- Boost-users - lists.boost.org

Boost in Eclipse CDT..
by Filip Balas 20 Dec '07

20 Dec '07

Hi All, I saw an earlier post that talked about this similar problem, but the only reply did not solve my problem. I have eclipse 3.2.2, cdt 3.1.1.1 I have to use these versions because I am also using the cell SDK 2.1. I am getting the error: expected primary-expression before ')' token expected primary-expression before '>' token The line of code looks like: #include <boost/filesystem/path.hpp> #include <boost/filesystem/operations.hpp> namespace fs = boost::filesystem; fs::path configPath(fs::initial_path<fs::path>()); I have 'boost_filesystem' in my libraries (-l) section in my Linker tab. I have '/usr/include/boost' in my include paths section (-l) in my compiler & debug options. (this is the right path) I am wondering if this may be a problem with the version of eclipse/cdt that I'm using, or if someone else has had this problem and knows of a solution? Thanks, Phil

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double arithmetic precession and equality
by Andrej van der Zee 20 Dec '07

20 Dec '07

Hi, I was wondering if boost provides any support for testing equality of two doubles. In principle in C/C++ you cannot rely on equality because it uses bitwise comparison of doubles and in arithmetic expressions results may have lost some precession. An example will help: #include <iostream> int main(void) { double start = 3.123; double end = 4.124; double diff = end - start; // == 1.001 ??? if (diff != 1.001) { std::cout << diff << " and " << 1.001 << " are not equal" << std::endl; } } On my machine, this example outputs: 1.001 and 1.001 are not equal I am using a lot of arithmetic expressions on floating-point values and also need to test for equality. Also, at compile-time I do not know the precession so comparing within the range of an epsilon seems impossible. So does boost have anything for this I don't know of? Or any other libraries? Thanks, Andrej ___________________________________________________________ Yahoo! Answers - Got a question? Someone out there knows the answer. Try it now. http://uk.answers.yahoo.com/

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[boost] [serialization] typeid information is not included in archives
by Andrei Popa 20 Dec '07

20 Dec '07

Hallo all,I just discovered the serialization library found it extremely nice and useful. I appreciate all work of the author.I have not yet build any program with the library, I just read the documentation.There is one think that do not fit to my use: "typeid information is not included in archives".The reason is "archive portability" and the solution "same sequence by save/load".But what if I do not know the sequence? What can I do then?Think about a CAD program. I do not know what the user will draw, a line, circle, rectangle and so on.And I have to save them in a file, at the load I need to know what type of object do I load.For me the "archive portability" is not so important. Is there a way to configure/change the library to save the name of the class specified by std::type_of::name() in the archive?Best regards,Andrei _________________________________________________________________ Express yourself instantly with MSN Messenger! Download today it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/

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Problem in accessing bundled properties with Dynamic Properties
by tonyaim83 20 Dec '07

20 Dec '07

Hi.. My Sample Previous code look like #include "src-graphml.hpp" using namespace std; using namespace boost; int main(int argc, char** argv) { typedef adjacency_list<vecS,vecS,directedS, property<vertex_name_t,string>, property<edge_weight_t,double> > graph_t; graph_t g; dynamic_properties dp; dp.property("color",get(vertex_name_t(),g)); dp.property("weight",get(edge_weight_t(),g)); return 0; } Now i have added one more property to the vertex and i m using bundled property for declaration.So now my code look like.. #include "src-graphml.hpp" using namespace std; using namespace boost; struct node { string name; string path; }; int main(int argc, char** argv) { typedef adjacency_list<vecS,vecS,directedS, node,property<edge_weight_t,double> > graph_t; graph_t g; dynamic_properties dp; dp.property("name",g().name); dp.property("file",g[*node].path); dp.property("weight",get(edge_weight, g)); return 0; } I have quoted with bold tag the one in which i m getting compilation error just let me know how to use it correctly.. Thanks in advance.. -- View this message in context: http://www.nabble.com/Problem-in-accessing-bundled-properties-with-Dynamic-… Sent from the Boost - Users mailing list archive at Nabble.com.

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[review][unordered] Unordered accepted
by Ion Gaztañaga 19 Dec '07

19 Dec '07

Hi to all, The Unordered library submitted by Daniel James has been *accepted* into Boost. Thanks to all reviewers and all who contributed to the library before the review. We've received 8 reviews (Thosten Ottosen, Chun Ping Wang, Hervé Brönnimann, John Torjo, Cromwell Enage, Jamie Allsop, Graham Mark and Paul Bristow), and all were positive (since Chun's only complain was packaging and his ratings were all above 7 out of 10). Darren Cook privately sent me a positive mini-review (attached below). If I've missed any review, please let me know. I plan to write a post this weekend with a summary of requests/suggestions and Daniel's replies. Congrats Daniel! Regards, Ion /////////////////////////////////////////////////////////// /////////////////////////////////////////////////////////// /////////////////////////////////////////////////////////// /////////////////////////////////////////////////////////// /////////////////////////////////////////////////////////// /////////////////////////////////////////////////////////// Hi Ion, Not critical but the images seem to be missing. E.g. on http://igaztanaga.drivehq.com/unordered/unordered/buckets.html If I find time I will try out the library and write a review in the week, but here is a mini-review (feel free to forward to the list - I'm not subscribed at the moment): Documentation: * Fine * The concrete examples of how to use a custom type, and a custom hash function, and do everything in portable TR1, are wonderful - I've searched before and never been able to find something as clear as this seems to be. * In Table 1.4: "No equivalent. No idea why." is not very Boost-like :-) . Isn't the reason simply that there is no ordering in hash containers, so therefore no ordering function? > > * What is your evaluation of the potential usefulness of the library? > > * Do you think the library should be accepted as a Boost library? Yes. It is essential it gets into Boost as rapidly as possible; in fact I think it should be released as a patch to the current release. Having all of TR1 except for the hashed containers is a nasty red pimple on the otherwise very handsome nose of Boost. In particular, Visual C++ *still* does not ship with TR1 ("no plans until 2009" was the rumour I found), so anyone wanting to ship portable code is relying on Boost. And, at least for me, unordered_map is the single most useful library in TR1. Darren

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[boost-users] [boost::lambda and ptrdiff_t].
by chun ping wang 19 Dec '07

19 Dec '07

Hi, does anyone know whats wrong with this code. It doesn't compile on gcc-mingw 4.1.2. it works on msvc visual studio 2005. code: template <class InputIterator> typename InputIterator::difference_type kmean::getClusterIndex(InputIterator first, InputIterator last) { typedef typename InputIterator::value_type T; BOOST_STATIC_ASSERT(boost::is_floating_point<T>::value); #ifdef __DEBUG__ boost::prof::profiler p; #endif T min(std::numeric_limits<T>::max()); typedef typename InputIterator::difference_type diff_type; diff_type index(0); diff_type currentIndex(0); std::for_each(first, last, ( boost::lambda::if_then(boost::lambda::_1 < boost::lambda::var(min), ( boost::lambda::var(min) = boost::lambda::_1, boost::lambda::var(index) = boost::lambda::var(currentIndex) )), ++boost::lambda::var(currentIndex) ) ); #ifdef __DEBUG__ std::cerr << "finish getClusterIndex\n"; #endif return index; } error message: C:/Boost/include/boost/lambda/detail/lambda_functor_base.hpp: In member function 'boost::lambda::identity<ptrdiff_t&>& boost::lambda::identity<ptrdiff_t&>::operator=(const boost::lambda::identity<ptrdiff_t&>&)': C:/Boost/include/boost/lambda/detail/lambda_functor_base.hpp:23: instantiated from 'typename InputIterator::difference_type kmean::getClusterIndex(InputIterator, InputIterator) [with InputIterator = __gnu_cxx::__normal_iterator<double*, std::vector<double, std::allocator<double> > >]' ./cs522/c++/kmeanMain.cpp:70: instantiated from here C:/Boost/include/boost/lambda/detail/lambda_functor_base.hpp:23: error: non-static reference member 'ptrdiff_t& boost::lambda::identity<ptrdiff_t&>::elem', can't use default assignment operator C:/Boost/include/boost/lambda/detail/lambda_functors.hpp: In member function 'boost::lambda::lambda_functor<boost::lambda::identity<ptrdiff_t&> >& boost::lambda::lambda_functor<boost::lambda::identity<ptrdiff_t&> >::operator=(const boost::lambda::lambda_functor<boost::lambda::identity<ptrdiff_t&> >&)': C:/Boost/include/boost/lambda/detail/lambda_functors.hpp:113: note: synthesized method 'boost::lambda::identity<ptrdiff_t&>& boost::lambda::identity<ptrdiff_t&>::operator=(const boost::lambda::identity<ptrdiff_t&>&)' first required here ./cs522/c++/def/kmeandef.hpp: In function 'typename InputIterator::difference_type kmean::getClusterIndex(InputIterator, InputIterator) [with InputIterator = __gnu_cxx::__normal_iterator<double*, std::vector<double, std::allocator<double> > >]': ./cs522/c++/def/kmeandef.hpp:406: note: synthesized method 'boost::lambda::lambda_functor<boost::lambda::identity<ptrdiff_t&> >& boost::lambda::lambda_functor<boost::lambda::identity<ptrdiff_t&> >::operator=(const boost::lambda::lambda_functor<boost::lambda::identity<ptrdiff_t&> >&)' first required here make: *** [project/kmeanMain.o] Error 1

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boost.test create test suites aith auto registration
by Brandon Olivares 19 Dec '07

19 Dec '07

Hi, The documentation says I can use syntax like: BOOST_AUTO_TEST_SUITE( test_suite_name ); // Test cases here BOOST_AUTO_TEST_SUITE_END(); I'm getting no errors, but I find that even when using this, testing errors are reported as being in the master test suite. Sample code: BOOST_AUTO_TEST_SUITE( StringUtility ); BOOST_AUTO_TEST_CASE( getWords ) { // This is only to test functionality of the test library BOOST_CHECK_EQUAL(1, 2); } BOOST_AUTO_TEST_SUITE_END(); Sample output (note that the other test case is from the main file): Running 2 test cases... ./StringUtilityTest.cc(7): error in "getWords": check 1 == 2 failed [1 != 2] *** 1 failure detected in test suite "War" I'd appreciate any help figuring this out. Thanks, Brandon

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Re: [Boost-users] [boost] [serialization] typeid information is not included in archives
by Andrei Popa 19 Dec '07

19 Dec '07

Hi Mahesh, I think I understand better what you are to say. I read about extended_type_info, I will try your solution. Thanks, Andrei _________________________________________________________________ Express yourself instantly with MSN Messenger! Download today it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/

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Boost shared pointers, PThreads and void* casts
by STenyaK (Bruno Gonzalez) 19 Dec '07

19 Dec '07

I haven't been able to find any clear explanation about this, so here it goes: I'm coding a multithreaded program using pthreads. The general behaviour is this: -A function starts. -The function creates a shared pointer "OBJ". -The function creates a Thread, passing "OBJ" as the parameter (having to cast it as void*). -The thread starts, getting a (void*) param which is casted back to "OBJ" (shared pointer type). -The function ends, and therefore its "OBJ" goes out of scope. -The thread" ends, so its "OBJ" goes out of scope too. (of course, the thread could at times end before the function instead) I'm afraid that the shared pointer does not behave well due to those nasty void* casts... maybe trying to delete twice the object. What's the proper way of coding this? Weak pointers maybe? Thanks a lot for any help. -- Saludos, Bruno González _______________________________________________ Msn/Jabber: stenyak AT gmail.com ICQ: 153709484 http://www.stenyak.com

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Re: [Boost-users] [boost] [serialization] typeid information is not included in archives
by Andrei Popa 19 Dec '07

19 Dec '07

Hi Mahesh, Actually I thought myself about a such solution. But how do you know to what class do you have to cast(dynamic_cast)? That is the Question! You do not know if you are reading in a "Circle" or a "Line"... If the implementation is made using typeid or class name I do not really care. Regards, Andrei _________________________________________________________________ Express yourself instantly with MSN Messenger! Download today it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/

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