January 2013 - Boost-users - lists.preview.boost.org

How to convert shared_ptr to pointer?
by young 03 Jan '13

03 Jan '13

I have shared_ptr<int> variable. I need to pass a int* pointer to a function call. How to pass shared_ptr<int> as int *? -- View this message in context: http://boost.2283326.n4.nabble.com/How-to-convert-shared-ptr-to-pointer-tp4… Sent from the Boost - Users mailing list archive at Nabble.com.

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[Polygon] Boolean (Clipping) performance
by kusogray 03 Jan '13

03 Jan '13

Hi there, I input 200,000 to both polygon set A and B, with each polygon contains 5~8 points then do the A^B; however, this instruction cost about *30 minutes.* my question is: I thought the O(n logn) algorithm with n ~ 1,000,000 just cost about at most 2 or 3 mins I checked the XOR AND OR result is correct, but the performance is weird, did I do anything wrong or misunderstanding? Thanks for reading this! -- View this message in context: http://boost.2283326.n4.nabble.com/Polygon-Boolean-Clipping-performance-tp4… Sent from the Boost - Users mailing list archive at Nabble.com.

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[system] local static and threading in C++03
by Felipe Magno de Almeida 02 Jan '13

02 Jan '13

Hello, Boost.System returns the system_category this way: BOOST_SYSTEM_DECL const error_category & system_category() { static const system_error_category system_category_const; return system_category_const; } But couldn't this make double construction/double free in C++03 systems if system_category is ran concurrently? Regards, -- Felipe Magno de Almeida

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[serialization] deserializing chunk by chunk
by Arash Abghari 02 Jan '13

02 Jan '13

Hi, I have an encrypted archive. I can decrypt the file chunk by chunk. I wonder if there is a way to deserialize each chunk on the fly. The main purpose is to reduce the memory footprint of the application since the archive can be a few hundred mega bytes. The problem as I mentioned is the file is encrypted and it has to be decrypted first in the memory and then deserialized. Thanks, Arash

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[filesystem] segfault in path::imbue after upgrade to boost 1.52
by Shawn Chidester 02 Jan '13

02 Jan '13

Just upgraded from boost 1.47 to 1.52 and I'm experiencing segmentation faults in boost::filesystem::path::imbue. This is on 64-bit Ubuntu 12.04 and 12.10. Compiling with g++-4.6 Here is a stack trace from valgrind: ==26893== Memcheck, a memory error detector ==26893== Copyright (C) 2002-2012, and GNU GPL'd, by Julian Seward et al. ==26893== Using Valgrind-3.9.0.SVN and LibVEX; rerun with -h for copyright info ==26893== Command: bin/example ==26893== ==26893== Invalid read of size 4 ==26893== at 0x9843970: std::locale::locale(std::locale const&) (in /usr/lib/x86_64-linux-gnu/libstdc++.so.6.0.17) ==26893== by 0x69FAD0F: boost::filesystem::path::imbue(std::locale const&) (path.cpp:918) ==26893== by 0x69FAC76: boost::filesystem::path::codecvt() (path.cpp:911) ==26893== by 0x69F8546: boost::enable_if<boost::filesystem::path_traits::is_pathable<boost::decay<char*>::type>, boost::filesystem::path&>::type boost::filesystem::path::operator=<char*>(char* const&) (path.hpp:202) ==26893== by 0x69F4737: boost::filesystem::detail::current_path(boost::system::error_code*) (operations.cpp:1077) ==26893== by 0x5AB0D2C: boost::filesystem::current_path() (operations.hpp:429) ==26893== by 0x5AB0447: __static_initialization_and_destruction_0(int, int) (example.cpp:53) ==26893== by 0x5AB0BB5: _GLOBAL__sub_I_example.cpp (example.cpp:1192) ==26893== by 0x400F315: call_init.part.0 (dl-init.c:85) ==26893== by 0x400F3EE: _dl_init (dl-init.c:52) ==26893== by 0x40016F9: ??? (in /lib/x86_64-linux-gnu/ld-2.15.so) The stack trace looks the same in GDB. In case it's of any use here's what "path_locale" looks like at path.cpp:918 (gdb) frame #1 0x00007ffff561ed10 in boost::filesystem::path::imbue (loc=...) at boost/libs/filesystem/src/path.cpp:918 918 std::locale temp(path_locale); (gdb) print path_locale $1 = {_M_impl = 0x0} I'm guessing the crash has to do with path_locale being uninitialized, but I don't know what to do about it (if that is indeed the problem). If anyone can provide some insight (or better yet, a solution) I would be very grateful! Thanks, Shawn

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Re: [Boost-users] Server failing when BOOST_ASIO_ENABLE_HANDLER_TRACKING is active
by Gonzalo Garramuno 02 Jan '13

02 Jan '13

On 01/01/13 22:11, Gonzalo Garramuno wrote: > Trying to track down when the socket closes on my program, I turned on > asio debugging. > > Server fails when BOOST_ASIO_ENABLE_HANDLER_TRACKING is active. > > Its stack trace is: > g > Scanning dependencies of target mrViewer > [ 9%] Building CXX object > mrViewer/src/CMakeFiles/mrViewer.dir/core/mrvServer.o > Linking CXX executable ../../../bin/mrViewer > [100%] Built target mrViewer > > # gga@gga-laptop1 /media/Linux/code/applications/mrViewer > # mar ene 01 10:04 [8] $ mrViewer /media/Linux/movies/Tangled.mov > [opengl] Using hardware shader profile: NVidia NV30 > [opengl] mrViewer supports YUV images through shaders. > [psql] Connected to database 'assets2d_development'. > > The code: > > boost::asio::io_service io_service; > tcp::endpoint listen_endpoint(tcp::v4(), s->port); > server rp(io_service, listen_endpoint, s->ui); > io_service.run(); > > fails with: > > @asio|1357088683.200673|0|socket@0x7f303d8d2d00.close > > Got signal 11, faulty address is 0x1, from 0x4d222a > [bt] Execution path: > [bt] > mrViewer(_ZN5boost4asio6detail15task_io_service16shutdown_serviceEv+0x3a) > [0x4d222a] > [bt] > mrViewer(_ZN5boost4asio6detail15task_io_service16shutdown_serviceEv+0x3a) > [0x4d222a] > [bt] mrViewer() [0x4dd2c9] > [bt] mrViewer(_ZN3mrv13server_threadEPKNS_10ServerDataE+0x408) [0x4e0e58] > [bt] /usr/lib/libboost_thread.so.1.48.0(+0xdda9) [0x7f304e191da9] > [bt] /lib/x86_64-linux-gnu/libpthread.so.0(+0x7e9a) [0x7f304f7f0e9a] > [bt] /lib/x86_64-linux-gnu/libc.so.6(clone+0x6d) [0x7f304da1ccbd] > pure virtual method called > terminate called without an active exception > Aborted (core dumped) >

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Converting a BOOST_FOREACH to use the new c++ 11 lambda syntax
by Sean Farrow 01 Jan '13

01 Jan '13

Hi Fokes: I'm trying to convert a BOOST_FOREACH loop to use the new lambda syntax: I have a ptree variable declared in a class of which the foreach is part. I also have a vector<std::wstring> that I need to use within my lambda. This all being the case, the following is the original BOOST_FOREACH: BOOST_FOREACH(boost::property_tree::ptree::value_type &v, IniTree) IniSections.push_back(ConvertToWString(v.first)); And the following is the converted lambda: std::for_each(IniTree.begin(), IniTree.end(), [&] (boost::property_tree::ptree::value_type &v) { IniSections.push_back(ConvertToWString(v.first)); }); Is this the right way to go about the conversion-have I missed anything? Any help appreciated. Regards Sean.

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