February 2010 - Boost-users

Error compiling boost:interprocess
by Daniel Veneros 08 Feb '10

08 Feb '10

Hi, I'm doing a program that uses threads to launch a function using threads. I implemented the following code: #include <iostream> #include <boost/thread.hpp> void NewFunc() { std::cout << "NewFunc running" << std::endl; //do something std::cout << "NewFunc finished" << std::endl; } int main(int argc, char* argv[]) { boost::thread FuncThread(NewFunc); FuncThread.join(); } And I receive a few errors: g++ -c -g -MMD -MP -MF build/Debug/GNU-Solaris-x86/main.o.d -o build/Debug/GNU-Solaris-x86/main.o main.cpp main.cpp: In function `int main(int, char**)': main.cpp:19: error: `boost' has not been declared main.cpp:19: error: `thread' undeclared (first use this function) main.cpp:19: error: (Each undeclared identifier is reported only once for each function it appears in.) main.cpp:19: error: expected `;' before "FuncThread" main.cpp:20: error: `FuncThread' undeclared (first use this function) Any idea why this is failing? Thanks

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A[MultiIndex] Erasing boost MultiIndex entry
by ishay lavi 08 Feb '10

08 Feb '10

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[signals2] analysing the signature
by Igor R 08 Feb '10

08 Feb '10

Hello, typedef signal<void (MyObject)> signal_type; Is there a way to get the type of the 1st argument, i.e. something that would return MyObject as a type. Thanks.

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Serialization of a unordered_map
by Basti Korf 08 Feb '10

08 Feb '10

Hallo, I just wondered, why there is no possibility to serialize a unordered map. Since the STL map is serialized, i take the file for it and changed all maps to boost::unordered_map (multimap). Or is there a better way, i just did not see? Here is the code: #ifndef BOOST_SERIALIZATION_UNORDEREDMAP_HPP #define BOOST_SERIALIZATION_UNORDEREDMAP_HPP // MS compatible compilers support #pragma once #if defined(_MSC_VER) && (_MSC_VER >= 1020) # pragma once #endif /////////1/////////2/////////3/////////4/////////5/////////6/////////7/////////8 // serialization/map.hpp: // serialization for stl map templates // (C) Copyright 2002 Robert Ramey - http://www.rrsd.com . // Use, modification and distribution is subject to the Boost Software // License, Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at // http://www.boost.org/LICENSE_1_0.txt) // See http://www.boost.org for updates, documentation, and revision history. #include <boost/unordered_map.hpp> #include <boost/config.hpp> #include <boost/serialization/utility.hpp> #include <boost/serialization/collections_save_imp.hpp> #include <boost/serialization/collections_load_imp.hpp> #include <boost/serialization/split_free.hpp> namespace boost { namespace serialization { template<class Archive, class Type, class Key, class Compare, class Allocator > inline void save( Archive & ar, const boost::unordered_map<Key, Type, Compare, Allocator> &t, const unsigned int /* file_version */ ){ boost::serialization::stl::save_collection< Archive, boost::unordered_map<Key, Type, Compare, Allocator> >(ar, t); } template<class Archive, class Type, class Key, class Compare, class Allocator > inline void load( Archive & ar, boost::unordered_map<Key, Type, Compare, Allocator> &t, const unsigned int /* file_version */ ){ boost::serialization::stl::load_collection< Archive, boost::unordered_map<Key, Type, Compare, Allocator>, boost::serialization::stl::archive_input_map< Archive, boost::unordered_map<Key, Type, Compare, Allocator> >, boost::serialization::stl::no_reserve_imp<boost::unordered_map< Key, Type, Compare, Allocator > > >(ar, t); } // split non-intrusive serialization function member into separate // non intrusive save/load member functions template<class Archive, class Type, class Key, class Compare, class Allocator > inline void serialize( Archive & ar, boost::unordered_map<Key, Type, Compare, Allocator> &t, const unsigned int file_version ){ boost::serialization::split_free(ar, t, file_version); } // multimap template<class Archive, class Type, class Key, class Compare, class Allocator > inline void save( Archive & ar, const boost::unordered_multimap<Key, Type, Compare, Allocator> &t, const unsigned int /* file_version */ ){ boost::serialization::stl::save_collection< Archive, boost::unordered_multimap<Key, Type, Compare, Allocator> >(ar, t); } template<class Archive, class Type, class Key, class Compare, class Allocator > inline void load( Archive & ar, boost::unordered_multimap<Key, Type, Compare, Allocator> &t, const unsigned int /* file_version */ ){ boost::serialization::stl::load_collection< Archive, boost::unordered_multimap<Key, Type, Compare, Allocator>, boost::serialization::stl::archive_input_multimap< Archive, boost::unordered_multimap<Key, Type, Compare, Allocator> >, boost::serialization::stl::no_reserve_imp< boost::unordered_multimap<Key, Type, Compare, Allocator> > >(ar, t); } // split non-intrusive serialization function member into separate // non intrusive save/load member functions template<class Archive, class Type, class Key, class Compare, class Allocator > inline void serialize( Archive & ar, boost::unordered_multimap<Key, Type, Compare, Allocator> &t, const unsigned int file_version ){ boost::serialization::split_free(ar, t, file_version); } } // serialization } // namespace boost #endif // BOOST_SERIALIZATION_UNORDEREDMAP_HPP Best regards, SK -- GRATIS für alle GMX-Mitglieder: Die maxdome Movie-FLAT! Jetzt freischalten unter http://portal.gmx.net/de/go/maxdome01

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Compilation/syntax error Boost.Lambda
by Joost Kraaijeveld 07 Feb '10

07 Feb '10

Hi, The code below does not compile and gives me 2 errors that, whatever I try, do not want to disappear. What am I doing wrong? TIA The errors: g++ -O0 -g3 -Wall -c -fmessage-length=0 -MMD -MP -MF"Main.d" -MT"Main.d" -o"Main.o" "../Main.cpp" ../Main.cpp: In function ‘std::map<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<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> > > > > getObjects(const Predicate&)’: ../Main.cpp:34: error: no matching function for call to ‘bind(<unresolved overloaded function type>, std::map<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<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> > > > >*&, std::pair<boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::action<2, boost::lambda::function_action<2, boost::lambda::detail::unspecified> >, boost::tuples::tuple<const std::basic_string<char, std::char_traits<char>, std::allocator<char> > 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> > >::* const, const boost::lambda::lambda_functor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> > >, boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::action<2, boost::lambda::function_action<2, boost::lambda::detail::unspecified> >, boost::tuples::tuple<std::basic_string<char, std::char_traits<char>, std::allocator<char> > 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> > >::* const, const boost::lambda::lambda_functor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> > > >&)’ ../Main.cpp: In function ‘int main(int, char**)’: ../Main.cpp:46: error: no match for ‘operator<<’ in ‘boost::lambda::operator<<(A&, const boost::lambda::lambda_functor<Arg>&) [with A = std::ostream, Arg = boost::lambda::lambda_functor_base<boost::lambda::action<2, boost::lambda::function_action<2, boost::lambda::detail::unspecified> >, boost::tuples::tuple<const std::basic_string<char, std::char_traits<char>, std::allocator<char> > 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> > >::* const, const boost::lambda::lambda_functor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> >](((const boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::action<2, boost::lambda::function_action<2, boost::lambda::detail::unspecified> >, boost::tuples::tuple<const std::basic_string<char, std::char_traits<char>, std::allocator<char> > 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> > >::* const, const boost::lambda::lambda_functor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> > >&)(& boost::lambda::bind(const Arg1&, const Arg2&) [with Arg1 = const std::basic_string<char, std::char_traits<char>, std::allocator<char> > 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> > >::*, Arg2 = boost::lambda::lambda_functor<boost::lambda::placeholder<1> >](((const boost::lambda::lambda_functor<boost::lambda::placeholder<1> >&)((const boost::lambda::placeholder1_type*)boost::lambda::<unnamed>::_1)))))) << std::endl’ ../Main.cpp: In function ‘std::map<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<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> > > > > getObjects(const Predicate&) [with Predicate = boost::function<bool(std::string)>]’: ../Main.cpp:45: instantiated from here ../Main.cpp:28: error: no matching function for call to ‘bind(<unresolved overloaded function type>, std::map<std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::basic_string<char, std::char_traits<char>, std::allocator<char> >, std::less<std::basic_string<char, std::char_traits<char>, std::allocator<char> > >, std::allocator<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> > > > >*, std::pair<boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::action<2, boost::lambda::function_action<2, boost::lambda::detail::unspecified> >, boost::tuples::tuple<const std::basic_string<char, std::char_traits<char>, std::allocator<char> > 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> > >::* const, const boost::lambda::lambda_functor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> > >, boost::lambda::lambda_functor<boost::lambda::lambda_functor_base<boost::lambda::action<2, boost::lambda::function_action<2, boost::lambda::detail::unspecified> >, boost::tuples::tuple<std::basic_string<char, std::char_traits<char>, std::allocator<char> > 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> > >::* const, const boost::lambda::lambda_functor<boost::lambda::placeholder<1> >, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type, boost::tuples::null_type> > > >)’ make: *** [Main.o] Error 1 The code: #include <iostream> #include <map> #include <boost/lambda/lambda.hpp> #include <boost/lambda/algorithm.hpp> #include <boost/lambda/bind.hpp> #include <boost/lambda/if.hpp> #include <boost/function.hpp> using namespace std; using namespace boost; using namespace boost::lambda; map<string, string> objects; template< typename Predicate > map<string, string> getObjects( const Predicate& aPredicate) { map<string, string> matchedObjects; for_each( objects.begin(), objects.end(), if_then( bind(aPredicate, boost::lambda::_1) , bind(&map<string, string>::insert, &matchedObjects , make_pair(bind(&map<string, string>::value_type::first, _1),bind(&map<string, string>::value_type::second,_1))))); return matchedObjects; } int main( int argc, char* argv[]) { objects.insert(make_pair("one","value")); objects.insert(make_pair("two","value")); objects.insert(make_pair("three","value")); function< bool (string)> predicate = _1 == "value"; map<string, string> matchedObjects = getObjects(predicate); for_each(matchedObjects.begin(),matchedObjects.end(),cout << bind(&map<string, string>::value_type::first, _1) << endl); } -- Groeten, Joost Kraaijeveld Askesis B.V. Molukkenstraat 14 6524NB Nijmegen tel: 024-3888063 / 06-51855277 fax: 024-3608416 web: www.askesis.nl

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[proto] Handling String Terminals
by David A. Greene 07 Feb '10

07 Feb '10

If I have a grammar like this: typedef boost::proto::literal<std::string>::type StringTerminal; typedef or_< StringTerminal, ... > Rule; and I do this: checkMatch<Rule>(boost::proto::lit(std::string("str"))); checkMatch<Rule>(std::string("str")); checkMatch<Rule>("str"); where checkMatch is a wrapper around matches<>, the first line is the only one that passes. This is presumably because the string needs to be "protoized" and to match StringTerminal it has to be cast to std::string explicitly. This is rather ugly for constructs like this: term["str"] => term[lit(string("str"))] I would really rather not have to do the lit(string()) thing. Is there a good strategy to avoid this clutter? I could predefine literals like this: StringTerminal strlit = {{"str"}}. term[strlit] but that's a bit burdensome on the user. Would the same massaging be needed for, say, term + "strlit" Perhaps I can reformulate the grammar to avoid the cluttter by using constructs that promote constants to proper proto terminals. Any advice? Thanks! -Dave

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Asio - Joining Sync to Async
by John D 07 Feb '10

07 Feb '10

Hello I am writing to ask if it is possible to do the following. I have a persistently connected async socket held lively with keep alives. I would like to take in a new synchronous connection and make the async socket the end point for form a relay. Wondering is this even possible and if so how would be a good approach to it. Thank you, John

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BoostCon 2010 tentative, fully scheduled program available
by Hartmut Kaiser 06 Feb '10

06 Feb '10

Hey all, The first tentative, fully scheduled program for BoostCon 2010 is now available at http://www.boostcon.com/program. We're quite fond of this program and we believe it contains something for almost everybody. We hope to convince you to join us at BoostCon 2010, May 10-14th, in the beautiful Aspen. For registration, accommodation, and more information please visit the conference website at http://www.boostcon.com. Please note the reduced early registration fee! Regards Hartmut Program Chair BoostCon 2010 --------------- Meet me at BoostCon www.boostcon.com

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PP: BOOST_PP_CAT concatenate an argument with a whitespace
by Hicham Mouline 06 Feb '10

06 Feb '10

Hi, BOOST_PP_CAT( MACRO1, MACRO2 ); MACRO1 expands to double MACRO2 expands to x BOOST_PP_CAT( MACRO1, MACRO2 ); therefore expands to doublex; I am trying to get the statement double x; I couldn't find any macro that expands to whitespace? I am missing something obvious here Regards,

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Standard error handler in gil jpeg_io extension calls exit()
by Peter Goetz 06 Feb '10

06 Feb '10

Hi, I'm using the gil jpeg_io extension like this: gil::rgb8_image_t img; gil::jpeg_read_image("test.jpg",img); As it turned out, if "test.jpg" is not a jpeg the program will quit with the message: "Not a JPEG file: starts with 0x6b 0x6a" although I put a try-catch-block around it. Digging a bit deeper, I found, that this is because in boost/gil/extension/io/jpeg_io_private.hpp the jpeg_reader::init() function uses the standard error handler: _cinfo.err=jpeg_std_error(&_jerr); which calls the exit() function. I'd prefer to have an exception and handle the exception in my main program rather than in the library. Is there a way to do that? To me it seems there's no other way than modifying the jpeg_io_extension. Or am I missing something? Any help is very appreciated! Peter

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