July 2012 - Boost-users - lists.preview.boost.org

boost::bind overloaded operators
by tolik levchik 11 Jul '12

11 Jul '12

Hello, i have some questions: 1) Why min_element give me errors without BOOST_RANGE_ENABLE_CONCEPT_ASSERT defined 0? Is it uses only for make error messages more readable? Is it safe to define it to 0? #include <vector> //#define BOOST_RANGE_ENABLE_CONCEPT_ASSERT 0 #include <boost/range.hpp> #include <boost/range/adaptors.hpp> #include <boost/range/algorithm.hpp> #include <boost/range/numeric.hpp> #include <boost/bind.hpp> struct foo{ int x; }; int main() { using namespace boost::adaptors; using boost::bind; std::vector<foo> vec; auto rng = vec | transformed(bind(&foo::x, _1)); boost::accumulate(rng, 0); // ok boost::min_element(rng); // error } 2) Why only logical operators overloaded for boost::bind and arithmetic one are not? Is it safe to define it manually with BOOST_BIND_OPERATOR?

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Using c++11 features in clang
by Marshall Clow 11 Jul '12

11 Jul '12

In response to a some questions on the boost-users list (and boost bug reports), I wrote up this: http://marshall.calepin.co/llvmclang-and-standard-libraries-on-mac-os-x.html I don't know if this should be a FAQ entry for Boost, or for clang. Suggestions/comments/edits welcome. -- Marshall Marshall Clow Idio Software <mailto:mclow.lists@gmail.com> A.D. 1517: Martin Luther nails his 95 Theses to the church door and is promptly moderated down to (-1, Flamebait). -- Yu Suzuki

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Windows 8/Windows Server 2012 compatibility
by Eli Zakashansky 11 Jul '12

11 Jul '12

Hi, Does anyone knows/tested boost compatibility with Windows 8/Windows Server 2012 ? I am currently using Boost 1.39.0, it works very well on prior versions of windows. Should Windows 8 be different ? did anyone faced compatibility issues ? Thanks in advance, Eli Zakashansky.

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Re: [Boost-users] boost::log & Visual Studio 2010 - problem with advanced event log backend
by Don 10 Jul '12

10 Jul '12

Konrad, I don't think the author of boost::log watches this mailing list. You might find more help at the boost-log sourceforge forum: http://sourceforge.net/projects/boost-log/forums/forum/710022. For what it's worth, I found using boost::log to be challenging, because there were lots of API changes between version 1 and 2, the API continues to change, and the documentation has not always kept up with the changes. Furthermore as the author makes changes he uses the current boost sandbox -- boost::log does not always build with the current released version of boost. If you already have a home-grown logging system in place, I'd question whether it is worth the effort to change. Don -------- Original Message -------- Subject: [Boost-users] boost::log & Visual Studio 2010 - problem with advanced event log backend. From: Konrad Rybacki <konrad.rybacki(a)gmail.com> To: boost-users(a)lists.boost.org Date: Tue, 10 Jul 2012 16:57:22 +0200 > Hi All, > > I am trying to introduce boost::log into one of projects I am working > on. The application already does some logging to the trace file and > additionaly uses Windows Event Log to post messages. What I am going > to do is to replace the existing logging framework with boost::log. >

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boost::log & Visual Studio 2010 - problem with advanced event log backend.
by Konrad Rybacki 10 Jul '12

10 Jul '12

Hi All, I am trying to introduce boost::log into one of projects I am working on. The application already does some logging to the trace file and additionaly uses Windows Event Log to post messages. What I am going to do is to replace the existing logging framework with boost::log. Being frank - these are my first attempts at boost at all. I am following exactly the steps from the examples section of the documentation. I have written the following code: boost::shared_ptr< sinks::event_log_backend > backend( new sinks::event_log_backend(( keywords::message_file = "<path to library>.dll", keywords::log_name = "My Application", keywords::log_source = "My Source" )) ); sinks::event_log::event_composer composer( sinks::event_log::direct_event_id_mapping<int>("EventId") ); composer[MY_APPLICATION_SESSION_CREATION_FAILURE] % fmt::message(); backend->set_event_composer(composer); boost::shared_ptr<sinks::synchronous_sink< sinks::event_log_backend>> sink( new sinks::synchronous_sink< sinks::event_log_backend >(backend) ); sink->set_filter( (flt::attr<SeverityLevel>("Severity") == info || flt::attr<SeverityLevel>("Severity") == warning || flt::attr<SeverityLevel>("Severity") == error || flt::attr<SeverityLevel>("Severity") == fatal) && flt::has_attr<int>("EventId") ); sinks::event_log::custom_event_type_mapping<SeverityLevel> mapping("Severity"); mapping[trace] = sinks::event_log::info; mapping[debug] = sinks::event_log::info; mapping[info] = sinks::event_log::info; mapping[warning] = sinks::event_log::warning; mapping[error] = sinks::event_log::error; mapping[fatal] = sinks::event_log::error; sink->locked_backend()->set_event_type_mapper(mapping); logging::core::get()->add_sink(sink); I am building the code with Visual Studio 2010. Unfortunately I get the following error: 1>F:\boost\boost\boost/function/function_template.hpp(153): error C2064: term does not evaluate to a function taking 3 arguments 1> class does not define an 'operator()' or a user defined conversion operator to a pointer-to-function or reference-to-function that takes appropriate number of arguments 1> F:\boost\boost\boost/function/function_template.hpp(147) : while compiling class template member function 'void boost::detail::function::void_function_obj_invoker3<FunctionObj,R,T0,T1,T2>::invoke(boost::detail::function::function_buffer &,T0,T1,T2)' 1> with 1> [ 1> FunctionObj=boost::log_mt_nt5::formatters::fmt_message<char>, 1> R=void, 1> T0=std::basic_ostream<char,std::char_traits<char>> &, 1> T1=const boost::log_mt_nt5::basic_attribute_values_view<char> &, 1> T2=const std::basic_string<char,std::char_traits<char>,std::allocator<char>> & 1> ] 1> F:\boost\boost\boost/function/function_template.hpp(907) : see reference to class template instantiation 'boost::detail::function::void_function_obj_invoker3<FunctionObj,R,T0,T1,T2>' being compiled 1> with 1> [ 1> FunctionObj=boost::log_mt_nt5::formatters::fmt_message<char>, 1> R=void, 1> T0=std::basic_ostream<char,std::char_traits<char>> &, 1> T1=const boost::log_mt_nt5::basic_attribute_values_view<char> &, 1> T2=const std::basic_string<char,std::char_traits<char>,std::allocator<char>> & 1> ] 1> F:\boost\boost\boost/function/function_template.hpp(722) : see reference to function template instantiation 'void boost::function3<R,T0,T1,T2>::assign_to<Functor>(Functor)' being compiled 1> with 1> [ 1> R=void, 1> T0=std::basic_ostream<char,std::char_traits<char>> &, 1> T1=const boost::log_mt_nt5::basic_attribute_values_view<char> &, 1> T2=const std::basic_string<char,std::char_traits<char>,std::allocator<char>> &, 1> Functor=boost::log_mt_nt5::formatters::fmt_message<char> 1> ] 1> F:\boost\boost\boost/log/sinks/event_log_backend.hpp(678) : see reference to function template instantiation 'boost::function3<R,T0,T1,T2>::function3<FormatterT>(Functor,int)' being compiled 1> with 1> [ 1> R=void, 1> T0=std::basic_ostream<char,std::char_traits<char>> &, 1> T1=const boost::log_mt_nt5::basic_attribute_values_view<char> &, 1> T2=const std::basic_string<char,std::char_traits<char>,std::allocator<char>> &, 1> FormatterT=boost::log_mt_nt5::formatters::fmt_message<char>, 1> Functor=boost::log_mt_nt5::formatters::fmt_message<char> 1> ] 1> LoggingFacility.cpp(111) : see reference to function template instantiation 'boost::log_mt_nt5::sinks::event_log::basic_event_composer<CharT>::event_map_reference &boost::log_mt_nt5::sinks::event_log::basic_event_composer<CharT>::event_map_reference::operator %<boost::log_mt_nt5::formatters::fmt_message<CharT>>(const FormatterT &)' being compiled 1> with 1> [ 1> CharT=char, 1> FormatterT=boost::log_mt_nt5::formatters::fmt_message<char> 1> ] The problem seems to be caused by the following expression: composer[MY_APPLICATION_SESSION_CREATION_FAILURE] % fmt::message(); Other backends work flawlessly. Event log files (.h/.mc/.dll) are OK too. Any help? Regards, Konrad Rybacki.

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boost compilation error on MSVS 2010
by NtVisigoth 10 Jul '12

10 Jul '12

Hello everybody. I have tried to compile boost-libraries and I have trouble with compileation. Try number #1: g:\Projects\boost_1_50_0>bootstrap.bat 1>stdout.txt 2> stderr.txt g:\Projects\boost_1_50_0\tools\build\v2\engine> stdout.txt: Building Boost.Build engine stderr.txt: \Microsoft was unexpected at this time. bootstrap.log: Setting environment for using Microsoft Visual Studio 2010 x86 tools. Try number #2: g:\Projects\boost_1_50_0>bootstrap.bat toolset=msvc 1>stdout.txt 2>stderr.txt g:\Projects\boost_1_50_0> stdout.txt: Building Boost.Build engine Failed to build Boost.Build engine. Please consult bootstrap.log for furter diagnostics. You can try to obtain a prebuilt binary from http://sf.net/project/showfiles.php?group_id=7586&package_id=72941 Also, you can file an issue at http://svn.boost.org Please attach bootstrap.log in that case. stderr.txt: - this file is empty bootstrap.txt: ### ### "Unknown toolset: toolset" ### ### You can specify the toolset as the argument, i.e.: ### .\build.bat msvc ### ### Toolsets supported by this script are: borland, como, gcc, gcc-nocygwin, ### intel-win32, metrowerks, mingw, msvc, vc7, vc8, vc9, vc10, vc11 ### What can I do?

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[Foreach] tweaked for speed -- a kludge worth refining?
by Paul Tuinenga 10 Jul '12

10 Jul '12

I admire the tight machine code BOOST_FOREACH teases compilers into generating. So what could be my problem? More speed! I have a situation with gathering floating-point data that may be of such low interest it's not worth pursuing for the library. In any case, I have my work-around (described below) that gets the job done. In this case, the need to accumulate: 1) using vectors of indices into another data vector (very NUMA) i.e. data[index] 2) there is always at least one index 3) majority of cases are two indices 4) but there may be several indices Obviously, it is best to go ahead and immediately process the (guaranteed) first index. This hides the cost of increment and loop-test in the latency of data fetch, even from L1 cache. But BOOST_FOREACH does not do that. So I hacked the macro. Works great! Creates the tightest machine code, boosting 2-element cases to the hardware limit (SSE/AVX instructions). Yes, there is the curly braces thing -- "crude but effective" is all I'm claiming. I'm sure there are better ways to alter the macro and/or use model; I'm interested to hear about that. - paul Example use: double accum = 0; ORG_BOOST_FOREACH(unsigned i, index) accum += data[i]; double temp, accum = 0; MOD_BOOST_FOREACH(unsigned i, index, temp = data[i]) accum += temp; temp = data[i]; } accum += temp; /////////////////////////////////////////////////////////////////////////////////////////////////////////////////// #define ORG_BOOST_FOREACH(VAR, COL) \ BOOST_FOREACH_PREAMBLE() \ if (boost::foreach_detail_::auto_any_t BOOST_FOREACH_ID(_foreach_col) = BOOST_FOREACH_CONTAIN(COL)) \ {} \ else if (boost::foreach_detail_::auto_any_t BOOST_FOREACH_ID(_foreach_cur) = BOOST_FOREACH_BEGIN(COL)) \ {} \ else if (boost::foreach_detail_::auto_any_t BOOST_FOREACH_ID(_foreach_end) = BOOST_FOREACH_END(COL)) \ {} \ else \ for (bool BOOST_FOREACH_ID(_foreach_continue) = true; \ BOOST_FOREACH_ID(_foreach_continue) && !BOOST_FOREACH_DONE(COL); \ BOOST_FOREACH_ID(_foreach_continue) ? BOOST_FOREACH_NEXT(COL) : (void)0) \ if (boost::foreach_detail_::set_false(BOOST_FOREACH_ID(_foreach_continue))) \ {} \ else \ for (VAR = BOOST_FOREACH_DEREF(COL); !BOOST_FOREACH_ID(_foreach_continue); BOOST_FOREACH_ID(_foreach_continue) = true) #define MOD_BOOST_FOREACH(VAR, COL, TMP) \ BOOST_FOREACH_PREAMBLE() \ if (boost::foreach_detail_::auto_any_t BOOST_FOREACH_ID(_foreach_col) = BOOST_FOREACH_CONTAIN(COL)) \ {} \ else if (boost::foreach_detail_::auto_any_t BOOST_FOREACH_ID(_foreach_cur) = BOOST_FOREACH_BEGIN(COL)) \ {} \ else if (boost::foreach_detail_::auto_any_t BOOST_FOREACH_ID(_foreach_end) = BOOST_FOREACH_END(COL)) \ {} \ else if (bool BOOST_FOREACH_ID(_foreach_continue) = false) \ {} \ else \ { \ /* some kind of BOOST-MPL "assert" here (debug only) to insure there is one item at least */ \ for (VAR = BOOST_FOREACH_DEREF(COL); !BOOST_FOREACH_ID(_foreach_continue); BOOST_FOREACH_ID(_foreach_continue) = true) \ TMP; \ for (BOOST_FOREACH_ID(_foreach_continue) ? BOOST_FOREACH_NEXT(COL) : (void)0; \ BOOST_FOREACH_ID(_foreach_continue) && !BOOST_FOREACH_DONE(COL); \ BOOST_FOREACH_ID(_foreach_continue) ? BOOST_FOREACH_NEXT(COL) : (void)0) \ if (boost::foreach_detail_::set_false(BOOST_FOREACH_ID(_foreach_continue))) \ {} \ else \ for (VAR = BOOST_FOREACH_DEREF(COL); !BOOST_FOREACH_ID(_foreach_continue); BOOST_FOREACH_ID(_foreach_continue) = true) ///////////////////////////////////////////////////////////////////////////////////////////////////////////////////

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chaining ouput iterator to input iterator
by MM 09 Jul '12

09 Jul '12

Hi, I have a function that transforms a serie of numbers into another serie: template <typename InputIterator, typename OutputIterator> void transform( InputIterator begin, InputIterator end, OutputIterator out ) { } and a 2nd function that calculates the standard deviation of a sample template <typename InputIterator > double stdev( InputIterator begin, InputIterator end) { } Is there a way to chain these existing functions in order to get the std dev of the transformed serie, without storing the intermediate numbers? Maybe with the help of some lazy iterator, or some lazy function? MM

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[Multi Index] Random Access Index C2247 Compile Error
by Steve Hibbert 09 Jul '12

09 Jul '12

Igor, thanks for getting back to me. Very good suggestion. I was trying to gain 'direct random access' to the items in the container by using the bracket operator on the MIC object, as you would do on a vector... "m_micOrders[index]". This is how example 10 in the Boost documentation shows the usage, using a text block stored in a MIC called tc, and using tc[pos] to access the pos'th element. After a review of the MIC source code and a bit of thinking, I have tried first getting a reference to the random access index, and then using the bracket operator on the reference to the index like this (where the random index is the seventh defined index in my case)... OrderMIC::nth_index<6>::type& index6 = m_micOrders.get<6>(); spOrder = index6[ index ]; It seems a general rule with MIC's is that you should never call any member functions on anything other than a reference to one of the indices. So, thanks very much for your help, and I am off and running again, much obliged. Steve

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[Multi Index] Random Access Index C2247 Compile Error
by Steve Hibbert 09 Jul '12

09 Jul '12

Thanks very much to Steven Watanabe for getting back to me regarding my lower_bound/upper_bound question - I will take a look at equal_range() as suggested. I have been reading around and found the random_access index. This is useful to me to find any random item in my multi_index container. I am having a problem compiling though, I get error c2247 when I try to use the square bracket operator [] to access a randomly indexed item. The error message says that this is an inheritance issue with the protected status of the operator... c:\program files\microsoft visual studio\myprojects\xmltest\xmltest\xmltestapp.cpp(899) : error C2247: 'boost::multi_index::detail::random_access_index<SuperMeta,TagList>::operator []' not accessible because 'boost::multi_index::detail::ordered_index<KeyFromValue,Compare,SuperMeta,TagList,Category>' uses 'protected' to inherit from 'boost::multi_index::detail::random_access_index<SuperMeta,TagList>' I have based my code on example 10 in the Multi Index Documentation source examples. I can see that Daniel Bradburn had the same problem, detailed in a post dated April 6th 2010. Joaquin M Lopez Munoz responded, asking for a little test project to demonstrate, but there I can find no resolution to his (and, thus, my) question. I have also tried using the "#define BOOST_NO_MEMBER_TEMPLATE_FRIENDS" line, but no joy. For now, I can work around by either hacking the protected state to public or iterating the container to a random point. I have updated Boost to 1_50 and created an isolated test case in a small project to replicate the issue. I am using Visual Studio 9 on Windows Vista. Thanks in advance for any help with this. Steve

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