September 2010 - Boost-users - lists.preview.boost.org

Understanding of Boost License
by Ronghui Yu 03 Sep '10

03 Sep '10

Hi, All, If I have a software developed based on Boost library, does it mean I have to open source this software? Thanks in advance -- =========================== Regards Ronghui Yu

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[filesystem] v3 recursive_directory_iterator does not enumerate entries
by Timothy Madden 03 Sep '10

03 Sep '10

Hello I use recursive_directory_iterator in my project and the dereference operarator on the iterator object always returns the the base directory that I am iterating over, and not the directory entries, each one in turn. Am I doing something wrong ? int iLevel = -1; // loop over and copy each file from the source directory for ( recursive_directory_iterator it(tmpName); it != recursive_directory_iterator(); it++ ) { //if (it.level() != iLevel) if (true) { // recursion just entered a new directory, create it #ifdef _DEBUG boost::filesystem::path dir_entry(*it); cout << "Entry: " << dir_entry << endl; cout << "\tas:"; for ( boost::filesystem::path::iterator p_it = dir_entry.begin(); p_it != dir_entry.end(); p_it++ ) { if (p_it != dir_entry.begin()) cout << "/"; cout << *p_it; } cout << endl; #endif iLevel = it.level(); } } Thank you, Timothy Madden

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Is there a way for a library to add symbols to the standard headers ?
by Timothy Madden 03 Sep '10

03 Sep '10

Hello To write a library to add a POSIX emulation layer on Windows, is there a way to add symbols from my library to C/C++ standard library headers, without getting into recursive inclusion ? For example, is there a way to get the 'Additions to fstream' from the boost::filesystem library, actually look like they are added to the standard <fstream> header ? I know users can use #include "cstdio" (with quotes instead of brackets) throughout a project, in order to later be able to include some local version of the header, if the need for it arise during during some porting at a later time for example. However this works for user-level code, while for a library it is not that simple any more ... Thank you, Timothy Madden

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gcc refuses to compile Boost.Extension example
by René Tschirley 03 Sep '10

03 Sep '10

Dear Boost experts, I struggle to get Jeremy Pack's Boost.Extension going. I want to use the platform independent way to explicitly load shared libraries. Starting with the tutorial, it took me some time to find this out: boost::extensions::shared_library lib("mylib.dll"); boost::function<void (int)> fun1(lib.get<void, int>("DoSomething")); works, but boost::function<void (void)> fun2(lib.get<void, void>("DoSomething")); does not work as the compiler (Eclipse CDT Helios using gcc 4.4.0 on Windows with MinGW) complains: somefile.cpp:74: error: no matching function for call to 'boost::extensions::shared_library::get(const char [12])' I'm a bit confused. Am I blind? Is this a bug? Weird feature? User-too-dumb-error? Sincerely, Rene

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BOOST_IS_MPI_DATATYPE macro and std::vector
by Prevrhal, Sven 03 Sep '10

03 Sep '10

I have a class whose data I want to send/recv and which are of type std::vector. However, once it's allocated the size of this vector is fixed during runtime. Can I use BOOST_IS_MPI_DATATYPE to speed up data transfer and how would I do it? Thanks, Sven ________________________________ The information contained in this message may be confidential and legally protected under applicable law. The message is intended solely for the addressee(s). If you are not the intended recipient, you are hereby notified that any use, forwarding, dissemination, or reproduction of this message is strictly prohibited and may be unlawful. If you are not the intended recipient, please contact the sender by return e-mail and destroy all copies of the original message.

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boost::shared_ptr vs std::shared_ptr
by Raindog 03 Sep '10

03 Sep '10

I was just watching the video here: http://channel9.msdn.com/shows/Going+Deep/C9-Lectures-Stephan-T-Lavavej-Sta… And was wondering if anyone had written up a brief guide about the differences between boost::shared_ptr and std::shared_ptr.

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treat a range of ranges as a single range?
by Nathan Ridge 03 Sep '10

03 Sep '10

Hello, Is it possible, using the facilities in Boost.Range, to treat a range whose elements are themselves ranges, as a range whose elements are the elements of the component ranges? For example, I would like to treat a range of strings as a range of characters. A detokenizer in essence. Thanks, Nate.

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replace_range already declared in this scope?
by Nathan Ridge 03 Sep '10

03 Sep '10

Hello, It seems the following two headers do not play nicely with each other: #include <boost/algorithm/string.hpp> #include <boost/range/adaptors.hpp> When both are included in a source file, I get the error: boost/range/adaptor/replaced.hpp:102: error: ‘replace_range’ is already declared in this scope Removing either of the headers fixes the problem, but I cannot do that since I need functionality from both. What can I do to fix this? I am using Boost 1.43. Thanks, Nate.

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Re: [Boost-users] Problem using serialization::xml_archive with polymrphic classes
by przemyslaw.sliwa＠uk.bnpparibas.com 03 Sep '10

03 Sep '10

Hello, thanks for help with this. This has fixed the problem. However, I have got a much more complicated example which fails. I have a simple inheritance structure with 4 classes, they derive a->b->c->d nothing complex. say a is the mose base and d is the most derived class, Each class has got a virtual destructor. I can easily serialize object of type d but I cannot do this with a pointer to a this class. Basicaly invoking in the code std::vector<b*> tmpCcys; ar & boost::serialization::make_nvp("currencyEvents", tmpCcys); does not work at all! I can get to the point // retrieve the true type of the object pointed to // if this assertion fails its an error in this library assert(NULL != this_type); const boost::serialization::extended_type_info * true_type = i.get_derived_extended_type_info(t); // note:if this exception is thrown, be sure that derived pointer // is either registered or exported. if(NULL == true_type){ boost::serialization::throw_exception( archive_exception( archive_exception::unregistered_class, true_type->get_debug_info() ) ); } in the oserializer.hpp where each element of the vector is dumped to the archive but call to i.get_derived_extended_type_info(t) throws an exception of an unknown type. It is not archive or event std::exception onlt catch(...) {...} can handle it and therefore it is not possible to see what is going on. The data under t looks fine but const extended_type_info * get_derived_extended_type_info(const T & t) const { // note: this implementation - based on usage of typeid (rtti) // only does something if the class has at least one virtual function. BOOST_STATIC_WARNING(boost::is_polymorphic<T>::value); return typeid_system::extended_type_info_typeid_0::get_extended_type_info( typeid(t) ); } simply throws something which is not possible to handle correctly. I cannot step into typeid(t) on windows and VC++2005. As mentioned i have no problems at all with serializing object. Serializing pointers deos not work att all! I am exporting the class using BOOST_CLASS_EXPORT_GUID(d, "CurrencyEvent") I have to mention that the most base class is a template and I export it as well using BOOST_CLASS_EXPORT_GUID(a<Currency>, "EventCurrency") BOOST_CLASS_EXPORT_GUID(a<CurrencyCouple>, "EventCurrencyCouple") similar BOOST_CLASS_EXPORT_GUID(b, "BaseCurrencyEvent") BOOST_CLASS_EXPORT_GUID(c, "RealCurrencyEvent") the classes a,b,c and d are within a namespace Events and defined/declared within a dll but this should not be a problem at all since I can serialize objects of the most derived class. Could someone help me with this issue? Thanks a lot in advance ___________________________________________________________ This e-mail may contain confidential and/or privileged information. If you are not the intended recipient (or have received this e-mail in error) please notify the sender immediately and delete this e-mail. Any unauthorised copying, disclosure or distribution of the material in this e-mail is prohibited. Please refer to http://www.bnpparibas.co.uk/en/information/legal_information.asp?Code=ECAS-… for additional disclosures.

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[Test] BOOST_*_EQUAL_COLLECTIONS ostream problem
by Thomas Suckow 02 Sep '10

02 Sep '10

I am attempting to compare two std::map<string,string> objects in Boost.Test but am finding that it is trying to stream the std::pair< const string, string > that results from dereferencing the iterator. /* Simplified Example */ AUTO_TEST_CASE( Map_Same ) { std::map< std::string, std::string > x; std::map< std::string, std::string > y; BOOST_CHECK_EQUAL_COLLECTIONS( x.begin(), x.end(), y.begin(), y.end() ); } Results in: /usr/include/boost/test/utils/wrap_stringstream.hpp: In function 'boost::basic_wrap_stringstream<CharT>& boost::operator<<(boost::basic_wrap_stringstream<CharT>&, const T&) [with CharT = char, T = std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> > >]': /usr/include/boost/test/test_tools.hpp:641: instantiated from 'boost::test_tools::predicate_result boost::test_tools::tt_detail::equal_coll_impl(Left, Left, Right, Right) [with Left = std::_Rb_tree_iterator<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >, Right = std::_Rb_tree_iterator<std::pair<const std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> > > >]' In my application the values a particular entry in the map will not reveal the problem, so I chose to suppress printing of the pair: typedef std::pair< const std::basic_string<char>,std::basic_string<char> > pair_type; BOOST_TEST_DONT_PRINT_LOG_VALUE( pair_type ); But alas, this did absolutely nothing. Confused, I tried: BOOST_CHECK_EQUAL( *x.begin(), *y.begin() ); And it compiled. Remove the suppression and the error returns. So the suppression works, just not in conjunction with BOOST_*_EQUAL_COLLECTIONS. Searching the mailing list revealed a post from 2005. http://article.gmane.org/gmane.comp.lib.boost.user/13146 He mentions as I also found that equal_coll_impl uses the stream operator directly on the dereferenced iterators. This *appears* to be bypassing the code that allows suppression. Though I may be wrong (I can rarely tell with boost). Can someone check on this and see if I am crazy? In the mean time I guess I just have to overload the stream operator. Regards, Thomas Suckow

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