading or investment advice, recommendations or endorsements of any kind. The information transmitted is intended only for the person or entity to which it is addressed and may contain confidential and/or privileged material. Any review, retransmission, dissemination or other use of, or taking of any action in reliance upon, this information by persons or entities other than the intended recipient is prohibited. If you received this in error, please contact the sender and delete the material from any computer.

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[BGL] property_map for or with bundled properties
by Cedric Laczny 12 Nov '10

12 Nov '10

Hi, I was trying to use an iterator_property_map with bundled properties and ran into difficulties. For those having thought about that, I want to post my solution and also address a question. Let's start with the solution: Imagine, one uses bundled properties and has defined the following EdgeProperty: struct EdgeProperty{ int edge_index; } and typedef adjacency_list<...> Graph; Whether this makes sense or not may also be discussed but is not important for the demonstration purposes. So if you now want to define an iterator_property_map that is based on the edge_index, it get's IMHO a bit more complicated than using internal properties: typedef property_map<Graph, int EdgeProperty::*>::type EdgeIndexMap; EdgeIndexMap e_index = get(&EdgeProperty::edge_index,g); std::vector< int > flag_vec(num_edges(g), 0); // Create the external property map iterator_property_map< std::vector< int >::iterator, EdgeIndexMap > flags(flag_vec.begin(), e_index); versus an example using vertex_index that is automatically created when using vecS for the vertices: typedef property_map<Graph, vertex_index_t>::type VertexIndexMap; VertexIndexMap v_index = get(vertex_index, g); std::vector< int > flag_vec(num_vertices(g), 0); // Create the external property map iterator_property_map< std::vector< int >::iterator, VertexIndexMap > flags(flag_vec.begin(), v_index); So far for the solution. I have also a question in this place: What does the "EdgeProperty::*" exactly do? The EdgeProperty is of course the bundle, but what about the "::*" is this some sort of RegEx for "all attributes of this bundle"? I looked at the code in properties.hpp and was able to generally understand the idea, but it did not become clear to me why the "::*" is needed. Thank you. Best, Cedric

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boost asio UDP issue...
by The Novice Coder 12 Nov '10

12 Nov '10

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Simulating Multi domain networks in BGL
by giridhar 12 Nov '10

12 Nov '10

Hello All, I need to implement(simulate) Multi domain networks in BGL. I am thinking that each domain will be represented by each single graph. Say if there are 3 domains, then there would be 3 different graphs. And after this, I need to connect few edges of these inter-graphs. Is this good Idea to implement different domains as different graphs or is there any other better method in BGL to do this? -- Regards, Giridhar

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boost::bind memory leak
by bit bit 11 Nov '10

11 Nov '10

I am using a shared_ptr to execute code on method exit as instructed in http://www.boost.org/doc/libs/1_44_0/libs/smart_ptr/sp_techniques.html#on_b… shared_ptr<void> shutdown(static_cast<void*>(0), bind(&Thread::AnnounceShutdown, this, ref(state_lock))); The above line of code causes a memory leak when an exception is thrown inside AnnounceShutdown(). I know I am not supposed to throw inside a destructor, but in this particular case I see no reason for a memory leak. AnnounceShutDown() does not allocate memory. I suspect ref() has something to do with that. debugger report: WARNING: Visual Leak Detector detected memory leaks! ---------- Block 14928 at 0x00000000006E6FF0: 56 bytes ---------- Call Stack: d:\program files\boost\boost_1_44_0\boost\smart_ptr\detail\shared_count.hpp (124): boost::detail::shared_count::shared_count<void * __ptr64,boost::_bi::bind_t<void,boost::_mfi::mf1<void,bIt::Thread,boost::upgrade_lock<boost::shared_mutex> & __ptr64>,boost::_bi::list2<boost::_bi::value<bIt::Thread * __ptr64>,boost::reference_wrapper<boos d:\program files\boost\boost_1_44_0\boost\smart_ptr\shared_ptr.hpp (199): boost::shared_ptr<void>::shared_ptr<void><void,boost::_bi::bind_t<void,boost::_mfi::mf1<void,bIt::Thread,boost::upgrade_lock<boost::shared_mutex> & __ptr64>,boost::_bi::list2<boost::_bi::value<bIt::Thread * __ptr64>,boost::reference_wrapper<boost::upgrade d:\ptyxiaki\owner\owner\thread\thread.cpp (690): bIt::Thread::Main ... .. . I have already resolved this issue using BOOST_SCOPE_EXIT instead of shared_ptr, but I am looking forward for a better solution with shared_ptr.

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Hashtable
by Ricardo Uribe Lobello 11 Nov '10

11 Nov '10

Good afternoon, I have been trying to use the boost::intrusive::hashtable class but i don't understand clearly how it works. Additionally, I would like to change the hashing function used. Where can i get some example of the hashtable usage? Thanks in advance Ricardo

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[1.45.0] Beta 1 available from SourceForge
by Beman Dawes 11 Nov '10

11 Nov '10

Boost release1.45.0 beta 1 is now available from SourceForge. For those who downloaded release candidate 1, note that beta 1 was build from a slightly later release candidate. See http://sourceforge.net/projects/boost/files/ This release contains numerous enhancements and bug fixes for existing libraries. For details of what's in the release, see http://beta.boost.org/users/news/version_1_45_0. Note that the links to files on this web page are for the final release - use the SourceForge link above to get the beta files. Please download the beta, give it a try, and report any problems you encounter. There are still a few serious bugs outstanding, and we will be working on clearing those before the final release. Thanks, -- The Boost Release Team

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[date_time][1.45] added missing includes (was: [1.45.0] Beta 1 available from SourceForge)
by Eric Niebler 11 Nov '10

11 Nov '10

On 11/10/2010 2:46 PM, Ruediger Berlich wrote: > In order to get it to compile I hat to make a single change: > I had to add "#include <boost/serialization/nvp.hpp>" prior to the inclusion > of the date_time libraries in a single file This seems pretty cut-n-dry. I hope nobody minds, but I went ahead and added the missing #include to gregorian/greg_serialize.hpp and posix_time/time_serialize.hpp on both trunk and release. -- Eric Niebler BoostPro Computing http://www.boostpro.com

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[BGL] Question on dijkstra-example.cpp
by Cedric Laczny 11 Nov '10

11 Nov '10

Hello, could you please explain what this code in the dijkstra-example (http://www.boost.org/doc/libs/1_44_0/libs/graph/example/dijkstra-example.cpp) exactly does? predecessor_map(&p[0]).distance_map(&d[0]) I understand the non-named-parameter version, but the combination of predecessor_map with distance_map is not so obvious to me. What does the "." do there? Do I get it right, that the predecessor_map or distance_map, respectively, automatically wrap the vectors p and d into iterator_property_maps? Thank you. Best regards, Cedric

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[iostreams] Problem with gzip_decompressor
by 陳韋任 11 Nov '10

11 Nov '10

Dear all, Some compressed data was stored in a vector<char> buf (don't know if it's a right way to store compressed data). I used the "buf" as a source, and tried to add a gzip_decompressor to restore those data. I have tried the following approach, but it doesn't work. vector<char> buf; /* fill in the buf */ namespace io = boost::iostreams; io::filtering_istream in(boost::make_iterator_range(buf)); in.push(io::gzip_decompressor()); What I got is an exception, terminate called after throwing an instance of 'boost::exception_detail::clone_impl<boost::exception_detail::error_info_injector <std::logic_error>>' what(): chain complete Aborted How can I compose a source which comes from a container, and add a gzip_decompressor to the source? Thanks in advance. Regards, chenwj -- Wei-Jen Chen (陳韋任) Programming Language and System Laboratory (EC131) Department of Computer Science, National Chiao Tung University

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[fusion] Using fusion::at_c on a sequence or an unused type
by teajay 10 Nov '10

10 Nov '10

Hi, I'm working on finalizing an extension to spirit/qi in which I need to extract an attribute from a fusion sequence in a parser context. The problem I'm facing is that this parser attribute can be an unused type or a valid fusion sequence. Just to illustrate my problem: template <typename Elements,typename Attribute> struct parser_dispachter { template <typename Index> void parse(Index &idx, Attribute &attr) { fusion::at_c<Index::value>(Elements).parse(fusion::at_c<Index::value>(attr)); } }; I actually have two cases: 1. Attribute = unused_type -> at_c replacement should return unused 2. Attribute = fusion sequence -> at_c replacement should return the corresponding attribute reference. What would be the best solution to extract the give attribute ? Regards, Thomas Bernard

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[build] installing layout=versioned into same 'prefix'
by Joe Steeve 10 Nov '10

10 Nov '10

Hello, I am doing this on Debian GNU/Linux. When installing with --layout=versioned, boost.Build creates symlinks without 'version tag' to libraries with version-tag in their name. This, IMHO, defeats the purpose of --layout=versioned. These symlinks collide with existing layout=system installation, in the same prefix. Is there any way to avoid this? Regards, Joe -- Joe Steeve HiPro IT Solutions Pvt. Ltd. http://hipro.co.in/ -- Joe Steeve HiPro IT Solutions Pvt. Ltd. http://hipro.co.in/

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[BFL] Efficient neighbourhood search in trees
by Vincent Spruyt 10 Nov '10

10 Nov '10

Hi all, I'm trying to calculate the average edge weight within a certain neighbourhood for each vertex in a tree. Basically, I have a (minimum spanning) tree and I want to remove all edges whose weight is much larger than the weight of edges closeby. The result would be a forrest of several connected components (I'm working on a clustering algorithm). Currently I naively iterate over each edge. For each edge, I find the source and target vertex. Then, for both the source and the target vertices, I calculate the average weight in a certain neighbourhood using a recursive function as following simplified pseudocode indicates: E: List of edges in MST getNeighbourhoodStats( depth, startvertex, edge ){ out_edges = getIncedentEdges(startvertex) foreach out_edges as out if( out!=edge){ totweight += getWeight(out); if(depth>0) getNeighbourhoodStats(depth-1, target(out), out) } end } main(){ foreach E as e //Get the total weight on the left of the edge int totweight_left=0; getNeighbourhoodStats( 5, source( e), E, totweight_left ) //Get the total weight on the right of the edge int totweight_right=0; getNeighbourhoodStats( 5, target( e), E, totweight_right ) end } However, this approach is rather inefficient as a lot of calculations are redundant (takes about 10ms for 300 edges which is way too slow for the purpose I had in mind). Any ideas for a better solution? Tnx a lot, Kind regards, Vincent

3 4

[Program Options] Positional args in help message
by Lindley M French 10 Nov '10

10 Nov '10

The examples for how to use positional arguments are great and seem to work fine. However, I'm wondering if there's an automatic way to include that information in the help message. In particular, since the tutorial goes to the trouble of telling you how to exclude the positional options from the options help, it would be nice to know what to replace it with. I could manually write a line detailing the usage before outputting the options description, of course, but I was wondering if there was anything in PO to handle this automatically.

3 2

[fusion] simple Fusion question
by Eric Niebler 10 Nov '10

10 Nov '10

Given an mpl::vector of keys, and a fusion::vector of values, what's the easiest way to create a fusion::map? The obvious solution of just zipping the two sequences and passing the result to fusion::as_map doesn't work because as_map (somewhat narrowly) requires all elements to be fusion::pair, and Fusion's zip algorithm produces sequences of vector2. I'd like to see this generalized so that (a) as_map only requires sequences of 2-tuples and (b) fusion::pair meets the requirements for 2-tuples. -- Eric Niebler BoostPro Computing http://www.boostpro.com

3 4

Boost Hashtable
by Ricardo Uribe Lobello 10 Nov '10

10 Nov '10

Good afternoon, I have been trying to use the boost::intrusive::hashtable class but i don't understand clearly how it works. Additionally, I would like to change the hashing function used. Where can i get some example of the hashtable usage? Thanks in advance Ricardo

1 0

[fusion] conversion from map *values* to vector
by alfC 09 Nov '10

09 Nov '10

I have a general fusion map for example map< pair<p, double> , pair<q, double> > if I use as_vector I get vector<pair<p, double> , pair<q, double> > is there a function that given the map converts it into vector<double, double> i.e. gives a vector with only the values of the key and not the keys/ value pair? Thank you, Alfredo

2 1

Boost 1.44.0 on a IBM P575 Power6 (AIX 6.1, XL C/C++ v10.1)
by Carmine Paolino 09 Nov '10

09 Nov '10

Hello, someone managed to compile Boost 1.44.0 on AIX with XL v10? We are currently working on a massively parallel network analyzer that uses the Parallel Graph Library, so getting it working on a cluster such as this it's fundamental. For more informations see this bug #4828 (https://svn.boost.org/trac/boost/ticket/4828) Any help will be appreciated, thanks in advance.

2 1

Re: [Boost-users] circular_buffer, debug and invalid iterator checking
by Jan Gaspar 09 Nov '10

09 Nov '10

Hi Antony, If you a problem only with iterator invalidation (which works in debug mode only) you can disable it completely. The documentation says: The debug support is enabled only in the debug mode (when the NDEBUG is not defined). It can also be explicitly disabled (only for circular_buffer) by defining BOOST_CB_DISABLE_DEBUG macro. Regards, Jan On 6 Nov 2010, at 01:17, Anthony Foglia <afoglia(a)princeton.com> wrote: The invalid iterator checking in the circular_buffer library is excessively strict. It checks not when an iterator is dereferenced, but whenever any operator involving that iterator is used. I have an class defined to keep the last few data points, up to either a maximum number, or some condition on the stored data (e.g. the sum must be below a threshold) is met. So I figured I'd store the data in a circular buffer, and push new data onto the front, and store my own iterator into it to use as the end. If my end iterator is pointing to the next to last element in the buffer, when a new item is pushed onto the front of the circular buffer, that iterator becomes invalid. But that's not a problem for me, because I don't read past it. _Except_ the validity of the iterator is checked even when using it in operator== (and other iterator comparison operators), so my lopp condition tests now throw because the end of my ranges are no longer valid. Why isn't iterator invalidation only checked on dereferencing? Is there any suggested convention for changing my code to work under debug? I would try checking for BOOST_CB_ENABLE_DEBUG and catching these cases before the push_front occurs, but that macro is undefined at the end of the header. Or I could try something more complicated without the macro check, such as storing my ends in reverse iterators, and converting them whenever I need to do comparisons, though that is rather painful. I've attached a simple example which demonstrates the problem, not that it fails when the distance from my_end to end and the next element is pushed into the front. -- Anthony Foglia Princeton Consultants (609) 987-8787 x233 <circular_buffer_test.cpp> _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

2 2

[Proto] First steps
by Luc Danton 09 Nov '10

09 Nov '10

Hello everyone, I've been meaning to learn to use Boost.Proto for quite some time and I've finally started getting my hands dirty in code ever since that fantastic video from BoostCon 2010. After the usual exercises that are presented in it and the docs, I've set up my own goal of trying to write composable futures (something that I think quite a lot of people have been doing in their own time). You can see the code at http://pastebin.com/DW4LckMP and I'd welcome comments on what I've been doing wrong and how I could improve the design. I also welcome answers to my following questions: * regarding copying, the docs present the following example: auto sum = boost::proto::lit(1) + 2; here, since the 1 is held by a reference which will outlive (in the variable sum) the actual literal expression (in the call to proto::lit) we will have UB. To avoid this exact problem, and since Boost.Proto is not move aware and std::future is move-only, my terminals are actually of the form: future_expresion<typename boost::proto::terminal<std::future&>::type> (where future_expression is the expression wrapper). Can I do this? Obviously I still have a problem if I do: std::future<int> fint = ... auto sum = ns::compose(fint) + 3; // then use sum.get() don't I? I can't solve it by using proto::deep_copy since std::future is move-only (apparently my terminals get stripped of their reference). This means that the 'correct' way of doing the above would be std::future<int> fint = ... auto const operand = 3; auto sum = ns::compose(fint) + operand; // use sum.get() thus separating lifetimes from computations (expression trees, really). * the following doesn't compile: struct local { int method() { return 1; } int method() const { return 2; } }; auto method = (int (local::*)()) &local::method; auto cmethod = (int (local::*)() const) &local::method; auto f1 = std::async([] { return local(); }); auto f2 = std::async([] { return local(); }); auto r1 = (ns::compose(f1)->*cmethod)(); // this line OK auto r2 = (ns::compose(f2)->*method)(); // Not OK! assert( r1.get() == 2 && r2.get() == 1 ); ( you can replace the above in main() instead of the previous ) Apparently the problem is an attempt to convert a pointer to const local to a pointer to non-const local. Invoking cmethod instead (with the appropriate assertion) is fine. I've checked that the result of ns::compose(f1).get() is indeed a local and not a const local via static_assert. This is using Boost 1.42. Any idea?

2 2

segfault using boost test
by David M. Lee 09 Nov '10

09 Nov '10

I'm consistently getting segfaults trying to use boost test on my Mac. The test works fine on Linux. This is Mac is running Snow Leopard. I compiled boost using Homebrew (http://mxcl.github.com/homebrew/; seehttps://github.com/mxcl/homebrew/blob/master/Library/Formula/boost.rb for the build formula), but I've also tried building Boost myself with the same results. Any help figuring this out would be greatly appreciated! Here's the test I'm running: #define BOOST_TEST_MODULE simple #include <boost/test/included/unit_test.hpp> BOOST_AUTO_TEST_CASE(testSimple) { BOOST_CHECK_EQUAL(true, true); } Here's the backtrace: Program received signal EXC_BAD_ACCESS, Could not access memory. Reason: KERN_INVALID_ADDRESS at address: 0x0000000000000000 0x0000000100265ccc in boost::unit_test::framework::get () (gdb) bt #0 0x0000000100265ccc in boost::unit_test::framework::get () #1 0x0000000100270855 in boost::unit_test::results_collector_t::assertion_result () #2 0x00000001000242cf in boost::unit_test::framework::assertion_result () #3 0x00000001000262a6 in boost::test_tools::tt_detail::check_impl () #4 0x000000010006aa01 in boost::test_tools::tt_detail::check_frwd<boost::test_tools::tt_detail::equal_impl_frwd, bool, bool> () #5 0x0000000100026409 in testSimple::test_method () #6 0x0000000100026468 in testSimple_invoker () #7 0x000000010004056d in boost::unit_test::ut_detail::invoker<boost::unit_test::ut_detail::unused>::invoke<void (*)()> () #8 0x0000000100040591 in boost::unit_test::ut_detail::callback0_impl_t<boost::unit_test::ut_detail::unused, void (*)()>::invoke () #9 0x000000010005bf38 in boost::unit_test::callback0<boost::unit_test::ut_detail::unused>::operator() () #10 0x0000000100014698 in boost::unit_test::(anonymous namespace)::zero_return_wrapper_t<boost::unit_test::callback0<boost::unit_test::ut_detail::unused> >::operator() () #11 0x00000001000146b9 in boost::unit_test::ut_detail::invoker<int>::invoke<boost::unit_test::(anonymous namespace)::zero_return_wrapper_t<boost::unit_test::callback0<boost::unit_test::ut_detail::unused> > > () #12 0x00000001000146d9 in boost::unit_test::ut_detail::callback0_impl_t<int, boost::unit_test::(anonymous namespace)::zero_return_wrapper_t<boost::unit_test::callback0<boost::unit_test::ut_detail::unused> > >::invoke () #13 0x000000010005c65c in boost::unit_test::callback0<int>::operator() () #14 0x000000010005c6a7 in boost::detail::do_invoke<boost::scoped_ptr<boost::detail::translate_exception_base>, boost::unit_test::callback0<int> > () #15 0x00000001000206f1 in boost::execution_monitor::catch_signals () #16 0x00000001000218da in boost::execution_monitor::execute () #17 0x00000001000240a0 in boost::unit_test::unit_test_monitor_t::execute_and_translate () #18 0x000000010006b78d in boost::unit_test::framework_impl::visit () #19 0x0000000100008b2e in boost::unit_test::traverse_test_tree () #20 0x0000000100023753 in boost::unit_test::traverse_test_tree () #21 0x00000001000233a8 in boost::unit_test::traverse_test_tree () #22 0x000000010002376a in boost::unit_test::traverse_test_tree () #23 0x000000010002aad6 in boost::unit_test::framework::run () #24 0x000000010002ae39 in boost::unit_test::unit_test_main () #25 0x000000010002b0c2 in main () Thanks! dave <>< -- David M. Lee Digium, Inc. | Software Developer 445 Jan Davis Drive NW - Huntsville, AL 35806 - USA Check us out at: www.digium.com & www.asterisk.org

2 4

[Boost 1.44][BGL] Compiling error with MinGW
by Florian.PONROY＠fr.thalesgroup.com 09 Nov '10

09 Nov '10

Hi folks, My C++ Windows/Linux project used to compile properly using the following items: * Boost 1.33.1, using BGL, Serialization, Thread ; * GNU g++ 4.1.2 under Linux ; * MinGW 3.4.5 under Linux (cross-compiling). I recently updated my Boost distribution to version 1.44. Unfortunately, I now have the following BGL/linking error compiling with MinGW : /path/to/liblocd_topology_manager.a(locTopology.o):locTopology.cpp:(.rdata$_ ZZN5boost3putINS_26vec_adj_list_vertex_id_mapINS_8propertyINS_13vertex_root_ tEiNS_11no_propertyEEEjEEEEvRKNS_17two_bit_color_mapIT_EENS_15property_trait sIS8_E8key_typeENS_18two_bit_color_typeEE17elements_per_char+0x0): multiple definition of `_elements_per_char' /path/to/liblocd_topology_manager.a(locTopology.o):locTopology.cpp:(.rdata$_ ZZN5boost3putINS_26vec_adj_list_vertex_id_mapINS_8propertyINS_13vertex_root_ tEiNS_11no_propertyEEEjEEEEvRKNS_17two_bit_color_mapIT_EENS_15property_trait sIS8_E8key_typeENS_18two_bit_color_typeEE17elements_per_char+0x0): first defined here I've checked the //www.boost.org/doc/libs/1_44_0/libs/graph/doc/trouble_shooting.html webpage, but I haven't seen any answer related to my problem. For sure, the MinGW compiler version we use is pretty old. Since updating it would be very cumbersome in our case, I would like to be sure it's actually a compiler issue. Thanks in advance for your advice. Best regards, -- Florian PONROY Thales Land & Joint France Tel. : +33(0)1 41 304 363 Fax : +33(0)1 41 303 907 Email : florian.ponroy(a)fr.thalesgroup.com

2 1

FW: Build boost win MinGW ?
by krys＠polarlights.net 09 Nov '10

09 Nov '10

Hi, I'm trying to use Boost 1.44 with QT Creator for this I have try this : 1 - download boost 1.44 from the Boost web site, and unzip it 2 - download the bjam.exe and copy it in the root of boost 3 - run the following command : d:\Boost\boost_1_44_0>bjam stage --build-type=complete --build-dir="d:\Boost144\ build" --toolset=gcc --stagedir="d:\Boost144" But I got the following errors : d:\Boost\boost_1_44_0>bjam stage --build-type=complete --build-dir="d:\Boost144\ build" --toolset=gcc --stagedir="d:\Boost144" notice: could not find main target stage notice: assuming it is a name of file to create. D:/Boost/boost_1_44_0/tools/build/v2/build\project.jam:737: in attribute warning: rulename $($(project).attributes).get expands to empty string D:/Boost/boost_1_44_0/tools/build/v2/build\project.jam:749: in project.target D:/Boost/boost_1_44_0/tools/build/v2\build-system.jam:707: in load d:\Boost\boost_1_44_0\tools\build\v2/kernel\modules.jam:283: in import d:\Boost\boost_1_44_0\tools\build\v2\kernel\bootst rap.jam:142: in boost-build d:\Boost\boost_1_44_0\boost-build.jam:17: in module scope D:/Boost/boost_1_44_0/tools/build/v2/build\project.jam:737: in project.attribute warning: rulename $($(project).attributes).get expands to empty string D:/Boost/boost_1_44_0/tools/build/v2/build\targets.jam:206: in object(project-ta rget)(a)43.__init__ D:/Boost/boost_1_44_0/tools/build/v2/kernel\class.jam:88: in new D:/Boost/boost_1_44_0/tools/build/v2/build\project.jam:749: in project.target D:/Boost/boost_1_44_0/tools/build/v2\build-system.jam:707: in load d:\Boost\boost_1_44_0\tools\build\v2/kernel\modules.jam:283: in import d:\Boost\boost_1_44_0\tools\build\v2\kernel\bootst rap.jam:142: in boost-build d:\Boost\boost_1_44_0\boost-build.jam:17: in module scope :/Boost/boost_1_44_0/tools/build/v2/build\project.jam:737: in project.attribute warning: rulename $($(project).attributes).get expands to empty string D:/Boost/boost_1_44_0/tools/build/v2/build\targets.jam:226: in object(project-ta rget)(a)43.get D:/Boost/boost_1_44_0/tools/build/v2\build-system.jam:720: in load d:\Boost\boost_1_44_0\tools\build\v2/kernel\modules.jam:283: in import d:\Boost\boost_1_44_0\tools\build\v2\kernel\bootst rap.jam:142: in boost-build d:\Boost\boost_1_44_0\boost-build.jam:17: in module scope D:/Boost/boost_1_44_0/tools/build/v2\build-system.jam:721: in load *** argument error * rule project.load ( jamfile-location ) * called with: ( ) * missing argument jamfile-location D:/Boost/boost_1_44_0/tools/build/v2/build\project.jam:53:see definition of rule 'load' being called d:\Boost\boost_1_44_0\tools\build\v2/kernel\modules.jam:283: in import d:\Boost\boost_1_44_0\tools\build\v2\kernel\bootst rap.jam:142: in boost-build d:\Boost\boost_1_44_0\boost-build.jam:17: in module scope Do you have an idea to solve my problem and build boost please ? Thx

1 0

[Fusion] functor fused and unfused at the same time
by alfC 09 Nov '10

09 Nov '10

Hi, I have an internally generated templated functor that naturally takes fusion sequences. since this function can also be called by the user I want to make it also "unfused" For example, the struct is struct F{ typedef result_of::make_map::type mapped_arguments; template<class Args> struct result{ typedef double type; }; double operator()(mapped_arguments const& args) const{ return at_key(args) + at_key<q>(args); } }; and can be called as F f; f(make_map<p,q>(one, two)); (I need this because of internal conventions of the library) but I want it to be also called as f(one, two); // somehow (I need this because the user can call it) I tried this struct F : unfused<F const&>{ typedef result_of::make_map::type mapped_arguments; template<class Args> struct result{ typedef double type; }; double operator()(mapped_arguments const& args) const{ return at_key(args) + at_key<q>(args); } }; but I get: usr/include/boost/utility/result_of.hpp:80: error: invalid use of incomplete type ‘const struct F’ I then tried this struct F_impl{ typedef result_of::make_map::type mapped_arguments; template<class Args> struct result{ typedef double type; }; double operator()(mapped_arguments const& args) const{ return at_key(args) + at_key<q>(args); } }; struct F : F_impl, unfused<F_impl const&>{ F() : unfused<F_impl const&>((F_impl const&)*this){} F(F_impl const& f) : F_impl(f), unfused<F_impl const&>((F_impl const&)*this){} template<class Args> struct result{ typedef typename F_impl::result<Args>::type type; }; using F_impl::operator(); }; which seems to work but looks and feels awkward. It works in the sense that F f; can be called clog << f(make_map<p,q>(1.,2.)) << endl; clog << fu(uno, dos) << endl; Is there any simpler way to get this. Thank you, Alfredo

1 1

[asio] __sync_lock_test_and_set problem, cross-compiling for ARM
by Igor R 09 Nov '10

09 Nov '10

Hello, I'm trying to cross-compile my project for Android (Win, cygwin, crystax-ndk). The linker emits the following error: ../asio/detail/gcc_fenced_block.hpp:41: undefined reference to `__sync_lock_test_and_set_4' I understand that in 1.44 I can disable this "fenced-block" by defining BOOST_ASIO_DISABLE_FENCED_BLOCK, but I'm not sure it's safe to do this. IUUC, __sync_lock_test_and_set gcc function is unavailable for some older arm-based platforms, but should be available for the newer ones, shouldn't it? So maybe I have to define some compiler flag to enable it? I'd appreciate any idea. Thanks.

2 1

[fusion][Functional] LValue arguments limitation
by alfC 09 Nov '10

09 Nov '10

Fusion manual says: Only LValue arguments are accepted. To overcome this limitation, apply Boost.Functional/Forward. I understand that this has to do with not being able to pass literal constants to the function, e.g. unfused<f> uf; uf(1., 2.); //can't First: 1) can anybody explain why is this? 2) uf( (double const&) 1., (double const&) 2. ); seems to work, but it is probably a hack. (not portable maybe?) 3) the manual says also to use Boost.Functional/Forward to overcome this limitation. What does it mean by this? Thank you, Alfredo

3 2

unable to load the module from simple example
by Cuma Tyszkiewicz 09 Nov '10

09 Nov '10

Hello I have followed the simple example from the python boost wiki page: my source file py_moddef.cc: ___________________________________________ #include <string> #include <boost/python.hpp> char const* greet() { return "hello, world"; } BOOST_PYTHON_MODULE(hello_ext) { using namespace boost::python; def("greet", greet); } ____________________________________________ In the next step I have built the shared library 1. g++ -c -fpic -I/usr/include/python2.6/ py_moddef.cc 2. ld -G py_moddef.o -o libpy_moddef.so The libpy_moddef.so file I have copied to the directory which next was included to PYTHONPATH >>> import sys >>> sys.path.append("the_path") I am not able to import the module "hello_ext" defined in py_moddef.cc, but I am able to import each other python module from this path, so something wrong is with the shared library. >>> import hello_ext ImportError: No module named hello_ext Please explain to me what is wrong. I will be gratefull for any help. Best regards Cuma

2 1

[xpressive] Using it with input iterators or how far the backtracing will go back
by Alex Dubov 09 Nov '10

09 Nov '10

Greetings. There exists a fairly common need to apply regexp matching to streams, rather than to blocks of data. Streams are represented by input iterators, which have no ability to decrement their value. On the other hand, xpressive requires a bidirectional iterator, to go back and forth as required by backtracking (if I understand correctly). One approach to work around this limitation is to create an iterator adapter, which will store a copy of every character delivered by input iterator and provide expressive with bidi iterator to work with. So the question is, how can one establish the size for this iterator adapter's internal storage so as to avoid match failures due to incomplete storage and avoid storing too much unnecessary data? I suppose, the storage can be reset when the match is reported. This, however, still leaves an open problem for situations where matches are separated by, possibly, gigabytes of non-matching data. Alternatively, may there be a way to relax the iterator requirements of the xpressive library itself? If xpressive could be made to store partial match data within its data structures, bidi iterators would not be strictly necessary. Thanks.

6 12

[GIL] any_image difference
by Olivier Tournaire 08 Nov '10

08 Nov '10

Hi all, What is the best way to compute the difference between 2 any_image? Of course, the input any_image may not be of the same type... So, if pixels are unsigned int for the 1st one and double for the 2nd one, the result must be stored as double. I (accidently) found pixel_minus_t in pixel_numeric_operations.hpp but cannot figure how to use it. Hope you could help. Regards, Olivier

2 6

signals2::slot_type & g++ anti-aliasing warning
by Ákos Maróy 08 Nov '10

08 Nov '10

Hi, I bumped into an issue, where g++ would give me an anti-aliasing warning for very basic / straightforward signals2 code. consider the following sample code: #include <iostream> #include <boost/bind.hpp> #include <boost/signals2.hpp> typedef boost::signals2::signal<void (void)> sig_t; void ff(void) { std::cout << "ff" << std::endl; } int main(void) { sig_t::slot_type ss = boost::bind(&ff); return 0; } when compiled with the -Wall and -O2 flags, I get the following compiler warning: ... sample.cxx:13: instantiated from here /home/maroy/src/mxp/usr/include/boost/function/function_base.hpp:321: warning: dereferencing type-punned pointer will break strict-aliasing rules /home/maroy/src/mxp/usr/include/boost/function/function_base.hpp:325: warning: dereferencing type-punned pointer will break strict-aliasing rules (I can provide the full compiler output if needed) this is with boost 1.44 on a linux x86_64, g++ version 4.4.3 omitting either the -O2 or the -Wall flags will make the warning go away. what am I doing wrong? Akos

3 4

[polygon] Valgrind errors when normalizing any angle polygons
by Josh Pieper 08 Nov '10

08 Nov '10

Hello, We have been using the 1.44.0 release of polygon for some internal projects and have come across a number of oddities. The first one I've got is a valgrind error when normalizing polygons with numerically large coordinate values. Using the gmp_override.hpp header does resolve these problems, but my understanding is that it is the intent for the library to merely be numerically imprecise, rather than crash, for coordinates which are too large. Our simplified test case is below, and was compiled on an AMD64 Ubuntu 10.4 system. The first call to Normalize has no problems, but the second call causes valgrind to report both uninitialized memory usage and invalid reads. (I can produce the valgrind log on demand, but it is somewhat large for inclusion in an email). While we have deployed 1.44.0 internally, I tested against the most recent svn version and the problem still exists. Is this merely a mis-use of the API? Regards, Josh Pieper ------------------------ #include <stdint.h> #include "boost_polygon/r66294/polygon/polygon.hpp" typedef boost::polygon::point_data<int32_t> BoostPoint; typedef boost::polygon::polygon_data<int32_t> BoostPolygon; typedef boost::polygon::polygon_set_data<int32_t> BoostPolygonSet; typedef boost::polygon::polygon_with_holes_data<int32_t> BoostPolygonWithHoles; typedef std::vector<BoostPolygonWithHoles> BoostPolygonWithHolesVector; template <typename Array> void Normalize(const Array& data, int32_t scale) { std::vector<BoostPoint> points; for (size_t i = 0; i < sizeof(data) / sizeof(*data); i += 2) { points.push_back(BoostPoint(data[i] / scale, data[i + 1] / scale)); } using namespace boost::polygon::operators; BoostPolygonSet poly_set; poly_set |= BoostPolygon(points.begin(), points.end()); BoostPolygonWithHolesVector normal; poly_set.get(normal); } int main() { int32_t data[] = { 0, 0, -1000000, -1000000, 19000000, -1000000, 18292893, 707106, 8292893, -9292893, 8170784, -9440890, 8078584, -9610754, 8000000, -10000000, 8078584, -10389245, 8170784, -10559109, 8292893, -10707106, 18292893, -20707106, 19000000, -19000000, -1000000, -19000000, 0, -20000000, 0, 0, }; Normalize(data, 10); // Fine. Normalize(data, 1); // Crashes. }

2 5

multi_array and variants
by Alle Meije Wink 08 Nov '10

08 Nov '10

Dear all, This still seems to be a problem that every once in a while someone tries to solve and then stops. It's my turn again... I'm trying to make a wrapper template class for 1,2,...8-dimensional images whose values can be char,short,...double to store brain image statistics. I had a go at this before and followed the suggestions described here http://lists.boost.org/boost-users/2009/08/50732.php What I now have is a class bisArray: ... template<typename T> class bisArray: public bisObject { typedef boost::variant < boost::multi_array_ref<T, 1>, boost::multi_array_ref<T, 2>, boost::multi_array_ref<T, 3>, boost::multi_array_ref<T, 4>, boost::multi_array_ref<T, 5>, boost::multi_array_ref<T, 6>, boost::multi_array_ref<T, 7>, boost::multi_array_ref<T, 8>, boost::multi_array_ref<T, 9> > bisArray_t; bisArray_t _bisArray; ... and a class bisImage, which has a bisArray as well as a pointer to the data as read from file (1-dimensional structure): ... template<typename T> class bisImage: public bisObject { public: /** Constructor using existing array data Reformats array as bisImage */ bisImage ( T* _data, size_t _dimensions, std::vector<size_t> _sizes ): data(_data), dimensions(_dimensions) { this.storage=bisArray<T>( _data, _dimensions, _sizes); this.dummy = T(); } ... When I try to initialise an image read from file using ... bisImage<unsigned char> newimage=bisImage<unsigned char> ((unsigned char *)testimage->data, ndim, dims); ... I get, as the first of many errors, this message bisimage.hpp|33|error: no matching function for call to ‘canabis::bisArray<unsigned char>::bisArray()’| That seems to suggest that I call an empty (default) constructor, which I don't do *anywhere* Has anyone ever tried to do something similar? Or do you have any thought about what I am doing wrong here? Is it multi_array complaining or variants? Many thanks Alle Meije

2 1

boost MPI issue on windows
by Nick Collier 08 Nov '10

08 Nov '10

Hi, I've got an MPI application that uses the boost mpi libraries. It runs fine on OSX and Linux when compiled using both debug and more optimized compiler flags. Unfortunately, on windows, the application only runs when compiled using Visual Studio 2008 debug configuration. When I run the executable compiled in the release configuration it crashes, but not in the same place every time in my code. It does only occur though when I make communicator::send and communicator::recv calls, sending and receiving vectors of ints. In those cases, I get exceptions like: {routine_=0x00d37d38 "MPI_Send" result_code_=805931010 message="MPI_Send: Invalid count, error stack: MPI_Send(176): MPI_Send(buf=0x001BF950, count=-1833296, MPI_PACKED, dest=1, tag=2001, MPI_COMM_WORLD) failed MPI_Send(101): Negative count, value is -1833296" } Sometimes its for a send and sometimes for a receive, but the exception is always for a "negative count" which looks suspiciously like an uninitialized integer. I figured I'm doing something wrong either in how I've compiled the boost libraries or in my own code (although its odd that it works in both linux and osx). Any suggestions obviously appreciated. This is for boost-1.39. We are prevented from using anything newer because the machine we ultimately deploy on has boost-1.39 installed. On windows, I'm using microsoft's mpi implementation (based on MPICH2) under windows 7. The boost mpi libraries are compiled in both static debug and release mt versions. thanks very much, Nick

6 31

[BGL] Unable to sort list of edge_descriptors
by Mike Douglass 08 Nov '10

08 Nov '10

I'm trying to sort a list of edge_descriptors, but I get the compiler error described below. typedef adjacency_list < vecS, vecS, bidirectionalS >::edge_descriptor edgeDescriptor; // defined globally template < typename Graph, typename edgeDescriptor > struct SortByName : public binary_function<edgeDescriptor, edgeDescriptor, bool> { bool operator()(const Graph & g, const edgeDescriptor& a, const edgeDescriptor& b) { return g[a].eName < g[b].eName; } }; template < typename Graph > void Sort_Test(Graph & g) { typedef std::list<edgeDescriptor> edge_list; typename graph_traits<Graph>::edge_iterator edge_iter, edges_end; edge_list A; for (tie(edge_iter, edges_end) = edges(g); edge_iter != edges_end; ++edge_iter) A.push_back(*edge_iter); for (edge_list::iterator i = A.begin(); i != A.end(); ++i) cout << " *i = " << " " << g[*i].eName << "\n"; // If the following line is commented out the program compiles and runs OK. A.sort(SortByName< typename Graph, typename edgeDescriptor >()); //With the above line uncommented the compiler says: /* ./Includes/Utilities.cpp: In function ‘void Sort_Test(Graph&)’: ./Includes/Utilities.cpp:539: error: wrong number of template arguments (1, should be 2) ./Includes/Utilities.cpp:513: error: provided for ‘template<class Graph, class edgeDescriptor> struct SortByName’ make: *** [plc] Error 1 */ } But clearly there are two template arguments - < typename Graph, typename edgeDescriptor > Thanks

4 7

Asio and bind. Queuing a bind call.
by Nick.Adamson＠generaldynamics.uk.com 08 Nov '10

08 Nov '10

Hi All. I'm putting together a class which provides a single point of contact to a resource. I'm planning on using the asio IO service in conjunction with a ASIO strand to control flow of method calls to my resource. I've got this working and ASIO has made this so easy. One of the things I've got to do is to be able to pause and queue function calls to the resource if the resource can't service the request. I figured the best way of doing this was putting the result of boost::bind in to some sort of queue when the resource is unavailable and then when it becomes available processing the items in the queue. Is this the best way to do it or does the strand or IO service have a way of doing it? As the result of boost::bind is a template I don't know of an stl or boost container which will store these objects. As there are a number of functions that can be called on my resource with differing arguments I don't think I can use a boost::function as I don't know the arguments to my generic post call. Here's some sudo code which may help to explain it. class CResourceManager { public: // post. // this function takes in a bound function and addes it to the queue of functions to call. // it reserves the sequence of calls by using the io strand. // this means that any function called by this post call is guaranteed to be called in sequence and will be the only function called at that time. template <typename CompletionHandler> void Post(CompletionHandler handler) { if (m_bStrandEnabled) { m_strand.post( handler ); } else { // strand is not enabled. ?????? m_queuedCalls.push( handler ); ????? } } void EnableStrand() { iterate through queue posting functions on to the strand. ?????? code would depend on container used. m_bStrandEnabled = true; } boost::asio::io_service &m_ioService; boost::asio::io_service::strand m_strand; private: bool m_bStrandEnabled; // as a boost bind function is templated we have to work out a way of putting an unknown template in to the queue. queuedfuncitoncontainer m_queuedCalls; } at the moment I don't know what type the "queuedfuncitoncontainer" should be. Because the result of boost::bind is dependent on the function being bound it doesn't seem like I can use stl::queue. Anyone have any ideas how I can do this? I've done a bit of googling and didn't really get any ware. I did look at the boost code to see how strand does it and it seems like its using raw pointers, I didn't really want to go down that road if I can help it. Thanks. Nick. Nick Adamson Software Engineer Advanced Projects and Technology General Dynamics United Kingdom Limited Bryn Brithdir, Oakdale Business Park, Blackwood, South Wales, NP12 4AA Telephone: +44 (0)1495 23 6467 Email: Nick.Adamson(a)generaldynamics.uk.com Website: www.generaldynamics.uk.com <http://www.generaldynamics.uk.com/> To help reduce waste paper, please only print this email if you really need to.

2 2

Re: [Boost-users] Does anybody interested in active object
by Marat Abrarov 08 Nov '10

08 Nov '10

To Dean Michael Berris: Thank you for your patience and detailed answers. > Nope, sorry, s11n_example::connection is not an active object. What it actually is, is an execution > context -- or sometimes people call it a continuation, a generator, or a state machine. Because you're > using the execution context relevant with a particular connection, it doesn't imply that the > operations are performed on a different thread. Ok. May be I'm wrong trying to name it "active object". "Continuation", "state machine", "execution context" - this is very close to what I had in mind. Therefore, I conclude that we understand each other (despite some language barriers with my hand). I thought all of "Continuation/state machine/execution context" was related to the pattern of "active object", hmm... > If you have unlimited number of cores and no limits on the number of threads you can spawn for each > active object you create, then yes. I think the main feature of "Continuation/state machine/execution context" is not saving threads, but organizing flexible and comfortable way of communication between state machines (yes - it is tasks and queues, but wrapped in async method call with callback). That is what I try to implement by means of Boost.Asio. It was chosen "historically" (started from network programming), but for the now times I see it is the best choice :) > Otherwise, you can stick with continuations, asynchronous completion handlers, and just plain data > parallelism. At the "samples" I develop (thanks to Boost.Asio examples - the are the first) the main goals were: 1) share execution context (thread pool) between different "state machines". 2) (make possible to) divide execution contexts of different "state machines" and application layers when it is needed (session and session_manager - not layers but are close to them). 3) develop a simple way of implementing async method call (for the "state machines") with required callback. (with required usage of "custom memory allocation" which can make usage of async methods as cheap as possible) Regards, Marat Abrarov. > Message: 3 > Date: Mon, 8 Nov 2010 10:29:02 +0800 > From: Dean Michael Berris <mikhailberis(a)gmail.com> > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Does anybody interested in active object > Message-ID: > <AANLkTimW0ozMYQ_GfstJw4mV111=2JTc0JSh+0YzLdYF(a)mail.gmail.com> > Content-Type: text/plain; charset=UTF-8 > > On Mon, Nov 8, 2010 at 7:11 AM, Marat Abrarov <abrarov(a)mail.ru> wrote: > > To Dean Michael Berris: > >> You'd be better of doing data parallelism with Boost.MPI > > > > No. Because I'm speaking about thread-based parallelism (with shared > > memory access). > > Processed-based parallelism and IPC supplement but don't replace > > thread-based parallelism in general. > > > > Well, which is why I said 'data parallelism'. This implies a whole different kind of programming, > which doesn't typically include threads and synchronization. ;) > > > > >> and/or Boost.Asio's io_service > >> run on multiple threads, and having independent tasks multiplexed > >> across a number of processors (either through processes or threads) > > > > Tie this tasks with the data they share and You will have an active object. > > Nope, sorry, that's not an active object. An Active Object requires that you have a at least one > thread of execution dedicated to the active object, and that you have a synchronous interface to that > object. > > > If the tasks don't have shared data - they don't need an active object. > > Active Objects really have nothing to do with shared data. It's a design pattern that prescribes a way > of isolating the synchronization and serialization of operations applied to an object that is assumed > to be shared across multiple threads of execution. The way the active object does it is by lining up > the operations to be performed asynchronously and perform those in a different thread of execution. > > You can implement an active object without involving shared data -- for example you want to model a > processor, or a math kernel, which does all its work on a single thread because maybe you have a > library underneath that is not thread-safe. In situations like these it makes sense to have an active > object implementation. > > > I think - active object is built on task-based parallelism but it does > > not mean that "active object" should replace "task-based parallelism" > > everywhere. > > > > I think you have it wrong. The active object pattern is a design pattern that doesn't know about task- > based parallelism. Task-based parallelism is a different pattern and different paradigm altogether. > The active object pattern by itself is just a design pattern, nothing more. > > > > >> But what you're describing is not the active object pattern. ;) > > > > http://en.wikipedia.org/wiki/Active_object > > http://en.wikipedia.org/wiki/Active_object_(Symbian_OS) > > What about ma::echo::server::session class - is it an active object? > > > > I haven't looked at your examples, because I was only commenting on the issue regarding massive > parallelism. Maybe when I have enough time I'll look through your examples. ;) > > > > > http://www.boost.org/doc/libs/1_44_0/doc/html/boost_asio/example/chat/ > > chat_c > > lient.cpp > > Is chat_client an active object? If "yes" then why? > > chat_client::write have no completion callback - and this is not > > enough sometimes (I can say "always", if You don't implementing > > "fire-and-forget" logic which is rather seldom). > > > > No, this is not an active object. An active object has its own lifetime thread. In this situation the > lifetime thread is shared between Boost.Asio's IO subsystem and all the ASIO related handlers. > > Also, you don't need a completion callback for a class to model the Active Object pattern. You can > create methods that return 'void' and just execute the actions asynchronously in its own lifetime > thread. > > > > > http://www.boost.org/doc/libs/1_44_0/doc/html/boost_asio/example/seria > > lizati > > on/connection.hpp > > s11n_example::connection is an active object and have completion callback... > > but it's much simpler then ma::echo::server::session_manager - I try > > to suggest "samples" that can help to build such a kind of complex > > active objects. > > > > Nope, sorry, s11n_example::connection is not an active object. What it actually is, is an execution > context -- or sometimes people call it a continuation, a generator, or a state machine. Because you're > using the execution context relevant with a particular connection, it doesn't imply that the > operations are performed on a different thread. > > All this is doing is encapsulating callbacks and the protocol implementation into an object. It > exposes a means of asynchronously scheduling operations, but it doesn't hide these details from the > interface. The goal of the active object pattern is to hide the asynchronous nature of the > implementation from the user of the object. > > > > > http://www.drdobbs.com/go-parallel/blog/archives/2009/09/parallelism_s > > ho.htm > > l > >> We are surrounded by parallelism even more so that serial activities. > >> Social and biological systems are immersed in parallelism and these > >> systems have worked out the kinks over millions of years. > >> In biological systems, independent units perform simple computations > >> or activities independently and in parallel. > > and > >> IMPLICATIONS FOR COMPLEX REALTIME SYSTEMS: > >> Complex real-time systems would be a sea of state machine objects > >> interacting with each other. There will be low level state machines > >> which would work together to implement high level state machine behavior. > > > > Here's the place for active object pattern. > > > > If you have unlimited number of cores and no limits on the number of threads you can spawn for each > active object you create, then yes. > Otherwise, you can stick with continuations, asynchronous completion handlers, and just plain data > parallelism. > > The place for an active object is where you have to expose a synchronous interface to a resource which > underneath performs the actions asynchronously. This is like the half-sync half-async pattern which, > once you understand, is what the active object implementation provides. > > -- > Dean Michael Berris > deanberris.com

2 1

Re: [Boost-users] [mpl] Iterator Concept Checking? SOLVED + Recommendation.
by Stirling Westrup 08 Nov '10

08 Nov '10

On Sun, Oct 31, 2010 at 6:16 PM, Stirling Westrup <swestrup(a)gmail.com> wrote: > On Sat, Oct 30, 2010 at 8:57 PM, David Abrahams <dave(a)boostpro.com> wrote: >> >> At Sat, 30 Oct 2010 17:55:35 -0400, >> Stirling Westrup wrote: >>> >>> I am writing some algorithms to operate on MPL sequences, and I would >>> like to use some form of concept checking to ensure that the types >>> passed in that are supposed to be iterators are, in fact, iterators. >>> I have solved the problem I was working on, but as I'm not completely happy with my solution, I thought I'd post it here and make a recommendation for a small change to MPL that would have simplified my work. I discovered while reading about the iterator_category metafunction that the iterator tags had ascending values. ( http://www.boost.org/doc/libs/1_44_0/libs/mpl/doc/refmanual/iterator-catego… ). This is only documented there, and not in the description of the individual iterator categories. In fact, the individual iterator categories are completely misleading as they state that there is a member named 'category' that is convertible to the type of the tag. Since a random iterator is a refinement of a forward iterator and therefor has at least the same set of requirements, it would imply that: BOOST_MPL_ASSERT (( is_convertible<RandomIterator::category,forward_iterator_tag>)) should succeed, and it does NOT. It would seem that one should use iterator_category to determine if something is an iterator or not, but its only actually defined when its type is an iterator, so that doesn't really work. I ended up writing my own version that was defined for all types, like this: struct non_iterator_tag : mpl::int_<INT_MIN> { typedef non_iterator_tag type; }; BOOST_MPL_HAS_XXX_TRAIT_NAMED_DEF(has_category,category,false) template<bool b, typename T> struct category_impl { typedef non_iterator_tag type; static const type::value_type value = type::value; }; template<typename T> struct category_impl<true,T> { typedef typename mpl::iterator_category<T>::type type; static const int value = type::value; }; // just like mpl::iterator_category<T> but can be passed any // type, and returns mplx::not_iterator_tag on bad types. Note // that this value will compare less-than any valid iterator // tag. template<typename T> struct category : category_impl<has_category<T>::value,T> {}; template<typename Iterator> struct is_forward_iterator { typedef typename mpl::greater_equal < typename category<Iterator>::type , mpl::forward_iterator_tag >::type type; }; template<typename Iterator> struct is_bidirectional_iterator { typedef typename mpl::greater_equal < typename category<Iterator>::type , mpl::bidirectional_iterator_tag >::type type; }; template<typename Iterator> struct is_random_access_iterator { typedef typename mpl::greater_equal < typename category<Iterator>::type , mpl::random_access_iterator_tag >::type type; }; The above works, but it relies upon me testing to see if there is an embedded category member, which I suspect is going to get deprecated by iterator_category<> just like all the other members were. It would be far preferable for me if there was an actual non_iterator_tag and iterator_category<> were already defined for all types, so it could both be used in a convenient manner, and so that there was an obvious way to write a specialization in the case that, for instance, one needed the type 'int' to be an iterator. In the very least, please update the documentation to mention the actual relationships between the tags in the discussion about the iterators, and to remove the incorrect 'convertible' description. -- Stirling Westrup Programmer, Entrepreneur. https://www.linkedin.com/e/fpf/77228 http://www.linkedin.com/in/swestrup http://technaut.livejournal.com

3 3

What's so cool about Boost.MPI?
by David Abrahams 08 Nov '10

08 Nov '10

Just wanted to call some attention to this article I wrote about Boost.MPI: http://daveabrahams.com/2010/09/03/whats-so-cool-about-boost-mpi/ I think it might be useful to link that from the Boost.MPI docs, too. -- Dave Abrahams BoostPro Computing http://www.boostpro.com

12 12

Re: [Boost-users] Does anybody interested in active object
by Marat Abrarov 08 Nov '10

08 Nov '10

To Dean Michael Berris: > You'd be better of doing data parallelism with Boost.MPI No. Because I'm speaking about thread-based parallelism (with shared memory access). Processed-based parallelism and IPC supplement but don't replace thread-based parallelism in general. > and/or Boost.Asio's io_service > run on multiple threads, and having independent tasks multiplexed > across a number of processors (either through processes or threads) Tie this tasks with the data they share and You will have an active object. If the tasks don't have shared data - they don't need an active object. I think - active object is built on task-based parallelism but it does not mean that "active object" should replace "task-based parallelism" everywhere. > But what you're describing is not the active object pattern. ;) http://en.wikipedia.org/wiki/Active_object http://en.wikipedia.org/wiki/Active_object_(Symbian_OS) What about ma::echo::server::session class - is it an active object? http://www.boost.org/doc/libs/1_44_0/doc/html/boost_asio/example/chat/chat_c lient.cpp Is chat_client an active object? If "yes" then why? chat_client::write have no completion callback - and this is not enough sometimes (I can say "always", if You don't implementing "fire-and-forget" logic which is rather seldom). http://www.boost.org/doc/libs/1_44_0/doc/html/boost_asio/example/serializati on/connection.hpp s11n_example::connection is an active object and have completion callback... but it's much simpler then ma::echo::server::session_manager - I try to suggest "samples" that can help to build such a kind of complex active objects. http://www.drdobbs.com/go-parallel/blog/archives/2009/09/parallelism_sho.htm l > We are surrounded by parallelism even more so that serial activities. > Social and biological systems are immersed in parallelism and these > systems have worked out the kinks over millions of years. > In biological systems, independent units perform simple computations > or activities independently and in parallel. and > IMPLICATIONS FOR COMPLEX REALTIME SYSTEMS: > Complex real-time systems would be a sea of state machine objects > interacting with each other. There will be low level state machines > which would work together to implement high level state machine behavior. Here's the place for active object pattern. Thanks for that attention that you have given to my question. Marat Abrarov. > -----Original Message----- > Date: Sun, 7 Nov 2010 12:58:06 +0800 > From: Dean Michael Berris <mikhailberis(a)gmail.com> > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Does anybody interested in active object > pattern? > Message-ID: > <AANLkTi=PTkqO2ngdYcNNbp12hNnS=8=PxK3YsccajpFV(a)mail.gmail.com> > Content-Type: text/plain; charset=UTF-8 > > On Sat, Nov 6, 2010 at 10:56 PM, Marat Abrarov <abrarov(a)mail.ru> wrote: > > > > Does anybody interested in active object pattern for massive parallelism > by means of C++? (Intel TBB doesn't offer a > > similar approach) > > > > I'm not sure how you think active objects help for massive parallelism > because the active object pattern implies that you're serializing > operations on a single object. > > I've used Boost.Asio to implement Active Objects but only in cases > where it makes sense -- like for example a concurrent accumulator or a > concurrent resource handle (log sink for example). You'd be better of > doing data parallelism with Boost.MPI and/or Boost.Asio's io_service > run on multiple threads, and having independent tasks multiplexed > across a number of processors (either through processes or threads). > > I remember reading about Microsoft's efforts (through Herb Sutter) to > introduce an "active" extension to Microsoft Visual C++, where you can > easily make classes that instantiate to active objects. I'm not sure > where that effort is now though. > > HTH > > -- > Dean Michael Berris > deanberris.com >

2 1

[GIL] Adding base_channel_type metafunction
by Nathan Crookston 08 Nov '10

08 Nov '10

All, Several months ago I submitted a patch to prevent warnings when performing certain channel conversions [1]. After some discussion with Christian a part of the patch was removed in favor of using the unsigned_integral_max_value metafunction. After tweaking my specializations of that metafunction my code compiled fine. Recently I modified my code to use GIL more extensively. I'm pleased with the reduced code footprint (a 5000 line file was reduced to ~150 lines), but unfortunately there are more warnings due to unsafe conversions with my now-more-extensive testing. Attached is a file which adds a base_channel_type metafunction which correctly determines the type which the channel constructor is expecting. I believe this is more correct than using unsigned_integral_max_value as the value_type of *max_value is not the same as the channel type for, e.g., 8-bit unsigned channels. Something like this metafunction has also been requested recently [2]. The following demonstrates its use for the built-in channel type models I'm aware of: ///////////BEGIN CODE//////////////////// #include <boost/cstdint.hpp> #include <boost/gil/gil_all.hpp> #include <boost/static_assert.hpp> #include <boost/type_traits/is_same.hpp> namespace gil = boost::gil; typedef gil::packed_image3_type<boost::uint16_t, 7,7,2, gil::bgr_layout_t>::type bgr772_image_t; typedef gil::kth_element_type<bgr772_image_t::value_type,0>::type b7_element_type; typedef gil::base_channel_type<b7_element_type>::type b7_type; BOOST_STATIC_ASSERT((boost::is_same<b7_type, boost::uint8_t>::value)); typedef gil::base_channel_type<gil::channel_type<gil::gray32f_pixel_t>::type>::type gray32f_type; BOOST_STATIC_ASSERT((boost::is_same<gray32f_type, float>::value)); typedef gil::base_channel_type<gil::channel_type<gil::rgb8_pixel_t>::type>::type rgb8_type; BOOST_STATIC_ASSERT((boost::is_same<rgb8_type, boost::uint8_t>::value)); int main() {} /////////END CODE///////////////// Adding the metafunction and using it to cast values prior to channel construction has removed the warnings from my testing. The diff file also contains changes to channel_algorithm.hpp to suppress warnings using the supplied metafunction. I'd be happy to write additional test cases, trac tickets, etc. The changes have been tested with g++3.4, g++4.3 and VC8 (VS2005). Thanks, Nate [1] <http://lists.boost.org/boost-users/2010/06/60066.php> [2] <http://lists.boost.org/Archives/boost/2010/07/169159.php>

2 9

the name of installed Boost libraries, with or without '-gcc'
by weining hao 07 Nov '10

07 Nov '10

Hi, I have installed boost 1.33-1 in SLES (SUSE Linux Enterprise Server) 11 manually by bjam 3.12, and in SLES10 sp2 via YAST2 (with the defalut bjam 3.1.4). I found that the installed libraries in SLES 11 are always with the postfix '-gcc', which is not appeared in the libraries in SLES 10 sp2 (For example, "libboost_filesystem-gcc.o" in SLES 11, but "libboost_filesystem.o" in SLES10 sp2). The '-gcc' also exists in the library name in SLES 9.3. Is it configurable to be with or without '-gcc', and in which file? Is it related to the SLES version, or bjam version? It is appreciated that you give some hints! Best regards, Weining

2 1

Does anybody interested in active object pattern?
by Marat Abrarov 07 Nov '10

07 Nov '10

Hello, Boost C++ Libraries' community. I'm trying to develop the idea of (most effective) building active objects by means of Boost C++ Libraries (not as libpoet does). I chose for this Boost.Asio as the only library supports flexible "custom memory allocation" mechanism. Here is my project: https://sourceforge.net/projects/asio-samples/ And here is short description of the concept: https://think-async.com/Asio/Examples This project isn't a library and won't be it. It is something like advanced examples for Boost.Asio. And I hope this "advanced examples" are very close to production-level code. Does anybody interested in active object pattern for massive parallelism by means of C++? (Intel TBB doesn't offer a similar approach) Regards, Marat Abrarov.

3 5

[iostreams] compressing and decompressing in memory
by Brian Budge 07 Nov '10

07 Nov '10

I've been searching around for examples for how to compress and decompress using the zip or gzip iostreams compressors into/out of memory buffers. Has anyone tried this? Would you use basic_array for this? Thanks, Brian

2 4

sizeof(boost::fusion:map)
by Robert Lupton the Good 06 Nov '10

06 Nov '10

I was very excited to find the boost::fusion library, expecting that I could use it to implement structs with introspection. I still think I can, but I was disappointed to see that I'm paying a size penalty. I'd have expected all the book-keeping to be handled at compile time. The following code prints sizeof(Foo) = 12 sizeof(FooS) = 4 with g++ 4.2 or 4.4 on an os/x 10.6 or Centos box. Here Foo is boost::fusion::map<boost::fusion::pair<Name, int> > Where are the extra 8 bytes going? With more complex boost::fusion objects I see an overhead of up to 16 bytes. gdb indicates that foo.data.vec has the desired size, but foo.data is larger, and foo is larger still; however, it doesn't indicate any data members --- is this some sort of alignment issue? Is there a way to generate a "packed boost::fusion::map" without this space overhead? R #include <iostream> #include "boost/fusion/container.hpp" struct Name {}; int main() { typedef boost::fusion::map<boost::fusion::pair<Name, int> > Foo; struct FooS { int age; }; std::cout << "sizeof(Foo) = " << sizeof(Foo) << " sizeof(FooS) = " << sizeof(FooS) << std::endl; }

5 11

boost regex no debug info and std::bad_cast
by justin 06 Nov '10

06 Nov '10

Hi, I'm trying to use boost/regex.hpp on OS X 10.6.4 10F569. $ g++ -v Using built-in specs. Target: i686-apple-darwin10 Configured with: /var/tmp/gcc/gcc-5664~89/src/configure --disable-checking --enable-werror --prefix=/usr --mandir=/share/man --enable-languages=c,objc,c++,obj-c++ --program-transform-name=/^[cg][^.-]*$/s/$/-4.2/ --with-slibdir=/usr/lib --build=i686-apple-darwin10 --program-prefix=i686-apple-darwin10- --host=x86_64-apple-darwin10 --target=i686-apple-darwin10 --with-gxx-include-dir=/include/c++/4.2.1 Thread model: posix gcc version 4.2.1 (Apple Inc. build 5664) BOOST BUILD $ ./bootstrap.sh --prefix=$BOOST_INSTALL $ ./bjam debug define=_GLIBCXX_DEBUG install --prefix=$BOOST_INSTALL MAKEFILE $ g++ -Wall -g -I~/Development/BOOST/boost_1_44_0 ~/Development/BOOST/BOOST_INSTALL/lib/libboost_regex.a example.cpp -o example example.cpp #include <iostream> #include <iterator> #include <algorithm> #include <boost/regex.hpp> int main() { std::string s("table.dat"); boost::regex expression("table.dat"); boost::regex_match(s, expression); return 0; } Problems (2): 1. $ ./example terminate called after throwing an instance of 'std::bad_cast' what(): std::bad_cast Abort trap 2. $ gdb example This GDB was configured as "x86_64-apple-darwin"...Reading symbols for shared libraries ... done warning: Could not find object file "/var/folders/Hk/HkJ3ILZ4GcOnWEOL-4iWEE+++TI/-Tmp-//ccC7Ee4y.o" - no debug information available for "example.cpp". Any help is appreciated, Justin -- View this message in context: http://boost.2283326.n4.nabble.com/boost-regex-no-debug-info-and-std-bad-ca… Sent from the Boost - Users mailing list archive at Nabble.com.

2 1

building boost for Android
by Igor R 06 Nov '10

06 Nov '10

Hello, Has anyone managed to build boost for this platform? Thanks.

3 2

Boost.MPI 1.44.0 fails to build when BOOST_MPI_HOMOGENEOUS is set
by Riccardo Murri 06 Nov '10

06 Nov '10

Hello, I'm trying to build Boost.MPI from the 1.44.0 sources; if I uncomment the `#define BOOST_MPI_HOMOGENEOUS` line in `boost/mpi/config.hpp`, then build fails with errors like this one (full compile log attached): ./boost/mpi/detail/binary_buffer_iprimitive.hpp: In member function ‘void boost::mpi::binary_buffer_iprimitive::load(T&) [with T = boost::archive::class_id_optional_type]’: ./boost/archive/detail/iserializer.hpp:107: instantiated from ‘static void boost::archive::load_access::load_primitive(Archive&, T&) [with Archive = boost::mpi::packed_iarchive, T = boost::archive::class_id_optional_type]’ ./boost/archive/detail/iserializer.hpp:356: instantiated from ‘static void boost::archive::detail::load_non_pointer_type<Archive>::load_primitive::invoke(Archive&, T&) [with T = boost::archive::class_id_optional_type, Archive = boost::mpi::packed_iarchive]’ ./boost/archive/detail/iserializer.hpp:433: instantiated from ‘static void boost::archive::detail::load_non_pointer_type<Archive>::invoke(Archive&, T&) [with T = boost::archive::class_id_optional_type, Archive = boost::mpi::packed_iarchive]’ ./boost/archive/detail/iserializer.hpp:586: instantiated from ‘void boost::archive::load(Archive&, T&) [with Archive = boost::mpi::packed_iarchive, T = boost::archive::class_id_optional_type]’ ./boost/archive/detail/common_iarchive.hpp:66: instantiated from ‘void boost::archive::detail::common_iarchive<Archive>::load_override(T&, int) [with T = boost::archive::class_id_optional_type, Archive = boost::mpi::packed_iarchive]’ ./boost/mpi/packed_iarchive.hpp:101: instantiated from ‘void boost::mpi::packed_iarchive::load_override(T&, int, mpl_::false_) [with T = boost::archive::class_id_optional_type]’ ./boost/mpi/packed_iarchive.hpp:118: instantiated from ‘void boost::mpi::packed_iarchive::load_override(T&, int) [with T = boost::archive::class_id_optional_type]’ ./boost/archive/detail/interface_iarchive.hpp:60: instantiated from ‘Archive& boost::archive::detail::interface_iarchive<Archive>::operator>>(T&) [with T = boost::archive::class_id_optional_type, Archive = boost::mpi::packed_iarchive]’ ./boost/archive/detail/common_iarchive.hpp:54: instantiated from ‘void boost::archive::detail::common_iarchive<Archive>::vload(boost::archive::class_id_optional_type&) [with Archive = boost::mpi::packed_iarchive]’ libs/mpi/src/request.cpp:120: instantiated from here ./boost/mpi/detail/binary_buffer_iprimitive.hpp:87: error: no matching function for call to ‘assertion_failed(mpl_::failed************ boost::serialization::is_bitwise_serializable<boost::archive::class_id_optional_type>::************)’ Boost 1.43.0 compiles just fine with BOOST_MPI_HOMOGENEOUS uncommented. I'm using GCC 4.4.5 on Ubuntu 10.10; OpenMPI 1.4.1 installed from the official Ubuntu package. Is this an issue with the sources? Best regards, Riccardo -- Riccardo Murri, Hadlaubstr. 150, 8006 Zürich (CH)

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Re: [Boost-users] boost regex no debug info and std::bad_cast
by justin 05 Nov '10

05 Nov '10

Different Code (example.cpp) #include <boost/lexical_cast.hpp> #include <iostream> using namespace::std; int main() { unsigned int x = 3; string s = boost::lexical_cast<string>(x); return 0; } Works $ g++ -Wall -g -I~/Development/BOOST/boost_1_44_0 example.cpp -o example Doesn't Work: including boost regex library $ g++ -Wall -g -I~/Development/BOOST/boost_1_44_0 ~/Development/BOOST/BOOST_INSTALL/lib/libboost_regex.a example.cpp -o example Seems to be a bug: https://svn.boost.org/trac/boost/ticket/4595 https://svn.boost.org/trac/boost/ticket/4595 Is this bug related to my previous question about using boost regex? Thanks -- View this message in context: http://boost.2283326.n4.nabble.com/boost-regex-no-debug-info-and-std-bad-ca… Sent from the Boost - Users mailing list archive at Nabble.com.

1 0

hybrid parallelism
by Hicham Mouline 05 Nov '10

05 Nov '10

Hello, Following a previous thread that asked about how to parallelize a large number of calculations, I took this summary: I am thinking of choosing a simple model whereby: There are M computers (possibly heterogeneous). I will stick to 1 process per computer. Each process will have N threads. Giving a total M*N "execution units". I will take a simple solution in that the M and N are fixed though determined at runtime. So there is this pool of M*N exec units and I give them 100 000 tasks to do. Those tasks get scheduled in the same process/computer, they share their memory. Each of the computers gets a duplicate of the memory used as inputs to the tasks. For thread pool, TBB, boost::asio were suggested. I believe there is also threadpool.sourceforge.net For the cross-computer communication, boost::mpi. Is this something boost::mpi + mpi can help with? Regards,

5 8

Statistical distributions in Boost.Math
by Paul A. Bristow 05 Nov '10

05 Nov '10

Recently I have been working on a few more Statistical Distributions for Boost.Math. These will be in release in 1.45 and some more in 1.46, (and soon, an update to http://sourceforge.net/projects/distexplorer/ Distribution Explorer, a mixed C++ and C# Windows application that allows you to explore the properties of various statistical distributions, & calculate the Cumulative Distribution Function CDF, Probability Distribution Function PDF, or quantiles/percentiles). inverse chisquare, inverse gamma distribution, inverse Gaussian, Wald. 1 I am looking for some examples of their use for the documentation. If you could to propose and/or help work up some not-too-complicated examples of applications of these (they seem to be popular with followers of the Reverend Bayes ;-) - please contact me privately. 2 Are there other distributions (or 'special' functions) that you, or your colleagues, friends or relations, would find useful? If you have suggestions or requests, please tell me. Thanks Paul --- Paul A. Bristow, Prizet Farmhouse, Kendal LA8 8AB UK +44 1539 561830 07714330204 pbristow(a)hetp.u-net.com

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[boost] [Review] Formal Review of Proposed Boost.Chrono Library Starts TOMORROW
by Anthony Williams 05 Nov '10

05 Nov '10

Hi everyone, The review of Vicente Botet's Chrono library starts TOMORROW (November 6th) and lasts until November 15th unless an extension occurs. What is it? ======== Boost.Chrono aims to implement the new time facilities in C++0x, as proposed in N2661 - A Foundation to Sleep On (http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2008/n2661.htm) That document provides background and motivation for key design decisions and is the source of a good deal of information in this documentation. See the current C++0x working draft at http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2010/n3126.pdf for details of what was accepted. The Boost.Chrono library provides: * A means to represent time durations: managed by the generic duration class . Examples of time durations include days, minutes, seconds and nanoseconds, which can be represented with a fixed number of clock ticks per unit. All of these units of time duration are united with a generic interface by the duration facility. * A type for representing points in time: time_point. A time_point represents an epoch plus or minus a duration. The library leaves epochs unspecified. A time_point is associated with a clock. * Several clocks, some of which may not be available on a particular platform: system_clock, monotonic_clock and high_resolution_clock. A clock is a pairing of a time_point and duration, and a function which returns a time_point representing now. * To make the timing facilities more generally useful, Boost.Chrono provides a number of additional clocks that are thin wrappers around the operating system's time APIs, thereby allowing the extraction of read (wall clock) time, user CPU time, system CPU time, - process_real_cpu_clock, captures real (wall clock) CPU times. - process_user_cpu_clock, captures user-CPU times. - process_system_cpu_clock, captures system-CPU times. - A tuple-like class __process_cpuclock_, that captures real, user-CPU, and system-CPU times together. - A thread_clock thread monotonic clock, when supported by a platform. * Boost.Chrono also includes typeof registration for duration and time_point to permit using emulated auto with C++03 compilers. * Boost.Chrono also provides I/O for duration and time_point. It builds on <boost/ratio/ratio_io.hpp> to provide readable and flexible formatting and parsing for types in <boost/chrono.hpp>. The duration unit names can be customized through a new facet: duration_punct. Getting the library ============= The latest version of this library may be downloaded from vault: http://www.boostpro.com/vault/index.php?action=downloadfile&filename=chrono… SVN: http://svn.boost.org/svn/boost/sandbox/chrono Boost.Chrono depends on Boost.Ratio http://www.boostpro.com/vault/index.php?action=downloadfile&filename=ratio.… and optionaly Boost.System Header Only http://www.boostpro.com/vault/index.php?action=downloadfile&filename=system…. and the docs may be viewed here HTML: http://svn.boost.org/svn/boost/sandbox/chrono/libs/chrono/doc/html/index.ht… PDF: http://svn.boost.org/svn/boost/sandbox/chrono/libs/chrono/doc/chrono.pdf You can get all these information also (which should avoid some long links) from http://svn.boost.org/trac/boost/wiki/LibrariesUnderConstruction#Boost.Chrono Writing a review ================ If you feel this is an interesting library, then please submit your review to the developer list (preferably), or to the review manager. Here are some questions you might want to answer in your review: - 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. Anthony Review Manager for the proposed Boost.Chrono library -- Author of C++ Concurrency in Action http://www.stdthread.co.uk/book/ just::thread C++0x thread library http://www.stdthread.co.uk Just Software Solutions Ltd http://www.justsoftwaresolutions.co.uk 15 Carrallack Mews, St Just, Cornwall, TR19 7UL, UK. Company No. 5478976 _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

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[boost][icl/itl] Interval Container Library ready for inclusion
by Joachim Faulhaber 05 Nov '10

05 Nov '10

Dear list! After the review of the Interval Template Library in February and its acceptance for inclusion, I worked on a number of suggestions and proposals from the reviewers, in order to improve the design and quality of the library. The library is now renamed to Boost.Icl: Interval Container Library. I have completed a release icl-4.0.0, where those suggestions are implemented. Apart from typos and flaws in the docs that might be there after renaming, this will be the version for inclusion into the next boost release (1.46.0). The now renamed library has a new path in the sandbox: https://svn.boost.org/svn/boost/sandbox/icl/ The sources are also in the vault http://www.boostpro.com/vault/index.php?&direction=0&order=&directory=Conta… and on sourceforge (extended version) http://sourceforge.net/projects/itl/ The BoostBook docs are online available here: http://www.joachim-faulhaber.de/boost_icl/doc/libs/icl/doc/html/index.html Many of the proposals from the reviewers were agreed upon during the discussion on the library. In particular I took into account suggestions by Jeff Flinn (JF), Luke Simonson (LS), Barend Gehrels (BG), Vicente Botet (VB), Thomas Klimpel (TK), Paul A. Bristow (PB), Robert Stewart (RS), John Reid (JR) and Markus Werle (MW). Some suggestions by Phil Endecott, Jerry Jeremiah, Brian Wood, Barend Gehrels, Luke Simonson and John Reid are not or not yet implemented for different reasons but they may be considered for the future evolution of the library. * The library has been renamed from Interval Template Library (ITL) to Interval Container Library (ICL) Its namespace is now icl instead of itl. (Renaming was suggested by MW). * Introduction of dynamically bounded and statically bounded intervals (JF,JR,VB) + The 'universal' interval class itl::interval has been replaced by + dynamically bounded discrete_interval and continuous_interval http://www.herold-faulhaber.de/boost_icl/doc/libs/icl/doc/html/boost_icl/ex… + statically bounded right_open_interval, left_open_interval closed_interval and open_interval and a uniform set of namespace global functions or interval_concept for them. Statically bounded intervals don't carry information about their interval bounds and use less memory. (JF,JR) http://www.herold-faulhaber.de/boost_icl/doc/libs/icl/doc/html/boost_icl/ex… + The interval class templates are now quite small. The functions are namespace global functions that make up an interval concept (JF,LS) + Added functions 'distance' and 'inner_complement' for intervals.(JR) http://www.herold-faulhaber.de/boost_icl/doc/libs/icl/doc/html/boost_icl/fu… * User defined interval types are now customizable (JF) + An interval_traits and dynamic_interval_traits template describes the generic properties of the interval concept ... + and allows to customize the icl library for user defined interval types. http://www.herold-faulhaber.de/boost_icl/doc/libs/icl/doc/html/boost_icl/ex… * Extraction of namespace global functions. (LS,JF,RS) + Member functions have been extracted form class templates as long as they are not needed to maintain type invariants. + The sets of namespace global functions build concepts icl::element_set, icl::element_map, icl::interval_set, icl::interval_map + Some functions have been renamed to conform existing standards (ISO/OGC). (BG) + std::set and other stl conformant set types are models of the icl's element_set concept. Class template icl::set has been removed. + Member functions for element iterations are extracted from the interval container class templates. (LS) * Names, referred to as 'colorful terminology' have been renamed (TK,VB,PB) + neutron -> identity_element + unon -> unit_element + ... and also their occurrence in composite identifiers If you find bugs in the library or typos or other flaws in the docs, please let me know so I can fix them before inclusion of the library into the next boost release. Enjoy, Joachim

6 5

[BGL] edge() function also inside AdjacencyList-concept?
by Cedric Laczny 05 Nov '10

05 Nov '10

Hi, I was wondering that the edge()-function (to see if there is an edge between two vertices and if so also return it) also exists for the AdjacenyList- concept?! As in the documentation, I find it only under "AdjacencyMatrix refines Graph" but nowhere else. Where is it defined and what is it's time complexity (just to make sure that my assumptions on the complexity are correct) please? Best regards, Cedric

3 3

[Asio]What's the behavior of socket.async_write() after socket.close() is called?
by 鑫炜廖 05 Nov '10

05 Nov '10

Hi, If I call socket.close() but I still have some data in my buffer, can I call async_write() later? When I call socket.close(), maybe an async_write operation is running, when it's complete I want to send data in another buffer(data written while previous async_write() is running, before socket.close() was called), but the socket is closed.Does it work in this situation?If not, what's the alternative way? The code looks like this: char front_buffer[kBufferSize]; char back_buffer[kBufferSize]; void HandleWrite(...) { //socket is closed. Does this work? socket.async_write(back_buffer, ...); } socket.async_write(front_buffer, HandleWrite); // write data to back_buffer socket.close();

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[Range] Creating a range for a scoped_array (with known length)
by Matthieu Brucher 05 Nov '10

05 Nov '10

Hi, I have a scoped_array with some chars inside (so a boost::scoped_array<char>). I want to use the string algorithms, but I can't managed to get a range from the scoped_array. I don't know if the data ends with a '\0' (it's received from asio with a read()), so I can't rely on as_literal. Is there a way of creating a Range directly with two iterators? Matthieu -- Information System Engineer, Ph.D. Blog: http://matt.eifelle.com LinkedIn: http://www.linkedin.com/in/matthieubrucher

3 4

get/set RTS on serial port - Linux
by Marce 05 Nov '10

05 Nov '10

Hi, In a later post of myself I asked about getting / setting the RTS line by software control (http://lists.boost.org/boost-users/2010/06/59700.php) I managed to get working as explained in Windows as replied in by Michael Caisse (http://lists.boost.org/boost-users/2010/06/59723.php) but in linux I'm not being able to get it working. I can control it in linux by calling ioctl ( ioctl(fd, TIOCMSET, &status) ) but in the set-option I do not have the file descriptor but the termios that I don't completely understand. Does someone provide me and example to make this 'option' This is my RTSControl option class: class RTSControl { public: explicit RTSControl(bool enable = false) : m_enable(enable) {}; boost::system::error_code store(BOOST_ASIO_OPTION_STORAGE& storage, boost::system::error_code& ec) const { #if defined(BOOST_WINDOWS) || defined(__CYGWIN__) if (m_enable) storage.fRtsControl = RTS_CONTROL_ENABLE; else storage.fRtsControl = RTS_CONTROL_DISABLE; #else #endif return ec; }; boost::system::error_code load(const BOOST_ASIO_OPTION_STORAGE& storage, boost::system::error_code& ec) { #if defined(BOOST_WINDOWS) || defined(__CYGWIN__) if (storage.fRtsControl == RTS_CONTROL_ENABLE) m_enable = true; else m_enable = true; #else #endif return ec; }; private: bool m_enable; }; BOOST_ASIO_OPTION_STORAGE is termios for Linux systems.

1 1

[Proto] lambda functions with named variables
by Hossein Haeri 04 Nov '10

04 Nov '10

Dear all, I am thinking of having creatures like lam(x)(x + 2) in my code which would be the Haskell equivalent for \x -> x + 2. In fact, I am working in an untyped world (with very limited functionality) and my typical lambda expressions would only include (function) applications, (lambda) abstractions, and let-bindings. It is exactly for the existence of let-bindings that I guess I can't resort to placeholders like: template<int> placeholder; const terminal<placeholder<0> >::type _1 = {{}}; const terminal<placeholder<1> >::type _2 = {{}}; const terminal<placeholder<2> >::type _3 = {{}}; ... The point is that I need to store what each variable is bound to. And, AFAIK, I can't store such information in std::map<> for _1 has a different type than _2 for example. So, the two hopes that I have in Proto for solving this problem are: 1) To provide a type T instances of which can act like untyped variables in accepting values of different C++ types. T should also be storable in a map-like container. Boost.Any comes to mind for the first requirement but the problem is that there is no meaningful operator < or operator == to use map or unordered_map for boost::any objects. Note that a1 != a2 needs to the case only when a1 and a2 are distinct variables. Can proto::_ be of any help here? 2) To provide a map-like container in which I can store things like boost::any objects. OK, maybe this is not for Proto to address but though it might still have something to offer... TIA, --Hossein

3 5

[proto]: Adding functions to the lazy vector example
by Noman 04 Nov '10

04 Nov '10

Hi I am experimenting with the lazy vector example. I want to add the functions to the example but not in the LazyVector class. Like for example I want to add a function INC which increments each element of the vector and returns a vector. How can I add this to the example? Thanks in anticipation Regards

2 6

bjam in 1.44 vs 1.39
by Jonathan Brannan 04 Nov '10

04 Nov '10

We recently switched from boost 1.39 to boost 1.44. We use the bjam and boost build packaged with the version of boost we use. It seems that the bjam packaged with 1.44 exists with 0 even if there is a failure: ...failed gcc.compile.c++ /home/foo/Foo.o... ...failed updating 1 target... machine:/home/foo # echo $? 0 It stops early with the -q and prints out that it failed, it just exits 0. bjam -v Boost.Jam Version 3.1.18. OS=LINUX. Copyright 1993-2002 Christopher Seiwald and Perforce Software, Inc. Copyright 2001 David Turner. Copyright 2001-2004 David Abrahams. Copyright 2002-2008 Rene Rivera. Copyright 2003-2008 Vladimir Prus. With Version 3.1.17. OS=LINUX version that came with 1.39, I get an exit status of 1, which is what I expect.

1 1

[mpl] Iterator Concept Checking?
by Stirling Westrup 04 Nov '10

04 Nov '10

I am writing some algorithms to operate on MPL sequences, and I would like to use some form of concept checking to ensure that the types passed in that are supposed to be iterators are, in fact, iterators. The MPL library doesn't seem to have is_XXX_iterator<T> checks, and I have run into some difficulties in determining how to write them. The MPL documents state that a random_access_iterator is a 'refinement' of a bidirectional_iterator which is a 'refinement' of a forward_iterator, but its not clear what refinement means in this context. I initially assumed that this meant that a random_access_iterator_tag was derived from a bidirectional_iterator_tag which was derived from a forward_iterator_tag. This does not appear to be the case, so the obvious test for an iterator (checking that the class contains a member named 'category' that is a type derived from the iterator tag of the least acceptable iterator) will not work. I am sure I could cobble together something that would work by examining the internals of the library, but I would far rather have some guidance on the correct way to see if an iterator matches a given iterator model, within the API of the library. Does anyone have any suggestions? -- Stirling Westrup Programmer, Entrepreneur. https://www.linkedin.com/e/fpf/77228 http://www.linkedin.com/in/swestrup http://technaut.livejournal.com

2 3

boost::recursive_mutex doesn't lock ???
by Chris 03 Nov '10

03 Nov '10

Hello. I have a question about mutexes: Scenario 1: (OK) int main() { boost::mutex io_mutex; io_mutex.lock(); // thread will be blocked now boost::mutex::scoped_lock lock(io_mutex); cout << "Test" // this statement is not executed: OK } So far no problem, but if I use recursive_mutex instead... Scenario 2: (NOT OK) int main() { boost::recursive_mutex io_mutex; io_mutex.lock(); // thread will NOT be blocked ??? boost::recursive_mutex::scoped_lock lock(io_mutex); cout << "Test" // this statement is executed ??? } no blocking occurs?? I tried with unique_lock instead of scoped_lock but still no blocking Why not? I don't understand. How does one lock a recursive_mutex then? thank you Chris

4 5

[Any] Operator ==
by Hossein Haeri 03 Nov '10

03 Nov '10

Dear all, Is there any way to implement an operator == (and perhaps also operator !=) for objects of type boost::any so that different instances are always != and an instance is always only == to itself -- regardless of the respective values? In case you're wondering why I'd interested in such operators, the answer is that I'm thinking of storing objects of type boost::any in an unordered_map. So, it would be equivalently helpful if you could provide a function object to be sent as the Pred template parameter to boost::unordered_map. TIA, --Hossein

4 7

[asio] Removing server socket from service
by Sakharuk, Vladimir 03 Nov '10

03 Nov '10

I have one thread how runs io_service. I have 2 servers (tcp) ports with all corresponded acceptor and bunch of sockets connected to both ports. I am looking into the way to stop just one server but still run the other one. I have implemented a "hard" way to stop server: remove acceptor, cancel/close sockets, that will trigger all read/write asynchronous callbacks, wait till they all done. but there is a incontinence I need to know how may callbacks still here. Is there any simpler way to do the same thing? Something like block the cancel call until all call back done? Please follow the attached hyperlink to an important disclosure: http://www.credit-suisse.com/legal/marketcommentary =============================================================================== Please access the attached hyperlink for an important electronic communications disclaimer: http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html ===============================================================================

4 6

[range] multiple adaptors on sequense
by Sam Fisher 03 Nov '10

03 Nov '10

Hello, Is it possible to apply multiple adaptors to a range-base sequence? Is looks like possible for simple types: #include <string> #include <vector> #include <boost/shared_ptr.hpp> #include <boost/make_shared.hpp> #include <boost/range/algorithm_ext/push_back.hpp> #include <boost/range/adaptor/uniqued.hpp> #include <boost/range/adaptor/transformed.hpp> #include <boost/assign.hpp> using boost::assign::operator +=; #include <boost/spirit/home/phoenix.hpp> namespace phx = boost::phoenix; int square(int val) { return val * val; } int range_test_simple() { typedef std::vector<int> V; V source; source += 1,1,1,2,2,2,3,3,3,4; using namespace boost::adaptors; V result; boost::push_back(result, source | transformed(&square)); // Ok boost::push_back(result, source | uniqued); // Ok boost::push_back(result, source | transformed(&square) | uniqued); // Ok boost::push_back(result, source | uniqued | transformed(&square)); // Ok return 0; } but how about this? (source is continued...) struct Foo { Foo(const std::string& name, int value) : name_(name), value_(value) { } std::string name_; int value_; }; typedef boost::shared_ptr<Foo> FooPtr; int range_test_complex() { typedef std::vector<FooPtr> V; V source; source += boost::make_shared<Foo>("Foo", 10), boost::make_shared<Foo>("Bar", 20), boost::make_shared<Foo>("Baz", 30), boost::make_shared<Foo>("Baz", 30) // duplicate is here ; std::vector<std::string> result1; std::vector<int> result2; using namespace boost::adaptors; using phx::arg_names::arg1; boost::push_back(result1, source | transformed(phx::bind(&Foo::name_, *arg1)) | uniqued); // Fails boost::push_back(result2, source | transformed(phx::bind(&Foo::value_, *arg1)) | uniqued); // Fails return 0; } What I'm doing wrong? I use MSVS 2010 and boost trunk. Thanks, Sam

2 3

Managing pipelines?
by Olivier Tournaire 03 Nov '10

03 Nov '10

Hi all, I am currently thinking on how to handle pipelines in some of my application. By pipeline, I mean "something" in which I can set an input, add some processing on that input, and retrieve the output (the result of the processing). If I am not clear enough, let's go with an example. Suppose I have an image, and I want first to crop it, then apply a filter on the crop and get the result in another image. Does boost has a library with such a feature? Best regards, Olivier ----------------------------------------------------- Olivier Tournaire MATIS - Institut Géographique National 73, Ave de Paris 94165 St Mandé cedex, France tel: (+33) 1 43 98 84 29 fax: (+33) 1 43 98 85 81

3 5

Re: [Boost-users] Boost-users Digest, Vol 2531, Issue 1
by Dhirendra Pal Singh 03 Nov '10

03 Nov '10

> > On Tue, Nov 2, 2010 at 10:06 AM, Dhirendra Pal Singh <s9_rose(a)yahoo.com> > wrote: > > Hi Folks, > > If this question has been asked already, I apologise, > but I have to go back to my group and present the answer. So > please bear with me. > > > > In my current project we are using boost extensively, > with exceptions disabled, until last week, when I started > using boost threads. I get the following error when > compiling... > > > > *************** > > > deepsin@deepsin-lnx01:~/code/boost_thread/boost_threads_eg1$ > g++ -fno-exceptions -g -I /usr/local/include/boost/ t1.cpp > -o t1 -lboost_thread > > In file included from > /usr/local/include/boost/exception_ptr.hpp:9, > > ? ? ? ? ? ? ? ? from > /usr/local/include/boost/thread/future.hpp:14, > > ? ? ? ? ? ? ? ? from > /usr/local/include/boost/thread.hpp:24, > > ? ? ? ? ? ? ? ? from t1.cpp:3: > > > /usr/local/include/boost/exception/detail/exception_ptr.hpp:17:2: > error: #error This header requires exception handling to be > enabled. > > ************** > > > > This means that any header file that includes, > thread.hpp can't be compiled with -fno-exceptions. I have > couple of questions if someone could help me with, I would > appreciate. > > It appears that this is due to a dependency of Boost Thread > on Boost > Exception's exception_ptr. Somebody should look into this > and either > remove that dependency or add #ifndef BOOST_NO_EXCEPTIONS > around the > relevant code (unfortunately I don't have time right now to > look into > this myself.) > > Emil Dotchevski > Reverge Studios, Inc. > http://www.revergestudios.com/reblog/index.php?n=ReCode > Thanks for a response Emil. Do you think you can spare some time for hand holding, so that I can make this change... :) Thanks PS: I love this link on your webpage. http://www.revergestudios.com/reblog/uploads/ReCode/languages1.jpg. Everybody in my group got a kick out of it.

1 0

Polymorphic serialization with polymorphic archives problems... [part 2]
by Bogdan 03 Nov '10

03 Nov '10

First I would like to confirm I tested Robert Ramey's fix (@60273) for multiple registrations and it looks good in my runs. Thank you Robert! On the other hand, I am under the impression there is a bug in void_caster::recursive_unregister(), although I am not 100% certain about the reason: that function member is called in the destructors of the void caster template classes and makes use of the void_caster_registry singleton (more specifically the type_set). I believe it searches the set for all the void caster entries that are descendants of the current one (i.e., the one being destroyed) and performs the following ops: - delete the shortcuts. - remove the corresponding entries from the set. However, void_caster::recursive_unregister() DOESN'T REMOVE FROM THE REGISTRAR the entry corresponding to the current void_caster(). This creates the problem below: consider a scenario where a dll containing some serialization functionality is loaded explicitly at runtime (i.e., using LoadLibrary() on Windows or dlopen on Unix). There are no parent-child relationships among the serialized classes registered by that DLL: all serialized classes are derived from one abstract base. While unloading the library, its void_caster singletons are destroyed but there are no shortcuts to remove from the global registrar since there are no parent-child relationships. All entries corresponding to those are still in the global registrar and POINT TO THE void_caster SINGLETONS ALREADY DESTROYED AND DISCARDED. When the main process exits, the registrar traversal repeats for whatever process-bound void_caster singletons are about to be destroyed. During these subsequent traversals, void_caster::recursive_unregister() visits the entries left after the previous explicit dll download and tries to identify the parent-child relationship. In doing so, it accesses the dangling vc pointers generating access violations: void_cast.cpp(Line 286): const void_caster * vc = *it; void_cast.cpp(Line 287): if(vc->m_parent == this){ //<--------------------- here is the access violation I can reproduce the crash systematically, but I am not sure about the reason or whether a simple unregistration is enough. I believe this is (again) a question for Robert, but I thank for any feedback I might get. Bogdan

2 1

[Graph] how to find all shortest paths (not just one of them)?
by Erik Sjölund 03 Nov '10

03 Nov '10

Hi, I managed to record a shortest path between two vertices by doing adjacency_list < vecS, vecS, undirectedS > g; std::vector<Vertex> p(boost::num_vertices(g)); Vertex vertex = *(boost::vertices(g).first); boost::breadth_first_search(g, vertex, boost::visitor( boost::make_bfs_visitor( boost::record_predecessors(&p[0], boost::on_tree_edge()) ) ) ); The shortest path can be found by inspecting the vector p. But my goal is slightly different. Does anyone know how to "record" all shortest paths between two vertices? (i.e. all paths having the minimal path length) cheers, Erik Sjölund

3 2

bjam and msvc PDB files destination directory?
by Martin B. 03 Nov '10

03 Nov '10

Hi! Is it possible to tell bjam to put the generated PDB files (MSVC) alongside the dll/lib files into the stage directory? Here's what I'm using so far: (Boost 1.44.0) bjam.exe --build-type=complete runtime-link=shared variant=release toolset=msvc-8.0 threading=multi debug-symbols=on debug-store=database define=_SECURE_SCL=0 --with-regex Is there an additional option that I can pass on the command line to have the (correctly generated) PDB files also copied into the stage directory? thanks! - Martin

1 0

[proto] : Using proto with NVIDIA CUDA nvcc (redux)
by Manjunath Kudlur 03 Nov '10

03 Nov '10

I remember there were postings in this mailing list before about trying to using proto with NVIDIA's CUDA compiler, and Joel Falcou has contributed some code to make proto work with nvcc. Well, I was trying few experiments with the most recent CUDA compiler release (3.2). I believe one of the exciting things about using proto with CUDA is the ability to write mini programs in different DSELs using proto and ship the mini programs over to the "device" side and execute it there. This idiom will look as follows : template<typename F> __global__ void kernel(F f) { f(...); } kernel<<<blocksize, gridsize>>>(a+b /* a big proto expression */); I tried to write the simplest form of the above use case : #include <boost/proto/proto.hpp> namespace proto=boost::proto; template<typename> struct expr; struct domain : proto::domain<proto::pod_generator<expr> > {}; template<typename E> struct expr { BOOST_PROTO_BASIC_EXTENDS(E, expr<E>, domain) }; template<typename F> __global__ void kernel(F f) { } struct term {}; expr<proto::terminal<term>::type> a = {{{}}}; expr<proto::terminal<term>::type> b = {{{}}}; expr<proto::terminal<term>::type> c = {{{}}}; int main() { kernel<<<1,1>>>(proto::deep_copy(b+c)); return 0; } Note the deep_copy when passing proto expression to kernel functions. Since proto captures terminals by reference, the host side pointers that are held in proto expressions won't make sense on the device side, so at the very least, we have to make copies of terminals before passing to the device. Now, compiling the above program with nvcc (CUDA 3.2, host compiler gcc 4.4.3, Ubuntu 10.04) results in the following error (besides spewing a bunch of warnings) : $ nvcc -v -keep t.cu -I $HOME/boost/boost-trunk/ ... t.cudafe1.stub.c: In function ‘void __device_stub__Z6kernelI4exprIN5boost5proto7exprns_10basic_exprINS2_3tag4plusENS2_7argsns_5list2IS0_INS4_IS6_NS8_IS0_INS4_INS5_8terminalENS7_4termI4termEELl0EEEESE_EELl2EEEES0_INS4_IS9_NSA_IiEELl0EEEEEELl2EEEEEvT_(_Z4exprIN5boost5proto7exprns_10basic_exprINS1_3tag4plusENS1_7argsns_5list2IS_INS3_IS5_NS7_IS_INS3_INS4_8terminalENS6_4termI4termEELl0EEEESD_EELl2EEEES_INS3_IS8_NS9_IiEELl0EEEEEELl2EEEE&)’: t.cudafe1.stub.c:8: error: invalid cast from type ‘const expr<boost::proto::exprns_::basic_expr<boost::proto::tag::address_of, boost::proto::argsns_::list1<expr<boost::proto::exprns_::basic_expr<boost::proto::tag::plus, boost::proto::argsns_::list2<expr<boost::proto::exprns_::basic_expr<boost::proto::tag::plus, boost::proto::argsns_::list2<expr<boost::proto::exprns_::basic_expr<boost::proto::tag::terminal, boost::proto::argsns_::term<term>, 0l> >, expr<boost::proto::exprns_::basic_expr<boost::proto::tag::terminal, boost::proto::argsns_::term<term>, 0l> > >, 2l> >, expr<boost::proto::exprns_::basic_expr<boost::proto::tag::terminal, boost::proto::argsns_::term<int>, 0l> > >, 2l> >&>, 1l> >’ to type ‘char*’ t.cudafe1.stub.c:8: error: invalid cast from type ‘const expr<boost::proto::exprns_::basic_expr<boost::proto::tag::address_of, boost::proto::argsns_::list1<expr<boost::proto::exprns_::basic_expr<boost::proto::tag::plus, boost::proto::argsns_::list2<expr<boost::proto::exprns_::basic_expr<boost::proto::tag::plus, boost::proto::argsns_::list2<expr<boost::proto::exprns_::basic_expr<boost::proto::tag::terminal, boost::proto::argsns_::term<term>, 0l> >, expr<boost::proto::exprns_::basic_expr<boost::proto::tag::terminal, boost::proto::argsns_::term<term>, 0l> > >, 2l> >, expr<boost::proto::exprns_::basic_expr<boost::proto::tag::terminal, boost::proto::argsns_::term<int>, 0l> > >, 2l> >&>, 1l> >’ to type ‘size_t’ # --error 0x1 -- The CUDA compiler works by splitting the original C++ code into "host" code and "device" code. The device code is completely lowered to C. So it seems like the above error is when passing a proto expression to the C-lowered version of device code. The proto expression is a simple POD type, so I am perplexed by the above error. (BTW, when the host compiler is gcc 4.1.3, the above program causes a segmentation fault in gcc, but that's for another forum). This might well be CUDA compiler's problem, but I dug a little deeper. I transformed the proto expression into a simpler POD type as follows : #include <boost/proto/proto.hpp> namespace proto=boost::proto; struct filler {}; template<typename tag, typename C0, typename C1=filler> struct myexpr { C0 c0; C1 c1; }; struct myadd {}; struct myterm {}; struct xform_callable : proto::callable { template<typename> struct result; template<typename This, typename LHS> struct result<This(LHS&)> { typedef myexpr<myterm, LHS> type; }; template<typename LHS> typename result<xform_callable(LHS&)>::type operator()(LHS &l) { myexpr<myterm, LHS> e = {l}; return e; } template<typename This, typename tag, typename LHS, typename RHS> struct result<This(tag, LHS, RHS)> { typedef myexpr<tag, LHS, RHS> type; }; template<typename tag, typename LHS, typename RHS> typename result<xform_callable(tag, LHS, RHS)>::type operator()(tag, LHS l, RHS r) { myexpr<tag, LHS, RHS> e = {l, r}; return e; } }; struct xform : proto::or_< proto::when<proto::plus<proto::_, proto::_>, xform_callable(myadd(), xform(proto::_left), xform(proto::_right))> , proto::when<proto::terminal<proto::_>, xform_callable(proto::_value)> > {}; template<typename> struct expr; struct domain : proto::domain<proto::pod_generator<expr> > {}; template<typename E> struct expr { BOOST_PROTO_BASIC_EXTENDS(E, expr<E>, domain) }; template<typename F> __global__ void kernel(F f) { } struct term {}; expr<proto::terminal<term>::type> a = {{{}}}; expr<proto::terminal<term>::type> b = {{{}}}; expr<proto::terminal<term>::type> c = {{{}}}; int main() { kernel<<<1,1>>>(xform()(b+c)); return 0; } The above program compiles fine with CUDA 3.2. That leaves me with the question : what does a proto expression contain more than myexpr above, that causes nvcc to fail? Again, this might be CUDA compiler's problem and they are the ones that should fix it. However, if someone in this forum can think of a simple fix to proto (or some other boost library that is actually causing the problem), that would be great too. The uniform template expansion across device and host code in CUDA programs is a powerful feature, and I envision some cool libraries that can be written using proto with CUDA. So making proto work with CUDA is a big win. Manjunath

5 12

[fusion] Are Sequence stream IO operators recursive?
by Hugh Dickinson 03 Nov '10

03 Nov '10

I'm trying to output an adapted fusion sequence (PMT::QE::DataSet<PMT::QE::Measurement>) containing other adapted fusion sequences to std::cout. I had hoped for recursive behaviour, such that the contents of each sub-sequence are printed in turn. Having looked at the code in $BOOST_ROOT/boost/fusion/sequence/io/detail/out.hpp it looks like: ---- PMT::QE::DataSet<PMT::QE::Measurement> output; ... Fill output ... std::cout << output << std::endl; ---- should work. Unfortunately, I'm getting compilation errors like: no match for ‘operator<<’ in ‘os << boost::fusion::operator* [with Iterator = boost::fusion::basic_iterator<boost::fusion::struct_iterator_tag, boost::fusion::assoc_struct_category, const PMT::QE::DataSet<PMT::QE::Measurement>, 0>](((const boost::fusion::iterator_base<boost::fusion::basic_iterator<boost::fusion::struct_iterator_tag, boost::fusion::assoc_struct_category, const PMT::QE::DataSet<PMT::QE::Measurement>, 0> >&)((const boost::fusion::iterator_base<boost::fusion::basic_iterator<boost::fusion::struct_iterator_tag, boost::fusion::assoc_struct_category, const PMT::QE::DataSet<PMT::QE::Measurement>, 0> >*)((const boost::fusion::basic_iterator<boost::fusion::struct_iterator_tag, boost::fusion::assoc_struct_category, const PMT::QE::DataSet<PMT::QE::Measurement>, 0>*)first))))’ The other errors simply replace the index 0 with 1 and 2 (PMT::QE::DataSet has 3 elements). On the other hand, the following does work: ---- PMT::QE::DataSet<PMT::QE::Measurement> output; ... Fill output ... std::cout << at_c<0>(output) << std::endl; std::cout << at_c<1>(output) << std::endl; std::cout << at_c<2>(output) << std::endl; ---- Is this the expected behaviour? What am I missing? Is there a way to achieve the desired recursive behaviour? Many thanks, Hugh

4 5

boost threads without exceptions...
by Dhirendra Pal Singh 03 Nov '10

03 Nov '10

Hi Folks, If this question has been asked already, I apologise, but I have to go back to my group and present the answer. So please bear with me. In my current project we are using boost extensively, with exceptions disabled, until last week, when I started using boost threads. I get the following error when compiling... *************** deepsin@deepsin-lnx01:~/code/boost_thread/boost_threads_eg1$ g++ -fno-exceptions -g -I /usr/local/include/boost/ t1.cpp -o t1 -lboost_thread In file included from /usr/local/include/boost/exception_ptr.hpp:9, from /usr/local/include/boost/thread/future.hpp:14, from /usr/local/include/boost/thread.hpp:24, from t1.cpp:3: /usr/local/include/boost/exception/detail/exception_ptr.hpp:17:2: error: #error This header requires exception handling to be enabled. ************** This means that any header file that includes, thread.hpp can't be compiled with -fno-exceptions. I have couple of questions if someone could help me with, I would appreciate. Q1). https://svn.boost.org/trac/boost/ticket/2100, actually says that threads can be compiled without exceptions. Unfortunately its not the case, as I looked at top-of-trunk codebase and the problem still exists. Is this true? I mean threads require exceptions for a fact that is?. If not then can someone help me how to get it to compile without exceptions, and discard the reset of my email please. Q2). If the answer to Q1 is "yes boost threads require exceptions", then was the decision conscious, given a ticked, was opened and closed specifically for this purpose. Q3). Also any idea what is needed to make boost threads work without exception. I mean in terms of man-hours. If my group is okay perhaps I may be willing to work on that change, submit it back to the community, but would need some sort of understanding of the work required and time needed. Any help would be much appreciated.... Thanks in advance... /dev/deep

3 2

cannot open shared object file
by Mike Douglass 03 Nov '10

03 Nov '10

Downloaded the trunk ( Today Nov 2 ) Did: ./bjam --with-libraries=graph,regex ./bjam compiled OK. mv boost-trunk/stage/lib/* /usr/local/lib mv boost-trunk/boost /usr/include my program plc.cpp compiled OK with the following makefile. g++ -ggdb -O3 plc.cpp -o plc -I./Includes -L/usr/local/lib -lboost_graph -lboost_regex But running plc gave the following error ./plc < graph.xml > out.xml ./plc: error while loading shared libraries: libboost_graph.so.1.45.0: cannot open shared object file: No such file or directory But clearly libboost_graph.so.1.45.0 is there. [george@localhost lib]$ ls -lrt /usr/local/lib total 6768 -rwxr-xr-x 1 root root 1155683 Nov 2 20:57 libboost_regex.so.1.45.0 -rwxr-xr-x 1 root root 1155683 Nov 2 20:57 libboost_regex.so -rw-r--r-- 1 root root 2563346 Nov 2 20:57 libboost_regex.a -rwxr-xr-x 1 root root 534275 Nov 2 20:57 libboost_graph.so.1.45.0 -rwxr-xr-x 1 root root 534275 Nov 2 20:57 libboost_graph.so -rw-r--r-- 1 root root 923492 Nov 2 20:57 libboost_graph.a [george@localhost lib]$ Whats wrong? Running Centos 5.5 [george@localhost Program]$ uname -a Linux localhost.localdomain 2.6.18-194.el5 #1 SMP Fri Apr 2 14:58:14 EDT 2010 x86_64 x86_64 x86_64 GNU/Linux Thanks

1 0

Multi file test module in Boost.Test
by Guillaume Dumont 03 Nov '10

03 Nov '10

Hi, I have been trying to get a multi file test module to execute without success. I have the following setup: // main.cpp #define BOOST_TEST_MODULE example #include <boost/test/unit_test.hpp> // suite1.cpp #include <boost/test/unit_test.hpp> BOOST_AUTO_TEST_SUITE(suite1); BOOST_AUTO_TEST_CASE(test1) { ... } BOOST_TEST_SUITE_END(); // suite2.cpp #include <boost/test/unit_test.hpp> BOOST_AUTO_TEST_SUITE(suite2); BOOST_AUTO_TEST_CASE(test2) { ... } BOOST_TEST_SUITE_END(); But only one of the two test cases runs. If I put the suites into the same .cpp file all the test cases are run. Is it possible to link against the static library variant of boost test and have a multi file test module? From what I understand it should be, but I can just find how. Thank you. -- Guillaume Dumont ========================= dumont.guillaume(a)gmail.com

1 0

[proto] vec3 sample error
by Kamil Zubair 02 Nov '10

02 Nov '10

I found a strange error when I try the vec3 sample from proto, my code is like this: struct Vec3SubscriptCtx : proto::callable_context< Vec3SubscriptCtx const > { typedef int result_type; Vec3SubscriptCtx(int i) : i_(i) {} // Index array terminals with our subscript. Everything // else will be handled by the default evaluation context. int operator ()(proto::tag::terminal, int const (&arr)[3]) const { return arr[this->i_]; } int i_; }; struct Vec3 : proto::extends<proto::terminal<int[3]>::type, Vec3> { explicit Vec3(int i=0, int j=0, int k=0) { (*this)[0] = i; (*this)[1] = j; (*this)[2] = k; } int &operator [](int i) { return proto::value(*this)[i]; } int const &operator [](int i) const { return proto::value(*this)[i]; } // Here we define a operator = for Vec3 terminals that // takes a Vec3 expression. template< typename Expr > Vec3 &operator =(Expr const & expr) { typedef Vec3SubscriptCtx const CVec3SubscriptCtx; (*this)[0] = proto::eval(proto::as_expr(expr), CVec3SubscriptCtx(0)); (*this)[1] = proto::eval(proto::as_expr(expr), CVec3SubscriptCtx(1)); (*this)[2] = proto::eval(proto::as_expr(expr), CVec3SubscriptCtx(2)); return *this; } template< typename Expr > Vec3 (Expr const & expr) { typedef Vec3SubscriptCtx const CVec3SubscriptCtx; (*this)[0] = proto::eval(proto::as_expr(expr), CVec3SubscriptCtx(0)); (*this)[1] = proto::eval(proto::as_expr(expr), CVec3SubscriptCtx(1)); (*this)[2] = proto::eval(proto::as_expr(expr), CVec3SubscriptCtx(2)); } void print() const { std::cout << '{' << (*this)[0] << ", " << (*this)[1] << ", " << (*this)[2] << '}' << std::endl; } }; int main(int argc, const char* argv[]) { Vec3 a(1, 2, 3); Vec3 b(3, 2, 1); Vec3 c; c = b; c.print(); return 0; } I expected that when c is printed it will display 3, 2, 1 ( the value of b ) but instead it print 0,0,0 like b is never assigned to c. I try this using vs 2010 with boost 1.44 in windows 7 64.

2 1

[serialization] Class version in binary archive
by Guy Prémont 02 Nov '10

02 Nov '10

Hi all, I have a whole hierarchy of classes that is serialized without problem using XML archive. When I wanted to use binary archive (that should be faster and smaller), i met an little problem. A bit of history, to make it easier to spot related changes in class versions, we decided not to go with serial class version numbers (1, 2, 3...) but with meaningful version numbers: internal branch number + date. We end up with class versions like 420100714 or 520101102. In XML or text, no problem at all. In binary, it took me a while to find out that class version numbers are serialized as unsigned char! However, the documentation here <http://www.boost.org/doc/libs/1_44_0/libs/serialization/doc/archive_referen ce.html> says unsigned int. It is a bit surprising, since the type passed to the serialization method is int. I understand that I need to create my own binary archive to implement save_override and load_override for version_type. However, doing the override means that i am preventing the use of standard boost binary archive. Is that a known bug, or is it even considered a bug? Thanks -- Guy Prémont, D.Sc. Architecte logiciel senior / Senior software architect CM Labs Simulations Inc. <blocked::http://www.cm-labs.com/> http://www.cm-labs.com/ Tel. 514-287-1166 ext. 237

1 0

Re: [Boost-users] [1.44 MSM meta state machine] accessing objects fromactions
by Christophe Henry 02 Nov '10

02 Nov '10

> Currently my queue object is a member of the state machine itself, so I > can write > > struct Send_ : public msm::front::state_machine_def<Send_> > { > string m_next_line_to_send; > socket m_socket; > string get_next_send_line(); > }; > > and in my a_send action > void operator()(Event &const &evt, Fsm &fsm, S&, T&) > { > fsm.m_next_line_to_send=fsm.get_next_send_line(); > fsm.m_socket.async_write(fsm.m_next_line_to_send); > } > > This works well as long as I am not using sub-statemachines. > > Here is my problem: > I would like to use a substate machine for the actual sending. The main > state machine has the states Disconnected, Working, Error, Shutdown. The > Working state should actually be a substate machine. > > The problem is, when a_send gets called by the substate machine Working, > the fsm object is of type Working. Correct. There is no "fsm call stack" yet. This gets complicated if you have a submachine of a submachine of ... For the moment I don't have this. > How can I access the member variables of the parent of a substate > machine? Or is there a better way of accessing the objects the state > machine should work with from actions? For the moment, all we can do is adding a pointer to the main fsm's data in the submachine. It is less elegant with the 1.44 than the coming 1.45: With 1.44 (for example inside the on_entry method of Send_): Send_::Working& w = fsm.get_state<Send_::Working&>(); w.data = &fsm.data; // w.data is a pointer True, this is not really nice. With the upcoming 1.45 (or trunk for the moment), you could use the new constructors: Send myfsm (msm::back::states_ << Working(data) ); //data being externally defined and Working_ having a corresponding constructor But this won't work for your case where data is contained in Send_ (and therefore does not exist at the time of construct). You can however reuse the same syntax with the new set_states method: Replace the version with get_state by: fsm.set_states(msm::back::states_ << Working(fsm.data)); //data being defined in Send_ and Working_ having a corresponding constructor. The whole explanation is there (http://svn.boost.org/svn/boost/trunk/libs/msm/doc/HTML/ch03s05.html#backend…) > The tutorial explains state machines very nicely with the example of a > CD player. But all the actions are empty and nowhere is explained, how > you would actually access a CD player member variable or other such > object so that you could actually manipulate the player to do something. Seems that I need to improve my doc here. It's too late for the 1.45 but I'll do it for the 1.46. I agree that this is still not perfect and it's on my list but the list is still pretty long so I hope this solution will be ok for the time being. Regards, Christophe

2 3

iostreams zip header
by Kraus Philipp 02 Nov '10

02 Nov '10

Hi, I'm using the gzip and bzip2 compression for compress data. That works fine, but can I remove the zip header in the output stream? The compressor is pushed into a filtering_streambuf and output stream, but I don't need the the zip header (only the compressed data). Is there any method to remove the zip header or should I write my own code at the gzip / bzip2 specifiation? Thanks Phil

1 0

[Review][Ratio] Boost.Ratio has been ACCEPTED
by Anthony Williams 02 Nov '10

02 Nov '10

The following message is a courtesy copy of an article that has been posted to gmane.comp.lib.boost.devel as well. Hi, I am pleased to announce that Boost.Ratio has been ACCEPTED into Boost. There were not as many reviews for Boost.Ratio as for some libraries, but they were overwhelmingly positive. Boost.Ratio is an important building block for other upcoming submissions, and provides an implementation of the C++0x rational arithmetic facilities. A few changes were requested by the reviewers, which I will list below. I know that Vicente has already started working on some of these. These changes should be addressed before the library appears in a Boost release. * Some of the macros had names with RATIO_RATIO in. These should be changed to just RATIO * The ratio_add, ratio_sub, ratio_multiply and ratio_divide templates should derive from the resulting ratio type as well as providing the nested ::type member, in order to closely emulate the template alias facility from C++0x * The typos in the documentation should be fixed, and the documentation reviewed for correctness and clarity (though several of the reviewers made positive comments on the quality of the documentation). * The library needs more tests under the Boost Software License. * All references to names from the boost namespace should be qualified with boost:: to avoid potential name clashes and ambiguity with names from the global namespace. * Sections commented out with #if 0 should be removed * The extensions beyond the facilities required by the C++0x draft should be able to be enabled or disabled through use of a configuration macro. * References to the tests, examples and documentation from within the code should be checked for correctness. I would like to thank Vicente for submitting the library and those that took the time to write a review. Anthony -- Author of C++ Concurrency in Action http://www.stdthread.co.uk/book/ just::thread C++0x thread library http://www.stdthread.co.uk Just Software Solutions Ltd http://www.justsoftwaresolutions.co.uk 15 Carrallack Mews, St Just, Cornwall, TR19 7UL, UK. Company No. 5478976

2 1

how to build non-boost asio without boost
by Jeff Graham 02 Nov '10

02 Nov '10

Everyone, I need a header-only version of ASIO for a stripped-down embedded system. I downloaded the latest and greatest asio version 1.4.5 from Chris Kohlkoff's think-asyn.com website. This version is supposedly the "boost-free" version. But I cannot get it to configure without boost. The web page certainly suggests "building" asio boost-free is possible. The release notes do not indicate otherwise. OTOH, the documentation only mentions configuring WITH boost. And, as mentioned in other discussions, the headers are full of #includes for boost files. I tried several obvious variations for configure that all fail, insisting on using boost (which does not exist on my system): ./configure -without-boost ./configure -without-boost ./configure -with-boost=no ./configure -with-boost= Could some kind soul please explain what I am doing wrong? I don't have bcp, but if I did, would that work? Thanks

2 1

Removing edges using remove_edge in adjacency list
by giridhar 02 Nov '10

02 Nov '10

Hello All, I am completely new to using BGL and STL. I know the concept of STL but had never used it before. I have to implement an algorithm for my thesis and I am trying to use BGL for that. I have made use of Dijkstra's algorithm that is inbuilt in BGL. Below is the code, which is similar to that in the reference manual with few changes. #include <iostream> #include <boost/config.hpp> #include <boost/graph/graph_traits.hpp> #include <boost/graph/adjacency_list.hpp> #include <boost/graph/dijkstra_shortest_paths.hpp> using namespace std; using namespace boost; /*struct flow_t { typedef edge_property_tag kind; }; struct capacity_t { typedef edge_property_tag kind; }; namespace boost { enum edge_flow_t { edge_flow}; enum edge_capacity_t {edge_capacity}; BOOST_INSTALL_PROPERTY(edge,capacity); } */ int main() { typedef property<vertex_distance_t,int, property <vertex_name_t,std::string> > VertexProperty; // typedef property<flow_t,capacity_t, int> Cap; typedef property<edge_weight_t,int> EdgeProperty; typedef adjacency_list < listS, vecS, directedS, VertexProperty, EdgeProperty > graph_t; typedef graph_traits < graph_t >::vertex_descriptor vertex_descriptor; // typedef graph_traits < graph_t >::edge_descriptor edge_descriptor; typedef std::pair<int, int> Edge; const int num_nodes = 5; enum nodes { A, B, C, D, E }; char name[] = "ABCDE"; Edge edge_array[] = { Edge(A, B), Edge(A, C), Edge(B, E), Edge(C, B), Edge(C, D), Edge(D, E) // , Edge(D, E), Edge(E, A), Edge(E, B) }; int weights[] = { 4, 1, 3, 2, 2, 3}; int num_arcs = sizeof(edge_array) / sizeof(Edge); graph_t g( edge_array, edge_array+num_arcs, weights, num_nodes); std::vector<vertex_descriptor> p(num_vertices(g)); std::vector<int> d(num_vertices(g)); vertex_descriptor s= vertex(A,g); dijkstra_shortest_paths(g,s,predecessor_map(&p[0]).distance_map(&d[0])); // std::cout<<"timepass"<<s<<std::endl; std::cout<<"Distaces and Parents"<<std::endl; graph_traits<graph_t>::vertex_iterator vi,vend; for(tie(vi,vend)=vertices(g);vi!=vend;++vi) { std::cout<<"distance("<<name[*vi]<<")= "<<d[*vi]<<","; std::cout<<"parent("<<name[*vi]<<")= "<<name[p[*vi]]<<std::endl; } std::cout<<std::endl; graph_traits<graph_t>::vertex_iterator i,iend; // std::cout<<"testing iterators "<<i<<","<<iend<<std::cout; for(tie(i,iend)=vertices(g);i!=iend;++i) { if(s==*i) continue; else remove_edge(name[*i],name[p[*i]],g); } cout<<"After removal of working path"<<std::endl; vertex_descriptor s1= vertex(A,g); std::vector<vertex_descriptor> p1(num_vertices(g)); std::vector<int> d1(num_vertices(g)); dijkstra_shortest_paths(g,s1,predecessor_map(&p1[0]).distance_map(&d1[0])); std::cout<<"Distaces and Parents"<<std::endl; graph_traits<graph_t>::vertex_iterator i1,end1; for(tie(i1,end1)=vertices(g);i1!=end1;++i1) { std::cout<<"distance("<<name[*i1]<<")= "<<d1[*i1]<<","; std::cout<<"parent("<<name[*i1]<<")= "<<name[p1[*i1]]<<std::endl; } std::cout<<std::endl; } Now I want to remove the edges that has been found by Dijkstra's algorithm or alter the weights of those edges found by dijkstra's to some high value. This is mainly to find different route to target. I know I am doing something wrong with iterator's. But I am not able to figure it out due to lack of knowledge in STL. I tried to find it online, but could not find satisfactory explanation. If someone could give some explanation, it would be really helpful for me. Please help. -- Regards, Giridhar

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boost::pool segfault
by Robert Dean 02 Nov '10

02 Nov '10

Hello, I attempted to use the boost::pool STL allocators for a work project which uses millions of objects as part of a memory resident data store. Unfortunately, this caused the program to always segfault with a std::bad_alloc error during initialization. Looking into the problem, it seems to be due to the "next_size <<= 1;" line found in malloc_need_resize and ordered_malloc_need_resize methods. Near as I can tell, every-time boost::pool allocates a new storage chunk it doubles the size request for the next allocation. For an application which uses gigabytes of storage, this means the memory pool requests more memory than the application uses without the pool, as well as sizes larger than the kernel can supply. Is there any way to control this behavior? Or do I have to write my own memory pool? Thanks you, Bob

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Is it possible to use boost:serialization with Managed c++?
by سیّد امین میرزایی 02 Nov '10

02 Nov '10

We have a native c++ class that is serialized perfectly using * boost::serialization*. Now we want to change some of its member fields to *property*, so we could use them in *PropertyGrids*. When we changed the class definiction to *ref class X*, we got a huge number of these compilation errors: #1: error C2893: Failed to specialize function template 'boost::archive::text_oarchive &boost::archive::detail::interface_oarchive<Archive>::operator <<(T &)' d:\someAddress\someFile.cpp 58 #2: error C2784: 'std::basic_ostream<_Elem,_Traits> &std::operator <<(std::basic_ostream<_Elem,_Traits> &,const std::_Smanip<_Arg> &)' : could not deduce template argument for 'std::basic_ostream<_Elem,_Traits> &' from 'boost::archive::text_oarchive' d:\someAddress\someFile.cpp 58 We have a lot of tiny classes here, so it would be a pain to write a wrapper for each of them! Here is the sample class we used: ref class gps_position2 { public: template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & seconds; } public: gps_position(){}; gps_position(float s) { this->seconds = s; } property float seconds; }; And here is the main test code: int main() { std::ofstream ofs("out.txt"); gps_position2 g(24.567f); // save data to archive { boost::archive::text_oarchive oa(ofs); // write class instance to archive oa << g; } // ................ return 0; } Is it even possible to use *boost::serialization* with managed classes? p.s. If we change the class usage code to this: ... gps_position2^ g = gcnew gps_position2(24.567f); ... then we get only 1 error: error C2027: use of undefined type 'boost::STATIC_ASSERTION_FAILURE<x>' D:\path\to\Boost\boostw\boost\archive\detail\check.hpp 60

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[lexical_cast] fails to convert between basic_strings with different traits
by Paul Graphov 01 Nov '10

01 Nov '10

Hello Boost Users, boost::lexical_cast fails to compile when both Target and Source template parameters are std::basic_string instantiations with different traits because deduce_char_traits class template has two suitable instantiations which are ambiguous. This is example where I use custom basic_string that is case insensitive: http://pastebin.com/jGF0yN2m Thanks.

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Re: [Boost-users] Spirit Porting
by Avi Bahra 01 Nov '10

01 Nov '10

Bryce Lelbach wrote: >Regarding IBM's compiler, I tried to obtain a testing version/demo. The vague >link to trial/demo stuff on their website seems to be broken (I tried it in IE >8 on Windows and w3m on Linux. I lack the supercomputing power needed to run >Firefox). >Avi, I'd love to try to help support you here, but I can't do much without at least >access to a trial version of the compiler. I've sent an email to IBM asking for >the production version of their compiler, but I doubt that will end well. I have had contact with Michael, from IBM, and took part in providing feedback for beta version of their latest v11.1 compiler. My number one issue was to make sure boost serialisation worked. To that end, they had devoted resources to make sure this worked. So on the whole I am happy with what they provided. There is however still a couple of outstanding issues with regards serialisation: o portable binary archive is broken o release mode of the compiler, crashes I have provided them test samples which show these issue, but I am not sure if any resource has been put to address this. Currently I use spirit classic and boost serialisation on AIX. I am very keen to move to spirit v2/Qi . So its also critical for me that IBM does address the issue at some point in the near future.(performance of spirit classic AST is really bad) I will contact Michael Wong and request that they look into this issue(Spirit V2) or make the compiler available to you. However their are no guarantees. If there any progress , I will report back on this mailing group. Best regards, Ta, Avi

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Segmentation fault boost::re_detail::perl_matcher
by manju k 01 Nov '10

01 Nov '10

Hello all, My application is using boost regular expression library. When my application calls regex_replace it seg faults in in this function. (gdb) where #0 0x00007f6e83cdf998 in boost::re_detail::perl_matcher<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, boost::regex_traits<char, boost::cpp_regex_traits<char> > >::find_imp() () from ../../../ThirdParty/redhat64/lib64/libboost_regex.so.5 #1 0x00007f6e83cdff15 in bool boost::regex_search<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > >, char, boost::regex_traits<char, boost::cpp_regex_traits<char> > >(__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, __gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, boost::match_results<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<boost::sub_match<__gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > > > >&, boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags, __gnu_cxx::__normal_iterator<char const*, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >) () from ../../../ThirdParty/redhat64/lib64/libboost_regex.so.5 #2 0x00007f6e83a5c5ef in boost::regex_replace<boost::re_detail::string_out_iterator<std::string>, __gnu_cxx::__normal_iterator<char const*, std::string>, boost::regex_traits<char, boost::cpp_regex_traits<char> >, char> () I am using boost 64bit library on 64bit RHEL 6. Has anyone faced the same problem earlier ? regards, manju

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std::string corrupt after including boost
by Simon Adler 01 Nov '10

01 Nov '10

Hello, I think the behavior of the std::string is just an example but in my application it seems to me the first stl element that is used. I have a larger project working with CLR in MC++. I included boost, because of boost::thread. Because auf the .net and CLR linking I compiled boost als shared libs and included BOOST_DYN_LINK in the preprocessor definitions. Compilation works fine. If i start the application in Debug mode i get strange behavior of my strings which results in a crash. For example an assignment like std::string test = "123"; will result in a string representation with additional malformed signs in front of the "123". I knew some behavior like this because of the Flags: #define _HAS_ITERATOR_DEBUGGING 0 #define _SECURE_SCL 0 #define _SCL_SECURE_NO_WARNINGS I usually not using them, but i have the suspicion that boost is using them and i got errors from there. Has anyone an idea what are possible solutions? Is boost introducing additional Macros that were changing the stl? Greetings Simon Adler

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Boost.Regex for variable argument term?
by Joost Kraaijeveld 01 Nov '10

01 Nov '10

Hi, I am trying to make a regex that matches a term with an arbitrary number of arguments. It has the format: TERM KEY(-?PRE:COL[,-?PRE:COL]*) with at least 1 PRE:COL and at most N (comma separated) PRE:COL, each of them possible prefixe with 1 '-' char I have the following: ^([[:word:]])[[:blank:]]*KEY\$-?[[:word:]]+:[[:word:]]+(,-?([[:word:]])+:([[:word:]]+))*\$ But this does not work: e.g. the string KEY1 KEY(TEK:KDE),NOCASE,OPT,PRIMARY has the following matches (notice the empty matches): what[0] = KEY1 KEY(TEK:KDE),NOCASE,OPT,PRIMARY what[1] = KEY1 what[2] = TEK what[3] = KDE what[4] = what[5] = what[6] = and the string KEY1 KEY(RKM:KEN,RKM:REL,RKM:VAL),NOCASE,OPT,PRIMARY has the following matches (notice match 4 and the lack of the last PRE:COL pair): auxWhat[0] = KEY1 KEY(RKM:KEN,RKM:REL,RKM:VAL),NOCASE,OPT,PRIMARY auxWhat[1] = KEY1 auxWhat[2] = RKM auxWhat[3] = KEN auxWhat[4] = ,RKM:VAL auxWhat[5] = RKM auxWhat[6] = VAL Is there a regex that sort of does does what I want? TIA -- Met vriendelijke groeten, Joost Kraaijeveld Askesis B.V. Molukkenstraat 14 6524NB Nijmegen tel: 024-3888063 / 06-51855277 fax: 024-3608416 web: www.askesis.nl

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[Boost.Spirit] Skippers for sub-grammars
by Vitaly Budovski 01 Nov '10

01 Nov '10

Hello, I've decided to break up my parser into sub-grammars to improve both the readability and compile time. I'm now trying to specify a skip parser for one of the sub-grammars, but I don't know how to do it. I'm familiar with specifying a skip parser in the parse functions, but not in the grammar itself. Could somebody please provide an example? Thanks. #include <boost/spirit/include/qi.hpp> #include <string> #include <iostream> using namespace boost::spirit; using namespace boost::spirit::ascii; template<class Iterator> struct sub_grammar_skipper: qi::grammar<Iterator> { sub_grammar_skipper(): sub_grammar_skipper::base_type(start) { start = ( *((char_ - eol) - lit(':')) >> lit(':') >> *blank >> *(char_ - eol) >> eol ) ; } qi::rule<Iterator> start; }; template<class Iterator> struct sub_grammar: qi::grammar<Iterator> { sub_grammar(): sub_grammar::base_type(start) { string = ( *(char_ - eol) ) ; name %= ( lit("NAME:") >> *blank >> string >> eol ) ; start = ( name ) ; } qi::rule<Iterator, std::string()> string; qi::rule<Iterator, std::string()> name; qi::rule<Iterator> start; }; template<class Iterator> struct test_grammar: qi::grammar<Iterator/*, sub_grammar_skipper<Iterator> */> { test_grammar(): test_grammar::base_type(start) { start = ( sg >> int_ ) ; } sub_grammar<Iterator> sg; qi::rule<Iterator/*, sub_grammar_skipper<Iterator> */> start; }; int main() { std::string str("NAME: John\nBLAH: blah\n10"); typedef std::string::const_iterator iterator; iterator first = str.begin(); iterator last = str.end(); test_grammar<iterator> tg; bool r = parse(first, last, tg); if(r && first == last) { std::cout << "Success!\n"; } else { std::cerr << "Failed to parse at: " << std::string(first, last) << std::endl; return 1; } return 0; }

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