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[future] Confused about the represents in Doc "boost::future"
by Cheng Mo 17 Feb '15

17 Feb '15

Hi all : I got confused in Doc of boost :: futures and I can't got the point of sort of terms. The represents in Overvies of Futures like " Instances can be freely copied and assigned, and boost::shared_future<R>::get() returns a non const reference so that multiple calls to boost::shared_future<R>::get() are safe." no doubt that a const reference .... are safe. a non const reference could be changed by external stimuli. isn't ? Or the key is "Instances can be freely copied" , so that we can say "are safe"? Cheer~ Martin

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[program options] examples where?
by U.Mutlu 16 Feb '15

16 Feb '15

In the online documentation tutorial there are multiple times mentioned references to the examples page. But where are these examples exactly located? On the documentation pages I couldn't find a link to the examples page. Do I need to install the complete boost developer version locally to get to the examples? -- cu Uenal

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[program options] an alternative for "add_options()" avail?
by U.Mutlu 15 Feb '15

15 Feb '15

Hi, I'm newbie to 'program options'. I just wanted to ask if there is an alternative for the below example from the online-doc: desc.add_options() ("help", "produce help message") ("compression", po::value<int>(), "set compression level") ; I would like to have something more traditional like the following single element addition alternative: desc.add_option("help", "produce help message"); desc.add_option("compression", po::value<int>(), "set compression level"); Is something like this already in the library? -- TIA Uenal

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meta state machine, process_event need to copy given event
by SBAM 13 Feb '15

13 Feb '15

Hello Christophe, I'm a boost msm first time user and I'm attempting to pass an event to my msm that cannot be copied. This event contains a /unique_ptr/ and my goal is to eventually steal it and store it under my msm. However, even with no deferred events, events are /copied/ to an internal queue, in /boost::msm::back::state_machine::do_pre_msg_queue_helper/. I just wanted to know if there was any chance /process_event/ could be overloaded and accept rvalue-ref or if by design, it's absolutely mandatory to copy those events. Many thanks for your great library -- View this message in context: http://boost.2283326.n4.nabble.com/meta-state-machine-process-event-need-to… Sent from the Boost - Users mailing list archive at Nabble.com.

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Performance optimization in Boost using std::vector<>
by saloo 13 Feb '15

13 Feb '15

Hello everybody, I have a question related to performance optimization using Boost. I found this link http://www.boost.org/doc/libs/1_41_0/doc/html/mpi/performance.html <http://www.boost.org/doc/libs/1_41_0/doc/html/mpi/performance.html> and trying to figure out which curve (on the graph in the link) represents the communication of std::vector<int> and std::vector<double>? Is communication using std::vector<int> and std::vector<double> optimized (is_mpi_datatype) or not? So I use "boost_mpi" and "boost_serialization" libraries. I include the header "#include <boost/serialization/vector.hpp>" in my code. Then I send directly std::vector<int> and std::vector<double> using "world.send(...) " and world.recv(...)" calls. I fill the vector with some values (for example I fill ten values) and I get the same ten values on other side of processor boundary. This thing works but I want to improve communication performance. I found out in this link http://www.boost.org/doc/libs/1_57_0/doc/html/mpi/tutorial.html under section "User-defined data types" that "Fixed data types can be optimized for transmission using the is_mpi_datatype type trait. ". Also I studied the information on http://www.boost.org/doc/libs/1_57_0/doc/html/mpi/tutorial.html#mpi.perform…. Also this link http://www.boost.org/doc/libs/1_46_1/libs/serialization/doc/wrappers.html#a… shows that std::vector<> are optimized for serialization. I am now confused that sending std::vector<> like this is good for performance optimization or not? What other better methods are available? Is something like this http://www.boost.org/doc/libs/1_57_0/doc/html/mpi/tutorial.html#mpi.skeleto… a good option? Best Regards, Salman Arshad -- View this message in context: http://boost.2283326.n4.nabble.com/Performance-optimization-in-Boost-using-… Sent from the Boost - Users mailing list archive at Nabble.com.

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Min cut between two vertices, undirected graph
by Mads Jensen 12 Feb '15

12 Feb '15

Hi, The Stoer Wagner implementation only takes as input a complete graph, and then it computes the min cut with the parity map indicating which cut set the vertex belongs to. I need something for computing the minimum cut between two arbitrary vertices given as input for an undirected graph. Edmonds Karps works just for a directed graph. Any help with this will be highly appreciated. -- Med Venlig Hilsen / Kind regards, Mads Jensen Max Jerry Horovitz: "Unfortunately, in America, babies are not found in cola cans. I asked my mother when I was four and she said they came from eggs laid by rabbis. If you aren't Jewish, they're laid by Catholic nuns. If you're an atheist, they're laid by dirty, lonely prostitutes." -- Mary and Max (2009)

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Which URL should I use in ExternalProject_Add
by Yi-Hong Lyu 12 Feb '15

12 Feb '15

Hello all, I used CMake's ExternalProject_Add to download and build boost in my project. The URL I used is ' http://sourceforge.net/projects/boost/files/boost/1.55.0/boost_1_55_0.zip/d…' and it works. However I got an error several days ago like: CMake Error: Problem with archive_read_open_file(): Unrecognized archive format It seems that what I download by CMake becomes 'HTML document, ASCII text' rather than 'Zip archive data, at least v2.0 to extract'. Could you tell me which URL should I use in ExternalProject_Add? Thanks, Yi-Hong

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boost iOS8 failure
by David Medine 11 Feb '15

11 Feb '15

First of all, I know that calls for help are not appropriate to the list, so let me disclaim by saying that I am not asking for help, simply reporting an issue. I am attempting to compile a C++ library (that uses boost) for iOS8 distribution. The library compiles fine on OSX (and Linux and Windows) but will not compile for iOS8. I get dozens of compiler complaints regarding boost headers that all involve some sort of 'Semantic Issue'. For example, in boost's hash.hpp, I get a 'No matching function for call to 'has_value' error on these lines (439-442): | BOOST_HASH_SPECIALIZE_REF(std::string) #if !defined(BOOST_NO_STD_WSTRING) BOOST_HASH_SPECIALIZE_REF(std::wstring) #endif | In this case I was able to skirt the issue by adding code to define the function hash_value for std::string and std::wstring: inline std::size_t hash_value( std::string const &v) { return hash_range(v.begin(), v.end()); } inline std::size_t hash_value( std::wstring const &v) { return hash_range(v.begin(), v.end()); } I am probably going to go through all such failures of clang to interpret the boost code correctly for iOS compilation and modify the source just so I can get this going. This is a major pain because there are dozens of these, many of which are far less straightforward to remedy. Besides I don't necessarily want a custom version of boost that ships with my library. I have the build settings in my iOS project (I'm using XCode) exactly the same as they are in the OSX project. I don't understand why the compiler behaves differently for these two targets. Finally, there are two stackoverflow questions that I posted related to this problem. http://stackoverflow.com/questions/28422862/clang-different-when-compiling-… http://stackoverflow.com/questions/28308466/ios8-boost-hash-hpp-system-cloc… THX!

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[gsoc15] Google Summer of Code 2015 ideas needed before 20th Feb
by Niall Douglas 11 Feb '15

11 Feb '15

Dear Boost community, The Google Summer of Code 2015 organisation application period has begun. We need project ideas for our ideas page at https://svn.boost.org/trac/boost/wiki/SoC2015, plus anyone willing to mentor. Last year we got eight slots, the previous year seven slots. Let's try to get back to ten slots for 2015! Niall & Boris --- Boost C++ Libraries Google Summer of Code 2015 admin https://svn.boost.org/trac/boost/wiki/SoC2015

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Problems/crash update a Spirit grammar from Boost 1.47 to 1.57
by Christoph Duelli 11 Feb '15

11 Feb '15

Updating Boost from 1.47 to 1.57 the code no longer compiles. It boils down to Both these includes are included (at various places) and these 2 lines compiled in 1.47 but no longer under 1.57. #include <boost/spirit/home/qi.hpp> #include <boost/spirit/home/phoenix.hpp> Changing #include <boost/spirit/home/phoenix.hpp> to #include <boost/phoenix.hpp> the code does compile, but causes crashes while parsing. (I was not able yet to narrow that down.) Is the correct way of porting a 1.47 boost spirit grammar to 1.57, to replace the old phoenix V2 header to #include <boost/phoenix.hpp> ? (Are there known issues? Or is there a "porting howto"?) Or is it still possible to use Spirit with Phoenix V2? Best regards -- Christoph Duelli --------------------------------------------------------------------------------- MELOS-Medizinische Labor-Organisations-Systeme GmbH Franz-Beer-Straße 6 86459 Gessertshausen Tel.: +49 8238/9611-0 Fax: +49 8238/9611-99 mailto: info(a)melosgmbh.de URL: www.melosgmbh.de Amtsgericht Augsburg, HRB 13226 USt-IdNr. DE 130 958 139 Geschäftsführer: Herbert Mayer, Andreas Manntz, Helmut Welsch -------------------------------------------- This e-mail (including any attachments) is confidential and may be privileged. If you have received it by mistake, please notify the sender by e-mail and delete it from your system. Any unauthorised use or dissemination of this e-mail or its contents in whole or in part is strictly prohibited. Please note that e-mails are susceptible to change. MELOS GmbH shall not be liable for the improper or incomplete transmission of the information contained in this communication nor for any delay in its receipt. MELOS GmbH does not guarantee that the integrity of this communication has been maintained nor that this communication is free of viruses, interceptions or interference.

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