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Boost.Threads question
by James Zappia 04 Dec '02

04 Dec '02

Hi, I'm a newbie to C++ and Boost and I'm trying to port a threaded C program I have to Boost.Threads. I'm trying to use scoped_try_lock to test a lock on mutex and it's not working. I'm obviously doing something wrong but I can't figure it out. Below is the source code. Any help would be greatly appreciated. Thanks, James SOURCE: #include <iostream> #include <boost/thread/thread.hpp> #include <boost/thread/exceptions.hpp> using namespace std; boost::try_mutex mutex; void thread_test( void ) { cout << "thread: locking mutex\n"; { boost::try_mutex::scoped_try_lock lock(mutex); cout << "thread: sleeping for 10 seconds\n"; sleep(10); } cout << "thread: unlocked mutex - goodbye!\n"; return; } int main( void ) { cout << "main: creating thread\n"; boost::thread thread(thread_test); cout << "main: sleeping for 2 seconds\n"; sleep(2); cout << "main: trying to lock mutex\n"; boost::try_mutex::scoped_try_lock lock(mutex,true); while ( !lock.try_lock() ) cout << "main: retrying to lock mutex\n"; cout << "main: joining thread\n"; thread.join(); cout << "main: thread joined\n"; return 0; }

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compose, bind and a doubled ref problem
by Markus Werle 04 Dec '02

04 Dec '02

Hi! The code below compiles fine if You return to Value semantics and replace "const Vector&" with "Vector". But with reference to vector two compilers (Intel-7.0 and gcc-3.2.1) "throw" with a "reference to reference" error. How can I achieve what I want here? Do I have to apply cref somewhere? I do not want to change the type of "l" in this example. Also the signature of Vector::operator() and GetValue is fixed. Anything else may undergo a change. #include <iostream> #include <cstddef> #include "boost/function.hpp" #include "boost/bind.hpp" #include "boost/compose.hpp" struct Vector { double operator()(size_t j) const { std::cerr << "get value at index " << j << std::endl; return 99.0; } }; double GetValue(const Vector& V, size_t j) { return V(j); } double Add(double d1, double d2) { return d1 + d2; } int main() { using namespace boost; Vector V; function<double (const Vector&, size_t)> g = GetValue; function<double (const Vector&)> h1 = bind(g, _1, 5); function<double (const Vector&)> h2 = bind(g, _1, 4); function<double (double, double)> Adder = Add; function<double (const Vector&)> l = compose_f_gx_hx(Adder, h1, h2); std::cerr << l(V) << std::endl; }

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error linking debug version boost_regex with Solaris compiler
by kurt_zhang 03 Dec '02

03 Dec '02

I compiled boost_regex lib on Solaris using the following compiler: > CC -V CC: Sun WorkShop 6 update 2 C++ 5.3 2001/05/15 The version without using -g links fine, however, when I compiled the lib with -g option using provided makefile sunpro_dbx.mk, the lib was built OK; then I tried to compile provided test programs using libs/regex/test/regress/sunpro_dbx.mk, I got the following error: > make -f sunpro_dbx.mak mkdir -p r mkdir -p rm rm -f *.o rm -fr SunWS_cache CC -I../../../../ -I./ -L../../build/sunpro_dbx -g -o r/regress tests.cpp parse.cpp regress.cpp -lboost_regex tests.cpp: parse.cpp: regress.cpp: Undefined first referenced symbol in file boost::detail::allocator<unsigned char>::allocator<char>#Nvariant 1 (const boost::detail::allocator<__type_1>&) /fsys/home/zhangku/re/libs/regex/ test/regress/SunWS_cache/CC_obj_O/OhCenAP7d5aN-_Bfr3wh.o boost::detail::allocator<unsigned char>::allocator<wchar_t>#Nvariant 1 (const boost::detail::allocator<__type_1>&) ../../build/sunpro_dbx/libboost_r egex.so ld: fatal: Symbol referencing errors. No output written to r/regress make: *** [r/regress] Error 1 Can anyone help me on this? Kurt

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Lambda questions
by Claus Rasmussen 02 Dec '02

02 Dec '02

Is it possible to discern one-argument lambda expressions from two-argument expressions ? I would like to do something like this: template<typename UNARY_LAMBDA_FUNC> void f(UNARY_LAMBDA_FUNC ulf) { ulf(arg); } template<typename BINARY_LAMBDA_FUNC> void f(BINARY_LAMBDA_FUNC blf) { blf(arg1, arg2); } -Claus

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RE: [Boost-Users] Re: Extended use of BGL File Dependency Example
by Tom Matelich 02 Dec '02

02 Dec '02

From: David Abrahams [mailto:dave@boost-consulting.com] > Tom Matelich <tmatelich(a)zetec.com> writes: > > > From: David Abrahams [mailto:dave@boost-consulting.com] > > Sent: Sunday, December 01, 2002 5:58 AM > >> Tom Matelich <tmatelich(a)zetec.com> writes: > >> > >> > trying to make my graphviz representation look nicer and I > >> was wondering if > >> > there is an algorithm already for simplifying: > > > > -----B\ > > A--< \ > > --------C > > D----------/ > > > > to: > > > > A---B---C > > D------/ > > > > This eliminated the A-C edge. > > > > Thanks for considering my problem. > > Maybe you want a minimum spanning tree, where the weight of each edge > in the tree is determined by the distance between its vertices in some > topological sort? > > That seems to solve the cases shown above pretty nicely. I had looked at the minimum spanning tree docs a bit, I thought it looked pretty good. The docs say undirected graph though. I'm currently using a directed graph. I suppose I could create a separate graph. Oh, I see, create an undirected graph with weights as you said, and use the minimum spanning algorithm to choose the useful edges. I like it, hope it works. Thanks, Tom ----------------------------------------------------------------------- DISCLAIMER: Information contained in this message and/or attachment(s) may contain confidential information of Zetec, Inc. If you have received this transmission in error, please notify the sender by return email. -----------------------------------------------------------------------

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RE: [Boost-Users] Re: Extended use of BGL File Dependency Example
by Tom Matelich 02 Dec '02

02 Dec '02

From: David Abrahams [mailto:dave@boost-consulting.com] Sent: Sunday, December 01, 2002 5:58 AM > Tom Matelich <tmatelich(a)zetec.com> writes: > > > trying to make my graphviz representation look nicer and I > was wondering if > > there is an algorithm already for simplifying: > > > > -----B\ > > A--< \ > > --------C > > > > to: > > > > A---B---C > > > > of course this is happening on a much larger scale. > > > > Thanks for any input you might have, > > That's known as a "topological sort", and can be done easily with a > depth-first search. I believe the graph library already has one: > > http://www.boost.org/libs/graph/doc/topological_sort.html > Hmm, its a little more complicated (I think). I'm using the topological sort for determining a build order. Now, I basically want to find a way to eliminate as many Edges as possible while still showing all dependencies. -----B\ A--< \ --------C D----------/ to: A---B---C D------/ This eliminated the A-C edge. Thanks for considering my problem. ----------------------------------------------------------------------- DISCLAIMER: Information contained in this message and/or attachment(s) may contain confidential information of Zetec, Inc. If you have received this transmission in error, please notify the sender by return email. -----------------------------------------------------------------------

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RE: [Boost-Users] Warnings compiling smart_ptr_test.cpp under MSVC++ 6.0
by Randy Bowen 01 Dec '02

01 Dec '02

Visual Studio 6 maintained at 255-character limit on identifiers in its debug information. You'll see this warning with just about any usage of STL containers and non-simple data types. It's basically harmless... annoying, but harmless. Randy Bowen -----Original Message----- From: fejimush [mailto:greitz@tomotherapy.com] Sent: Wednesday, November 13, 2002 10:59 AM To: Boost-Users(a)yahoogroups.com Subject: [Boost-Users] Warnings compiling smart_ptr_test.cpp under MSVC++ 6.0 I am brand new to boost. I have been able to compile and link smart_ptr_test.cpp. I have also been able to successfully run the test without errors. Can anyone tell me why I am getting numerous warnings? (shown below) One more item, the warning takes me to c:\...\VC98\Include\UTILITY Is this a stl implentation problem? Thanks in advanced. ---------------Build Output----------------------- Compiling... smart_ptr_test.cpp c:\program files\microsoft visual studio\vc98\include\utility(25) : warning C4786: 'std::_Tree<boost::shared_ptr<int>,boost::shared_ptr<int>,std:: set<boost::shared_ptr<int>,std::less<boost::shared_ptr<int> >,std::allocator<boost::shared_ptr<int> > > ::_Kfn,std::less<boost::shared_ptr<int> >,std::allocator<boost::shared_ptr<int> > >::iterator' : identifier was truncated to '255' characters in the debug information c:\boost_1_29_0\libs\smart_ptr\smart_ptr_test.cpp(198) : see reference to class template instantiation 'std::pair<std::_Tree<boost::shared_ptr<int>,boost::shar ed_ptr<int>,std::set<boost::shared_ptr<int>,std::less<boost::shared_pt r<int> >,std ::allocator<boost::shared_ptr<int> > >::_Kfn,std::less<boost::shared_ptr<int> >,std::allocator<boost::shared_ptr<int> > >::iterator,bool>' being compiled c:\program files\microsoft visual studio\vc98\include\utility(25) : warning C4786: 'std::_Tree<boost::shared_array<char>,boost::shared_array<char> ,std::set<boost::shared_array<char>,std::less<boost::shared_array<char > >,std::allocator<boost::shared_ array<char> > >::_Kfn,std::less<boost::shared_array<char> >,std::allocator<boost::shared_array<char> > >::iterator' : identifier was truncated to '255' characters in the debug information c:\boost_1_29_0\libs\smart_ptr\smart_ptr_test.cpp(242) : see reference to class template instantiation 'std::pair<std::_Tree<boost::shared_array<char>,boost::s hared_array<char>,std::set<boost::shared_array<char>,std::less<boost:: shared_array <char> >,std::allocator<boost::shared_array<char> > >::_Kfn,std::less<boost::shared_array<char> >,std::allocator<boost::shared_array<char> > >::iterator,bool>' being compiled c:\program files\microsoft visual studio\vc98\include\utility(21) : warning C4786: 'std::pair<std::_Tree<boost::shared_ptr<int>,boost::shared_ptr< int>,std::set<boost::shared_ptr<int>,std::less<boost::shared_ptr<int> >,std::allocator<boost::shared_pt r<int> > >::_Kfn,std::less<boost::shared_ptr<int> >,std::allocator<boost::shared_ptr<int> > >::iterator,bool>::pair<std::_Tree<boost::shared_ptr<int>,boost::share d_ptr<int>,std::set<boost::shared_ptr<int>,std::less<boost::shared_ptr <int> >,std::allo cator<boost::shared_ptr<int> > >::_Kfn,std::less<boost::shared_ptr<int> >,std::allocator<boost::shared_ptr<int> > >::iterator,bool>' : identifier was truncated to '255' characters in the debug information c:\program files\microsoft visual studio\vc98\include\utility(21) : warning C4786: 'std::pair<std::_Tree<boost::shared_array<char>,boost::shared_a rray<char>,std::set<boost::shared_array<char>,std::less<boost::shared_ array<char> >,std::allocator<boos t::shared_array<char> > >::_Kfn,std::less<boost::shared_array<char> >,std::allocator<boost::shared_array<char> > >::iterator,bool>::pair<std::_Tree<boost::shared_array<char>,boost::sh ared_array<char>,std::set<boost::shared_array<char>,std::less<boos t::shared_array<char> >,std::allocator<boost::shared_array<char> > >::_Kfn,std::less<boost::shared_array<char> >,std::allocator<boost::shared_array<char> > >::iterator,bool>' : identifier was truncated to '255' characters in the debug information c:\boost_1_29_0\boost\checked_delete.hpp(28) : warning C4786: 'std::_Tree<boost::shared_array<char>,boost::shared_array<char> ,std::set<boost::shared_array<char>,std::less<boost::shared_array<char > >,std::allocator<boost::shared_array<char> > >::_Kfn ,std::less<boost::shared_array<char> >,std::allocator<boost::shared_array<char> > >::_Nil' : identifier was truncated to '255' characters in the debug information c:\boost_1_29_0\boost\checked_delete.hpp(28) : warning C4786: 'std::_Tree<boost::shared_array<char>,boost::shared_array<char> ,std::set<boost::shared_array<char>,std::less<boost::shared_array<char > >,std::allocator<boost::shared_array<char> > >::_Kfn ,std::less<boost::shared_array<char> >,std::allocator<boost::shared_array<char> > >::_Nilrefs' : identifier was truncated to '255' characters in the debug information c:\boost_1_29_0\boost\checked_delete.hpp(28) : warning C4786: 'std::_Tree<boost::shared_ptr<int>,boost::shared_ptr<int>,std:: set<boost::shared_ptr<int>,std::less<boost::shared_ptr<int> >,std::allocator<boost::shared_ptr<int> > >::_Kfn,std::less<boos t::shared_ptr<int> >,std::allocator<boost::shared_ptr<int> > >::_Nilrefs' : identifier was truncated to '255' characters in the debug information c:\boost_1_29_0\boost\checked_delete.hpp(28) : warning C4786: 'std::_Tree<boost::shared_array<char>,boost::shared_array<char> ,std::set<boost::shared_array<char>,std::less<boost::shared_array<char > >,std::allocator<boost::shared_array<char> > >::_Kfn ,std::less<boost::shared_array<char> >,std::allocator<boost::shared_array<char> > >' : identifier was truncated to '255' characters in the debug information c:\boost_1_29_0\boost\checked_delete.hpp(28) : warning C4786: 'std::_Tree<boost::shared_array<char>,boost::shared_array<char> ,std::set<boost::shared_array<char>,std::less<boost::shared_array<char > >,std::allocator<boost::shared_array<char> > >::_Kfn ,std::less<boost::shared_array<char> >,std::allocator<boost::shared_array<char> > >::const_iterator' : identifier was truncated to '255' characters in the debug information c:\boost_1_29_0\boost\checked_delete.hpp(28) : warning C4786: 'std::_Tree<boost::shared_array<char>,boost::shared_array<char> ,std::set<boost::shared_array<char>,std::less<boost::shared_array<char > >,std::allocator<boost::shared_array<char> > >::_Kfn ,std::less<boost::shared_array<char> >,std::allocator<boost::shared_array<char> > >::iterator' : identifier was truncated to '255' characters in the debug information c:\boost_1_29_0\boost\checked_delete.hpp(28) : warning C4786: 'std::_Tree<boost::shared_array<char>,boost::shared_array<char> ,std::set<boost::shared_array<char>,std::less<boost::shared_array<char > >,std::allocator<boost::shared_array<char> > >::_Kfn ,std::less<boost::shared_array<char> >,std::allocator<boost::shared_array<char> > >::_Node' : identifier was truncated to '255' characters in the debug information c:\boost_1_29_0\boost\checked_delete.hpp(28) : warning C4786: 'std::_Tree<boost::shared_array<char>,boost::shared_array<char> ,std::set<boost::shared_array<char>,std::less<boost::shared_array<char > >,std::allocator<boost::shared_array<char> > >::_Kfn ,std::less<boost::shared_array<char> >,std::allocator<boost::shared_array<char> > >::_Redbl' : identifier was truncated to '255' characters in the debug information c:\boost_1_29_0\boost\checked_delete.hpp(28) : warning C4786: 'std::_Tree<boost::shared_ptr<int>,boost::shared_ptr<int>,std:: set<boost::shared_ptr<int>,std::less<boost::shared_ptr<int> >,std::allocator<boost::shared_ptr<int> > >::_Kfn,std::less<boos t::shared_ptr<int> >,std::allocator<boost::shared_ptr<int> > >::const_iterator' : identifier was truncated to '255' characters in the debug information c:\boost_1_29_0\boost\checked_delete.hpp(28) : warning C4786: 'std::_Tree<boost::shared_ptr<int>,boost::shared_ptr<int>,std:: set<boost::shared_ptr<int>,std::less<boost::shared_ptr<int> >,std::allocator<boost::shared_ptr<int> > >::_Kfn,std::less<boos t::shared_ptr<int> >,std::allocator<boost::shared_ptr<int> > >::iterator' : identifier was truncated to '255' characters in the debug information c:\boost_1_29_0\boost\checked_delete.hpp(28) : warning C4786: 'std::_Tree<boost::shared_ptr<int>,boost::shared_ptr<int>,std:: set<boost::shared_ptr<int>,std::less<boost::shared_ptr<int> >,std::allocator<boost::shared_ptr<int> > >::_Kfn,std::less<boos t::shared_ptr<int> >,std::allocator<boost::shared_ptr<int> > >::_Redbl' : identifier was truncated to '255' characters in the debug information c:\boost_1_29_0\boost\checked_delete.hpp(28) : warning C4786: 'std::pair<std::_Tree<boost::shared_ptr<int>,boost::shared_ptr< int>,std::set<boost::shared_ptr<int>,std::less<boost::shared_ptr<int> >,std::allocator<boost::shared_ptr<int> > >::_Kfn,std: :less<boost::shared_ptr<int> >,std::allocator<boost::shared_ptr<int> > >::iterator,bool>' : identifier was truncated to '255' characters in the debug information c:\boost_1_29_0\boost\checked_delete.hpp(28) : warning C4786: 'std::pair<std::_Tree<boost::shared_array<char>,boost::shared_a rray<char>,std::set<boost::shared_array<char>,std::less<boost::shared_ array<char> >,std::allocator<boost::shared_array<char> > >::_Kfn,std::less<boost::shared_array<char> >,std::allocator<boost::shared_array<char> > >::iterator,bool>' : identifier was truncated to '255' characters in the debug information Linking... GRPostOffice.exe - 0 error(s), 17 warning(s) Info: <http://www.boost.org> Wiki: <http://www.crystalclearsoftware.com/cgi-bin/boost_wiki/wiki.pl> Unsubscribe: <mailto:boost-users-unsubscribe@yahoogroups.com> Your use of Yahoo! Groups is subject to the Yahoo! Terms of Service <http://docs.yahoo.com/info/terms/> . [Non-text portions of this message have been removed]

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RE: [Boost-Users] Extended use of BGL File Dependency Example
by Tom Matelich 01 Dec '02

01 Dec '02

> I was excited to get to use the graph library for a > dependency tracking tool > we needed, now I have a feature that I don't know how to do. This is > mapping library/executable dependencies and we have a lot of apps with > common sub-libraries. I'd like to extract a full-rebuild > order for only > certain nodes, i.e. what libs do I need to build for apps A > and B? Since > its a DAG, I thought something about reachability, perhaps? > I'm not too > familiar with graph theory :( Okay, so I solved that one with using a "depends on" relationship rather than "used by", then used a breadth_first_search. Now I have a tougher question, maybe I'll get an answer this time :). I'm trying to make my graphviz representation look nicer and I was wondering if there is an algorithm already for simplifying: -----B\ A--< \ --------C to: A---B---C of course this is happening on a much larger scale. Thanks for any input you might have, Tom pardon the disclaimer... ----------------------------------------------------------------------- DISCLAIMER: Information contained in this message and/or attachment(s) may contain confidential information of Zetec, Inc. If you have received this transmission in error, please notify the sender by return email. -----------------------------------------------------------------------

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boost::iterator_adaptor
by Julia Donawald 01 Dec '02

01 Dec '02

Hi, I am trying to write my own iterator - class and using for that the boost::iterator_adaptor. I could find on the webpage several examples of how to connect an existing iterator like std::string::iterator or a simple array as "base-class" for my new iterator, but what can I do if I dont have any base-iterator? In the documentation I found the following sentence: "The Iterator Adaptor library allows you transform an arbitrary ``base'' type into a standard-conforming iterator with the behaviors you choose. Doing so is especially easy if the ``base'' type is itself an iterator." In my situation I dont have any base type which is an iterator, so how should I now create such a base-type? Which are the specifications of such a base-type? Where can I get information on how to create a new base-type? I am trying to write an iterator which reads records from a file or a database and always when I do the it++ the next record is read from the file or database. Thanks a lot in advance Julia

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FW: [Boost-Users] Spirit build problems on msvc
by HartmutKaiser＠t-online.de 30 Nov '02

30 Nov '02

Holger Thiele wrote: > Spirit has been accepted into boost, so i guess this is the > correct group > for posting this question. > Trying to build the simplexml example, i get the following > output from msvc6 > sp5 > (and similar ones from msvc 7): > [sniped error messages] Not all features of spirit are supported for all compilers (yet). Please have a look at http://spirit.sourceforge.net/wiki/index.php?page=Compiler+Table, where you can find a list of supported compilers (which compiler can handle which sample/feature). Regards Hartmut PS: I took the liberty to forward your message to the spirit mailing list. > I downloaded the spirit-only-1.5.1.zip and included it in my > boost directory > tree. > > Any ideas?

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