May 2009 - Boost-users - lists.preview.boost.org

[interprocess] managed_mapped_file under cygwin
by Bob Walters 18 May '09

18 May '09

>From what I've read, cygwin supports mmap, and so I figured there was a chance that boost::interprocess::managed_mapped_file was valid on windows when compiling with cygwin. I've built the boost libraries using cygwin with boost_1_39_0, using a user-config.bjam with: using gcc : cygwin_4.3.2 : /usr/bin/g++-4 : <compileflags>-DBOOST_POSIX_API <compileflags>-DBOOST_POSIX_PATH ; Under cygwin, I have g++ 3.4.4 g++-4 4.3.2 I think you can reproduce this with a source file that just includes <boost/interprocess/managed_mapped_file.hpp> I'm getting the following compile error: g++-4 -DHAS_STDINT_H -I/cygdrive/c/workspaces/cdds_head/stldb_lib -I/cygdrive/c/c++/boost_1_39_0 -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"database.d" -MT"database.d" -o"database.o" "../database.cpp" (I also get this with g++) In file included from C:\C++\boost_1_39_0/boost/interprocess/detail/managed_open_or_create_impl.hpp:17, from C:\C++\boost_1_39_0/boost/interprocess/managed_mapped_file.hpp:20, from C:\workspaces\cdds_head\stldb_lib/stldb/containers/trans_map.h:23, from ../trans_map.h:18, from ../database.h:13, from ../database.cpp:8: C:\C++\boost_1_39_0/boost/interprocess/mapped_region.hpp: In constructor 'boost::interprocess::mapped_region::mapped_region(const MemoryMappable&, boost::interprocess::mode_t, boost::interprocess::offset_t, size_t, const void*)': C:\C++\boost_1_39_0/boost/interprocess/mapped_region.hpp:403: error: request for member 'is_xsi' in 'map_hnd', which is of non-class type 'boost::interprocess::mapping_handle_t' C:\C++\boost_1_39_0/boost/interprocess/mapped_region.hpp:406: error: request for member 'handle' in 'map_hnd', which is of non-class type 'boost::interprocess::mapping_handle_t' The above suggests that in detail/os_file_functions.hpp, mapping_handle_t is being given the windows definition rather than the posix definition, somehow. However, I've also noticed that if I #include <boost/interprocess/windows_shared_memory.hpp>, I do trip the #error caused by !defined(BOOST_INTERPROCESS_WINDOWS), so that proves that it isn't, in which case I don't quite understand where this error is coming from. Any help is appreciated. Thanks, - Bob Walters

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Buffer overrun when building read_graphviz using VC7.1
by Paul De La Musica 18 May '09

18 May '09

Hi, I got two buffer overrun errors building Boost 1.38.0 on MSVC 7.1.3088. One of them occurred while building the library to be used with read_graphviz. Is there a place to download a pre-built libbgl-viz.lib? Paul

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PropertyTree's XML parsers survey
by Tan, Tom (Shanghai) 18 May '09

18 May '09

>From: "Robert Ramey" <ramey(a)rrsd.com> >Subject: Re: [Boost-users] PropertyTree's XML parsers survey >The serialization library has been using the spirit library >for parsing XML for years. This is for both utf-8 and wide characters > >Robert Ramey I just played with the examples demo_xml_load along with boost 1.39. As I mainly use xml as configuration files. I found some features I really like are missing: - often I need to edit the xml file manually with 3rd tools(gedit, kate notepad++ etc) other than the app itself. When saving back with those editors, they may add some BOM bytes(0xFFFE for UTF16LE, 0xFEFF for UTF16BE, 0xefbbbf for utf8) and replace the line-breakers(0x0a, 0x0a0d) with another fashion(e.g 0x0d0a -> 0x0a) the system default. In such cases, I wish boost.serialize would detect and ignore them as the real data the xml carries do NOT change. - I often embed some comment nodes inside the xml to facilitate the manual edit. E.g, enumeration of accepted value some fields. I wish boost.serialize ignores them when parsing, and embbded them when saving(is this possible). - I wish only the hierarchy not the order or nodes matters. Ex. <a> <first = "1st"> <second = "2nd"> </a> Would be equivalent to <a> <second = "2nd"> <first = "1st"> </a> It seems not to be support yet. On the whole, my impression is boost.serialize imposes some restrictions (orders for instance) that make sense to plain text files, but limits the buil-in flexibility that coming with xml.

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Re: [Boost-users] [serialization] xml tag names and exceptions
by Ashley Smith 18 May '09

18 May '09

> AMDG > > Ashley Smith wrote: > >> Hi, I've been using boost for a while now and it's brilliant! :D >> >> Anyway, I'm using serialization in my code and was wondering why I was >> catching an exception where the what() reported "uninitialized >> exception". Eventually I worked it out (After much debugging) that I was >> catching the exception like this: >> >> } catch( std::exception & e ) { >> std::cout << e.what() << std::endl; >> >> I found out that my xml tags could not have namespace qualifiers in them >> (I.e. "blah::abc" would not work) and that it would throw a >> boost::archive::xml_archive_exception. This obviously didn't work with >> an std::exception and defaulted to an uninitialised exception. So my >> question is: am I catching the exceptions in the wrong way? Whats the >> right way? Should I use a more specific boost exception class? >> >> > > Can you catch xml_archive_exception instead of std::exception? > It almost sounds like the exception has been sliced. > > In Christ, > Steven Watanabe > Thanks for replying. Thats strange, it catches the boost::archive::xml_archive_exception, but it is still set as an uninitialized exception. I'm sure this is what is being thrown though. I think the source of the exception is in boost/archive/impl/basic_xml_oarchive.ipp Thanks

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MPL if_ not following true branch
by Cory Nelson 18 May '09

18 May '09

This code doesn't seem to ever follow the true branch of the if_... it's like the eval_if is clobbering it. Can someone tell me what I'm doing wrong (other than not using a map.. this is a reduction of some other code that can't use a map)? #include <iostream> #include <typeinfo> #include <boost/mpl/if.hpp> #include <boost/mpl/eval_if.hpp> #include <boost/mpl/identity.hpp> #include <boost/type_traits/is_same.hpp> #include <boost/static_assert.hpp> template<typename T> struct choose_type { struct int_tag {}; struct float_tag {}; template<typename InvalidT> struct invalid_type_specified { BOOST_STATIC_ASSERT(sizeof(InvalidT) == 0); }; typedef typename boost::mpl::if_< boost::is_same<T, int>, int_tag, typename boost::mpl::eval_if< boost::is_same<T, float>, boost::mpl::identity<float_tag>, invalid_type_specified<T> >::type >::type type; }; int main() { std::cout << typeid(choose_type<int>::type).name() << std::endl; return 0; } -- Cory Nelson

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boost compression
by einav_i2 18 May '09

18 May '09

Hi! Can anyone send an exmaple of a string to string compression (not file) using boost iostreams and gzip? Thanks, Einav -- View this message in context: http://www.nabble.com/boost-compression-tp23482602p23482602.html Sent from the Boost - Users mailing list archive at Nabble.com.

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Re: [Boost-users] PropertyTree's XML parsers survey
by Tan, Tom (Shanghai) 18 May '09

18 May '09

>The serialization library has been using the spirit library >for parsing XML for years. This is for both utf-8 and wide characters >Robert Ramey Thanks for this info, I'll dig into that. Some quick questions though. There are two things that I prefer XML configurations to other formats: - I can manually edit the config file with other editors(notpad++, kate, gedit etc). However, different text editors may add additional BOM bytes(0xFFFE for UTF16LE, 0xFEFF for UTF16BE, 0xefbbbf for utf8) when saving back, does the serialization library detects them and ignore them when it sees them? - unlike JSON, I can embed comment nodes inside the XML to make it more readable, ex. , it this possible with boost.serialization?

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[Boost] [Test] [1.38] "can't use testing tools before framework is initialized"
by Greg Christopher 18 May '09

18 May '09

Hi, I am trying to integrate boost.test into an existing test program with its own framework. Therefore I'd like to use that program's main. I am currently running into this runtime error when calling BOOST_WARN_MESSAGE(1, "string"). I have tried three different things to avoid this condition: 1) I declared a TEST_SUITE using the BOOST_AUTO_TEST_SUITE() and END() macros. Probably not what I want because I want my own main to keep control, but figured it would generate a main that would allow the initialization to happen. 2) I called init_unit_test_suite( argc, argv ). Even though it was called, I am still getting this. 3) I defined a cpp_main(). This never got called. I was hoping that the existence of this symbol would cause initialization to happen elsewhere. My desired control flow is to have this test program in control and to use the BOOST logging tools. I am trying to slip in boost.test with a minimum of changes to this program. I have hooked its logging function to call boost logging facilities instead; just can't get past this problem. Thanks for any help! Greg

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[boost.filesystem] remove issue
by Sean Farrow 17 May '09

17 May '09

Hi: I am using the following code with boost.filesystem: size_t origsize = strlen(argv[0]) + 1; size_t convertedChars = 0; wchar_t wcstring[1024]; mbstowcs_s(&convertedChars, wcstring, origsize, argv[0], strlen(argv[0])); boost::filesystem::wpath path(wcstring); path.filename() =L"compilation date.txt"; if (boost::filesystem::exists(path)) // boost::filesystem::remove(path); I have defined: #define BOOST_FILESYSTEM_NO_DEPRECATED The line that causes probles is: // boost::filesystem::remove(path); Anyone got any ideas why this line causes a window error report to be generated. For reference I'm including: #include <stdlib.h> #include <fstream> #include <boost/date_time/gregorian/gregorian.hpp> #include <boost/filesystem/path.hpp> #include <boost/filesystem/operations.hpp> #include <string> Cheers Sean. __________ Information from ESET NOD32 Antivirus, version of virus signature database 4081 (20090517) __________ The message was checked by ESET NOD32 Antivirus. http://www.eset.com

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[serialization] xml tag names and exceptions
by Ashley Smith 17 May '09

17 May '09

Hi, I've been using boost for a while now and it's brilliant! :D Anyway, I'm using serialization in my code and was wondering why I was catching an exception where the what() reported "uninitialized exception". Eventually I worked it out (After much debugging) that I was catching the exception like this: } catch( std::exception & e ) { std::cout << e.what() << std::endl; I found out that my xml tags could not have namespace qualifiers in them (I.e. "blah::abc" would not work) and that it would throw a boost::archive::xml_archive_exception. This obviously didn't work with an std::exception and defaulted to an uninitialised exception. So my question is: am I catching the exceptions in the wrong way? Whats the right way? Should I use a more specific boost exception class? Thank-you! - Ash

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