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boost::posix::time_duration
by Michael Thurston 02 Nov '07

02 Nov '07

[boost][date_time] Hi there, I have a question about the boost::posix::time_duration class. It has accessors such as: - hours() - minutes() that return a data type of long. I would have expected it to return a datatype of boost::int64_t (or boost::int32_t) because could there be a risk that the return value would cause an overflow on an 8 bit embedded platform. Regards, Michael

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C++ & Enterprise Solutions
by Stefan Kok 02 Nov '07

02 Nov '07

Dear List If this is not the correct list to post to. Then please forgive my ignorance. I have been admiring the work of Boost and its contributors for some time now. My questions / comments : 1) Would their be any benefit to the community, developing a specification for C++ similar to SUN's J2EE and JEE specification ? I do realize this would require a mammoth effort as well as commitment in terms of resources. 2) Is it possible to establish such a project under the open source banner ? Given the commitment and resources required. 3) Would this be reinventing the wheel ? I know SUN & Java got there first (the J2EE thing). But C++ does have some very powerful features which makes it unique in some ways, templates for one. Thank you in advance. Stefan.

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[Boot.Pool] Opinions about inconsistent pointer types
by David Baird 01 Nov '07

01 Nov '07

Hi, I was looking through the Pool code and noticed that it presents inconsistent pointer types to the user ("void *" versus "char *"). For example, if the user wants to implement his/her own user allocator, they have to write it like, e.g. (using "char *" as the pointer type): struct default_user_allocator_new_delete { typedef std::size_t size_type; typedef std::ptrdiff_t difference_type; static char * malloc(const size_type bytes) { return new (std::nothrow) char[bytes]; } static void free(char * const block) { delete [] block; } }; However, other classes return "void *" as their pointer types, e.g. singleton_pool: template <typename Tag, unsigned RequestedSize, typename UserAllocator, typename Mutex, unsigned NextSize> struct singleton_pool { static void * malloc() { pool_type & p = singleton::instance(); details::pool::guard<Mutex> g(p); return p.p.malloc(); } } Is it really important that the types be different? I just think it might be more elegant to use "void *" in more places - it would make more things the same and be similar to e.g. "std::malloc/free". -David

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Serialization of C dynamic data
by Lorenzo Cavallaro 31 Oct '07

31 Oct '07

Hi, I'm trying to serialize the following piece of code (a data structure whose object size is dynamically allocated and it should use the correct size/len which has been serialized). typedef struct data { char *payload; size_t len; } data_t; vector<data_t *> v; So I added the corresponding serialize function to the structure definition void serialize(Archive & ar, const unsigned int file_version) { ar & len; for (int i = 0; i < len; i++) ar & payload[i]; } Moreover, I added a default constructor which is invoked by the serialization library whenever the object has to be unserialized data::data() { /* no error checking */ payload = (char *)calloc(1, X); len = X; } Now, of course X is fixed. I'd like to reuse the serialized 'size' (ar & size) as argument to the calloc to be able to create an object with the right size instead of having to approximate (exceeding, of course) its real dimension. Do you have any idea how to get it work the way I'd like to, please? -- if it's possible, of course. Nevertheless to say that with a right X everything works fine. I was thinking to iterate over all the elements, after the unserialization step is over, to reallocate payload using the right len... but it sucks :-) TIA, bye Lorenzo -- Lorenzo `Gigi Sullivan' Cavallaro <sullivan(a)security.dico.unimi.it> GPG key at http://security.dico.unimi.it/~sullivan/sullivan.asc Until I loved, life had no beauty; I did not know I lived until I had loved. (Theodor Korner) See the reality in your eyes, when the hate makes you blind. (A.H.X)

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[Boost users] [interprocess]: static_pointer_cast on offset_ptr
by Lars Hagström 31 Oct '07

31 Oct '07

Hi, In offset_ptr.hpp the static_pointer_cast<> &co are commented out. Why is this? I need something of the kind to do casts from a void* to a bool*, for example. Is there something I am missing? Lars

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REGEXP - Serializing regexp ?
by Jacques-Olivier Goussard 31 Oct '07

31 Oct '07

Hi I'm trying to use the boost-regexp package and I'm facing an issue with this. I'm basically applying a replace algo on a list of strings using a huge list of regular expressions. It seems that the boost-regexp API allows me only to either load all regular expressions in memory (i.e creating the regexp at process start) or load one regexp at a time but re-compile it each time. Is there a way to save to disk the compiled version of the regexp (so that the regexp package would not have to re-create the statemachine) ? If not, what would be the best approach for doing this ? Thanks /jog

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Re: [Boost-users] Regex: Invalid preceding regular expression, problem
by Brian Krahmer 31 Oct '07

31 Oct '07

> Nope there's a bug in the options you are using - boost::regex::extended > enables the "POSIX extended" flavour of regular expressions - and these > don't support non-greedy repeats. Use boost::regex::perl if you want to use > these (since you are using Perl-style regexes). > > HTH, John. > That helps very much. Thanks for clearing that up for me, John. brian

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Preprocessor lib question -- how to fold a macro that produces comma in its output across a sequence?
by Yu Di 31 Oct '07

31 Oct '07

Hi, I am trying to use the preprocessor lib to generate something like Cons<a, Cons<b, Cons<c, Cons<d, Nil> > > > from (a) (b) (c) (d) I tried something like #define START(x) Cons<x,Nil> #define ADD(s,state,x) Cons<x,state > #define GENERATE(x) BOOST_PP_SEQ_FOLD_RIGHT(ADD,START(BOOST_PP_SEQ_HEAD(BOOST_PP_SEQ_REVERSE(x))),BOOST_PP_SEQ_POP_BACK(x)) but immediately got into trouble with the commas. The best I can do is to add parentheses around the content of START and ADD, but that generated (Cons<a, (Cons<b, (Cons<c, (Cons<d, Nil>) >) >) >) which is not valid. Is there any way I can achieve the desired output? Thanks, Di, Yu 10.30 __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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FILE boost\preprocessor\arithmetic\dec.hpp
by question boost 31 Oct '07

31 Oct '07

Hi, I' ve the following error message: FILE C:\Documents and Settings\src\boost\preprocessor\arithmetic\decc.hpp LINE 17 boost/preprocessor/config/config.hpp no such file or directory So I look at decc.hpp, it contains the line # include <boost/preprocessor/config/config.hpp> and I look at the directory C:\Documents and Settings\src\boost\preprocessor\config, it contains the file config.hpp IS ANYONE GOING TO TELL ME WHAT IS THE PROBLEM WITH THOSE BOOST FILES? THANK YOU VERY MUCH David _________________________________________________________________ Vous êtes plutôt Desperate ou LOST ? Personnalisez votre PC avec votre série TV préférée ! http://specials.divertissements.fr.msn.com/SeriesTV.aspx

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graph python bindings : unpickle hangs
by John Reid 31 Oct '07

31 Oct '07

Hi, Unpickling an empty boost.graph seems to hang. E.g. In [1]: import boost.graph as bgl In [2]: g=bgl.Graph() In [3]: import cPickle In [4]: cPickle.dumps(g) Out[4]: 'cboost.graph._graph\nGraph\np1\n(tRp2\n((dp3\nI0\n(l(d(dtb.' In [5]: cPickle.loads(cPickle.dumps(g)) *** never returns *** I'm using the latest SVN revision of bgl-python. John.

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Extracting libraries from boost?
by Angel Tsankov 31 Oct '07

31 Oct '07

Can libraries in boost be used on their own, i.e. can I extract one of them and use it in a project? In particular, I only need the smart_ptr and ref libraries in one of my projects.

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Regex: Invalid preceding regular expression problem
by Brian Krahmer 31 Oct '07

31 Oct '07

Hello, I'm a new member to the mailing list. BTW, thanks to everyone who contributes to boost. It's a fantastic software. I am having a problem with building an expression object. The line in question reads 'boost::regex expression(pattern, options);', where I'm using the boost::regex::extended option, and the pattern looks like this: "^([0-7]\\..*|8\\.0(\\.[0-3](\\.[0-3])?)?)[^.0-9]*?$". I fired up a ruby interpreter, and it handled the regex fine (using "8.0.0.1 (en-US)" as a positive, and "9.0.0.1 (en-US)" as a negative). Can anybody tell me what is wrong with this regex, or confirm that there may be a bug in the library? thanks, brian

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[Regex] Why does this example code not compile?
by Mike Thornton 31 Oct '07

31 Oct '07

Using g++ on a GNU Ubuntu Linux 7.04 machine, I am unable to compile the boost example code (saved as test.cpp) at http://www.boost.org/libs/regex/example/snippets/partial_regex_match.cpp Although I can compile my own code which does not use boost, I get a lot of garbled output from the example code...part of which is listed below. Any ideas on what is wrong and how to fix it? test.cpp : (.text._ZN5boost9re_detail12perl_matcherIN9__gnu_cxx17__normal_iteratorIPKcSsEESaINS_9sub_matchIS6_EEENS_12regex_traitsIcNS_16cpp_regex_traitsIcEEEEEC1ES6_S6_RNS_13match_resultsIS6_S9_EERKNS_11basic_regexIcSD_EENS_15regex_constants12_match_flagsES6_[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> > >::perl_matcher(__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> > >)]+0xea): undefined reference to `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> > >::construct_init(boost::basic_regex<char, boost::regex_traits<char, boost::cpp_regex_traits<char> > > const&, boost::regex_constants::_match_flags)' Thanks. Mike

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Using date/time to format date strings
by Andrew 31 Oct '07

31 Oct '07

Hi all, I'm trying to use the date time library to to do some string formatting but I'm afraid there's something I'm missing. What I'd like to do is feed in a string "05/Aug/2007 11:30" and convert it to an ISO formatted string - could anyone point me in the right direction? I've examined both the documentation and the sample code in io_tutorial.cpp but I'm afraid it hasn't helped - the code below is as far as I've gotten and simply returns the input string unchanged. I'm using boost 1.34.1 with MSVC 2005. Thanks much, Andrew //Begin snippit string formatDate(string inpDate) { stringstream ss; local_date_time checkDate(not_a_date_time); local_time_input_facet* input_facet = new local_time_input_facet(); local_time_facet* output_facet = new local_time_facet(); ss.imbue(locale(locale::classic(), output_facet)); ss.imbue(locale(ss.getloc(), input_facet)); input_facet->format("%d/%b/%Y %H:%M"); output_facet->set_iso_format(); ss << inpDate; return ss.str(); }

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[statechart] direct manipulation of event queue?
by Chris Paulse 30 Oct '07

30 Oct '07

How easy would it be to directly remove specific types of events from a state machine's event queue?

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Beginner question about PocketPC 2003
by Dmytro Bogovych 30 Oct '07

30 Oct '07

Greetings. I downloaded 1.34.1 build from Boost Consulting. It comes with prebuilt libraries for VS 2005. I like it very much as I use Boost.Thread in my projects. But this package comes without prebuild libraries for PocketPC 2003 ARM target. How can I build them? I read about bjam but don't see what arguments I should set. This - bjam --v2 "-sTOOLS=msvc" "-sBUILD=release <windows>pocketpc2003 <charset>wide <architecture>arm4" install doesn't work. Sorry for stupid question.

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[multi-index] bug or not?
by Ovanes Markarian 30 Oct '07

30 Oct '07

Hello! I have a question regarding the multi-index behaviour, Let's say I have a multi-index container containing some hashed keys. What should happen with this container is empty and I retrieve an indexed by hash view into it? I have on Visual C++ 2005 an access violation, since I am trying to retrieve a view by it's hashed keys into the const container. Many thanks, Ovanes

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Errors in custom predicate support docu
by Jens Seidel 30 Oct '07

30 Oct '07

Hi, I tried a few times to report the following bug to trac but it was always rejected as spam!?? According to http://www.boost.org/libs/test/doc/components/test_tools/custom_predicate_s… there exists a class boost::test_tools::extended_predicate_value. (Or is it a user supplied class?) Nevertheless I didn't found such a class in Boost.test and even trunk contains only predicate_result which is different. This makes predicate support very hard to use for me. Please provide proper documentation for it! I hope this is the right way to run tests in a loop and to condense the output. Jens

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serialization: curious un-serializing issue RFI
by Hugh Hoover 30 Oct '07

30 Oct '07

I have a curious problem that's just sprung up, after changing from using plain-old-pointers to using boost::shared_ptrs internally in my data structures (stl hash_map and map) The problem is that while the XML archive works correctly, both text and binary fail (they all used to work). This is using gcc 4.0.1 on darwin and VC8 on windows, boost version is 1.34.1 The failure occurs while unserializing an archive, specifically when trying to read back a shared_ptr to an already unserialized object. In the archive, it shows the object (pointer) as an object_reference (the same reference id in XML and text). While the XML version reads the pointer back correctly, the text version fails and returns NULL. I have not determined the exact reason why the text version fails (it doesn't throw, just returns NULL). The serialization does not appear to have any problems. Since my actual code is reasonably complicated, and I haven't created a simplified version that demonstrates the problem, I'm not including code now - I'd just like to find out if this sounds familiar to anyone, that is, working under XML but failing under text and binary. It does appear to be shared_ptr specific, too, since everything was working before replacing naked pointers with shared_ptrs.

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Serialization and raw pointer arrays
by Eric 30 Oct '07

30 Oct '07

Hi, I've inherited some complex math code that makes large usage of Matrices based on raw pointer arrays. I need to serialize/deserialize these arrays as is and am looking to use boost::serialization package. My attempt at doing so results in the following errors (mostly about non integral array size). As I do not know the array size when it is created (and lots of code accesses the pointer directly as a chunk of memory that has been allocated, what are my options to get this to work? Errors: /usr/include/boost/archive/detail/oserializer.hpp: In function `void boost::archive::save(Archive&, T&) [with Archive = boost::archive::text_oarchive, T = Dummy]': /usr/include/boost/archive/basic_text_oarchive.hpp:78: instantiated from `void boost::archive::basic_text_oarchive<Archive>::save_override(T&, int) [with T = Dummy, Archive = boost::archive::text_oarchive]' /usr/include/boost/archive/detail/interface_oarchive.hpp:78: instantiated from `Archive& boost::archive::detail::interface_oarchive<Archive>::operator<<(T&) [with T = Dummy, Archive = boost::archive::text_oarchive]' serialize_array.cpp:56: instantiated from here /usr/include/boost/archive/detail/oserializer.hpp:567: error: incomplete type `boost::STATIC_ASSERTION_FAILURE< false>' used in nested name specifier /usr/include/boost/archive/detail/oserializer.hpp:567: error: size of array has non-integral type `<type error>' Code: #include <boost/serialization/split_member.hpp> #include <fstream> #include <iostream> #include <boost/archive/text_oarchive.hpp> #include <boost/archive/text_iarchive.hpp> using namespace std; class Dummy { public: friend class boost::serialization::access; Dummy() {pVal=NULL;size=0;} ~Dummy() {delete [] pVal;} template<class Archive> void save(Archive & ar, const unsigned int version) const { ar & size; for (int i=0; i<size; i++) { ar & pVal[i]; } } template<class Archive> void load(Archive & ar, const unsigned int version) { ar & size; pVal = new int[size]; for (int i=0; i<size; i++) { ar & pVal[i]; } } int* pVal; int size; }; BOOST_CLASS_VERSION(Dummy, 1) int main(int argc, char** argv) { Dummy d; d.size = 5; d.pVal = new int[d.size]; for (int i=0; i< d.size; i++) { d.pVal[i] = i+10; } ofstream ofOut("testSer.txt"); { boost::archive::text_oarchive oa(ofOut); oa << d; } Dummy load; { ifstream ifIn("testSer.txt"); boost::archive::text_iarchive ia(ifIn); ia >> load; } cout << "size="<<load.size<<endl; for (int i=0; i< load.size; i++) { cout << load.pVal[i] <<endl; } return -1; } Thanks, Eric

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boost.graph python bindings: read_graphml: No to_python (by-value) converter found for C++ type: struct boost::graph_exception
by John Reid 30 Oct '07

30 Oct '07

Hi, When I try to read a graphml file an exception is thrown but cannot be passed back to python through boost.python as no converter is registered. I'm using SVN version 338 from https://svn.osl.iu.edu/svn/projects_viz/bgl-python. The output is: c:\dev\python\boost\graph\__init__.py in read_graphml(filename) 624 """ 625 try: --> 626 graph = Digraph.read_graphml(filename) 627 except UndirectedGraphError: 628 graph = Graph.read_graphml(filename) <type 'exceptions.TypeError'>: No to_python (by-value) converter found for C++ type: struct boost::graph_exception If I just try the following: bgl.Graph.read_graphml(filename) I get something that might be a different symptom of the same problem: <type 'exceptions.SystemError'>: 'finally' pops bad exception The graphml file is: <?xml version="1.0" encoding="UTF-8"?>  <graphml xmlns="http://graphml.graphdrawing.org/xmlns/graphml" xmlns:y="http://www.yworks.com/xml/graphml" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://graphml.graphdrawing.org/xmlns/graphml http://www.yworks.com/xml/schema/graphml/1.0/ygraphml.xsd"> <key id="d0" for="node" yfiles.type="nodegraphics"/> <key id="d1" for="edge" yfiles.type="edgegraphics"/> <graph id="G" edgedefault="directed"> <node id="n0"> <data key="d0" > <y:ShapeNode > <y:Geometry x="0.0" y="0.0" width="30.0" height="30.0"/> <y:Fill color="#FFCC00" transparent="false"/> <y:BorderStyle type="line" width="1.0" color="#000000" /> <y:NodeLabel x="13.0" y="13.0" width="4.0" height="4.0" visible="true" alignment="center" fontFamily="Dialog" fontSize="13" fontStyle="plain" textColor="#000000" hasBackgroundColor="false" hasLineColor="false" modelName="internal" modelPosition="c" autoSizePolicy="content"></y:NodeLabel> <y:Shape type="ellipse"/> </y:ShapeNode> </data> </node> <node id="n1"> <data key="d0" > <y:ShapeNode > <y:Geometry x="18.0" y="68.0" width="30.0" height="30.0"/> <y:Fill color="#FFCC00" transparent="false"/> <y:BorderStyle type="line" width="1.0" color="#000000" /> <y:NodeLabel x="13.0" y="13.0" width="4.0" height="4.0" visible="true" alignment="center" fontFamily="Dialog" fontSize="13" fontStyle="plain" textColor="#000000" hasBackgroundColor="false" hasLineColor="false" modelName="internal" modelPosition="c" autoSizePolicy="content"></y:NodeLabel> <y:Shape type="rectangle"/> </y:ShapeNode> </data> </node> <edge id="e0" source="n0" target="n1"> <data key="d1" > <y:PolyLineEdge > <y:Path sx="0.0" sy="0.0" tx="0.0" ty="0.0"/> <y:LineStyle type="line" width="1.0" color="#000000" /> <y:Arrows source="none" target="standard"/> <y:BendStyle smoothed="false"/> </y:PolyLineEdge> </data> </edge> </graph> </graphml> Thanks for a great library, John.

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Re: [Boost-users] [reflection] Compilation errors
by Ovanes Markarian 30 Oct '07

30 Oct '07

Hi Christian, I assume you need to use either wchar_t or set in Visual C++ the charset not to multi-byte but not implemented. Otherwise you are trying to use pass single-byte strings as multi-byte string params. Best Regards, Ovanes On 10/29/07, Christian Henning <chhenning(a)gmail.com> wrote: > > Hi there, I just pulled the latest reflection code from the sandbox > and tried to compile the example. But unfortunately there are > compilation errors. > > For example: > > c:\boost-sandbox\boost\extension\impl\library_impl.hpp(37) : error > C2664: 'LoadLibraryW' : cannot convert parameter 1 from 'const char *' > to 'LPCWSTR' > > Is the relection lib in a usable stage? > > Thanks, > Christian > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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using ref() with threads
by Andrey Tcherepanov 30 Oct '07

30 Oct '07

Hello folks, we recently got stuck with one minor inconvenience with boost thread (which we fixed), but somehow we cannot explain why it did not work. We are using 1.34.1 and VS 2005 SP1 the sample that did not work properly was aproximately like this (not compilable) class Super_Func { protected: bool * _die; SomeObscureIPWorksBasedDaemon _daemon; public: Super_Func(bool* t) : _die(t), _daemon("localhost", 12345) {} void operator()() { while (!*_die) { _daemon.do_background_stuff(); if (_daemon.has_data()) us_process_data(_daemon.get_data()); } } }; int main() { bool die = false; Super_Func sf(&die); boost::thread main_thread(boost::ref(sf)); main_thread.join(); return 0; } Everything compiled without hick-up, and even created the thread (well, at least debugger showed it, and stopped in while loop). But all the TCP/IP related stuff in thread did not work (was sort of stuck). Once we replaced above with void Super_Func(bool* die) { SomeObscureIPWorksBasedDaemon _daemon("localhost", 12345); while (!*_die) { _daemon.do_background_stuff(); if (_daemon.has_data()) us_process_data(_daemon.get_data()); } } int main() { bool die = false; boost::thread main_thread(boost::bind(Super_Func, &die)); main_thread.join(); return 0; } everything magically worked! Well, if I do not miss some obvious error somewhere in the first example (which I might)... then I do not know why it did not work. I was under impression that ref() is just a way to pass "reference" to the anything (including functional object), so it will create copy of ref, and not Super_Func class itself. Any insight is appreciated. Thank you very much, Andrey.

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Request to know about "dynamic expression evaluation"
by Borse, Ganesh 29 Oct '07

29 Oct '07

Hi, I would like to perform the dynamic expression evaluation in my c++ application. The dynamic expressions are like the SQL queries. Since the expressions could be nested & hence the parsing & evaluation of such expressions is reducing the performance of my application. May I please know, whether BOOST provides a support for such dynamic expression evaluation in C++? Please guide. Thanks in advance for the guidance. Regards, Ganesh ============================================================================== Please access the attached hyperlink for an important electronic communications disclaimer: http://www.credit-suisse.com/legal/en/disclaimer_email_ib.html ==============================================================================

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bis
by question boost 29 Oct '07

29 Oct '07

Hi, it seems the problem is at step 2. When I do: C:\Documents and Settings\src\boost\tools\build\v2> bjam --version I get the message: Mingwbing++ n'est pas reconnu en tant que command interne ou externe,un programme exécutable ou un fichier de commandes. Change the "\" by "/" is apparently not the solution. Thank you for your help. David _________________________________________________________________ Vous êtes plutôt Desperate ou LOST ? Personnalisez votre PC avec votre série TV préférée ! http://specials.divertissements.fr.msn.com/SeriesTV.aspx

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