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Spirit: parsing tab separated values and no_skip
by Mauricio Gomes 18 May '10

18 May '10

Hi Harmut, Did you uncomment the line: //#include <boost/spirit/include/qi_no_skip.hpp> ? It is commented out in the code below. If I include this line, compilation fails. You also have to check optimizations because the code below is not using no_skip[] in the grammar so there is a chance that a smart compiler that is not in debug mode might ignore the non-used code. In my case I am in debug mode, no optmizations and including the qi_no_skip.hpp header suffices to get the error. Thanks for your attention ! 1. Re: Spirit: parsing tab separated values and no_skip > compilation error. (Hartmut Kaiser) > ---------------------------------------------------------------------- > > Message: 1 > Date: Thu, 13 May 2010 18:28:19 -0500 > From: "Hartmut Kaiser" <hartmut.kaiser(a)gmail.com> > To: <boost-users(a)lists.boost.org> > Subject: Re: [Boost-users] Spirit: parsing tab separated values and > no_skip compilation error. > Message-ID: <0d5301caf2f3$fa1c64e0$ee552ea0$(a)gmail.com> > Content-Type: text/plain; charset="iso-8859-1" > > > I am a beginner with Spirit. I just read the tutorial and I am playing > > around with some examples. > > Environment: boost 1.43, Windows Vista, Code::Blocks, mingw, gcc 4.5. > > > > My goal is to build a tab separated values parser. > > If you have an example on how to parse something like: > > string/t/tdouble/tdouble > > it would be great. Contiguous tabs should be considered as one tab, not > an > > empty field. > > > > To start I just tried to parse a tab separated list of strings but I am > > having some difficulties. > > > > Is there another skip parser to be used instead of space (for full code > > see the end of the message below) ? > > I have changed the commas to tabs in the code below but it failed. I > guess > > it was because it was skipping them (space skipper). > > > > ??????? bool r = phrase_parse(first, last, > > > > ??????????? //? Begin grammar > > ??????????? ( > > ??????????????? +(char_ - ',') % ',' > > ??????????? ) > > ??????????? , > > ??????????? //? End grammar > > > > ??????????? space, v); > > > > This code works with commas but it fails with '\t'. > > > > I tried to use no_skip[] but it failed to compile the header #include > > <boost/spirit/include/qi_no_skip.hpp>: > > > > C:\boost_1_43_0\boost\spirit\home\qi\directive\no_skip.hpp|30|error: > > 'no_skip' is not a member of 'boost::spirit::tag'| > > > > For full error message see the end of the message below. > > > > Any suggestions ? > > > > Thank you for your attention, > > Mau. > > > > #include <boost/config/warning_disable.hpp> > > #include <boost/spirit/include/qi.hpp> > > #include <boost/spirit/include/phoenix_core.hpp> > > #include <boost/spirit/include/phoenix_operator.hpp> > > #include <boost/spirit/include/phoenix_stl.hpp> > > //#include <boost/spirit/include/qi_no_skip.hpp> > > > > #include <iostream> > > #include <string> > > #include <vector> > > > > #define VECTOR_TYPE std::string > > > > namespace client > > { > > ??? namespace qi = boost::spirit::qi; > > ??? namespace ascii = boost::spirit::ascii; > > > > ??? > ////////////////////////////////////////////////////////////////////// > > ///// > > ??? //? Our number list compiler > > ??? > ////////////////////////////////////////////////////////////////////// > > ///// > > ??? //[tutorial_numlist4 > > ??? template <typename Iterator> > > ??? bool parse_numbers(Iterator first, Iterator last, > > std::vector<VECTOR_TYPE>& v) > > ??? { > > ??????? using qi::double_; > > ??????? using qi::phrase_parse; > > ??????? using qi::_1; > > ??????? using ascii::space; > > ??????? using qi::char_; > > > > ??????? bool r = phrase_parse(first, last, > > > > ??????????? //? Begin grammar > > ??????????? ( > > ??????????????? +(char_ - ',') % ',' > > ??????????? ) > > ??????????? , > > ??????????? //? End grammar > > > > ??????????? space, v); > > > > ??????? if (first != last) // fail if we did not get a full match > > ??????????? return false; > > ??????? return r; > > ??? } > > ??? //] > > } > > > > > ////////////////////////////////////////////////////////////////////////// > > // > > //? Main program > > > ////////////////////////////////////////////////////////////////////////// > > // > > int > > main() > > { > > ??? std::cout << > > "/////////////////////////////////////////////////////////\n\n"; > > ??? std::cout << "\t\tA comma separated list parser for Spirit...\n\n"; > > ??? std::cout << > > "/////////////////////////////////////////////////////////\n\n"; > > > > ??? std::cout << "Give me a comma separated list of numbers.\n"; > > ??? std::cout << "The numbers will be inserted in a vector of numbers\n"; > > ??? std::cout << "Type [q or Q] to quit\n\n"; > > > > ??? std::string str; > > ??? while (getline(std::cin, str)) > > ??? { > > ??????? if (str.empty() || str[0] == 'q' || str[0] == 'Q') > > ??????????? break; > > > > ??????? std::vector<VECTOR_TYPE> v; > > ??????? if (client::parse_numbers(str.begin(), str.end(), v)) > > ??????? { > > ??????????? std::cout << "-------------------------\n"; > > ??????????? std::cout << "Parsing succeeded\n"; > > ??????????? std::cout << str << " Parses OK: " << std::endl; > > > > ??????????? for (std::vector<VECTOR_TYPE>::size_type i = 0; i < v.size(); > > ++i) > > ??????????????? std::cout << i << ": " << v[i] << std::endl; > > > > ??????????? std::cout << "\n-------------------------\n"; > > ??????? } > > ??????? else > > ??????? { > > ??????????? std::cout << "-------------------------\n"; > > ??????????? std::cout << "Parsing failed\n"; > > ??????????? std::cout << "-------------------------\n"; > > ??????? } > > ??? } > > > > ??? std::cout << "Bye... :-) \n\n"; > > ??? return 0; > > } > > This example compiles fine for me (VC10, g++ 4.5). Is it supposed to fail? > > Regards Hartmut >

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BoostCon 2011 Dates and Hotel Discount (this week only!)
by David Abrahams 18 May '10

18 May '10

Hi All, BoostCon #4 was a resounding success, with 95 registrants—attendance holding steady in the face of a poor economy—and nothing but smiles all ’round. One participant was heard to say “after last year, I thought about not coming because I was sure nothing could possibly be cooler that experience, but this is even better.” I'll have more to say about the event soon, but for now a couple important details about next year: 1. Next year, BoostCon is scheduled a week later: May 15-20, 2011 which avoids a conflict with Mother's Day, a perennial issue for some attendees… and is a bit less likely to bring us snow ;-) 2. Because BoostCon has been an excellent regular customer, the Aspen Meadows is offering a $20/night discount for any Boost participant who books on or before **this Friday**, May 21 2010. After taxes, etc., that's more than a $100 savings. Use the following link to make your reservation: https://resweb.passkey.com/Resweb.do?mode=welcome_ei_new&eventID=2547965&fr… Lastly, the Meadows wants you to know that your companies or universities are welcome back for other meetings, and requests that, if you had a good hotel experience this year, you please post positive feedback on http://tripadvisor.com. See you next year, if not before! Cheers, -- Dave Abrahams Meet me at BoostCon: http://www.boostcon.com BoostPro Computing http://www.boostpro.com

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Re: [Boost-users] shared_ptr question
by Peter Dimov 18 May '10

18 May '10

David Michael Bond wrote: ... > I looked into it more and it seems if I comment out the memcpy in the > get_ether_header function I do not get the segfault. > > ether_header Frame::get_ether_header( ) { > ether_header ret ; > memcpy( &ret, this->bytes.get(), this->size ) ; > return ret ; > } > > Its fine to return that stack var right there right? That should just copy > the memory into the return value for the stack? It's fine to return a stack variable, but it may not be fine to memcpy into it, depending on how ether_header is defined and whether this->size may exceed sizeof(ether_header). To investigate further, you might want to look at the stack backtrace when the segfault occurs. Your shared_ptr use seems fine, so it's probably ~Frame that is crashing (unless there is memory damage).

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[BGL] Is adjacency_iterator not Equality Comparable?
by Hossein Haeri 18 May '10

18 May '10

Dear all, [Boost 1.42, GCC 3.4.5 under MinGW in WinXP] I have a piece of program like this: typedef graph_type::adjacency_iterator iterator; iterator begin, end; boost::tie(begin, end) = boost::adjacent_vertices(curr_, *graph_ptr_); //... ArrFreq nextArr = l.front(); //... iterator i = find(begin, end, nextArr); And, I get the error message in the P.S. once I try the last line above. I was wondering if that's because: 1) adjacency_iterator is not equality comparable. Or, 2) the value type of adjacency_iterator is not comparable with the graph's vertex type. Or, 3) even something else? TIA, --Hossein P.S. /lib/gcc/mingw32/3.4.5/../../../../include/c++/3.4.5/bits/stl_algo.h:172: error: no match for 'operator==' in '((boost::iterator_facade<boost::adjacency_iterator<boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, ArrFreq, TransRule::Type, boost::no_property, boost::listS>, size_t, boost::detail::out_edge_iter<__gnu_cxx::__normal_iterator<boost::detail::sep_<size_t, boost::property<boost::edge_bundle_t, TransRule::Type, boost::no_property> >*, std::vector<boost::detail::sep_<size_t, boost::property<boost::edge_bundle_t, TransRule::Type, boost::no_property> >, std::allocator<boost::detail::sep_<size_t, boost::property<boost::edge_bundle_t, TransRule::Type, boost::no_property> > > > >, size_t, boost::detail::edge_desc_impl<boost::directed_tag, size_t>, ptrdiff_t>, ptrdiff_t>, size_t, boost::detail::iterator_category_with_traversal<std::input_iterator_tag, boost::random_access_traversal_tag>, size_t, ptrdiff_t>*)(&__first))->boost::iterator_facade<I, V, TC, R, D>::operator* [with Derived = boost::adjacency_iterator<boost::adjacency_list<boost::vecS, boost::vecS, boost::directedS, ArrFreq, TransRule::Type, boost::no_property, boost::listS>, size_t, boost::detail::out_edge_iter<__gnu_cxx::__normal_iterator<boost::detail::sep_<size_t, boost::property<boost::edge_bundle_t, TransRule::Type, boost::no_property> >*, std::vector<boost::detail::sep_<size_t, boost::property<boost::edge_bundle_t, TransRule::Type, boost::no_property> >, std::allocator<boost::detail::sep_<size_t, boost::property<boost::edge_bundle_t, TransRule::Type, boost::no_property> > > > >, size_t, boost::detail::edge_desc_impl<boost::directed_tag, size_t>, ptrdiff_t>, ptrdiff_t>, Value = size_t, CategoryOrTraversal = boost::detail::iterator_category_with_traversal<std::input_iterator_tag, boost::random_access_traversal_tag>, Reference = size_t, Difference = ptrdiff_t]() == __val' FlowGraph.cpp:148: note: candidates are: bool operator==(const ArrFreq&, const ArrFreq&) bool operator==(const Arrangement&, const Arrangement&)

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error boost spirit
by khaled hamidouche 18 May '10

18 May '10

Hello with Joel Falcou we are wondring to write a parser to parse mathematical expression like (N1*3+N2/N3) ... with N1, N2, N3 are variables where their value are in an std vector so I take the calc example and I change it. my code looks like this #include <boost/config/warning_disable.hpp> #include <boost/spirit/include/qi.hpp> #include <boost/spirit/include/phoenix_operator.hpp> #include <boost/spirit/home/phoenix/container.hpp> #include <iostream> #include <string> #include <vector> namespace client { namespace qi = boost::spirit::qi; namespace ascii = boost::spirit::ascii; void do_add() { std::cout << "add\n"; } /////////////////////////////////////////////////////////////////////////// // Our calculator grammar /////////////////////////////////////////////////////////////////////////// template <typename Iterator> struct calculator : qi::grammar<Iterator, int(), ascii::space_type> { calculator(std::vector<int> const & vec) : calculator::base_type(expression), vect(vec) { using qi::_val; using qi::_1; using qi::uint_; using ascii::char_; int index; // vect.resize(3); // // // vect[0]=10; // vect[1]=11; // vect[2]=12; //vect=vec; expression = term [_val = _1] >> *( ('+' >> term [_val += _1]) | ('-' >> term [_val -= _1]) ) ; term = factor [_val = _1] >> *( ('*' >> factor [_val *= _1]) | ('/' >> factor [_val /= _1]) ) ; factor = uint_ [_val = _1] | char_ >>uint_ [_val = at(vect,_1)] | '(' >> expression [_val = _1] >> ')' | ('-' >> factor [_val = -_1]) | ('+' >> factor [_val = _1]) ; } qi::rule<Iterator, int(), ascii::space_type> expression, term, factor; std::vector<int> vect; }; } /////////////////////////////////////////////////////////////////////////////// // Main program /////////////////////////////////////////////////////////////////////////////// int main() { std::cout << "/////////////////////////////////////////////////////////\n\n"; std::cout << "Expression parser...\n\n"; std::cout << "/////////////////////////////////////////////////////////\n\n"; std::cout << "Type an expression...or [q or Q] to quit\n\n"; using boost::spirit::ascii::space; typedef std::string::const_iterator iterator_type; typedef client::calculator<iterator_type> calculator; std::vector<int> vec(3); vec[0]=10; vec[1]=11; vec[2]=12; calculator calc(vec); // Our grammar std::string str; int result; while (std::getline(std::cin, str)) { if (str.empty() || str[0] == 'q' || str[0] == 'Q') break; std::string::const_iterator iter = str.begin(); std::string::const_iterator end = str.end(); bool r = phrase_parse(iter, end, calc, space, result); if (r && iter == end) { std::cout << "-------------------------\n"; std::cout << "Parsing succeeded\n"; std::cout << "result = " << result << std::endl; std::cout << "-------------------------\n"; } else { std::string rest(iter, end); std::cout << "-------------------------\n"; std::cout << "Parsing failed\n"; std::cout << "stopped at: \": " << rest << "\"\n"; std::cout << "-------------------------\n"; } } std::cout << "Bye... :-) \n\n"; return 0; } when I compile I get this error /home/hamidou/LLVM/parser /main.cpp:296: instantiated from here /usr/local/include/boost-1_42/boost/spirit/home/phoenix/core/detail/function_eval.hpp:135: error: invalid initialization of reference of type ‘int&’ from expression of type ‘const int’ Process terminated with status 1 (0 minutes, 11 seconds) 1 errors, 1 warnings when I remove the use of the vector vect inside my grammar it works fine !! So, please what I did wrong ?? Thank you so much for helping me

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Re: [Boost-users] shared_ptr question
by Soumen Ghosh 18 May '10

18 May '10

I'm not sure but can you test it following way: Defer this declaration " boost::shared_ptr<Frame> rx" in following way and see if that helps ... boost::shared_ptr<Frame> &rx = processing_queue.back( ) ; Regards, ~ Soumen On Tue, May 18, 2010 at 9:30 AM, David Michael Bond <david.bond(a)iol.unh.edu>wrote: > Hello, > I am learning shared_ptrs and I am running into a segfault. I'm fairly > certain it's because of some misunderstanding I have. > > Here is some code. I have altered it to just so the relevant data: > > ---- START CODE ---- > std::deque<boost::shared_ptr<Frame> > processing_queue ; > void this_is_called() { > boost::shared_ptr<Frame> rx ; > interface->open( "eth0" ) ; > while( running ) { > interface->rx_frame( this->processing_queue ) ; > if( !processing_queue.empty( ) ) { > rx = processing_queue.back( ) ; > if( rx ) { > std::cout > << "Received Frame of Ethertype " > << ntohs( rx->get_ether_header( ).ether_type ) > << "." << std::endl ; > } > } > } > } > } > > // rx frame from interface and add onto processing_queue > boost::shared_ptr<Frame> last_rx_frame ; // (CLASSXX member) > void CLASSXX::rx_frame( std::deque<boost::shared_ptr<Frame> >& > processing_queue ) { > // Do some stuff to receive frame.. (int size= # bytes in frame) > last_rx_frame.reset(new Frame( )) ; > last_rx_frame->bytes.reset( new u_char[size]) ; > memcpy( last_rx_frame->bytes.get(), frame_bytes, size) ; > last_rx_frame->size = size ; > processing_queue.push_back( this->last_rx_frame ) ; > } > > ---- END CODE ---- > > The program receives one frame and successful and outputs it: > Received Frame of Ethertype 0x800. > But the second time when it gets to 'rx = processing_queue.back( ) ;' I > have > a segfault. > > My understanding of shared_ptrs is that when this assignment is done rx > will > have its ref count decremented (possibly leading to it being deleted). The > back of the processing_queue will then become rx do to the assignment and > that shared ptrs reference count will be increased by one. Anyone know what > my misconception is? Any idea what's causing the segfault? > > Thanks! > -David > > > > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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Re: [Boost-users] linking for release, has debug baggage
by Edward Rankin 18 May '10

18 May '10

On Mon, May 17, 2010 at 6:53 PM, <boost-users-request(a)lists.boost.org>wrote: > > Message: 3 > Date: Sun, 16 May 2010 20:25:14 -0700 > From: Dan Bloomquist <danb(a)lakeweb.net> > To: boost-users(a)lists.boost.org > Subject: [Boost-users] linking for release, has debug baggage > Message-ID: <4BF0B71A.7020804(a)lakeweb.net> > Content-Type: text/plain; charset=ISO-8859-1; format=flowed > > > Hi, > I have a large project and for what ever reason if I add xpressive.hpp > in my precompiled header, it completly kills intelligence. So I figured > I'd move the stuff I want to use off to a lib. Works fine in debug but > if I build the release, this lib tries to link in the Microsoft debug libs. > > In my project: > 1>mfcs90.lib(nolib.obj) : warning LNK4098: defaultlib 'mfc90d.lib' > conflicts with use of other libs; use /NODEFAULTLIB:library > 1>mfcs90.lib(nolib.obj) : warning LNK4098: defaultlib 'mfcs90d.lib' > conflicts with use of other libs; use /NODEFAULTLIB:library > and just this one in the test solution: > 1>msvcrt.lib(cinitexe.obj) : warning LNK4098: defaultlib 'msvcrtd.lib' > conflicts with use of other libs; use /NODEFAULTLIB:library > > I have been able to recreate the problem in a small solution that should > not dependent on my directories other than setting the boost path: > > <http://lakeweb.net/downloads/RaVpath.zip> > (20k) vc 2008 (9.0) boost 1_42 > > And I don't know, this may have nothing to do with boost, but I have > other dlls and libs without this problem. It is coming from > 'boost::filesystem' as best as I can determine. > > And maybe someone has seen this before and knows off the top of their head. > > Thanks, Dan. > What's happening here is that the libs you built were built against the microsoft debug libs. You will need to build a separate set of libs which were built against the microsoft release libs. This means when you are compiling your actual program in release mode, you will need to point the linker to the new set of libs you built. Edward

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Re: [Boost-users] shared_ptr question
by Michael Jackson 18 May '10

18 May '10

On 5/18/10 12:00 AM, in article 37128.3139721074$1274188512(a)news.gmane.org, "David Michael Bond" wrote: > rx = processing_queue.back( ) ; > if( rx ) { I think your problem is the misunderstanding of the shared_ptr. The shared_ptr is a class that _wraps_ another pointer (whether valid or not) and keeps a reference count to how many other variables are using the pointer. The following line: if (rx) is only testing if the wrapper is valid, NOT the actual pointer itself that is being wrapped. What you really want is: If (rx.get() != NULL) -- Mike Jackson

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Re: [Boost-users] shared_ptr question
by richard.carless＠uk.bnpparibas.com 18 May '10

18 May '10

I think it's down to your use of reset. Why not just assign? last_rx_frame = new Frame; On the multiple thread note, when you put these functions on seperate threads you will need to marshal the use of the queue. Cheers Rich Internet david.bond(a)iol.unh.edu Sent by: boost-users-bounces(a)lists.boost.org 18/05/2010 14:23 Please respond to boost-users(a)lists.boost.org To boost-users(a)lists.boost.org cc Subject Re: [Boost-users] shared_ptr question No, but eventually I will be accessing the shared_ptrs from different threads. -David From: boost-users-bounces(a)lists.boost.org [mailto:boost-users-bounces@lists.boost.org] On Behalf Of richard.carless(a)uk.bnpparibas.com Sent: Tuesday, May 18, 2010 9:22 AM To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] shared_ptr question are you running these functions on different threads? Internet david.bond(a)iol.unh.edu Sent by: boost-users-bounces(a)lists.boost.org 18/05/2010 05:00 Please respond to boost-users(a)lists.boost.org To Boost-users(a)lists.boost.org cc Subject [Boost-users] shared_ptr question Hello, I am learning shared_ptrs and I am running into a segfault. I'm fairly certain it's because of some misunderstanding I have. Here is some code. I have altered it to just so the relevant data: ---- START CODE ---- std::deque<boost::shared_ptr<Frame> > processing_queue ; void this_is_called() { boost::shared_ptr<Frame> rx ; interface->open( "eth0" ) ; while( running ) { interface->rx_frame( this->processing_queue ) ; if( !processing_queue.empty( ) ) { rx = processing_queue.back( ) ; if( rx ) { std::cout << "Received Frame of Ethertype " << ntohs( rx->get_ether_header( ).ether_type ) << "." << std::endl ; } } } } } // rx frame from interface and add onto processing_queue boost::shared_ptr<Frame> last_rx_frame ; // (CLASSXX member) void CLASSXX::rx_frame( std::deque<boost::shared_ptr<Frame> >& processing_queue ) { // Do some stuff to receive frame.. (int size= # bytes in frame) last_rx_frame.reset(new Frame( )) ; last_rx_frame->bytes.reset( new u_char[size]) ; memcpy( last_rx_frame->bytes.get(), frame_bytes, size) ; last_rx_frame->size = size ; processing_queue.push_back( this->last_rx_frame ) ; } ---- END CODE ---- The program receives one frame and successful and outputs it: Received Frame of Ethertype 0x800. But the second time when it gets to 'rx = processing_queue.back( ) ;' I have a segfault. My understanding of shared_ptrs is that when this assignment is done rx will have its ref count decremented (possibly leading to it being deleted). The back of the processing_queue will then become rx do to the assignment and that shared ptrs reference count will be increased by one. Anyone know what my misconception is? Any idea what's causing the segfault? Thanks! -David _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users ___________________________________________________________ This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and delete this e-mail. Any unauthorised copying, disclosure or distribution of the material in this e-mail is prohibited. Please refer to http://www.bnpparibas.co.uk/en/information/legal_information.asp?Code=ECAS-… for additional disclosures. _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users ___________________________________________________________ This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and delete this e-mail. Any unauthorised copying, disclosure or distribution of the material in this e-mail is prohibited. Please refer to http://www.bnpparibas.co.uk/en/information/legal_information.asp?Code=ECAS-… for additional disclosures.

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Re: [Boost-users] shared_ptr question
by richard.carless＠uk.bnpparibas.com 18 May '10

18 May '10

are you running these functions on different threads? Internet david.bond(a)iol.unh.edu Sent by: boost-users-bounces(a)lists.boost.org 18/05/2010 05:00 Please respond to boost-users(a)lists.boost.org To Boost-users(a)lists.boost.org cc Subject [Boost-users] shared_ptr question Hello, I am learning shared_ptrs and I am running into a segfault. I'm fairly certain it's because of some misunderstanding I have. Here is some code. I have altered it to just so the relevant data: ---- START CODE ---- std::deque<boost::shared_ptr<Frame> > processing_queue ; void this_is_called() { boost::shared_ptr<Frame> rx ; interface->open( "eth0" ) ; while( running ) { interface->rx_frame( this->processing_queue ) ; if( !processing_queue.empty( ) ) { rx = processing_queue.back( ) ; if( rx ) { std::cout << "Received Frame of Ethertype " << ntohs( rx->get_ether_header( ).ether_type ) << "." << std::endl ; } } } } } // rx frame from interface and add onto processing_queue boost::shared_ptr<Frame> last_rx_frame ; // (CLASSXX member) void CLASSXX::rx_frame( std::deque<boost::shared_ptr<Frame> >& processing_queue ) { // Do some stuff to receive frame.. (int size= # bytes in frame) last_rx_frame.reset(new Frame( )) ; last_rx_frame->bytes.reset( new u_char[size]) ; memcpy( last_rx_frame->bytes.get(), frame_bytes, size) ; last_rx_frame->size = size ; processing_queue.push_back( this->last_rx_frame ) ; } ---- END CODE ---- The program receives one frame and successful and outputs it: Received Frame of Ethertype 0x800. But the second time when it gets to 'rx = processing_queue.back( ) ;' I have a segfault. My understanding of shared_ptrs is that when this assignment is done rx will have its ref count decremented (possibly leading to it being deleted). The back of the processing_queue will then become rx do to the assignment and that shared ptrs reference count will be increased by one. Anyone know what my misconception is? Any idea what's causing the segfault? Thanks! -David _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users ___________________________________________________________ This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and delete this e-mail. Any unauthorised copying, disclosure or distribution of the material in this e-mail is prohibited. Please refer to http://www.bnpparibas.co.uk/en/information/legal_information.asp?Code=ECAS-… for additional disclosures.

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