June 2005 - Boost-users - lists.preview.boost.org

Boost.Function: How does the template param mechanism work?
by Brian Braatz 21 Jun '05

21 Jun '05

My question is, given: boost::function< int (char, long) > func(&f); how is it possible to pass the (char,long)? (I tried to receive this in a template as a single template param, or as three , but neither worked) I have been studying the headers, but the indirection used (FTSE :) ) is making it hard for me to figure this one out. The reason I am asking I is I am trying to clean up the syntax of some template params and I would like to use this technique. i.e. I would like to write: struct A {}; struct B {}; struct C {}; struct D {}; struct E {}; struct F {}; typedef MyThingdef< (A,B), (C,D), (E,F) > splat; instead of typedef MyThingdef< A,B, C,D, E,F > splat; Any direction on things to research or dig into appreciated. Thanks Brian

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Serialization truncation?: xml_oarchive, ostringstream vs. ofstream
by Benjamin.Sternlieb＠ubs.com 21 Jun '05

21 Jun '05

Hi, I was trying out boost serialization and ran into a snag. If I serialize the same object onto two xml_oarchives, one constructed with a ostringstream and one constructed with an ofstream, I get differing results - the file based xml is well formed, but the string based xml is missing its final closing tag. Here is the generating code snippet: // now serialize ostringstream os; boost::archive::xml_oarchive ar(os); ofstream ofs("/home/sternlbe/boo.xml"); boost::archive::xml_oarchive ar2(ofs); Portfolio& port = *p; ar << BOOST_SERIALIZATION_NVP(port); ar2 << BOOST_SERIALIZATION_NVP(port); string s = os.str(); LOG_DEBUG(logger) << "Xml string: \n" << s; For the file output, I get the (correct) result: <?xml version="1.0" encoding="UTF-8" standalone="yes" ?> <!DOCTYPE boost_serialization> <boost_serialization signature="serialization::archive" version="3"> <port class_id="0" tracking_level="1" version="0" object_id="_0"> <m_id>2124433</m_id> <m_name>This is a stub!</m_name> <m_isLoaded>0</m_isLoaded> </port> </boost_serialization> However, the string result is missing the final line (closing tag): <?xml version="1.0" encoding="UTF-8" standalone="yes" ?> <!DOCTYPE boost_serialization> <boost_serialization signature="serialization::archive" version="3"> <port class_id="0" tracking_level="1" version="0" object_id="_0"> <m_id>2124433</m_id> <m_name>This is a stub!</m_name> <m_isLoaded>0</m_isLoaded> </port> Any thoughts? Thanks in advance, Ben Visit our website at http://www.ubs.com This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. E-mail transmission cannot be guaranteed to be secure or error-free as information could be intercepted, corrupted, lost, destroyed, arrive late or incomplete, or contain viruses. The sender therefore does not accept liability for any errors or omissions in the contents of this message which arise as a result of e-mail transmission. If verification is required please request a hard-copy version. This message is provided for informational purposes and should not be construed as a solicitation or offer to buy or sell any securities or related financial instruments.

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boost log and vc 7
by Oliver Schoenborn 21 Jun '05

21 Jun '05

Hi, I am trying to create a dll for boost log v1.33(ie a dll containing code compiled from functions.cpp, log.cpp and log_manager.cpp) using VC++ 7.1 on WinXP. I get the same error whether I do it from VisualStudio or using bjam. The bjam file is : dll libboost_log : functions.cpp log.cpp log_manager.cpp : <include>c:/Boost/include/boost-1_32 <include>../../include ; and the vc-Link fails with the message that it "cannot open file 'boost_log-vc71-mt-gd-1_32.lib'". I have *no* idea where or how vc-Link comes to the conclusion that it needs that lib file. Any ideas? Thanks, Oliver p.s. The output from bjam session is: $ bjam ...patience... ...found 310 targets... ...updating 2 targets... vc-Link libboost_log.dll\vc-7_1\debug\threading-multi\libboost_log.dll libboost_log.dll\vc-7_1\debug\threading-multi\libboost_log.lib LINK : fatal error LNK1104: cannot open file 'boost_log-vc71-mt-gd-1_32.lib' CALL "C:\Program Files\Microsoft Visual Studio .NET 2003\VC7\bin\VCVARS32.BAT" >nul "C:\Program Files\Microsoft Visual Studio .NET 2003\VC7\bin\link" /nologo /INCREMENTAL:NO /DEBUG /DLL /subsystem:console /out:"libboost_log.dll\vc-7_1\debug\threading-multi\libboost_log.dll" /IMPLIB:"libboost_log.dll\vc-7_1\debug\threading-multi\libboost_log.lib" @"libboost_log.dll\vc-7_1\debug\threading-multi\libboost_log.CMD" ...failed vc-Link libboost_log.dll\vc-7_1\debug\threading-multi\libboost_log.dll libboost_log.dll\vc-7_1\debug\threading-multi\libboost_log.lib... ...failed updating 2 targets... --------------------------------------------- Oliver Schoenborn Consultant, Modelling & Simulation Greenley & Associates Inc. 5 Corvus Court Ottawa, ON K2E 7Z4 Canada D: (613) 247-0342 x217 C: (613) 371-4773 F: (613) 225-4281 www.greenley.ca <http://www.greenley.ca/>

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Re: [Boost-users] Reusing indexing base from multi_array_ref
by Sohail Somani 20 Jun '05

20 Jun '05

I should be slightly more careful, version without accesses below: #include <boost/multi_array.hpp> int main() { typedef boost::multi_array<double, 2> array_type; typedef boost::multi_array_ref<double,2> array_type_ref; typedef array_type::index_range range; typedef boost::multi_array_types::extent_range extent_range; array_type A(boost::extents[extent_range(1,4)][extent_range(1,10)]); // [1,4),[1,10) A[3][9]=95; array_type::array_view<1>::type f = A[boost::indices[range()][9]]; assert(f[2]==A[3][9]); // Would like to have assert(f[3]==A[3][9]). f.reindex(1); assert(f[3]==A[3][9]); // Do I *have* to reindex in this way? } Thanks.

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Reusing indexing base from multi_array_ref
by Sohail Somani 20 Jun '05

20 Jun '05

Hi, Any comments? #include <iostream> #include <boost/multi_array.hpp> int main() { using std::cout; using std::endl; typedef boost::multi_array<double, 2> array_type; typedef boost::multi_array_ref<double,2> array_type_ref; typedef array_type::index_range range; typedef boost::multi_array_types::extent_range extent_range; array_type A(boost::extents[extent_range(1,4)][extent_range(1,10)]); // 3x9 A[4][2]=95; array_type::array_view<1>::type f = A[boost::indices[range()][2]]; assert(f[3]==A[4][2]); // Would like to have assert(f[3]==A[4][2]). f.reindex(1); assert(f[4]==A[4][2]); // Do I *have* to reindex in this way? What if the indexing base gets more complicated? }

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Is it possible to use smart pointer w/ boost.multiarray or bind lapack/blas w/ boost.multiarray???
by Jack Nguyen 20 Jun '05

20 Jun '05

Any pointer/link is appreciated dat

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Boost String Algorithms Library Questions
by J Liu 20 Jun '05

20 Jun '05

Hi, I am using boost 1.32 with msvc 6. When I run the string example in the package, I keep getting this kind of errors: boost.cpp C:\dev\RWREPL~1\YUKON-~1\boost_1_32_0\boost/algorithm/string/yes_no_type.hpp(22) : error C2265: '<Unknown>' : reference to a zero-sized array is illegal C:\dev\RWREPL~1\YUKON-~1\boost_1_32_0\boost/algorithm/string/yes_no_type.hpp(23) : see reference to class template instantiation 'boost::algorithm::size_descriptor<I>' being compiled C:\dev\RWREPL~1\YUKON-~1\boost_1_32_0\boost/algorithm/string/detail/collection_traits.hpp(312) : error C2039: 'value_type' : is not a member of '`global namespace'' C:\dev\RWREPL~1\YUKON-~1\boost_1_32_0\boost/algorithm/string/detail/collection_traits.hpp(323) : see reference to class template instantiation 'detail::array_traits<T>' being compiled C:\dev\RWREPL~1\YUKON-~1\boost_1_32_0\boost/algorithm/string/detail/collection_traits.hpp(312) : error C2146: syntax error : missing ';' before identifier 'value_type' C:\dev\RWREPL~1\YUKON-~1\boost_1_32_0\boost/algorithm/string/detail/collection_traits.hpp(323) : see reference to class template instantiation 'detail::array_traits<T>' being compiled C:\dev\RWREPL~1\YUKON-~1\boost_1_32_0\boost/algorithm/string/detail/collection_traits.hpp(312) : error C2868: 'value_type' : illegal syntax for using-declaration; expected qualified-name C:\dev\RWREPL~1\YUKON-~1\boost_1_32_0\boost/algorithm/string/detail/collection_traits.hpp(323) : see reference to class template instantiation 'detail::array_traits<T>' being compiled C:\dev\RWREPL~1\YUKON-~1\boost_1_32_0\boost/algorithm/string/detail/collection_traits.hpp(314) : error C2039: 'iterator' : is not a member of '`global namespace'' C:\dev\RWREPL~1\YUKON-~1\boost_1_32_0\boost/algorithm/string/detail/collection_traits.hpp(323) : see reference to class template instantiation 'detail::array_traits<T>' being compiled C:\dev\RWREPL~1\YUKON-~1\boost_1_32_0\boost/algorithm/string/detail/collection_traits.hpp(314) : error C2146: syntax error : missing ';' before identifier 'iterator' ............... Could anybody tell me what the problem is? BTW, I have no problem using the date time lib. Thanks a lot! J.L

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Re: [Boost-users] Aborting a Boost.Thread
by Foster, Gareth 20 Jun '05

20 Jun '05

> > Does GNOME have this, too? The FM is written with gtkmm. > > Something like: > > http://developer.gnome.org/doc/API/gnome-vfs/ > > But it's C and I have no idea if C++ wrapper is present or not. > Try http://gtkmm.org/ - look up Gnome::Vfs, there are C++ wrappers for all the Gnome/GTK+ stuff there. Gaz

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Re: [Boost-users] Tokenizer Question
by Victor A. Wagner Jr. 20 Jun '05

20 Jun '05

At 19:19 2005-06-11, you wrote: > > for tokenizing on whitespace, simple stream input (>>) to a > > std::string suffices. > >My own tokenizer does just that--and puts the tokens into a deque. > > > IMO, it's hardly worth troubling yourself with a tokenizer > > for whitespace. > >Well, not really. When parsing line-oriented output and semi-known >structured lines it's handy to be able to sometimes work with a line's >tokens as if they were in a vector or deque. string yourline; istringstream is(yourline); deque<string> yourvec((istream_iterator<std::string>(is)), istream_iterator<std::string>()); voila, a deque it would be interesting to profile that against the hypothetical indexable tokenizer. >In fact, I was going to add a suggestion that the tokenizer also have the [] >operator so that the individual tokens could be addressed as tok[1], etc. > >-Tom > >_______________________________________________ >Boost-users mailing list >Boost-users(a)lists.boost.org >http://lists.boost.org/mailman/listinfo.cgi/boost-users Victor A. Wagner Jr. http://rudbek.com The five most dangerous words in the English language: "There oughta be a law"

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Aborting a Boost.Thread
by Matthias Kaeppler 20 Jun '05

20 Jun '05

Hello, I am currently working on a filemanager for the Linux operating system, and I'm currently thinking about how to implement copying operations, such that 1. The GUI won't be blocked when operating on files 2. File operations can be cancelled at any time I thought about using Boost.Thread to run all the copy operations (which will be performed by Boost.Filesystem). However, I'm not quite sure how to handle this situation: Say copying a huge file, maybe 1GB+, is in progress. The progress will be displayed in a dialog window, as usual. Now the user decides that he wants to stop the copy operation, and clicks a cancel button. Now what do I do? The only means to terminate a thread that I know of is: 1. Killsignal it (I don't think boost supports it, since it's probably highly platform dependent) 2. Check for a terminate flag once in a while and return from the method once it is set. But how am I supposed to do the latter? The copy function doesn't return until it's finished right? So I can't check for a condition, because the copy-thread itself is blocked until it's done. I'm completely stuck here, help greatly appreciated. Cheers, Matthias -- Matthias Kaeppler

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