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Re: [Boost-users] [FunctionTypes] Getting functor/lambda parameters (VS2012)
by Mateusz Loskot 12 Oct '13

12 Oct '13

On 11 October 2013 22:46, Stzpz <newstzpz(a)gmail.com> wrote: > I am not sure what is lacking in VS2012, but there is some way to overcome > this problem. > > template<class T, int argNo> > struct FunctorParameterType > { > static auto init() -> typename decltype(&T::operator()) > { > typedef typename decltype(&T::operator()) func_type; > return func_type(); > } > typedef typename decltype(FunctorParameterType<T, argNo>::init()) func_type; > typedef boost::function_types::parameter_types<func_type> parameter_types; > > typedef typename boost::mpl::at_c<parameter_types, argNo>::type type; > }; Nice one, thanks! I'll give it a try when I need it again. Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

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[system] Default error codes
by Gavin Lambert 10 Oct '13

10 Oct '13

boost/system/error_code.hpp defines "errc" as a collection of standard error codes (based on posix). It also defines a constructor for error_code and error_condition that allows them to accept a single parameter of an enum type when is_error_code_enum is defined to true for that enum type. It does not, however, actually do this for its own errc enum. As a result, code such as this fails to compile: boost::system::error_code ec(boost::system::errc::operation_canceled); Is there some good reason for this, or is it an oversight? It's certainly more annoying to have to explicitly specify the generic_category().

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[iostreams] - Using sparse Windows files
by Byrne, Kevin 10 Oct '13

10 Oct '13

Hello, I am trying to write cross-platform Boost code that utilizes sparse files on Windows7 and FreeBSD. I already have Windows code that creates and accesses a sparse file. I am of the understanding that Boost code cannot create a Windows7 sparse file for me so I am trying to create the file using the Windows code and then replace my ReadFileEx() and WriteFileEx() with Boost streams. I have had luck with using iostreams::file to access an existing Windows sparse file but it fails when I have to read a sparse area thinking it is at the end of the file. I tried creating a stream using an existing HANDLE but was not successful in reading or writing file content. Before I proceed further I thought I would ask first if Boost is capable of using Windows7 sparse file technology. If it is capable I would appreciate some guidance on how. I have done a bit of searching on the web with not much helpful information. Regards, Kevin

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1.55.0 beta 1 release candidates available for testing
by Marshall Clow 10 Oct '13

10 Oct '13

Release candidate files for 1.55.0 beta 1 are available at http://boost.cowic.de/rc/ As always, the release managers would appreciate it if you download the candidate of your choice and give building it a try. Please report both success and failure, and anything else that is noteworthy. This helps ensure the candidates build OK before we push them out to SourceForge. The files (and associated md5s) are: 9fa020efb06f5485628c646451b927c6 *boost_1_55_0b1_rc1.tar.gz 02d26b038ac96f19c3478d0c45a63c9b *boost_1_55_0b1_rc1.tar.bz2 de5f7d60b2387c4fe3d03eb327f095a9 *boost_1_55_0b1_rc1.zip 7deb9063846873452e6ec6918cb75a87 *boost_1_55_0b1_rc1.7z Thanks, --The release managers

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[type_traits] ice_or / ice_and not documented but recommended in coding guidelines
by Adam Romanek 10 Oct '13

10 Oct '13

Hi, I have a concern about the usage of boost::type_traits::ice_or and boost::type_traits::ice_and. I've seen it used in many places and it's even recommented in Coding Guidelines for Integral Constant Expressions [1]. The question is: why isn't it documented? Is there any reason for it? Is there any "public" (documented) equivalent? WBR, Adam Romanek [1] - http://www.boost.org/development/int_const_guidelines.html

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How to choose which library version to choose?
by Michael Kragh Pedersen 10 Oct '13

10 Oct '13

I have downloaded and built the Boost library, as according to these instructions: http://theseekersquill.wordpress.com/2010/08/24/howto-boost-mingw/ I need to use the serialization library, so I looked at the stage\lib folder, only to 16 different library files! Some are named mt, some sd, some s or d, and some a combination thereof, all this following libboost_serialization-mgw48. Some are dll files and some are a files. I tried using –lboost_serialization, as I have seen this mentioned on a lot of forums, but Eclipse says it can’t find that library. So how on Earth am I supposed to figure out which of the many files to link to?!

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Serialization unsupported version, going from 1.47.0 to 1.54.0
by Robert Bielik 10 Oct '13

10 Oct '13

Hi all, Just updated to using boost 1.54.0 and I've gotten problems with my application serializing data with 1.54.0 and a server application deserializing with 1.47.0, using text archives. I noticed the thread http://stackoverflow.com/questions/6015339/boost-serialization-archive-unsu… however it seems only to be issue with binary archives ?? Ideas ? TIA /Rob

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Example calc4.cpp for others grammars
by Olivier Austina 10 Oct '13

10 Oct '13

Hi all, I would like to customize the example calc4.cpp at http://www.boost.org/doc/libs/1_47_0/libs/spirit/example/qi/compiler_tutori… the following grammar: G-------> { A+; C} A--------> {B; C} B--------->E (like arithmetic expression grammar in calc4.cpp) How to modifier this boost variant instruction for this grammar or there no need to change it: typedef boost::variant< nil , unsigned int , boost::recursive_wrapper<signed_> , boost::recursive_wrapper<program> > In general what to put in boost variant for specific grammar (or AST). Any suggestion is welcome. Thank you. Regards Olivier

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[Fusion] Simple transform not working in 1.54?
by Andrew 10 Oct '13

10 Oct '13

Hi, Can anyone shed any light on why this simple test case results in an instantiation of ‘struct inspect<boost::fusion::vector2<boost::fusion::detail::apply_transform_result<int>...' instead of the expected 'struct inspect<boost::fusion::vector2<int, int(double)>>' ? Sorry about the use of pastebin, boost.codepad.org is down. http://pastebin.com/kctYLfag

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Re: [Boost-users] Boost range iterator pointing to wrong element
by Giorgos Sermaidis 09 Oct '13

09 Oct '13

Dear Nate and Gavin, Thank you so much for such a detailed explanation! It is very clear now. boost-users-request(a)lists.boost.org wrote: >Send Boost-users mailing list submissions to > boost-users(a)lists.boost.org > >To subscribe or unsubscribe via the World Wide Web, visit > http://lists.boost.org/mailman/listinfo.cgi/boost-users >or, via email, send a message with subject or body 'help' to > boost-users-request(a)lists.boost.org > >You can reach the person managing the list at > boost-users-owner(a)lists.boost.org > >When replying, please edit your Subject line so it is more specific >than "Re: Contents of Boost-users digest..." > > >Today's Topics: > > 1. [thread] Test if a thread is running (Patrick Steele) > 2. Re: [thread] Test if a thread is running (Kim Barrett) > 3. Re: [thread] Test if a thread is running > (christoph.kliemt(a)pgxml.net) > 4. Type Erasure: Infinite loop when accessing an element of a > container of any<>, where the element is another container > (Alexandre Pretyman) > 5. Re: [boost] [1.55.0] Beta 1 Available (Rich E) > 6. Re: Boost range iterator pointing to wrong element (Nathan Ridge) > 7. Re: [thread] Test if a thread is running (Patrick Steele) > > >---------------------------------------------------------------------- > >Message: 1 >Date: Tue, 8 Oct 2013 17:15:05 +0100 >From: Patrick Steele <steele.patrick(a)gmail.com> >To: boost-users(a)lists.boost.org >Subject: [Boost-users] [thread] Test if a thread is running >Message-ID: > <CAFXDkHyrnTqijUc09otuNs7w+DwXSTue5eLh0-HZBvq+RH=HSg(a)mail.gmail.com> >Content-Type: text/plain; charset="iso-8859-1" > >boost = 1.54 >OS = Windows 7 >compiler = Visual Studio 2005 > >Hi, >in order to test if a boost.thread is running I used timed_join as per >http://stackoverflow.com/questions/1667420/how-can-i-tell-reliably-if-a-boo…, >which recommended that I should be able to call timed_join with a wait time >of 0 ie >bool isThreadRunning = ! m_Thread.timed_join( boost::get_system_time() ); >I have just upgraded to boost 1.54 to see that this no longer appears to >work and that the timed_join function is being deprecated. >Can you tell me how I should now check whether a thread is running please? >Thanks, >Patrick >

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