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

[OT] Calling Overmind
by John Phillips 18 Oct '10

18 Oct '10

Overmind, Would you please contact either me (John Phillips) or Ron Garcia off list? Thanks. John

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boost asio: repeated reading to delimiter
by Cattus Cerebrum 17 Oct '10

17 Oct '10

A very newbie question from a beginner user of boost::asio. I have used BSD socket interface a lot in the past, and would like to start using boost::asio for my networking code. I have a server that is providing data through a network socket. The data is a continuous stream of bytes, with different data elements separated from each other by a zero byte. Would reading into a streambuf with the help of async_read_until() be a good way of handling this situation? The code I am thinking of replacing uses select() to wait for arriving data, and then reads it into a circular buffer. Thanks.

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Forward declarations and iterator_facade<>
by Phil Endecott 17 Oct '10

17 Oct '10

Dear Experts, I have code something like this: struct S; class iter: public boost::iterator_facade<iter,S,......> { ... }; struct S { ... }; This used to work, but stopped recently; I believe it may have been after upgrading gcc, not after upgrading Boost itself, but I'm uncertain about that. The problem is that something inside iterator_facade calls boost::is_POD<S>, which (not unreasonably) doesn't seem to work for the forward-declared S. I've never been entirely sure what you're allowed to do with forward-declared types like that. Was I just lucky that it worked before, or is this a regression? Re-ordering the code to remove the circular dependencies will be painful, so if anyone has any other hints I would love to hear them. Thanks, Phil.

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link error on serialization demo.cpp
by jiryih.tsaur＠nomura.com 16 Oct '10

16 Oct '10

Tried to compile demo.cpp and getting link error below. Any suggestions? g++ -c -I. -I/usr/include -I/usr/include/c++/4.1.2 -I/usr/include/boost -I/home/jitsaur/usr/include -g -D_DEBUG -o demo.o demo.cpp g++ -I. -I/usr/include -I/usr/include/c++/4.1.2 -I/usr/include/boost -I/home/jitsaur/usr/include -g -D_DEBUG -o demo demo.o demo.o: In function `archive_exception': /home/jitsaur/usr/include/boost/archive/archive_exception.hpp:45: undefined reference to `vtable for boost::archive::archive_exception' ... PLEASE READ: This message is for the named person's use only. It may contain confidential, proprietary or legally privileged information. No confidentiality or privilege is waived or lost by any mistransmission. If you receive this message in error, please delete it and all copies from your system, destroy any hard copies and notify the sender. You must not, directly or indirectly, use, disclose, distribute, print, or copy any part of this message if you are not the intended recipient. Nomura Holding America Inc., Nomura Securities International, Inc, and their respective subsidiaries each reserve the right to monitor all e-mail communications through its networks. Any views expressed in this message are those of the individual sender, except where the message states otherwise and the sender is authorized to state the views of such entity. Unless otherwise stated, any pricing information in this message is indicative only, is subject to change and does not constitute an offer to deal at any price quoted. Any reference to the terms of executed transactions should be treated as preliminary only and subject to our formal written confirmation.

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[CfP] 5th Annual BoostCon, Aspen (CO, USA), May 15-20, 2011
by Hartmut Kaiser 16 Oct '10

16 Oct '10

Please distribute. ------------------ 5TH ANNUAL BOOST CONFERENCE 2011 Aspen CO, USA, May 15 - 20, 2011, www.boostcon.com CALL FOR PARTICIPATION We invite you to submit session proposals to the 5th Annual Boost Conference: BoostCon 2011 (Aspen CO, USA, May 15 - 20, 2011). Traditionally the main face-to-face event for all things Boost (www.boost.org) BoostCon 2011 will present leading speakers from the whole C++ community. >From using the Boost libraries to writing and maintaining them, from evangelizing to deploying Boost within your organization, from infrastructure and process to vision and mission, and the new C++ Standard, BoostCon brings together the sessions, the colleagues, and the inspiration to support your work with C++ and Boost in particular for the next year. To reflect the breadth of the Boost community, the conference includes sessions aimed at three constituencies: Boost end-users, hard-core Boost library and tool developers, and academics focusing on researcher. The program fosters interaction and engagement within and across those groups, with an emphasis on hands-on, participatory sessions. SESSION TOPICS Topics of interest include, but are not restricted to, the following: * General tutorial sessions introducing one or more Boost libraries * In-depth sessions on using specific Boost libraries * Case studies on using Boost * Experts panels * Advanced sessions on implementation techniques used within Boost libraries * C++0x and how it changes life for users and library writers * Development workshops to extend or enhance existing Boost libraries * Workshops on design process * Infrastructure workshops such as Build tools, Website, Testing * Concepts and Generic Programming * Hardware and infrastructure presentations focused on how libraries can make better use of the technology * Software development tools and their application to C++ and or Boost * Other topics likely to be of great interest to Boost users and developers Interactive and collaborative sessions are encouraged, as this is the nature of both the on-line Boost community and the style of learning and participation that has proven most successful at such events. Sessions can be tutorial based, with an emphasis on interaction and participant involvement, or workshop based, whether hands-on programming or paper-based, discussion-driven collaborative work. SESSION FORMATS Presentations ------------- Presentations focus on a practitioner's ideas and experience with anything relevant to Boost and Boost users. Panels ------------- Panels feature three or four people presenting their ideas and experiences relating to Boost's relevant, controversial, emerging, or unresolved issues. Panels may be conducted in several ways, such as comparative, analytic, or historic. Tutorials ------------- Tutorials are sessions at which instructors teach conference participants specific Boost-relevant skills. Workshops ------------- Workshops provide an active arena for advancements in Boost-relevant topics. Workshops provide the opportunity for experienced practitioners to develop new ideas about a topic of common interest and experience. Author's Corner Presentations These were introduced at BoostCon 2008, and were a great success. They are short (30 minute) sessions, focusing on tips on usage and design. In addition, we're looking to uncover the hidden design gems in Boost libraries. Tool Vendors Presentations We actively encourage tool vendors and ISP's to submit proposals for a special Tool Vendors Session Track aimed at products related to Boost and C++ (compilers, libraries, tools, etc.). Other formats may also be of interest. Don't hold back a proposal just because it doesn't fit into a pigeonhole. SUBMITTING A PROPOSAL Standard Sessions are 90 minutes. You may submit a proposal for fractions or multiples of 90-minutes. Fractional proposals will be grouped into 90 minute sessions covering related topics. Longer sessions, such as tutorials and classes, will be assigned 90 minute, three hour (i.e. half day), or six hour (i.e. full day) time slots. Please include: * The working title. * Type of session: presentation, panel, tutorial, workshop, authors corner, vendor track, other. * A paragraph or two describing the topic covered, suitable for the conference web site. * Proposed length: 10-20 minute short talks, 45 minutes, 90 minutes, half day, full day. * Alternate lengths, if you are willing to make adjustments: 10-20 minute short-talks, 45 minutes, 90 minutes, half-day, full day. * Audience: users, developers, both. * Level: basic, intermediate, advanced. * A biography, suitable for the conference web site. * Your contact information (will not be made public). SUBMISSION DETAILS All submissions have to be done through the EasyChair conference management system: http://www.easychair.org/conferences/?conf=boostcon2011. If you have not already registered at EasyChair, you will need to do so in order to submit your proposal. All submissions will go through a peer review process. Authors are invited (but are not required) to submit PDF versions of full papers of up to 10 pages in ACM conference proceedings format (see http://www.acm.org/sigs/publications/proceedings-templates) The full papers are not required unless you want them published in the proceedings. All accepted proposals will be made available in the Association for Computing Machinery (ACM) Digital Library (approval pending). Best papers, after further reviews, will be considered to be book chapters or journal articles in a renowned journal. The session materials go on the BoostCon website and will be available to attendees. For general information on the BoostCon 2011 paper submission or the scope of technical papers solicited, please refer to the conference website at www.boostcon.com. For any other questions about the submission process or paper format, please contact the Program Committee at boostcon2011(a)easychair.com. If you have any technical problems with EasyChair, please contact EasyChair for help. Note: Presenters must agree to grant a non-exclusive perpetual license to publish submitted materials, either electronically or in print, in any media related to BoostCon. IMPORTANT DATES Proposal submissions due: December 10th, 2011. Proposals decisions sent (tentative program available): January 17th, 2011. Fully scheduled program available: February 7th, 2011. Session materials due: April 15th, 2011. Hartmut Kaiser, email: hartmut.kaiser(a)gmail.com (Program Committee Chair) David Abrahams, email: dave(a)boostpro.com (Conference Chair) On behalf of the conference organizers

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[Boost.MPI] question about serializing custom object
by Cristobal Navarro 16 Oct '10

16 Oct '10

hello everybody, this is first post i have some questions after reading the Boost documentation of serialization and MPI, is it possible to serialize my custom objects with Boost.serialize and then send/receive them using plain openMPI as MPI_BYTE type?? the other question is on the tutorials i only found examples of serializing objects to archive and saving to file, but i didnt find any example where they serialize it to a binary form and send them through mpi, is there any example of this type on the documentation? best regards Cristobal

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[MPI, serialization] Segmentation fault in heterogeneous cluster
by Francesco Biscani 16 Oct '10

16 Oct '10

Hello, I'm getting a segfault when using Boost.MPI on a cluster of heterogeneous machines (x86_64 and ppc64). The problem arises when the "slave" machine, ppc64, receives its payload from the "master" machine, x86_64, and tries to unpack the archive. Tracing down the issue with valgrind and in debug mode, the problem arises here: ==28632== Invalid write of size 8 ==28632== at 0x10429DDC: boost::archive::detail::basic_iarchive_impl::load_pointer(boost::archive::detail::basic_iarchive&, void*&, boost::archive::detail::basic_pointer_iserializer const*, boost::archive::detail::basic_pointer_iserializer const* (*)(boost::serialization::extended_type_info const&)) (basic_iarchive.cpp:453) ==28632== by 0x1042772F: boost::archive::detail::basic_iarchive::load_pointer(void*&, boost::archive::detail::basic_pointer_iserializer const*, boost::archive::detail::basic_pointer_iserializer const* (*)(boost::serialization::extended_type_info const&)) (basic_iarchive.cpp:564) ==28632== by 0x10468707: void boost::archive::detail::load_pointer_type<boost::mpi::packed_iarchive>::invoke<pagmo::population*>(boost::mpi::packed_iarchive&, pagmo::population*&) (iserializer.hpp:518) ==28632== by 0x104683EF: void boost::archive::load<boost::mpi::packed_iarchive, pagmo::population*>(boost::mpi::packed_iarchive&, pagmo::population*&) (iserializer.hpp:586) ==28632== by 0x10468223: void boost::archive::detail::common_iarchive<boost::mpi::packed_iarchive>::load_override<pagmo::population*>(pagmo::population*&, int) (common_iarchive.hpp:68) ==28632== by 0x10468023: void boost::archive::basic_binary_iarchive<boost::mpi::packed_iarchive>::load_override<pagmo::population*>(pagmo::population*&, int) (basic_binary_iarchive.hpp:67) ==28632== by 0x10467E27: void boost::mpi::packed_iarchive::load_override<pagmo::population*>(pagmo::population*&, int, mpl_::bool_<false>) (packed_iarchive.hpp:98) ==28632== by 0x10467C27: void boost::mpi::packed_iarchive::load_override<pagmo::population*>(pagmo::population*&, int) (packed_iarchive.hpp:115) ==28632== by 0x1046798F: boost::mpi::packed_iarchive& boost::archive::detail::interface_iarchive<boost::mpi::packed_iarchive>::operator>><pagmo::population*>(pagmo::population*&) (interface_iarchive.hpp:60) ==28632== by 0x104676BB: void boost::serialization::nvp<pagmo::population*>::load<boost::mpi::packed_iarchive>(boost::mpi::packed_iarchive&, unsigned int) (nvp.hpp:87) ==28632== by 0x104674AF: void boost::serialization::access::member_load<boost::mpi::packed_iarchive, boost::serialization::nvp<pagmo::population*> >(boost::mpi::packed_iarchive&, boost::serialization::nvp<pagmo::population*>&, unsigned int) (access.hpp:101) ==28632== by 0x104672CF: boost::serialization::detail::member_loader<boost::mpi::packed_iarchive, boost::serialization::nvp<pagmo::population*> >::invoke(boost::mpi::packed_iarchive&, boost::serialization::nvp<pagmo::population*>&, unsigned int) (split_member.hpp:54) ==28632== Address 0x4b65d98 is not stack'd, malloc'd or (recently) free'd The issue is in the method basic_iarchive_impl::load_pointer, around line 450: int i = cid; cobject_id_vector[i].bpis_ptr = bpis_ptr; Indeed, a printf confirms that i == 512 while cobject_id_vector.size() == 3. This also provokes the assertion new_cid == cid to fail one line below (where new_cid == 2). The same code, run locally on the ppc64 acting both as slave and master with mpirun -np 2, runs ok. Boost version is 1.42.0, MPI implementation is openMPI 1.4.2. Can this be related to some endianness issue? Is Boost.MPI expected to work on heterogeneous clusters? Thanks, Francesco.

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[serialization] check_object_versioning(), STATIC_ASSERTION_FAILURE
by Витя Истомин 15 Oct '10

15 Oct '10

Please help, or point me where should i read about it. What is this versioning and why my code was compiled with boost 1.39 will get compilation errors in 1.43? Code: #include <list> #include <boost/serialization/access.hpp> #include <boost/serialization/level.hpp> #include <boost/serialization/split_member.hpp> #include <boost/serialization/tracking.hpp> #include <boost/serialization/list.hpp> #include <boost/serialization/variant.hpp> #include <boost/serialization/version.hpp> ... typedef boost::variant <__int32, unsigned __int32, std::string, std::wstring > param_t; // note: I've tried to use boost::int32_t and others, result is the same typedef std::list< param_t > params_list_t; ... class instruction { public: ... private: friend class boost::serialization::access; /**< Make accessible private members for boost serialization */ void save (boost::archive::xml_oarchive& ar, unsigned int version) const; void load (boost::archive::xml_iarchive& ar, unsigned int version); BOOST_SERIALIZATION_SPLIT_MEMBER() private: ... params_list_t m_params; /**< List of parameters */ }; BOOST_CLASS_IMPLEMENTATION(instruction, boost::serialization::object_serializable); BOOST_CLASS_TRACKING(instruction, boost::serialization::track_never) BOOST_CLASS_IMPLEMENTATION(nvp<instruction>, boost::serialization::object_serializable) BOOST_CLASS_TRACKING(nvp<instruction>, boost::serialization::track_never) BOOST_CLASS_VERSION(instruction, 1); BOOST_CLASS_IMPLEMENTATION(param_t, boost::serialization::object_serializable); BOOST_CLASS_TRACKING(param_t, boost::serialization::track_never) BOOST_CLASS_IMPLEMENTATION(nvp<param_t>, boost::serialization::object_serializable) BOOST_CLASS_TRACKING(nvp<param_t>, boost::serialization::track_never) BOOST_CLASS_VERSION(param_t, 1) BOOST_CLASS_VERSION(params_list_t, 1) BOOST_CLASS_IMPLEMENTATION(nvp<params_list_t>, boost::serialization::object_serializable) BOOST_CLASS_TRACKING(nvp<params_list_t>, boost::serialization::track_never) BOOST_CLASS_IMPLEMENTATION(params_list_t, boost::serialization::object_serializable); BOOST_CLASS_TRACKING(params_list_t, boost::serialization::track_never) BOOST_CLASS_IMPLEMENTATION(nvp<instructions_list_t>, boost::serialization::object_serializable) BOOST_CLASS_TRACKING(nvp<instructions_list_t>, boost::serialization::track_never) BOOST_CLASS_IMPLEMENTATION(instructions_list_t, boost::serialization::object_serializable) BOOST_CLASS_TRACKING(instructions_list_t, boost::serialization::track_never) CPP file: void instruction::save (boost::archive::xml_oarchive& ar, unsigned int version) const { // ... ar << BOOST_SERIALIZATION_NVP(m_params); // error is here, all other lines commented // ... } Error (MS VS2008): 1>d:\Work\manager\third_party\boost\include\boost/archive/detail/check.hpp(78) : error C2027: use of undefined type 'boost::STATIC_ASSERTION_FAILURE<x>' 1> with 1> [ 1> x=false 1> ] 1> d:\Work\manager\third_party\boost\include\boost/archive/detail/oserializer.hpp(307) : see reference to function template instantiation 'void boost::archive::detail::check_object_versioning<T>(void)' being compiled 1> with 1> [ 1> T=const params_list_t 1> ] 1> d:\Work\manager\third_party\boost\include\boost/archive/detail/oserializer.hpp(525) : see reference to function template instantiation 'void boost::archive::detail::save_non_pointer_type<Archive>::invoke<const T>(Archive &,const T &)' being compiled 1> with 1> [ 1> Archive=boost::archive::xml_oarchive, 1> T=const params_list_t 1> ] 1> d:\Work\manager\third_party\boost\include\boost/archive/detail/common_oarchive.hpp(69) : see reference to function template instantiation 'void boost::archive::save<Archive,T>(Archive &,T &)' being compiled 1> with 1> [ 1> Archive=boost::archive::xml_oarchive, 1> T=const params_list_t 1> ] ... This is a first error message place: template<class T> inline void check_object_versioning(){ typedef BOOST_DEDUCED_TYPENAME mpl::or_< BOOST_DEDUCED_TYPENAME mpl::greater< serialization::implementation_level<T>, mpl::int_<serialization::object_serializable> >, BOOST_DEDUCED_TYPENAME mpl::equal_to< serialization::version<T>, mpl::int_<0> > > typex; // trap attempts to serialize with objects that don't // save class information in the archive with versioning. BOOST_STATIC_ASSERT(typex::value); } I have understanding about what is BOOST_STATIC_ASSERT, but I haven't any ideas about what I'm doing wrong. Changelog reading between 1.39 and 1.43 hasn't clarified anything. -- реклама ----------------------------------------------------------- Три новые линейки хостинг-планов - всё что нужно Вашему сайту! 6 месяцев хостинга бесплатно и домен в подарок. http://Hvosting.ua

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[fusion] proposal BOOST_FUSION_ADAPT_FUNCTION, BOOST_FUSION_DEFINE_FUNCTION, etc
by alfC 15 Oct '10

15 Oct '10

Hi, I am using Boost.Fusion lately. Sometimes one has a function with several parameters, int f(double d , int i , std::string s){ ...bla bla ... } the logic of the program says that sometimes that same funcion will be called by generic code and in such case it is better if "f" where defined as taking a fusion::vector as argument. int f(fusion::vector<double, int, std::string>) // another function, could be an overload even since there is only one why to define this adaptor function, e.g. int f(fusion::vector<double, int, std::string> x){ return f(at_c<0>(x), at_c<1>(x), at_c<2>(x));\ } and it is pretty mechanical. I was wondering if it would be a good idea to have, with consistency with the BOOST_FUSION_ADAPT_STRUCT, something called BOOST_FUSION_ADAPT_FUNCTION BOOST_FUSION_ADAPT_FUNCTION( int, f, double, int, std::string ) (or something like that) that defines the second / fusion-compatible version of f. It could be even a BOOST_FUSION_DEFINE_FUNCTION( int, f, (double, d), (int, i), (std::string, s), ( ... code using variables d, i, s or at_key<d_>, at_key<i_>, at_key<s_> ... ) ) that defines simultaneously the raw-C function, f(double, int, string) *and* the fusion friendly version f(vector<...>). I could probably program these macro for specific cases but not a general one since I don't know enough macro syntax to make it work. Do you think it is a good idea or it is already doable with existing Fusion features? Thank you, Alfredo

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[iostreams] changing char_type of bzip2_compressor
by Matthias Vallentin 15 Oct '10

15 Oct '10

I am having trouble with typedef'ing a custom bzip2_compressor that works with unsigned char instead of plain char. This is the pipeline: typedef boost::uint8_t uint8 typedef boost::iostreams::filtering_stream< boost::iostreams::input, uint8> filtering_istream; typedef boost::iostreams::filtering_stream< boost::iostreams::output, uint8> filtering_ostream; typedef boost::iostreams::basic_bzip2_compressor< std::allocator<uint8>> bzip2_compressor; // FIXME: The bzip2_compressor as defined above does not fit in // the pipeline, what is the correct way to typedef it? std::vector<uint8> raw; auto range = boost::make_iterator_range(start, end); // args of type uint8*. filtering_istream in(range); filtering_ostream out; -> out.push(bzip2_compressor()); out.push(boost::iostreams::back_inserter(raw)); boost::iostreams::copy(in, out); The line with the arrow causes the following errors below, presumable due to an incorrect typedef of the basic_bzip2_compressor. I could not find the correct way to typedef it by crawling through the bzip2.hpp header file of the iostreams library. Any ideas? I am using g++ 4.6 with -std=gnu++0x for C++0x support. Matthias Error subset: [..] ../boost/iostreams/chain.hpp:258: error: no matching function for call to 'std::list<boost::iostreams::detail::linked_streambuf<unsigned char, std::char_traits<unsigned char> >*, std::allocator<boost::iostreams::detail::linked_streambuf<unsigned char, std::char_traits<unsigned char> >*> >::push_back(std::auto_ptr<boost::iostreams::stream_buffer<boost::iostreams::basic_bzip2_compressor<std::allocator<unsigned char> >, std::char_traits<unsigned char>, std::allocator<unsigned char>, boost::iostreams::output> >::element_type*)' [..] /opt/local/include/gcc46/c++/bits/streambuf.tcc:89: error: invalid conversion from 'std::basic_streambuf<char, std::char_traits<unsigned char> >::char_type*' to '__gnu_cxx::char_traits<unsigned char>::char_type*' [-fpermissive] /opt/local/include/gcc46/c++/bits/char_traits.h:188: error: initializing argument 1 of 'static __gnu_cxx::char_traits<_CharT>::char_type* __gnu_cxx::char_traits<_CharT>::copy(__gnu_cxx::char_traits<_CharT>::char_type*, const char_type*, std::size_t) [with _CharT = unsigned char, __gnu_cxx::char_traits<_CharT>::char_type = unsigned char, std::size_t = long unsigned int]' [-fpermissive] /opt/local/include/gcc46/c++/bits/streambuf.tcc:89: error: invalid conversion from 'const char_type*' to 'const char_type*' [-fpermissive] /opt/local/include/gcc46/c++/bits/char_traits.h:188: error: initializing argument 2 of 'static __gnu_cxx::char_traits<_CharT>::char_type* __gnu_cxx::char_traits<_CharT>::copy(__gnu_cxx::char_traits<_CharT>::char_type*, const char_type*, std::size_t) [with _CharT = unsigned char, __gnu_cxx::char_traits<_CharT>::char_type = unsigned char, std::size_t = long unsigned int]' [-fpermissive] /opt/local/include/gcc46/c++/bits/streambuf.tcc: In member function 'std::streamsize std::basic_streambuf<_CharT, _Traits>::xsgetn(std::basic_streambuf<_CharT, _Traits>::char_type*, std::streamsize) [with _CharT = char, _Traits = std::char_traits<unsigned char>, std::streamsize = long int, std::basic_streambuf<_CharT, _Traits>::char_type = char]': [..] .._client.cc:170: instantiated from here /opt/local/include/gcc46/c++/bits/streambuf.tcc:55: error: invalid conversion from 'std::basic_streambuf<char, std::char_traits<unsigned char> >::char_type*' to '__gnu_cxx::char_traits<unsigned char>::char_type*' [-fpermissive] /opt/local/include/gcc46/c++/bits/char_traits.h:188: error: initializing argument 1 of 'static __gnu_cxx::char_traits<_CharT>::char_type* __gnu_cxx::char_traits<_CharT>::copy(__gnu_cxx::char_traits<_CharT>::char_type*, const char_type*, std::size_t) [with _CharT = unsigned char, __gnu_cxx::char_traits<_CharT>::char_type = unsigned char, std::size_t = long unsigned int]' [-fpermissive] /opt/local/include/gcc46/c++/bits/streambuf.tcc:55: error: invalid conversion from 'std::basic_streambuf<char, std::char_traits<unsigned char> >::char_type*' to 'const char_type*' [-fpermissive] /opt/local/include/gcc46/c++/bits/char_traits.h:188: error: initializing argument 2 of 'static __gnu_cxx::char_traits<_CharT>::char_type* __gnu_cxx::char_traits<_CharT>::copy(__gnu_cxx::char_traits<_CharT>::char_type*, const char_type*, std::size_t) [with _CharT = unsigned char, __gnu_cxx::char_traits<_CharT>::char_type = unsigned char, std::size_t = long unsigned int]' [-fpermissive]

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