May 2014 - Boost-users - lists.preview.boost.org

Wrapper for maybe an iterator
by Jens Müller 20 May '14

20 May '14

Hi, I am looking for an iterator that can be incremented safely (but not dereferenced) without when it has been default-constructed, and when it has been constructed with another iterator, it is just a proxy for that iterator. Is there such a thing in Boost? BR, Jens

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Graph Library Question
by Ken Kazinski 20 May '14

20 May '14

Hi, I was able to find the shortest distances between my starting node and the rest of the nodes. Now I would like to output the path between my starting node and destination node. I have tried a number of different examples but none of them seem to do what I want. I am pretty sure I need to use some type of get but I can not find it in the documentation. Thanks for any help.

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Re: [Boost-users] [Graph] CSR from list of tuples
by Jeremiah Willcock 20 May '14

20 May '14

Is there any that you could build three separate vectors for the different components? That would allow the storage from two of the vectors to be reused as-is in the CSR graph. Otherwise, the best you can do is probably to accept an extra copy (but you should be able to get it to that using multi-pass iteration over the input vector). -- Jeremiah Willcock <div>-------- Original message --------</div><div>From: Sensei <senseiwa(a)gmail.com> </div><div>Date:05/20/2014 9:52 AM (GMT-07:00) </div><div>To: boost-users(a)lists.boost.org </div><div>Subject: [Boost-users] [Graph] CSR from list of tuples </div><div> </div>Dear all, I need to construct (and use) a graph that can handle millions of nodes, with minimal overhead, and as suggested I am using a CSR graph. As I understand from the documentation, it is unmodifiable. Arcs are created at runtime in a parallel fashion, and my choice was to use a vector of std::tuple<std::size_t, std::size_t, int> (that is, node, node, weight) with Intel's TBB. This is the problem: can I avoid temporary vectors to construct my graph? Right now the only way I see is to create the vector of arcs (as std::pair) and the vector of weights, but this is a waste of time and memory. Do you have any helpful suggestions? Cheers & Thanks! _______________________________________________ Boost-users mailing list Boost-users(a)lists.boost.org http://lists.boost.org/mailman/listinfo.cgi/boost-users

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Compiling with Python 3.3.5?
by Paul Hoffman 20 May '14

20 May '14

Greetings. I am compiling Boost 1.54.0 from source on a Debian 7.0.0 system built on a virtual machine. When that system has Python 3.1.5, Boost compiles. However, for a different program on that system, I need a newer Python. I started a new VM, installed Python 3.3.5 instead of 3.1.5, and tried to build Boost the same way. That dies, spewing a lot of stuff that looks like: ...found 10793 targets... ...updating 68 targets... gcc.compile.c++ bin.v2/libs/python/build/gcc-4.7/release/threading-multi/numeric.o In file included from ./boost/python/detail/prefix.hpp:13:0, from ./boost/python/numeric.hpp:8, from libs/python/src/numeric.cpp:6: ./boost/python/detail/wrap_python.hpp:50:23: fatal error: pyconfig.h: No such file or directory compilation terminated. "g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pthread -fPIC -DBOOST_ALL_NO_LIB=1 -DBOOST_PYTHON_SOURCE -DNDEBUG -I"." -I"/usr/local/include/python3.3" -c -o "bin.v2/libs/python/build/gcc-4.7/release/threading-multi/numeric.o" "libs/python/src/numeric.cpp" ...failed gcc.compile.c++ bin.v2/libs/python/build/gcc-4.7/release/threading-multi/numeric.o... gcc.compile.c++ bin.v2/libs/python/build/gcc-4.7/release/threading-multi/list.o In file included from ./boost/python/detail/prefix.hpp:13:0, from ./boost/python/list.hpp:8, from libs/python/src/list.cpp:5: ./boost/python/detail/wrap_python.hpp:50:23: fatal error: pyconfig.h: No such file or directory compilation terminated. . . . I don't see anything on the requirements page about a particular version of Python, but I could have missed it. Clues greatly appreciated. --Paul Hoffman

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[Test] Boost.Test for Property Tree Issue
by Pritesh Acharya 19 May '14

19 May '14

Boost version: 1.55.0 OS: Windows 8 IDE: Visual Studio 2010 I have a small class which just parses a std::string using boost::property_tree::read_json. I'm trying to test my method with invalid input to make sure my method handles the exception. However, when I execute GetPropertyTreeFromJsonInValidInput2 (source code in attachment), I get exception in the visual studio itself and I have to break the execution. (snapshot is included in attachment). I'm a new user of boost, so don't know where to look for the solution.

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What is the best way to obtain a constant one for any numeric type?
by Javier Dehesa 19 May '14

19 May '14

Is there any trait in Boost that allows me to get the value of one for any numeric type? What I'm looking for is something that would work like the following: boost::numeric_traits<int>::one; // 1 boost::numeric_traits<long>::one; // 1L boost::numeric_traits<double>::one; // 1.0 boost::numeric_traits<float>::one; // 1.0f And so on. Does it exist, or something equivalent? I've looked into NumericConversion, but I haven't quite found something similar. What I'm using now is something equivalent to the following: template<class Number> Number one() { return Number(1); } Maybe this is safe enough? I know I can do this trait by myself, but I would like to avoid it if possible, specially considering that I'm working on an already complex Boost library. Thanks. -- Javier Dehesa

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Re Stability of serialization across boost versions
by Brian Wood 18 May '14

18 May '14

Sohail Somani writes: > On 18/05/2014 4:34 AM, John Maddock wrote: >>> Any feedback or suggestions other than not using boost for serialization? >> >> It was my understanding that stuff like that should be supported, if you >> have a test case then filing a bug report would seem to be in order? > > Based on the error, it seems like what is happening is that a newer > version of Boost is attempting to communicate with an older version of > Boost. The actual exception is from the archive itself, IIUC. The > library has explicitly said this is not supported, unfortunately. > > To the OP, I'd suggest not upgrading Boost serialization or requiring > upgrading in lockstep. Upgrading multiple hosts in random order means > new communicating with old. This is an unsupported use case. I have a serialization option. It isn't a Boost library, but it has support for some Boost types and we're willing to add support for other Boost types. -- Brian Ebenezer Enterprises - "He who *refreshes* *others* will *himself* be refreshed." Proverbs 11:25 http://webEbenezer.net

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Stability of serialization across boost versions
by Jeff Abrahamson 18 May '14

18 May '14

A program I wrote using the Boost serialization library trips up when communicating with instances of itself on hosts with different versions of the library. terminate called after throwing an instance of 'boost::archive::archive_exception' what(): unsupported version It's not reasonable to require that users of my software upgrade their hosts in lock step with each other, all at once or not at all. But library skew on the order of a bit over two years at least (consider users of Ubuntu LTS) arises naturally and quite often. I think the solution would be for boost serialize to offer an API point that says "write with binary protocol n", which leaves the library free to read with any protocol it knows. When I feel that n+1 has existed for long enough, I can tell my program to use n+1. Unfortunately, and I'd like to be shown wrong, I don't think the library provides such an API point. Any feedback or suggestions other than not using boost for serialization? Jeff Abrahamson http://jeff.purple.com/ http://blog.purple.com/jeff/

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Sequence of boost::logic::tribools - let indeterminate entries inherit from their neighbours
by Jens Müller 17 May '14

17 May '14

Hi, I have a sequence of tribools and I want element with a indeterminate value to inherit from their neighbours. Does such an algorithm exist already in Boost? If not, do you think it would be a useful addition? BR, Jens

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"Trac thinks your submission might be Spam. To prove otherwise please provide a response to the following."
by Nico Schlömer 16 May '14

16 May '14

Hi all, I would like to make contributions to Boost on trac <https://svn.boost.org/trac/boost>, but whenever I would like to make comment a bug report, it gets recognized as spam, and I'm redirected to a captcha-page that I think should contain a captcha, but does _not_ <https://svn.boost.org/trac/boost/captcha#trac-add-comment>. Any hints? Cheers, Nico

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[Concept.Check] BOOST_CONCEPT_ASSERT and OutputIterator
by Jens Müller 15 May '14

15 May '14

Hi, what might be wrong about this concept check? BOOST_CONCEPT_ASSERT( ( OutputIterator< std::back_insert_iterator< std::vector< bool > >, bool > ) ); It causes this compiler error: > In file included from /home/jens/hacon/build/boost-1.46.1/boost/concept/assert.hpp:36:0, > from /home/jens/hacon/build/boost-1.46.1/boost/concept_check.hpp:20, > from /home/jens/hacon/build/boost-1.46.1/boost/bimap/detail/bimap_core.hpp:31, > from /home/jens/hacon/build/boost-1.46.1/boost/bimap/bimap.hpp:61, > from /home/jens/hacon/build/boost-1.46.1/boost/bimap.hpp:13, > from src/XYZ.cpp:8: > src/xyz.cpp: In function ‘{anonymous}::triboolInheritFromAnyNeighborConverter_c<BoolOutputIterator> {anonymous}::makeTriboolInheritFromAnyNeighborConverter(BoolOutputIterator)’: > src/xyz.cpp:546:5: error: ‘*’ cannot appear in a constant-expression > BOOST_CONCEPT_ASSERT( ( OutputIterator< std::back_insert_iterator< std::vector< bool > >, bool > ) ); > ^ > src/XYZ.cpp:546:5: error: a call to a constructor cannot appear in a constant-expression > BOOST_CONCEPT_ASSERT( ( OutputIterator< std::back_insert_iterator< std::vector< bool > >, bool > ) ); > ^ > src/XYZ.cpp:546:5: error: template argument 1 is invalid > BOOST_CONCEPT_ASSERT( ( OutputIterator< std::back_insert_iterator< std::vector< bool > >, bool > ) ); > ^ > src/XYZ.cpp:546:5: error: template argument 1 is invalid > BOOST_CONCEPT_ASSERT( ( OutputIterator< std::back_insert_iterator< std::vector< bool > >, bool > ) ); > ^ > src/XYZ.cpp:546:105: error: invalid type in declaration before ‘;’ token > BOOST_CONCEPT_ASSERT( ( OutputIterator< std::back_insert_iterator< std::vector< bool > >, bool > ) ); Thanks, Jens P.S.: I of course have: #include <vector> #include <boost/concept_check.hpp> #include <boost/concept/assert.hpp>

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[ASIO] Multicast Regression?
by Aaron_Wright＠selinc.com 14 May '14

14 May '14

I previously used ASIO from Boost 1.49 to send out multicast UDP messages up to 64K bytes in size without a problem. Now with ASIO from Boost 1.55 I can't seem to send out a multicast UDP message greater than 1500 bytes. I get this error: Code=1784 Category=system Message=The supplied user buffer is not valid for the requested operation I've looked at the code between Boost 1.49 and 1.55, (basic_datagram_socket.hpp, datagram_socket_services.hpp, win_iocp_socket_service_base.hpp and ipp) and very little has changed. Am I missing something that changed between the two? I'm using Windows and Microsoft Visual Studio 2010 for both 1.49 and 1.55. Hopefully someone has an idea of where to look. Thanks. --- Aaron Wright

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[Graph] Caching Dijkstra results
by Sensei 14 May '14

14 May '14

Dear all, I need to find the shortest path from a node to another, and this operation will be performed several times with different source/destination nodes. In many cases, I would need the same source, so I was thinking about caching the results from Dijkstra. Sincerely, I don't know what I should cache. My initial thought is creating a hashmap with key being the source node, and value something that allows me to easily retrieve the path. What do you think I need to cache? Does it suffices to have a map from node index (std::size_t) to the node's predecessor map? Thanks & Cheers!

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[thread] pthread/once.cpp doesn't compile for iOS
by Igor R 14 May '14

14 May '14

I'm upgrading Boost in an iOS project form 1.53 to 1.55, and getting the following error: cc1plus: error in backend: Couldn't allocate input reg for constraint 'Q'! cc1plus: error in backend: Couldn't allocate input reg for constraint 'Q'! lipo: can't figure out the architecture type of: /var/folders/j1/9fz1wymd0xs91683nq8gzwhr0000gn/T//ccBue08f.out "/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/usr/bin/llvm-g++" -ftemplate-depth-128 -O3 -finline-functions -Wno-inline -Wall -pedantic -gdwarf-2 -fexceptions -isysroot /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS6.1.sdk -pthread -arch arm -Wextra -Wno-long-long -Wno-variadic-macros -Wunused-function -arch armv7 -arch armv7s -fpermissive -pedantic -DBOOST_ALL_NO_LIB=1 -DBOOST_ATOMIC_STATIC_LINK=1 -DBOOST_SYSTEM_STATIC_LINK=1 -DBOOST_THREAD_BUILD_LIB=1 -DBOOST_THREAD_DONT_USE_CHRONO -DBOOST_THREAD_POSIX -DNDEBUG -D_LITTLE_ENDIAN -I"." -c -o "bin.v2/libs/thread/build/darwin-6.1~iphone/release/architecture-arm/link-static/macosx-version-iphone-6.1/target-os-iphone/threading-multi/pthread/once.o" "libs/thread/src/pthread/once.cpp" Is it a known issue? Is there a workaround? Thanks.

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boost::geometry::model::linestring
by alev mutlu 13 May '14

13 May '14

Hi all, I have the following code. I can correctly print the content of line_smp with boost::geometry::dsv but get strange results when I copy line_smp into a vector and then print the content of the vector. Any ideas on what I am doing wrong? bg::model::d2::point_xy p; while(rs->next()){ bg::set<0>(p, i); bg::set<1>(p, rs->getDouble("num")); i++; line +=p; } boost::geometry::simplify(line, line_smp, 0.3); std::cout<< " original: " << boost::geometry::dsv(line) << std::endl << "simplified: " <<boost::geometry::dsv(line_smp) << std::endl; std::vector<xy> v; v.clear(); std::copy(line_smp.begin(), line_smp.end(), std::back_inserter(v)); stringstream sa, ssa; for(int ia = 0; ia < v.size(); ia++){ sa << bg::get<1>(v[i]); cout << sa; sa.str(""); }

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[boost] [mpl] Hard upper limit for range_c
by Javier Dehesa 13 May '14

13 May '14

I was testing for_each and range_c and I've discovered that there's a hard limit in the range_c template. I'm attaching an example (copied from the for_each docs http://www.boost.org/doc/libs/1_55_0/libs/mpl/doc/refmanual/for-each.html) to illustrate it. This program compiles fine for me (g++ 4.9.0), but if I set NUM to a number over 890, the compilation fails. I receive an error about template instantiation depth, so I guess I could tune it in the compiler to make it work. But, anyway, why is this template recursively defined? Is it on purpose? I get that maybe range_c was intended just for small ranges, but, is it the only way it can work? Also, it only allows for statically defined range limits. Also, whenever it compiles, the bigger the number you put, the longer it takes to compile. Thanks. -- Javier Dehesa

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geomety::within not compiling for model::box
by mark meijer 13 May '14

13 May '14

Is this not supported for box type? NOT_IMPLEMENTED_FOR_THIS_TYPES Thanks for having a look, Mark typedef boost::geometry::model::d2::point_xy<int16_t, boost::geometry::cs::cartesian> FrameCoord_t; typedef boost::geometry::model::box<FrameCoord_t> FrameBox_t; FrameBox_t box1; FrameBox_t box2; boost::geometry::assign_values(box1, 10, 10, 20, 20); boost::geometry::assign_values(box2, 0, 0, 100, 100); bool is_within = boost::geometry::within(box1, box2); 15>ClCompile: 15> Main.cpp 15>G:\work\software-external\libs\Boost\boost_1_51_0\boost/geometry/strategies/within.hpp(57): error C2664: 'boost::mpl::assertion_failed' : cannot convert parameter 1 from 'boost::mpl::failed ************(__thiscall boost::geometry::strategy::within::services::default_strategy<TagContained,TagContaining,CastedTagContained,CastedTagContaining,CsTagContained,CsTagContaining,GeometryContained,GeometryContaining>::NOT_IMPLEMENTED_FOR_THIS_TYPES::* ***********)(boost::mpl::assert_::types<T1,T2>)' to 'boost::mpl::assert<false>::type' 15> with 15> [ 15> TagContained=boost::geometry::box_tag, 15> TagContaining=boost::geometry::box_tag, 15> CastedTagContained=boost::geometry::box_tag, 15> CastedTagContaining=boost::geometry::areal_tag, 15> CsTagContained=boost::geometry::cartesian_tag, 15> CsTagContaining=boost::geometry::cartesian_tag, 15> GeometryContained=Media::DetectionBox_t, 15> GeometryContaining=Media::DetectionBox_t, 15> T1=Media::DetectionBox_t, 15> T2=Media::DetectionBox_t 15> ] 15> No constructor could take the source type, or constructor overload resolution was ambiguous 15> G:\work\software-external\libs\Boost\boost_1_51_0\boost/geometry/algorithms/within.hpp(285) : see reference to class template instantiation 'boost::geometry::strategy::within::services::default_strategy<TagContained,TagContaining,CastedTagContained,CastedTagContaining,CsTagContained,CsTagContaining,GeometryContained,GeometryContaining>' being compiled 15> with 15> [ 15> TagContained=boost::geometry::box_tag, 15> TagContaining=boost::geometry::box_tag, 15> CastedTagContained=boost::geometry::box_tag, 15> CastedTagContaining=boost::geometry::areal_tag, 15> CsTagContained=boost::geometry::cartesian_tag, 15> CsTagContaining=boost::geometry::cartesian_tag, 15> GeometryContained=Media::DetectionBox_t, 15> GeometryContaining=Media::DetectionBox_t 15> ] 15> FrameProcessorVideoIq.cpp(357) : see reference to function template instantiation 'bool boost::geometry::within<Media::DetectionBox_t,Media::DetectionBox_t>(const Geometry1 &,const Geometry2 &)' being compiled 15> with 15> [ 15> Geometry1=Media::DetectionBox_t, 15> Geometry2=Media::DetectionBox_t 15> ] 15>G:\work\software-external\libs\Boost\boost_1_51_0\boost/geometry/strategies/within.hpp(57): error C2866: 'boost::geometry::strategy::within::services::default_strategy<TagContained,TagContaining,CastedTagContained,CastedTagContaining,CsTagContained,CsTagContaining,GeometryContained,GeometryContaining>::mpl_assertion_in_line_40' : a const static data member of a managed type must be initialized at the point of declaration 15> with 15> [ 15> TagContained=boost::geometry::box_tag, 15> TagContaining=boost::geometry::box_tag, 15> CastedTagContained=boost::geometry::box_tag, 15> CastedTagContaining=boost::geometry::areal_tag, 15> CsTagContained=boost::geometry::cartesian_tag, 15> CsTagContaining=boost::geometry::cartesian_tag, 15> GeometryContained=Media::DetectionBox_t, 15> GeometryContaining=Media::DetectionBox_t 15> ] 15>G:\work\software-external\libs\Boost\boost_1_51_0\boost/geometry/algorithms/within.hpp(285): error C2039: 'type' : is not a member of 'boost::geometry::strategy::within::services::default_strategy<TagContained,TagContaining,CastedTagContained,CastedTagContaining,CsTagContained,CsTagContaining,GeometryContained,GeometryContaining>' 15> with 15> [ 15> TagContained=boost::geometry::box_tag, 15> TagContaining=boost::geometry::box_tag, 15> CastedTagContained=boost::geometry::box_tag, 15> CastedTagContaining=boost::geometry::areal_tag, 15> CsTagContained=boost::geometry::cartesian_tag, 15> CsTagContaining=boost::geometry::cartesian_tag, 15> GeometryContained=Media::DetectionBox_t, 15> GeometryContaining=Media::DetectionBox_t 15> ] 15>G:\work\software-external\libs\Boost\boost_1_51_0\boost/geometry/algorithms/within.hpp(291): error C2955: 'boost::type' : use of class template requires template argument list 15> G:\work\software-external\libs\Boost\boost_1_51_0\boost/type.hpp(14) : see declaration of 'boost::type' 15> 15>Build FAILED. 15>

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DateTime library - how to count "working days"?
by qplace 13 May '14

13 May '14

I need to find a day that stands 30 working days from a specific date, ignoring holidays. Currently I am doing it like this: boost::gregorian::date lastdate; int maxdays(30); for (int i = maxdays; i != 0; --i) { // skip weekends gregorian_calendar::day_of_week_type dow = lastdate.day_of_week(); while ( (dow == Sunday ) || (dow == Saturday) ) { lastdate -= boost::gregorian::date_duration(1); dow = lastdate.day_of_week(); } lastdate -= boost::gregorian::date_duration(1); } I did not find the iterator that can do it cleaner, but may be there is one? Thanks.

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date_time output facet question
by Erik Türke 13 May '14

13 May '14

Hi all, i am trying to find out how to use date time output facet on a format like "%m-%d %T [%module:%level] %message" in a way that i get the date_time and the residual format ([%module:%level] %message). At the moment i am just getting the date and time without the rest of the format. Is there any chance to achieve that? Thanks in advance!

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date time output facet question
by Erik Türke 13 May '14

13 May '14

Hi all, i am trying to find out how to use date time output facet on a format like "%m-%d %T [%module:%level] %message" in a way that i get the date_time and the residual format ([%module:%level] %message). At the moment i am just getting the date and time without the rest of the format. Is there any chance to achieve that? Thanks in advance!

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Boost.Log - textual format with severity
by Keith Bennett 12 May '14

12 May '14

Hello! I'm new to boost log (like many others, I imagine since it's only a relatively new library). I'm trying to specify a format textually (eg, keywords::format = "blahblah", instead of using a compiled expression). The idea is that the format can be reconfigured easily either through a command line parameter or through the configuration file without needing to recompile. However, it seems that anything specifying %Severity% when using a custom severity_level enum will simply not be output at all. Take the example from libs/log/example/keywords/main.cpp Simply changing line 86 to be: logging::add_console_log(std::clog, keywords::format = "%Severity% %TimeStamp%: %_%"); will exhibit the problem I believe I am trying to resolve. My suspicion is that the core doesn't know about the custom Severity attribute because it hasn't been registered and so is unable to parse %Severity% to any formatter. In contrast, the add_file_log below that does correctly output the severity level because it uses a compiled expression and is therefore able to deduce what needs to be done (am I correct in that assumption)? I seem to be unable to add an attribute to resolve this without rolling my own attribute class. How do I add an attribute or formatter related to the Severity which was declared with BOOST_LOG_ATTRIBUTE_KEYWORD? I think it's worth noting that if I remove the template parameter to severity_logger on line 123 so that it matches thus: src::severity_logger< > slg; It then devolves into a standard int instead of an enum and the output is "correctly" seen -- as an int and not as a human-readable string. While this is okay for now, I would of course want it to be human-readable if possible. This is as it is in the example in libs/log/example/settings_file/main.cpp. Any help would be appreciated. -- This message contains confidential information and is intended only for the individual named. If you are not the named addressee you should not disseminate, distribute or copy this e-mail. Please notify the sender immediately by e-mail if you have received this e-mail by mistake and delete this e-mail from your system. If you are not the intended recipient you are notified that disclosing, copying, distributing or taking any action in reliance on the contents of this information is strictly prohibited.

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Re: [Boost-users] [RFC] Modern CORBA C++ IDL Mapping and implementation
by Felipe Magno de Almeida 12 May '14

12 May '14

Sorry if this ends up duplicate. But I've sent it to the developer's list and it came back. Hello Boosters, Where I work we are implementing an open source, modern, CORBA implementation and IDL mapping. We want it to support C++ and C++11 IDL mapping, but we also want to create another IDL mapping. This new IDL mapping is being experimentated in the following url https://github.com/expertisesolutions/mORBid/tree/concepts It still has some very problematic issues (like compilation-time of generated code) and of course it is still far from completion. But, we would like to hear suggestions about this approach. What we did was that an IDL interface is mapped to a typedef for boost::type_erasure (I found the idea quite cool for the reasons that I'll mention below) with the requirements defined in the IDL, e.g. its operations. The IDL also emits a model for this type_erasure which is the actual stub class and is called remote_reference. It also emits a proxy_reference model for the same type_erasure typedef which receives a std::reference_wrapper and proxies the calls, this is needed because type_erasure can't switch between by-reference and by-value in runtime. Why I believe this approach is better than current IDL to C++11 mapping: Because the IDL to C++11 mapping is too intrusive. You can't really use normal classes you have written for use as servants in CORBA because you have to inherit from Skeletons classes *and* you have to use the *exact* same signature as defined in the mapping. This is *way too restricted*. This is also inerent to the OO paradigm that CORBA uses. But, we can mimic the same features using type-erasure instead of directly using dynamic polymorphism. This gives a much greater freedom to users. It might be that Boost.type_erasure is not the best tool here because of compile-time and compiler memory usage, but the idea surely is. We still haven't seriously profiled boost.type_erasure yet, but we will do so as soon as possible. I think it might be very interesting to experiment with lite concepts and Boost.concept_check as well. Also, we created a EDSL for GIOP and IIOP mapping based on the boost.spirit infrastructure. We use that to treat alignment and endianness automatically and to use the same grammar for generation and parsing of IIOP messages. The message header grammar is defined like this: start = "GIOP" & octet('\1') /* GIOP major version */ & octet('\0') /* GIOP minor version */ & endianness [ octet(MessageType) /* message_type */ & raw_size(ulong_)[body] ] ; Which is compiled to IIOP parser or generator through boost.spirit infrastructure of make_terminal, make_directive and etc. This works splendid well and is really easy to use, extend, is statically checked and has great performance. Whoever feel interested, please take a look and comments are highly appreciated. Regards, -- Felipe Magno de Almeida

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boost 1.55 build / install on OSX - why are aliases used instead of symlinks?
by Colby Boles 08 May '14

08 May '14

I recently installed and built boost 1.55 on an OSX machine of mine. With my current make system for my app (qmake) I needed to specify where the lib and include directories for boost were and thought the best thing to do would be to set them to \usr\local\lib \usr\local\include where I can see in the lib case there are links to the various library modules and in the include case there is a link to the boost include directories. The problem is that the boost installation makes these links using aliases instead of symlinks, so everything appears fine browsing in the Finder, but at the command line, the compiler can't see these directories. I'm able to change the aliases to symlinks, or point to the actual boost directories (e.g. \usr\local\Cellar\boost\1.55.0_1\*) and everything works, but it seems like the intention was to have symlinks at \usr\local\lib and \usr\local\include so that one can just point to these places and be version agnostic? Thanks, Colby

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Check if a type has a member function (inhrited member functions also) with Boost TTI
by Hijok Payne 08 May '14

08 May '14

Boost TTI has very convenient macros for checking if a type has a member function. See http://www.boost.org/doc/libs/1_55_0/libs/tti/doc/html/the_type_traits_intr… If I have not missing something BOOST_TTI_HAS_MEMBER_FUNCTION returns false for inherited member functions. Is there a convenient Boost solution for doing this? There is a SO<http://stackoverflow.com/questions/1966362/sfinae-to-check-for-inherited-me…> solution based on SFINAE. But I would like to avoid that and would prefer a Boost solution, since that way I am more sure it works on more compilers and I want avoid maintaining code for each such specific behavior.

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boost tti has_member_function
by Matei David 08 May '14

08 May '14

I'm trying to use boost tti has_member_function to test if a user-specified allocator has the expected methods. However, this fails with standard allocators. #include <iostream> #include <memory> #include <boost/tti/has_member_function.hpp> BOOST_TTI_HAS_MEMBER_FUNCTION(deallocate) typedef std::allocator< int > T; int main() { std::cout << has_member_function_deallocate< void (T::*) (T::pointer, T::size_type) >::value << "\n"; } I tried gcc-4.8.2 and clang-3.4. I'm compiling with: {g++|clang++} -std=c++11 -I${BOOST}/include -Wall -Wextra -pedantic -Wno-ignored-qualifiers -g3 -O0 In both cases, I get a 0. However, using "-E" and grep-ing for "\<deallocate\>", I see this signature: void deallocate(pointer __p, size_type) Shouldn't I be getting a 1? Am I using it the wrong way? Thanks

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