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

mpl::vector -> boost::tuple
by Markus Werle 09 Jul '04

09 Jul '04

Hi! The example in libs/mpl/example/tuple_from_list.cpp and gen_linear_hierarchy from http://aspn.activestate.com/ASPN/Mail/Message/boost/1166644 template< typename Types, typename Unit, typename Root = mpl::none > struct gen_linear_hierarchy { typedef typename mpl::fold<Types,Unit,Root> ::type type; // here }; /* usage example: template< class Base, class T > struct EventHander : public Base { virtual void OnEvent(T& obj, int eventID) = 0; }; typedef gen_linear_hierarchy< mpl::list<Window,Button,ScrollBar> , EventHander<_1,_2> > ::type v; */ all seem to me work fine with default constructible types. What I need is a type generator which provides a constructor, such that code like this one works for mpl::vectors (or other mpl::sequences) with arbitrary length: ------------- class C { C(std::string const & gaga) {} }; struct gen_linear_hierarchy_with_constructor // your idea missing here { // and here }; typedef gen_linear_hierarchy_with_constructor<mpl::vector<C, C> >::type mytuple; mytuple mt("test", "Thanks for your help"); ------------------ Markus P.S.: David and Aleksey, if you read this here: I could not find your "coming soon" book at awprofessional.com. What's the current state of the book I wait for so long already ...

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Relational DB Model Tools
by Hossein Haeri 09 Jul '04

09 Jul '04

Dear all, I wonder knowing where the "Relational Database Model" stuff are in the boost repository. How knows? Thanks a lot, --Hossein __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Adapting Iterator Adaptor
by Duane Murphy 08 Jul '04

08 Jul '04

We are still using boost 1.27. We are getting to the point that there are features of the latest boost release that we want to use. Of course there are barriers. One barrier is iterator_adaptor. Iterator_adapter went through a significant rewrite. We have several (>10) iterators written using the older implementation. We are trying to gauge the impact of changing to the latest boost. Do we need to largely rewrite these iterators? Is the interface close enough for this to be a reasonably simple task? Simply how do we get our old iterators to the new adaptor? Thanks for the help, ...Duane

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Generic Class Factory
by Mark Loew 08 Jul '04

08 Jul '04

I have to create a class factory and was looking for a generic class factory that I could work with. I looked in the boost documentation but didn't find anything. Is there something there that I am missing or do I need to roll my own? Mark Loew, MCSD, MCSE Application Development Consultant Sagestone Consulting www.sagestone.com <http://www.sagestone.com/> Grand Rapids, MI 616-954-9556 x149 Microsoft Gold Certified Partner mloew(a)sagestone.com

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RE: [Boost-users] Generic Class Factory
by Jim.Hyslop 07 Jul '04

07 Jul '04

Mark Loew wrote: > I have to create a class factory and was looking for a > generic class factory that I could work with. I looked in > the boost documentation but didn't find anything. Is there > something there that I am missing or do I need to roll my own? It's not part of boost, but have a look at: http://www.cuj.com/documents/s=7994/cujcexp1906hyslop/ There's a follow-up in the July and August, 2003 print editions of CUJ. -- Jim Hyslop Senior Software Designer Leitch Technology International Inc. (http://www.leitch.com) Columnist, C/C++ Users Journal (http://www.cuj.com/experts)

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Feature request for boost::filesystem
by Delfin Rojas 07 Jul '04

07 Jul '04

Hello everybody, I'm new to this mailing list. The first thing I should say is I love boost and I think it is a great library and I'm really thankful to all its contributors. Now, that being said, I'm sending this email to ask about a feature in the boost::filesystem library that I believe would be valuable to have. Currently the only library that supports file and directory operations in boost is boost::filesystem. Thanks tot hat library I don't have to use platform specific file manipulation rutines for things like copying a file, deleting all files in a directory, iterating through a directory, etc. Now, all the operations in boost::filesystem take a boost::filesystem::path as an object encapsulating a platform independent "path" to a file or a directory. My problem is this path can only be built using a single char (ANSI) character string. This doesn't allow me to use boost::filesystem in windows with Unicode support since I cannot convert a wide string (UTF16) path to a boost::filesystem::path object. I believe it must not be too difficult to add Unicode path support to boost::filesystem since only the "path" class would need to be modified I think. Another small feature I think could be interesting is a convenience function to set the current path (cd operation). There is a function already to get the current path but not to set it. I do not know if this is the right group to ask for these features. If not please point me in the right direction. Thanks a lot Delfin Rojas Delfin(a)moodlogic.com

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RE: [Boost-users] Problem with boost random library.
by Tom Matelich 07 Jul '04

07 Jul '04

This is totally a shot in the dark, but the last time I had this problem, my static class members inside a gcc library were not getting constructed because I wasn't using gcc as my linker. Perhaps those two have static non-POD members and the others don't. > -----Original Message----- > From: boost-users-bounces(a)lists.boost.org > [mailto:boost-users-bounces@lists.boost.org] On Behalf Of > Joshua Little > Sent: Saturday, July 03, 2004 8:09 PM > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] Problem with boost random library. > > > Just to make sure I answer my own mails as much as possible. > I tried a > few different random generators. Rand48, mt11213b, and > minstd_rand and > they all worked inside of my game. So it seems like mt19937 and the > lagged_fibonacci's are causing the problem. So obviously I > can use one > of the other generatrors but its still bothers me that the > mt19937 and > lagged_fibonaccis generators segfaults for reasons that are > not apparent > to me. Maybe this information will help give ideas to anyone > who might > know what might be wrong, maybe there is a difference between the > generator types that might be causing the problem? > Thanks, > Joshua. > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/bo> ost-users > ----------------------------------------------------------------------- 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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thread and Mac OS X
by Tristan King 07 Jul '04

07 Jul '04

i've written a little test to see if i've installed boost properly on my mac #include <boost/thread.hpp> #include <boost/shared_ptr.hpp> #include <boost/bind.hpp> #include <iostream> void simple_thread( boost::shared_ptr<int> p ) { std::cout << (*p) << std::endl; } int main (int argc, char * const argv[]) { boost::thread_group threads; for ( int i = 0 ; i < 5 ; i++ ) { boost::shared_ptr<int> p( new int(i) ); threads.create_thread( boost::bind( &simple_thread, p ) ); } threads.join_all( ); return 0; } in xcode (a C++ Tool project) this compiles fine, however on runtime i get the following error: ZeroLink: unknown symbol '__ZN5boost12thread_groupC1Ev' boost_test has exited due to signal 6 (SIGABRT). using g++ i get the following errors (ignoring warnings) g++ main.cpp -o boost_test -I/usr/local/include/boost-1_31 -L/usr/local/lib ld: Undefined symbols: boost::thread_group::create_thread(boost::function0<void, std::allocator<boost::function_base> > const&) boost::thread_group::join_all() boost::thread_group::thread_group[in-charge]() boost::thread_group::~thread_group [in-charge]() i originally built boost using the command line sudo bjam -sTOOLS=darwin install can anyone help me with what i am missing here? thanks --Tristan

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RE: [Boost-users] [pool] Speed of pool_allocator<>
by Klaus Nowikow 06 Jul '04

06 Jul '04

Peter Dimov wrote: > Klaus Nowikow wrote: > > template <class Allocator> > > double Test() > > { > > std::vector<Allocator::value_type, Allocator> Vector; > > boost::timer Timer; > > > > for(int i = 0; i < NUM_ELEMENTS; ++i) > > { > > Vector.push_back(i); > > } > > > > return Timer.elapsed(); > > } > > If I read the code correctly, you don't create or delete > objects. You create > and delete (large) arrays of objects. I changed the test program (see below). Now I use object_pool<> to create and destroy a number of elements (I use a vector<C*> to store them in the meantime). The results are even worse than before: new/delete: 0.08s object_pool: 25.20s Note that I created a class non_pool with an interface similar to object_pool to be able to use one function template for both tests. // MemoryPoolTest.cpp #include <boost/timer.hpp> #include <boost/pool/object_pool.hpp> #include <vector> #include <iostream> enum { NUM_ELEMENTS = 100000 , CHUNK_SIZE = NUM_ELEMENTS }; class C { int i_; char c_; }; struct Empty { }; template <class T, class U = Empty> struct non_pool // create, destroy with new and delete { explicit non_pool(int) { } T* construct() const { return new T; } void destroy(T* pT) { delete pT; } }; template <template <class, class> class Pool> double Test() { Pool<C> P(CHUNK_SIZE); boost::timer Timer; std::vector<C*> V; for(int i = 0; i < NUM_ELEMENTS; ++i) { V.push_back(P.construct()); } for(std::vector<C*>::iterator pos = V.begin(), end = V.end(); pos != end; ++pos) { P.destroy(*pos); } return Timer.elapsed(); } int main(int, char**) { std::cout << "Starting memory pool test" << std::endl; double Time; std::cout << "Allocating with new : "; Time = Test<non_pool>(); std::cout << Time << "s" << std::endl; std::cout << "Allocating with boost::object_pool<>: "; Time = Test<boost::object_pool>(); std::cout << Time << "s" << std::endl; return 0; }

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errors building boost on Mac OS X
by Tristan King 06 Jul '04

06 Jul '04

Hi, i get a few errors when building the following libraries on Mac OS X 10.3.4 libboost_test_exec_monitor libboost_unit_test_framework i'm building using bjam, and the following command line bjam -sTOOLS-darwin install sniplets of the errors are as follows: darwin-Link-DyLib-action bin/boost/libs/test/build/libboost_prg_exec_monitor.dylib/darwin/debug/shared-linkable-true/libboost_prg_exec_monitor-d-1_31.dylib ld: Undefined symbols: cpp_main(int, char**) .... darwin-Link-DyLib-action bin/boost/libs/test/build/libboost_test_exec_monitor.dylib/darwin/debug/shared-linkable-true/libboost_test_exec_monitor-d-1_31.dylib ld: Undefined symbols: test_main(int, char**) .... darwin-Link-DyLib-action bin/boost/libs/test/build/libboost_unit_test_framework.dylib/darwin/debug/shared-linkable-true/libboost_unit_test_framework-d-1_31.dylib ld: Undefined symbols: init_unit_test_suite(int, char**) am i missing something here? thanks --Tristan

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