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mapped_file_sink
by Alf Kraus 01 Feb '07

01 Feb '07

does anyone have an example of using *mapped_file_sink *to create and write into a memory mapped file?

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mapped_file_sink
by Alf Kraus 01 Feb '07

01 Feb '07

I'm trying to create memory mapped files using mapped_file_sink: mapped_file_params mfParams( fileName ); mfParams.new_file_size = filesize; mapped_file_sink mfSink( mfParams ); trying to use any of its funtions like: const char *ptStart = mfSink.data(); the compiler tells me that I have no access to them for they are private members since inherited from mapped_file I know thats a piece of cake but just cant solve it. Cheers Alf

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problem with boost/iterator/zip_iterator.hpp
by Tim Axelrod 01 Feb '07

01 Feb '07

Hello, If more than one source file includes boost/iterator/zip_iterator.hpp, the loader complains about a multiply defined function: tsa@mops2.lsstcorp.org:~/VW/TSA> g++ -o nothing nothingMain.cc nothing.cc /tmp/ccT5Bn0N.o: In function `boost::detail::tuple_impl_specific::tuple_equal(boost::tuples::null_type, boost::tuples::null_type)': nothing.cc:(.text+0x0): multiple definition of `boost::detail::tuple_impl_specific::tuple_equal(boost::tuples::null_type, boost::tuples::null_type)' /tmp/ccH8Z9eR.o:nothingMain.cc:(.text+0x0): first defined here collect2: ld returned 1 exit status I'm using boost_1_33_1. The source files are attached. Regards, Tim Axelrod

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shmem map tutorial
by Jan Stetka 31 Jan '07

31 Jan '07

I've put together a tutorial on how to use interprocess map. Its at http://myweb.tiscali.co.uk/janstetka/interprocess_map.html Perhaps there could be a link from the interprocesses documentation if it goes down well. Thanks PS:I tried to use the wiki but the syntax is a bit too difficult for me especially formating code so I've put it on my own site for now.

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matrix inversion
by Umut Tabak 31 Jan '07

31 Jan '07

hi list, I have been experimenting to find the incerse aof a matrix with ublas but there is a problem: I have been looking at the code on http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl?LU_Matrix_In… But there is sth wrong with that code because assign function template does not take a ublas::matrix<> as a direct parameter, it should ne converted to a matrix_expression but how may I do that. I did the inversion by using the assignment operator but wondered how it could be done thorough assign function template. The code on the viki works if you change the line with the assign to inverse=ublas::identity_matrix<T>(A.size1()); Maybe it can be of help. My best,

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Re: [Boost-users] problems with serialization library
by mauro gargano 31 Jan '07

31 Jan '07

thanks a lot Mark Wyszomierski!

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Question about using Boost::for_each function to set a local variable if a condition is met
by Meryl Silverburgh 31 Jan '07

31 Jan '07

Hi, I am trying to Boost::for_each function to set a local variable if all elements in this is DEFAULT type. Here is my code, but I don't know how to implement the last part of the if_then call. boolean rtnValue = false; for_each(mylist.begin(), mylist.end(), if_then( bind(&ListItem::getType, _1) == DEFAULT, set the local value to true if true if all of them are DEFAULT type )); if you can give me some pointers, I will be appreciated. Thank you.

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Open file name starting with "." in boost::filesystem
by Peng Yu 31 Jan '07

31 Jan '07

Hi, The following program gives some error. Can somebody let me know if it is possible to open filenames starting with "."? Thanks, Peng int main() { boost::filesystem::ofstream file(".abc"); } $ ./main-g.exe terminate called after throwing an instance of 'boost::filesystem::filesystem_error' what(): boost::filesystem::path: invalid name ".abc" in path: ".abc" Aborted

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[boost.threads] condition api question
by Frank Mori Hess 30 Jan '07

30 Jan '07

I'm curious why the boost::condition class requires a seperate mutex object to be created, and a corresponding scoped lock argument passed to the wait functions. Wouldn't it be easier to just keep a mutex inside the condition object and automatically lock it at the beginning of the wait functions? What am I missing here? -- Frank

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[lexical_cast] converting "true" to bool fails - why?
by Markus Werle 30 Jan '07

30 Jan '07

Hi! The following code snippet prints "failure!" during execution: #include <boost/lexical_cast.hpp> #include <iostream> int main() { try { bool test = boost::lexical_cast<bool>("true"); } catch (boost::bad_lexical_cast const &) { std::cerr << "failure!\n"; } } IIRC there was some way to achieve a conversion using the correct locale and stringstreams. Is there a way to obtain a successful conversion with lexical_cast, too? Markus

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