January 2010 - Boost-users - lists.preview.boost.org

Non-Boost question: HTML parser with hpricot
by Boost lzw 09 Jan '10

09 Jan '10

Hi folks, Sorry for posting a question unrelated to boost. I know pretty well that boost has perfect solutions to it. But I am working on a legacy system using Hpricot of Ruby on Rail. So only Hpricot-specific suggestions please. Thank you. In my HTML parser, I can parse a html file with the following hpricot commands: (1) doc = open( "MyFileToParse.html" ) { |f| Hpricot(f) } (2) elements = (doc.search("/html/body/table/tr/td/table/tr/td/font") ) (3) puts (elements[13]).inner_html to get the following output: Giaever G, et al (2002). Functional profiling of the Saccharomyces c erevisiae genome. Nature, 418:387-91. [<a href=" http://www.ncbi.nlm.nih.gov/entr ez/query.fcgi?cmd=Retrieve&db=PubMed&list_uids=12140549&dopt=Abstract" target="_ blank">PubMed</a>] How can I proceed to get the following results (3) and (4) respectively? (3) Giaever G, et al (2002). Functional profiling of the Saccharomyces c erevisiae genome. Nature, 418:387-91. (4) http://www.ncbi.nlm.nih.gov/pubmed/12140549?dopt=Abstract NOTE: to get (4) I need to take two more steps: (5) replace "&" with "?" (6) replace "PubMed" with "pubmed" (this might be trivial, but how?) in the process of parsing in addition to "normal" HTML parsing. Thanks a lot in advance. Robert

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Problem with boost::thread::sleep
by Rob Yull 08 Jan '10

08 Jan '10

Using Boost 1.41, MSVC 2005, Win 7 x64 (compiling 32-bit). I was trying to set a small delay in a loop, so the loop doesn't consume all of the processor, using boost::thread::sleep(). I tried using the example from the threading documentation (http://www.boost.org/doc/libs/1_41_0/doc/html/thread/time.html#thread.time. get_system_time): boost::thread::sleep(boost::posix_time::milliseconds(25)); I keep getting a compiler error from the line above. Error 2 error C2664: 'boost::thread::sleep' : cannot convert parameter 1 from 'boost::date_time::subsecond_duration<base_duration,frac_of_second>' to 'const boost::system_time &' Is there something else I need to be doing to make this work? -Rob Yull

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Automatic thread join
by Lloyd 08 Jan '10

08 Jan '10

Hi, Is there a way to join a thread automatically to the main thread when it finishes execution? In my case, the main thread does not call the "thread->join()", so even if the work of the thread is over, the thread never joins to the main thread. What is the technique usually used to make a thread join to its main thread, so as to avoid wastage of resources. Thanks, Lloyd ___________________ Happy New Year 2010

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boost::crc - newbie help
by Paul Caswell 08 Jan '10

08 Jan '10

Hello all, I've the task of implementing the following CRC computation and was wondering whether I could use boost::crc to save me a lot of hassle. ------------------------ Default 32-bit Parity (CRC) This 32-bit CRC is the same as that described in EKMS 304 ([6]) and EKMS 322 ([8]) and could be used as a CRC method in the keyAlgorithm Attribute (with OID { 1 2 826 0 1145 0 5 1 }). Let g(x) be the polynomial x32 + x22 + x2 + x + 1. Let d(x) be the k bits of data to have parity applied to them. The first bit of data is the coefficient of the (k-1)st power of x etc. Let f(x) be the polynomial naturally represented by the initial fill 0xF8DD4258, i.e. x31 + x30 + x29 + x28 + x27 + x23 + x22 + x20 + x19 + x18 + x16 + x14 + x9 + x6 + x4 + x3. Then the output is c(x) = x32d(x) + xkf(x) mod g(x). The polynomial c(x) is then interpreted as a stream with the coefficient of x31 coming first and the coefficient of x0 coming last. The 32-bit parity is then c(x). This calculation can be done using a simple shift register as shown below. The shaded stages represent ones in the initial fill. The logic steps k times to determine c(x), which is the final state of the register. <diagram omitted> ------------------------ Any advice and or help would be appreciated. Regards, Paul This email and any files transmitted with it may be confidential, legally privileged and protected in law and are intended solely for the use of the individual to whom it is addressed. Any view or opinions presented are solely those of the author and do not necessarily represent those of Stonewood Group Ltd. If you have received this Email in error please contact the sender by return and confirm that its contents have been destroyed without further distribution or disclosure. Please email admin(a)stonewood.co.uk with any questions relating to this disclaimer. Stonewood Group Ltd has Registered Offices at Sandford Lane, Wareham, Dorset BH20 4DY. The company is registered in England and Wales under no: 3007498.

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Thread not interrupted in runtime linked library
by Lloyd 08 Jan '10

08 Jan '10

Hi, Using boost thread a new thread is created. The thread loads a DLL using LoadLibrary() call, gets the procedure address by calling GetProcAddress() and executes the procedure. The body of procedure is an infinite loop. When I try to interrupt the thread from main thread it is not interrrupted! What could be the reason? In all other cases the thread is interrupted except when it is inside the dynamically (runtime) linked library procedure. What could be the reason? Please share some idea... Thank you very much Lloyd ___________________ Happy New Year 2010

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Xpressive continuing search from previous match
by K. Noel Belcourt 08 Jan '10

08 Jan '10

Hi, I have a search for a regular expression like this. sregex_iterator cur(buffer.begin(), buffer.end(), defined_re), end; for(; cur != end; ++cur) { ... But what I really want to do is perform a new regex search starting at the location in the buffer marking the end of the previous search. Is there a way to get the buffer index from the previous search so I can start the new search past the previous search? I apologize if this is easy to do, I must have missed it with my quick perusal through the documentation. Thanks. -- Noel Belcourt

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Defining Statements with Proto
by David A. Greene 08 Jan '10

08 Jan '10

A few years ago, I asked how to define a grammar with Proto to match something like this: if_(expr) [ stmt, stmt, ... ].else [ stmt, stmt, ... ]; The answer was to do this: struct Grammar; struct ExpressionGrammar; struct StatementGrammar; struct Domain; template<typename Expr> struct Expression : proto::extends<Expr, Expression<Expr>, Domain> { typedef proto::extends<Expr, Expression<Expr>, Domain> base_type; Expression(Expr const & expr = Expr()) : base_type( expr ) {} }; struct Domain : proto::domain< proto::generator< Expression >, Grammar> {}; struct If {}; BOOST_PROTO_DEFINE_FUNCTION_TEMPLATE( 1 , if_ , Domain , (If) , BOOST_PP_SEQ_NIL ); // Here is the grammar for if_ statements // matches if_(e1)[e2] struct IfGrammar : boost::proto::subscript< boost::proto::arg< boost::proto::unary_expr< If, ExpressionGrammar >, >, StatementGrammar > {}; // An else_ "operator" template<typename Expr> struct Expression< Expr , typename enable_if<proto::matches<Expr, IfGrammar> >::type > : proto::extends<Expr, Expression<Expr>, Domain> { Expression() : else_(proto::make_expr<Else>(*this)) {}; proto::result_of::make_expr< Else, // else is now an "operator" Expression<Expr> const >::type const else_; }; // matches if_(e1)[e2].else_[e3] struct IfElseGrammar : boost:proto::subscript< boost::proto::arg< boost::proto::unary_expr< Else, IfGrammar >, >, StatementGrammar > {}; I didn't understand it then and I don't now. :) However, it seems to be obsolete since BOOST_PROTO_DEFINE_FUNCTION_TEMPLATE doesn't seem to exist anymore (it's not documented, anyway). So how would this be formulated in modern Boost.Proto? I'm guessing I will need an expression template wrapper (called Expression<> above) that uses some combination of BOOST_PROTO_BASIC_EXTENDS, BOOST_PROTO_EXTENDS_SUBSCRIPT and BOOST_PROTO_EXTENDS_FUNCTION. But of course not all statements have a valid operator() overload and no expressions do. I guess the grammar will take care of that, yes? I'm really puzzled about how to do the ".else_" part. I was hoping I could look to Phoenix to get a clue but it doesn't seem to use Proto. Any help? Thanks! -Dave

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[foreach] BOOST_FOREACH question...
by barcaroller 08 Jan '10

08 Jan '10

Does the BOOST_FOREACH macro work for empty sequences or must a size check be done explicitly? list<int> mylist; if (!mylist.empty()) // <--- necessary? { foreach(int& i, mylist) { // take action } } The reason I ask is that neither begin() nor end() return valid iterators for empty sequences, but it is my understanding that BOOST_FOREACH needs iterators to work properly.

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fusion and mpl
by Peter Foelsche 08 Jan '10

08 Jan '10

I need to be able to convert a mpl sequence into something like a tuple: typedef boost::mpl::vector<double> CMplSequence; typedef CCreateVectorFromMpl<CMplSequence>::type CVector; I need to have runtime access with constant index: CVector s; get<0>(s) = 1.0; std::cout << get<0>(s) << "\n"; I need to be able to retrieve the type at compile time: typedef CGetType<CVector, boost::mpl::long_<0> >::type CFirstType; I already wrote something like this using std::pair as the tuple but I'm running into problems storing reference types on Windows. Peter

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boost::multi_array equivalent for runtime number of dimensions
by Hicham Mouline 07 Jan '10

07 Jan '10

Hello, I only know at runtime the dimension and extends of a multidimensional array, though the number of dimensions is always < 10 for e.g. Is there a container that allows this? Otherwise, I can write code for multi_array<T, 2> multi_array<T, 3> . multi_array<T, 10>, do a switch case on the dimensions variable, and select the appropriate code, regards,

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[Math/Statistical Distributions+Random] Random number generation
by Marco Guazzone 07 Jan '10

07 Jan '10

Hi all! I'm a "boost newbie" so sorry for too trivial questions. Just trying to use boost for some statistical experiments, involving statistical distribution fitting, quantile generation (for goodness-of-fit tests), random variate generation, and so on. . The "Math/Statistical Distribution" library is great and almost complete. But I'm just curious why the random number generation (provided by the "Random" lib) and this library have not been integrated. For instance, the boost::random::exponential_distribution and the boost::math::exponential_distribution are two different worlds. I think a function like this below would be very helpful: --- [snip] --- template <typename Generator, typename RealType, typename Policy> inline RealType rand(Generator& rng, const exponential_distribution<RealType, Policy>& dist) { return -1.0 / dist.lambda() * std::log(1.0-rng()); } --- [snip] --- or something similar (e.g., rand implemented as a class method) In this case only two objects are needed: * boost::random::mersenne_twister * boost::math::exponential_distribution Instead, actually I have to keep different objects. For instance, for the exponential distribution: * boost::random::exponential_distribution * boost::random::mersenne_twister * boost::random::variate_generator * boost::math::exponential_distribution Unluckely I can't use boost::math::exponential_distribution in place of boost::random::exponential_distribution since boost::random::variate_generator expects a specific interface for the distribution. Well, what is the rationale behind the choice of this separation? Do you think would be useful to provide this kind of integration? Thank you very much in advance!! Cheers -- Marco

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Re: [Boost-users] BGL: shared_ptr as bundled properties > how to generate properties maps ???
by Damien Maupu 07 Jan '10

07 Jan '10

>On Wed, 6 Jan 2010, Emil Dotchevski wrote: > > On Wed, Jan 6, 2010 at 8:20 AM, Damien Maupu <damien.maupu_at_[hidden]> wrote: >>> I write something like: >>> typedef boost::shared_ptr<Vertex> VertexPtr; >>> typedef boost::shared_ptr<Edge> EdgePtr; >>> typedef adjacency_list<vecS, vecS, directedS, VertexPtr, EdgePtr> Graph; >> >> It is probably not a good idea to use shared_ptr for graphs; some >> graphs have cycles and this will lead to leaks (if your data structure >> is a DAG, you're fine.) >I don't think that will be an issue -- his shared pointers link to >properties; the graph structure itself is in BGL data structures. >However, if the properties refer to other graph vertices or edges, there >is an issue of dangling references if those objects are removed from the >graph. >-- Jeremiah Willcock Hi, I am not sure I understand why using smart pointer should be an issue. Could you explain me in little more details? Do you know how to get properties maps if bundle properties are pointer or smart pointers? Thank you Damien

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ASIO async_read_until with condition + strand
by Christophe Bourez 07 Jan '10

07 Jan '10

Can someone help with the boost async_read_until with condition ? I need to implement a request/response protocol. * A request cannot be send until the response has been completely read from the server. * Response's length from the server is unknown. The data must be parsed thanks to a parser to understand the content of the buffer. The parser is capable to return a code specifying whether the data is complete, which could require more reading on the socket. I'd like to implement my client asynchronously using ASIO. Here is the solution I implemented: the async send handler calls async_read whose handler calls async_read handler again until the message is complete. Due to the here above constraints, I am forced to queue the requests and async send the next request by the end of the handler of the current response (when it is complete, otherwize it async_reads again). I have tried to use async_read_until with a condition, but the parser was invoked very (too) often (every 2 bytes) and penalizes the performance. Would it be possible to reduce the number of calls to the condition (by reading at once the maximum of bytes present on the socket for example)? I'd like to async send the requests as soon as I can, in order to avoid the queue. Is it possible to implement a solution by using the ASIO strands? If yes, I have the feeling that the way I implemented the response handling will not work with the strand because the handler of async_read calls async_read again, which will probably come at the end of the strand's queue (which may contain many async_send requests). Could async_read_until with a condition solves this issue by avoiding to async_read again? Any help will be very appreciated. Christophe

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[thread] Getting this warning message with optimization turn on
by Shiou Ming Lee 07 Jan '10

07 Jan '10

Hi, I'm building my program that depends on Boost.thread, but getting following warning message, only when compiler's optimization been turn on. C:/boost_1_41_0/boost/thread/win32/thread_heap_alloc.hpp: In member function `bool gUtil::GLog::LogWriterManager::startAsyncLogging(unsigned int)': C:/boost_1_41_0/boost/thread/win32/thread_heap_alloc.hpp:156: warning: 'heap_memory' might be used uninitialized in this function In the mentioned function, startAsyncLogging(unsigned int), there's only one line of code that involves Boost.thread: // loggingThread is class LogWriterManager's member, of boost::thread type. loggingThread = boost::thread(boost::bind(&LogWriterManager::loggingThreadFunc, this)); This happens for MinGW 3.4 on Windows Vista SP1 32-bits, but not for GCC 4.4 on Fedora 11 x86. The Boost release is of version 1.41.0. Any idea what should I do for this warning message? Or should I just leave optimization on and ignore this message? Thanks & Regards Shiou Ming

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[Signals2] How to connect member functions with more than one argument?
by Marco Guazzone 07 Jan '10

07 Jan '10

Dear all, I am new to Boost.Signals2, so sorry for the possibly trivial question. My problem is that I am not able to connect a member function with more than one argument to a signal. My test code is the following: --- [code] --- #include <boost/bind.hpp> #include <boost/signals2.hpp> #include <iostream> template <typename IntT=int, typename RealT=double> struct event_consumer { typedef IntT int_type; typedef RealT real_type; typedef boost::signals2::signal<void (int_type,real_type)> signal_type; typedef event_consumer<int_type,real_type> self_type; void consume() { sig.connect(boost::bind(&self_type::process, this, _1)); sig(2,0.5); } void process(int_type x, real_type y) { std::cout << "X: " << x << " -- Y: " << y << std::endl; } signal_type sig; }; int main() { event_consumer<> consumer; consumer.consume(); } --- [/code] --- When I compile it (with g++ 4.4.2 and flags --ansi --Wall) I get this error: --- [error] --- $ g++ -Wall -ansi -o test_signal test_signal.cpp In file included from .../boost/bind.hpp:22, from test_signal.cpp:1: .../boost/bind/bind.hpp: In instantiation of ‘boost::_bi::result_traits<boost::_bi::unspecified, void (event_consumer<int, double>::*)(int, double)>’: ...//boost/bind/bind_template.hpp:15: instantiated from ‘boost::_bi::bind_t<boost::_bi::unspecified, void (event_consumer<int, double>::*)(int, double), boost::_bi::list2<boost::_bi::value<event_consumer<int, double>*>, boost::arg<1> > >’ test_signal.cpp:15: instantiated from ‘void event_consumer<IntT, RealT>::consume() [with IntT = int, RealT = double]’ test_signal.cpp:32: instantiated from here .../boost/bind/bind.hpp:69: error: ‘void (event_consumer<int, double>::*)(int, double)’ is not a class, struct, or union type In file included from ...//function/detail/maybe_include.hpp:23, from .../boost/function/detail/function_iterate.hpp:14, from .../boost/preprocessor/iteration/detail/iter/forward1.hpp:57, from .../boost/function.hpp:64, from .../boost/signals2/signal.hpp:18, from .../boost/signals2.hpp:16, from test_signal.cpp:2: .../boost/function/function_template.hpp: In static member function ‘static void boost::detail::function::void_function_obj_invoker2<FunctionObj, R, T0, T1>::invoke(boost::detail::function::function_buffer&, T0, T1) [with FunctionObj = boost::_bi::bind_t<boost::_bi::unspecified, void (event_consumer<int, double>::*)(int, double), boost::_bi::list2<boost::_bi::value<event_consumer<int, double>*>, boost::arg<1> > >, R = void, T0 = int, T1 = double]’: .../boost/function/function_template.hpp:913: instantiated from ‘void boost::function2<R, T1, T2>::assign_to(Functor) [with Functor = boost::_bi::bind_t<boost::_bi::unspecified, void (event_consumer<int, double>::*)(int, double), boost::_bi::list2<boost::_bi::value<event_consumer<int, double>*>, boost::arg<1> > >, R = void, T0 = int, T1 = double]’ .../boost/function/function_template.hpp:722: instantiated from ‘boost::function2<R, T1, T2>::function2(Functor, typename boost::enable_if_c<boost::type_traits::ice_not::value, int>::type) [with Functor = boost::_bi::bind_t<boost::_bi::unspecified, void (event_consumer<int, double>::*)(int, double), boost::_bi::list2<boost::_bi::value<event_consumer<int, double>*>, boost::arg<1> > >, R = void, T0 = int, T1 = double]’ .../boost/function/function_template.hpp:1064: instantiated from ‘boost::function<R(T0, T1)>::function(Functor, typename boost::enable_if_c<boost::type_traits::ice_not::value, int>::type) [with Functor = boost::_bi::bind_t<boost::_bi::unspecified, void (event_consumer<int, double>::*)(int, double), boost::_bi::list2<boost::_bi::value<event_consumer<int, double>*>, boost::arg<1> > >, R = void, T0 = int, T1 = double]’ .../boost/function/function_template.hpp:1105: instantiated from ‘typename boost::enable_if_c<boost::type_traits::ice_not::value, boost::function<R(T0, T1)>&>::type boost::function<R(T0, T1)>::operator=(Functor) [with Functor = boost::_bi::bind_t<boost::_bi::unspecified, void (event_consumer<int, double>::*)(int, double), boost::_bi::list2<boost::_bi::value<event_consumer<int, double>*>, boost::arg<1> > >, R = void, T0 = int, T1 = double]’ .../boost/signals2/detail/slot_template.hpp:156: instantiated from ‘void boost::signals2::slot2<R, T1, T2, SlotFunction>::init_slot_function(const F&) [with F = boost::_bi::bind_t<boost::_bi::unspecified, void (event_consumer<int, double>::*)(int, double), boost::_bi::list2<boost::_bi::value<event_consumer<int, double>*>, boost::arg<1> > >, R = void, T1 = int, T2 = double, SlotFunction = boost::function<void(int, double)>]’ .../boost/signals2/detail/slot_template.hpp:81: instantiated from ‘boost::signals2::slot2<R, T1, T2, SlotFunction>::slot2(const F&) [with F = boost::_bi::bind_t<boost::_bi::unspecified, void (event_consumer<int, double>::*)(int, double), boost::_bi::list2<boost::_bi::value<event_consumer<int, double>*>, boost::arg<1> > >, R = void, T1 = int, T2 = double, SlotFunction = boost::function<void(int, double)>]’ test_signal.cpp:15: instantiated from ‘void event_consumer<IntT, RealT>::consume() [with IntT = int, RealT = double]’ test_signal.cpp:32: instantiated from here .../boost/function/function_template.hpp:153: error: no match for call to ‘(boost::_bi::bind_t<boost::_bi::unspecified, void (event_consumer<int, double>::*)(int, double), boost::_bi::list2<boost::_bi::value<event_consumer<int, double>*>, boost::arg<1> > >) (int&, double&)’ --- [/error] --- Thank you very much for the support!!! Best, -- Marco

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[Preprocessor] how to use REPEAT_FROM_TO for 2 arguments
by Kai Liu 07 Jan '10

07 Jan '10

Hi, I am trying to use the preprocessor library to simplify the code I have. The problem: I have many lines of the following assignments: mybfclass x_0_mybf; mybfclass x_1_mybf; ... mybfclass1 x_0_mybf1; mybfclass1 x_1_mybf1; ... mybfclass2 x_0_mybf2; mybfclass2 x_1_mybf2; then I defined several vectors: vector<mybfclass*> x_mybf; vector<mybfclass1*> x_mybf1; vector<mybfclass2*> x_mybf2; * use the boost preprocessor library, I write the following code: #define* DECLX_mybf(z, n, text) BOOST_PP_CAT(text, BOOST_PP_CAT(_, mybf)).push_back(&BOOST_PP_CAT(text, BOOST_PP_CAT(BOOST_PP_CAT(_, n), BOOST_PP_CAT(_, mybf)))); *#define* DECLX_mybf1(z, n, text) BOOST_PP_CAT(text, BOOST_PP_CAT(_, mybf)).push_back(&BOOST_PP_CAT(text, BOOST_PP_CAT(BOOST_PP_CAT(_, n), BOOST_PP_CAT(_, mybf)))); *#define* DECLX_mybf2(z, n, text) BOOST_PP_CAT(text, BOOST_PP_CAT(_, mybf)).push_back(&BOOST_PP_CAT(text, BOOST_PP_CAT(BOOST_PP_CAT(_, n), BOOST_PP_CAT(_, mybf)))); BOOST_PP_REPEAT_FROM_TO(0, 2, DECLX_mybf, x); *// generated: x_mybf.push_back(&x_0_mybf); x_mybf.push_back(&x_1_mybf); * BOOST_PP_REPEAT_FROM_TO(0, 2, DECLX_mybf1, x); *// generated: x_mybf1.push_back(&x_0_mybf1); x_mybf1.push_back(&x_1_mybf); * BOOST_PP_REPEAT_FROM_TO(0, 2, DECLX_mybf2, x); *// generated: x_mybf2.push_back(&x_0_mybf2); x_mybf2.push_back(&x_1_mybf); * but I think it is too much coding here, since I have to write a macro for each mybf occurrence, DECLX_mybf I have difficulty to use the BOOST_PP_REPEAT_FROM_TO for two argument, since the macro(z, x, data) can only accept one argument data, however, I need to pass two arguments x and mybf to the macro, in order to generate a mybfclass1 x_0_mybf. does anyone know how to apply macro to generate the above structure? thanks. /Kenny * *

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[BGL] simple problem: how to detect connections in a dag?
by Olaf Krzikalla 06 Jan '10

06 Jan '10

Hi @boost, we have a rather simple problem here for which we however couldn't find a simple solution in the BGL. Probably because we aren't graph experts. We have a dag and two vertices in this dag. Now we just want to know if these vertices are connected (acrtually we don't need the path), that is if one vertex is in a parent chain of the other. Thanks in advance Olaf Krzikalla

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Re: [Boost-users] [asio] Sending large packages
by Nicola Michael Gutberlet 06 Jan '10

06 Jan '10

Doesn't anyone have any ideas? Did anyone receive this mail? Best regards and a happy new year ;-) _____ From: Nicola Michael Gutberlet [mailto:nicola.gutberlet@hhi.fraunhofer.de] Sent: 15 December 2009 17:28 To: 'boost-users(a)lists.boost.org' Subject: RE: [asio] Sending large packages Some testing showed that the maximum package (load) size of boost::asio::write/read() for a TCP socket seems to be 1007 kB _____ From: Nicola Michael Gutberlet [mailto:nicola.gutberlet@hhi.fraunhofer.de] Sent: 15 December 2009 17:11 To: 'boost-users(a)lists.boost.org' Subject: [asio] Sending large packages Dear all, Is there a well-defined way of sending large packages over TCP? Or do I have to split the packages on my own? For explanation: I want to send images (size around 6MB). Best regards, Nicola

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[bjam][1.41.0] Build with variant=release, debug fails
by Richard Hadsell 06 Jan '10

06 Jan '10

I am trying to build the Boost 1.41.0 libraries with this command: bin/bjam --user-config=user-config.LINUX_AMDF7 threading=multi instruction-set=opteron address-model=64 variant=release,debug,profile link=static,shared --stagedir=stageF7 stage The last time I built Boost libraries was version 1.35.0. I eliminated all of the other options to narrow the problem to just this option: variant=release,debug The build starts up successfully, if I select just one option for variant (debug or release), but it fails when I try to build both. These are the error messages: error: Duplicate name of actual target: <pstageF7/lib>libboost_date_time.a error: previous virtual target { common%common.copy-libboost_date_time.a.STATIC_LIB { gcc%gcc.archive-libboost_date_time.a.STATIC_LIB { gcc%gcc.compile.c++-gregorian/greg_month.o.OBJ { gregorian/greg_month.cpp.CPP } } { gcc%gcc.compile.c++-gregorian/greg_weekday.o.OBJ { gregorian/greg_weekday.cpp.CPP } } { gcc%gcc.compile.c++-gregorian/date_generators.o.OBJ { gregorian/date_generators.cpp.CPP } } } } error: created from ./stage-proper error: another virtual target { common%common.copy-libboost_date_time.a.STATIC_LIB { gcc%gcc.archive-libboost_date_time.a.STATIC_LIB { gcc%gcc.compile.c++-gregorian/greg_month.o.OBJ { gregorian/greg_month.cpp.CPP } } { gcc%gcc.compile.c++-gregorian/greg_weekday.o.OBJ { gregorian/greg_weekday.cpp.CPP } } { gcc%gcc.compile.c++-gregorian/date_generators.o.OBJ { gregorian/date_generators.cpp.CPP } } } } error: created from ./stage-proper error: added properties: <debug-symbols>on <inlining>off <optimization>off <runtime-debugging>on <variant>debug error: removed properties: <debug-symbols>off <define>NDEBUG <inlining>full <optimization>speed <runtime-debugging>off <variant>release /netDISKS/cgi/LINUX_AMD64/cgi/vendor/library/boost/boost_1_41_0/tools/build/v2/build/virtual-target.jam:490: in actualize-no-scanner from module object(file-target)@4821 /netDISKS/cgi/LINUX_AMD64/cgi/vendor/library/boost/boost_1_41_0/tools/build/v2/build/virtual-target.jam:135: in object(file-target)(a)4821.actualize from module object(file-target)@4821 /netDISKS/cgi/LINUX_AMD64/cgi/vendor/library/boost/boost_1_41_0/tools/build/v2/build-system.jam:717: in load from module build-system /netDISKS/cgi/LINUX_AMD64/cgi/vendor/library/boost/boost_1_41_0/tools/build/v2/kernel/modules.jam:283: in import from module modules /netDISKS/cgi/LINUX_AMD64/cgi/vendor/library/boost/boost_1_41_0/tools/build/v2/kernel/bootstrap.jam:142: in boost-build from module /netDISKS/cgi/LINUX_AMD64/cgi/vendor/library/boost/boost_1_41_0/boost-build.jam:17: in module scope from module The user-config contains just these 2 lines: using gcc : 4.1.2 : /usr/bin/g++ : <compileflags>"-fPIC -fno-strict-aliasing -fno-tree-ccp" <linkflags>"-fPIC -fno-strict-aliasing -fno-tree-ccp" ; using python : 2.5 : /usr ; It seems possible that the libraries would build correctly in separate steps, but I am concerned that the debug, release, and profile versions will be mixed up. Is this just a problem for the date_time library, or is there something wrong with the build rules? If someone can give me a reliable workaround, I would appreciate it. (I am building with g++ 4.1.2 on a Fedora 7 x86_64 Linux system.) -- Dick Hadsell 203-992-6320 Fax: 203-992-6001 Reply-to: hadsell(a)blueskystudios.com Blue Sky Studios http://www.blueskystudios.com 1 American Lane, Greenwich, CT 06831-2560

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Reducing the size of .obj file which does serialization
by Gokulakannan Somasundaram 06 Jan '10

06 Jan '10

Hi, I have a parent class which has around 200 sub-classes. While serializing the entire hierarchy, i have lot of base class pointers and STLs of base class pointers. From the documentation, i found that if i have to serialize the polymorphic pointers, then i have to do a BOOST_EXPORT of all the relevant subclasses. But after doing that, i find my .obj file to be around 37MB. I am using the text archive in my code. When i tried the polymorphic_text_archive, the size only reduced by 3MB. Can someone help me on how i should go about reducing the .obj file size? Some of my questions are a) One approach, i could think of is to create a virtual function in the hierarchy, which just takes the Archive and does the serialization. This would help me, because i don't need to have the BOOST_EXPORT, which increases the size of the .obj file. b) Why is BOOST_EXPORT required for polymorphic_text_archive? Since it anyway uses virtual functions instead of templates, why does it need the derived class definition. Thanks, Gokul.

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[Filesystem] directory iteration throws
by gast128 06 Jan '10

06 Jan '10

Hello all, I was writing a simple application to enumerate files sorted on their size. I used the recursive_directory_iterator for this task. However on my Windows XP machine the directory iteration stops because of a throwing constructor. It is easy reproducable, by creating a directory with contents and remove all security attributes (except for the system account, leave there all permissions enabled) and use that directory for iteration, i.e. my c:\temp\bla directory contained 1 file and I removed the security attributes for the directory Bla. Tracing thru the source code of Boost.FileSystem the directory is opened with a '::FindFirstFileA' call which returns an 'INVALID_HANDLE_VALUE', resulting in a throw. This stops further iteration of the directory. Is there a way to work around this?

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Return value of bool boost::interprocess::shared_memory_object::remove(const char * name)
by Jarno 06 Jan '10

06 Jan '10

Hello, It seems to me that the static function bool remove(const char * name) in class boost::interprocess::shared_memory_object returns false when it should return true and vice versa. The documentation on boost interprocess says: "The remove operation might fail returning false if the shared memory does not exist, the file is open or the file is still memory mapped by other processes" However, the following simple test program for example prints "should not print" on Windows XP 64. I'm compiling with MSVC 2008 and using boost 1.41.0. /* Test program */ #include <boost/interprocess/shared_memory_object.hpp> #include <iostream> int main(int argc, char* argv[]) { using namespace boost::interprocess; using namespace std; { shared_memory_object shm(open_or_create, "foo", read_write); } if(shared_memory_object::remove("foo")) cout << "should print" << endl; if(shared_memory_object::remove("foo")) cout << "should not print" << endl; return 0; } /* Test program ends */ Am I interpreting the documentation correctly? Regards, Jarno

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Thread is not interrupted
by Lloyd 06 Jan '10

06 Jan '10

Hi, I am using boost::asio to create a server. When a new connection is established (inside the asio read handle) a new thread (boost::thread) is created. The thread object pointer is kept in a static vector. When the next connection is established, the thread pointer available in the static vector is read and interrupted. But the thread is not interrupted! The thread is just an infinite loop, in which interruption is enabled. I have wrttien the exception handler also. Not able to understand why this is not working in this situation. Otherwise this works. To make this clear given below are the code snippets... //ASIO based read handler void TCPConnection::HandleRead(const boost::system::error_code& Error) { TCPConnection::Threadvector[0]->interrupt(); //Threadvector is static variable in the class, for easy reading written like this boost::thread *th=new boost::thread(boost::bind(&TCPConnection::ExecutionRoutine,shared_from_this(),Command)); TCPConnection::Threadvector.push_back(th); } //ExecutionRoutine looks like this int TCPConnection::ExecutionRoutine(string Command) { try { while(1) { boost::this_thread::interruption_point(); } } catch(boost::thread_interrupted const&) { return 0; } return 0; } Please share some idea... Thanks, Lloyd ___________________ Happy New Year 2010

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[GIL] Packing to 6 bytes
by Eloi Du Bois 06 Jan '10

06 Jan '10

Hi, I have a question: I need to create a view that hold 12 bit channel data packed as follow: 0000R0000G0000B0000;0000R0000G0000B0000;0000R0000G0000B0000;.... Meaning that each channel is shifted by 4 bits. The pixel is holden on 48 bits = 6 bytes. I have created my view like as follow: /// My 12 bits special rgb packed to 6 bytes typedef const packed_channel_reference<uint64_t, 04, 12, true> rgb12_packed_channel0_t; typedef const packed_channel_reference<uint64_t, 20, 12, true> rgb12_packed_channel1_t; typedef const packed_channel_reference<uint64_t, 36, 12, true> rgb12_packed_channel2_t; typedef mpl::vector3<rgb12_packed_channel0_t, rgb12_packed_channel1_t, rgb12_packed_channel2_t> rgb12_packed_channels_t; typedef packed_pixel<packed_channel_value<48>, rgb12_packed_channels_t, rgb_layout_t> rgb12_packed_pixel_t; typedef view_type_from_pixel<rgb12_packed_pixel_t>::type rgb12_packed_view_t; The thing is that I would now like to copy data to another rgb16_view_t... But this is not working because, in my opinion, 48 bits is between 32 and 64. I have been thinking of the solution that Christian gave me and that consist on doing something like this: T p( pData, 0 ); for( typename DST_V::y_coord_t y = 0; y < height; ++y ) { typename DST_V::x_iterator it = dst.row_begin( y ); for( typename DST_V::x_coord_t x = 0; x < width; ++x ) { color_convert( *p, *it ); ++p; ++it; } } where T is a bit_aligned_pixel_iterator and DST_V=rgb16_view_t but this can't be working on my case because channels are shifted by 4 bits ! If you could help me, I would really appreciate. I think all those cases are a good robustness test for gil. Regards, Eloi.

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Trying to build docs....
by Marshall Clow 05 Jan '10

05 Jan '10

I'm trying to generate the docs for boost. I'm looking at the instructions at <http://www.boost.org/doc/libs/1_41_0/doc/html/boostbook/getting/started.html> I've installed: docbook-xml-4.2 docbook-xsl-175.2 fop-0.95 Jimi 1.0 (and done the 'move and rename' bit into fop) I believe that I've set up my user-config.jam correctly (attached). And when I try to build something, I get errors about "unable to external entity <a sourceforge URL>". If I take the <a sourceforge URL> and try to curl it, I get something that looks reasonable. Any suggestions? [ Oh, yeah: Mac OS X 10.6, gcc 4.2.1, from the trunk. ] -- Marshall > $ bjam --v2 onehtml > ...patience... > ...found 1251 targets... > ...updating 1 target... > xslt-xsltproc ../../../bin.v2/libs/fusion/doc/darwin-4.2.1/debug/fusion.html > warning: failed to load external entity "http://docbook.sourceforge.net/release/xsl/current/html/docbook.xsl" > compilation error: file /Users/marshall/Sources/boost/tools/boostbook/xsl/html-single.xsl line 15 element import > xsl:import : unable to load http://docbook.sourceforge.net/release/xsl/current/html/docbook.xsl > warning: failed to load external entity "http://docbook.sourceforge.net/release/xsl/current/html/admon.xsl" > compilation error: file /Users/marshall/Sources/boost/tools/boostbook/xsl/admon.xsl line 12 element import > xsl:import : unable to load http://docbook.sourceforge.net/release/xsl/current/html/admon.xsl > warning: failed to load external entity "http://docbook.sourceforge.net/release/xsl/current/lib/lib.xsl" > compilation error: file /Users/marshall/Sources/boost/tools/boostbook/xsl/relative-href.xsl line 12 element import > xsl:import : unable to load http://docbook.sourceforge.net/release/xsl/current/lib/lib.xsl > > XML_CATALOG_FILES="../../../bin.v2/boostbook_catalog.xml" > export XML_CATALOG_FILES > "xsltproc" --stringparam boost.libraries "../../../libraries.htm" --stringparam boost.root "../../../.." --stringparam chunk.first.sections "1" --stringparam chunk.section.depth "4" --stringparam generate.section.toc.level "4" --stringparam html.stylesheet "../../../../doc/html/boostbook.css" --stringparam toc.max.depth "3" --stringparam toc.section.depth "3" --xinclude -o "../../../bin.v2/libs/fusion/doc/darwin-4.2.1/debug/fusion.html" "/Users/marshall/Sources/boost/tools/boostbook/xsl/html-single.xsl" "../../../bin.v2/libs/fusion/doc/darwin-4.2.1/debug/fusion.docbook" > > ...failed xslt-xsltproc ../../../bin.v2/libs/fusion/doc/darwin-4.2.1/debug/fusion.html... > ...failed updating 1 target... > > mclow-mac:doc marshall$ curl http://docbook.sourceforge.net/release/xsl/current/lib/lib.xsl | bbedit > % Total % Received % Xferd Average Speed Time Time Time Current > Dload Upload Total Spent Left Speed > 100 18500 100 18500 0 0 76291 0 --:--:-- --:--:-- --:--:-- 141k >

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