January 2014 - Boost-users - lists.boost.org

Help compiling/linking boost example
by zaphod742 . 25 Jan '14

25 Jan '14

I installed boost-all-dev using apt-get on Ubuntu. I am trying to compile this example program of sync_client.cpp http://www.boost.org/doc/libs/1_45_0/doc/html/boost_asio/example/http/clien… I get this error .. $ sudo g++ sync_client.cpp -I usr/local/include/boost -L /usr/local/lib /tmp/ccaVkCWp.o: In function `__static_initialization_and_destruction_0(int, int)': sync_client.cpp:(.text+0xd61): undefined reference to `boost::system::generic_category()' sync_client.cpp:(.text+0xd6d): undefined reference to `boost::system::generic_category()' sync_client.cpp:(.text+0xd79): undefined reference to `boost::system::system_category()' /tmp/ccaVkCWp.o: In function `boost::system::error_code::error_code()': sync_client.cpp:(.text._ZN5boost6system10error_codeC2Ev[_ZN5boost6system10error_codeC5Ev]+0x17): undefined reference to `boost::system::system_category()' /tmp/ccaVkCWp.o: In function `boost::asio::error::get_system_category()': sync_client.cpp:(.text._ZN5boost4asio5error19get_system_categoryEv[boost::asio::error::get_system_category()]+0x5): undefined reference to `boost::system::system_category()' /tmp/ccaVkCWp.o: In function `boost::asio::detail::posix_tss_ptr_create(unsigned int&)': sync_client.cpp:(.text._ZN5boost4asio6detail20posix_tss_ptr_createERj[boost::asio::detail::posix_tss_ptr_create(unsigned int&)]+0x19): undefined reference to `pthread_key_create' /tmp/ccaVkCWp.o: In function `boost::asio::detail::posix_thread::~posix_thread()': sync_client.cpp:(.text._ZN5boost4asio6detail12posix_threadD2Ev[_ZN5boost4asio6detail12posix_threadD5Ev]+0x26): undefined reference to `pthread_detach' /tmp/ccaVkCWp.o: In function `boost::asio::detail::posix_thread::join()': sync_client.cpp:(.text._ZN5boost4asio6detail12posix_thread4joinEv[boost::asio::detail::posix_thread::join()]+0x2b): undefined reference to `pthread_join' /tmp/ccaVkCWp.o: In function `boost::asio::detail::posix_tss_ptr<boost::asio::detail::call_stack<boost::asio::detail::task_io_service>::context>::~posix_tss_ptr()': sync_client.cpp:(.text._ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_15task_io_serviceEE7contextEED2Ev[_ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_15task_io_serviceEE7contextEED5Ev]+0x15): undefined reference to `pthread_key_delete' /tmp/ccaVkCWp.o: In function `boost::asio::detail::posix_tss_ptr<boost::asio::detail::call_stack<boost::asio::detail::strand_service::strand_impl>::context>::~posix_tss_ptr()': sync_client.cpp:(.text._ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_14strand_service11strand_implEE7contextEED2Ev[_ZN5boost4asio6detail13posix_tss_ptrINS1_10call_stackINS1_14strand_service11strand_implEE7contextEED5Ev]+0x15): undefined reference to `pthread_key_delete' collect2: ld returned 1 exit status How can I solve this error?

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Fwd: [boost] Boost.Fiber review January 6-15
by Nat Goodspeed 23 Jan '14

23 Jan '14

SUMMARY The review of the proposed Boost.Fiber library ended on January 15, 2014. The verdict is: not in its present form. The lively discussions during the course of the review indicate considerable interest in this library, however, and every submitted review can be read as: perhaps, if certain changes are made. This produced a long list of suggestions, which constitutes the bulk of this report. On behalf of the Boost community, I would like to commend Oliver Kowalke for the work he has put into the Fiber library so far. I encourage him to continue to evolve this library and to bring it back for a mini-review. Rather than considering the subject library as a whole, a Boost mini-review zooms in on particular issues. That seems an appropriate tool to use for further evaluation of the Fiber library -- always subject, of course, to the approval of the Review Wizards. I received seven formal votes, abbreviated here: Niall Douglas: YES, IF Eugene Yakubovich: YES, AND Antony Polukhin: YES, IF Vicente J. Botet Escriba: NO, UNTIL Agustín K-ballo Bergé: NO, IN CURRENT STATE Hartmut Kaiser: NO, IN CURRENT FORM Thomas Heller: NO, IN CURRENT FORM I thank each of these reviewers, and indeed everyone who investigated the Fiber library and participated in the discussions. If you feel that I have misrepresented your position, or have omitted or garbled an important point, please respond: the archived mail thread should accurately reflect the will of the community, even if this message does not. >From the long list of suggestions, a few key themes emerged. PERFORMANCE Many respondents requested performance tests (specifics below). There were a number of suggestions about possible performance pitfalls in the current implementation, such as use of STL containers (with consequent heap allocations) and locks for thread safety. Several people suggested implementing performance tests *before* starting any such optimizations, which seems like sensible advice. Niall Douglas pointed out that picking some fixed number of fibers is less interesting than showing how resource consumption rises with the number of fibers: "I think it isn't unreasonable for a library to enter Boost if it has good performance *scaling* to load (e.g. O(log N)), even if performance in the absolute or comparative-to-near-alternatives sense is not great. "Absolute performance can always be incrementally improved later, whereas poor performance scaling to load usually means the design is wrong and you're going to need a whole new library with new API. "This is why I really wanted to see performance scaling graphs. If they show O(N log N) or worse, then the design is deeply flawed and the library must not enter Boost. Until we have such a graph, we can't know as there is no substitute for empirical testing." Given the truth of that last observation, I have recast certain suggested optimizations as requests for measured performance cost. Performance requests include: - empty function (create, schedule, execute, delete one fiber) - same with one yield - overhead of using a future object - tests as described in [1]; such tests should allow comparing with TBB, qthreads, openmp, HPX - construct and join a single fiber vs. construct and join a single thread (empty function) - construct and join several fibers vs. construct and join several threads (empty function) - construct and detach a single fiber vs. construct and detach a single thread (empty function) - cost of STL containers (std::vector, std::map, std::deque) - cost of fiber interruption support (same as next bullet?) - cost of thread safety: intra-thread fibers vs. inter-thread fibers - cost of round_robin_ws vs. round_robin scheduler - cost of building on Coroutine vs. building on Context Once Fiber performance tests are available, I trust the community will assist Oliver in running them on systems otherwise unavailable to him. There was some disagreement on whether it is essential for the Fiber library to attain a certain level of performance before it should be accepted. Respondents fall into two broad camps. Some see fibers as lightweight threads (without the overhead of kernel context switching). They assert that since the API is that of std::thread, the only reason to accept a separate library would be astounding performance. They note that on some hardware it is already plausible to run hundreds of thousands of concurrent std::threads. Others see fibers as a tool for organizing code based around asynchronous operations (rather than chains of callbacks). They assert that for such purposes, eliminating the kernel from context switching is sufficient performance guarantee. I myself maintain that cooperative context switching provides important functionality you cannot reasonably get from std::thread. The Fiber library attempts to address both use cases. (It was suggested that if its primary target were code organization, perhaps it should be renamed something other than "Fiber.") In any case, the community clearly wants to see Fiber performance data. Some requested CPU cycles to eliminate clock speed differences, also memory consumption. ARMv7 data was requested for "extra bonus points." DOCUMENTATION Many respondents requested additional documentation, or clarifications. Requests include: - Rationale page explaining what's there, what's not and why. Explain distinction between Coroutine library and Fiber library. If certain Fiber functionality is intended to support yet another library (rather than being complete in itself), call out what would need to be added. - A section on how to install and run the tests and examples. The need to embed in a Boost tree is implied but not stated. Mention the need to build the library and link with it. - Explain synchronization between fibers on different threads. Must the code take more care with this than with synchronizing fibers on the same thread? - Clarify that an exception raised by a fiber function calls std::terminate(), as with std::thread, rather than being consumed. - More clearly explain migrating a fiber from one scheduler to another. - Document async() in a way compatible with the C++ standard. - Clarify thread-local effect of set_scheduling_algorithm(). There was a request to put this function in a this_thread nested namespace to further clarify. - Move algorithm class documentation to "Extension" or "Customization" section. Clarify that it's not part of the baseline library functionality, but a customization point. - Document fiber::id. - Better document promise/future for void and R& (per C++ standard). - Document thread safety of each support class (or method, if it varies by method). - Document complexity guarantees per API. - Document exception safety per API. - Document supported architectures (perhaps link to Coroutine library's list); state minimum compiler versions. - Document the get/set overloads of thread_affinity() and priority() separately. Perhaps rename setters to set_thread_affinity() and set_priority(). - Explain how portable is fiber priority, if it's specific to a scheduler. What does priority mean when you migrate a fiber from one thread (one scheduler instance) to another? - Document the library's ASIO support. Link to Coroutine's ASIO yield functionality; ensure that ASIO yield is adequately explained. In particular, distinguish it from this_fiber::yield. - Better explain (and/or comment) publish-subscribe example, also other existing examples. In addition to the documentation requests above, there were requests for additional examples: - Simple example of ASIO callback implementation vs. the same logic using Fiber's ASIO support, a la [4]. - Example of a fiber pool. - Example of an arbitrary thread B filling a future on which a fiber in thread A is waiting. - Example of an arbitrary thread B posting to an asio::io_service running fibers in thread A. - Either defend fibers::condition_variable from spurious wakeups in existing examples, OR document the stronger condition_variable guarantee. - Example of M:N threading with ASIO. That might involve either one io_service per CPU, with fiber migration; or a single io_service with run() calls from each CPU, grouping fibers for each CPU into strands. - Example of one thread with many fibers making service requests on a pool of worker threads performing blocking calls. - Example of using thread_specific_ptr to manage lifespan of user-specified scheduler. - Example of the owner of a fiber changing the fiber's thread affinity vs. the fiber itself. When would you use each tactic? - Load example programs into an Examples appendix so that Google searches can turn up library documentation. LIBRARY API - Four people overtly approved the close parallel with std::thread and its support classes. - Allocating a default scheduler object, rather than specifying a default template param, was praised. - Three people called out the set difference between Boost.Thread features and Fiber (e.g. future::get_exception_ptr()). One wants these implemented immediately; another says they can be added later; the third simply requests that they be documented, with rationale. - Two people frowned on introducing operator bool methods not found in std::thread or Boost.Thread. - C++11 support was mentioned, notably Boost macros such as BOOST_RV_REF and BOOST_EXPLICIT_OPERATOR_BOOL. Also mentioned were: C++11 idioms; C++11 std::thread patterns; move construction; initializer lists; rvalue this overloads; deleting operators. - The fiber constructor and async() should accept a move-only callable. - At least for a C++11 compiler, fiber constructor and async() should accept variadic parameters. These should support move-only types, like Boost.Thread. C++03 support for variadic parameters would be nice, but is less important. - Every API involving time point or duration should accept arbitrary clock types, immediately converting to a canonical duration type for internal use. - Queues should support value_pop() returning item by value. This supports an item type without a default constructor. - Nested scoped_lock typedef has been deprecated in thread library. Remove in Fiber library. - Align the return type of shared_future::get() with the standard. In general, ensure that parameter types and return types are aligned with the standard. - A couple of people were bothered by the use of types in the detail namespace as parameters or return values in the algorithm API. (I note, however, that extending e.g. Boost.Range can involve touching its detail namespace. A customization point for a library may be a bit of a gray area.) - There was a suggestion to rename algorithm to scheduler. In that case, presumably set_scheduling_algorithm() could be renamed set_scheduler(). - There was a request to rename round_robin_ws to round_robin_work_stealing. - A couple of people consider the algorithm API too monolithic, pointing to redundancies in the round_robin, round_robin_ws and asio round_robin implementations. They suggested teasing out distinct classes, so that (for instance) a user-coded scheduler might be able to override a single method to respect fiber priority. In fact Eugene Yakubovich offered to experiment with refactoring the algorithm class this way. - There was a request for set_scheduling_algorithm() to return the previous pointer. (It might be useful for the requester to explain the anticipated use case. An earlier iteration of set_scheduling_algorithm() did return the previous pointer; Oliver intentionally changed that behavior.) - fiber_group got one thumbs-up and two thumbs-down. Options: retain; improve to use move support rather than fiber*; discard. There is an opportunity to improve on thread_group; naturally there is risk in diverging from thread_group. - Request deferred futures for lazy evaluation. - There was a suggestion to introduce a global object to coordinate thread-specific fiber schedulers, in the hope that the global object could perform all relevant locking and the thread-specific fiber schedulers could themselves be thread-unsafe. - There was a request to unify steal_from() and migrate_to() into a single method. I infer that this is predicated on the previous suggestion. - Request future::then() et al, per [5]. (Someone please clarify the present status of N3784?) - Request enriched barrier support per [6] and [7]. (Someone please clarify the present status of N3817?) - There are two fiber properties specific to particular schedulers: thread_affinity (used only by round_robin_ws) and priority (as yet unused by any scheduler). What if a user-coded scheduler requires a fiber property that does not yet exist? Is there a general approach that could subsume the present support for thread_affinity and priority, in fiber and this_fiber? Could the initial values for such properties be passed as part of the fiber constructor's attributes parameter? - One use case was surfaced that may engage the previous bullet: the desire to associate a given fiber with any of a group of threads, such as the set of threads local to a NUMA domain or physical CPU. IMPLEMENTATION - Replace std::auto_ptr with boost::scoped_ptr. The former produces deprecation warnings on GCC. - Reduce redundancy between try_lock() and lock(). - boost::fibers::asio::detail::yield_handler::operator()() calls algorithm::spawn() before algorithm::run(). Does this allow the scheduler to choose the next fiber to run, e.g. a user-coded scheduler that respects fiber priority? - Add memory transaction support to spinlock a la [8]. - Intel TSX lock avoidance would be nice. LINKS [1] https://github.com/STEllAR-GROUP/hpx/tree/master/tests/performance [2] http://stellar.cct.lsu.edu/pubs/isc2012.pdf [3] http://stellar.cct.lsu.edu/pubs/scala13.pdf [4] https://ci.nedprod.com/job/Boost.AFIO%20Build%20Documentation/Boost.AFIO_Do… [5] http://www.open-std.org/JTC1/SC22/WG21/docs/papers/2013/n3784.pdf [6] http://www.boost.org/doc/libs/1_55_0/doc/html/thread/synchronization.html#t… [7] http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2013/n3817.html#barrier_… [8] https://github.com/BoostGSoC/boost.afio/blob/master/boost/afio/detail/ Nat Goodspeed Boost.Fiber Review Manager ________________________________

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[Graph] initialize_vertex change vertex color (visitor)
by The Maschine 23 Jan '14

23 Jan '14

Hi all, I would like to build a visitor (for dikstra) with the initialise_vertex acting as 'colour map' modifier. I want to exclude some vertices from the search based on a condition. So I want to set some vertices 'black' in the init part of the algorithm. class dijkstra_2step : public boost::default_dijkstra_visitor { public: dijkstra_2step(std::vector<Weight> dists, double threshold): distances(dists), threshold(threshold) {} // THIS PART IS NOT CORRECT!!!! // void initialize_vertex(boost::graph_traits <unGraph>::vertex_descriptor u, const unGraph& g){ if( distances[u] > threshold ) color[u] = black; // ?????? } ////////// std::vector<Weight> distances; double threshold; }; Any help for the above visitor? How to I access the colour? I couldn't find something online. Thanks

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[qi::phrase_parse] how to retain minus as string
by Uthpal Urubail 23 Jan '14

23 Jan '14

I am trying to store minus as the string in the key. I think its getting conflict with to(a-z) symbol key = +qi::char_(".a-zA-Z0-9") | qi::lexeme[('[' >> +qi::char_("@ + - * . ( , ) $ a-zA-Z0-9 ") >> ']')]; value = +qi::char_("a-zA-Z0-9") ; I have the string like below: std::string input = “[(@vala - @valb) * @valc]:real"; Can someone help me to resolve this? Regards, UJ

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Build boost using CMake
by Chameera Wijebandara 23 Jan '14

23 Jan '14

Hi, I am new to the Boost. And I have to build Boost libraries with CMake. Any Suggestions? -- Thanks, Chameera

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Server failing when BOOST_ASIO_ENABLE_HANDLER_TRACKING is active
by Gonzalo Garramuno 22 Jan '14

22 Jan '14

Trying to track down when the socket closes on my program, I turned on asio debugging. Server fails when BOOST_ASIO_ENABLE_HANDLER_TRACKING is active. Its stack trace is: g Scanning dependencies of target mrViewer [ 9%] Building CXX object mrViewer/src/CMakeFiles/mrViewer.dir/core/mrvServer.o Linking CXX executable ../../../bin/mrViewer [100%] Built target mrViewer # gga@gga-laptop1 /media/Linux/code/applications/mrViewer # mar ene 01 10:04 [8] $ mrViewer /media/Linux/movies/Tangled.mov [opengl] Using hardware shader profile: NVidia NV30 [opengl] mrViewer supports YUV images through shaders. [psql] Connected to database 'assets2d_development'. The code: boost::asio::io_service io_service; tcp::endpoint listen_endpoint(tcp::v4(), s->port); server rp(io_service, listen_endpoint, s->ui); io_service.run(); fails with: @asio|1357088683.200673|0|socket@0x7f303d8d2d00.close Got signal 11, faulty address is 0x1, from 0x4d222a [bt] Execution path: [bt] mrViewer(_ZN5boost4asio6detail15task_io_service16shutdown_serviceEv+0x3a) [0x4d222a] [bt] mrViewer(_ZN5boost4asio6detail15task_io_service16shutdown_serviceEv+0x3a) [0x4d222a] [bt] mrViewer() [0x4dd2c9] [bt] mrViewer(_ZN3mrv13server_threadEPKNS_10ServerDataE+0x408) [0x4e0e58] [bt] /usr/lib/libboost_thread.so.1.48.0(+0xdda9) [0x7f304e191da9] [bt] /lib/x86_64-linux-gnu/libpthread.so.0(+0x7e9a) [0x7f304f7f0e9a] [bt] /lib/x86_64-linux-gnu/libc.so.6(clone+0x6d) [0x7f304da1ccbd] without the #define the code works reliably except sometimes the socket closes unexpectedly.

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Re: [Boost-users] Interprocess: rbtree_best_fit ABI change from 1.53 to 1.55 ?
by Arunski, Kevin 22 Jan '14

22 Jan '14

> El 22/01/2014 16:14, Arunski, Kevin escribió: > > Hello, I have been using a boost::interprocess::map stored in a > > managed mapped file segment, using the rb_best_fit allocation > > algorithm. > > > > I have observed that starting in boost 1.55, I cannot interoperate > > with instances of this allocator that were created by programs > > compiled by boost 1.53. > > > > It appears that the size of a boost::intrusive multiset object has > > changed, and this changes the representation of the rb_best_fit > > algorithm within the shared memory region. > > Sorry about that. That must be a bug. Can you tell me please the sizes > you get in both versions? Sure. In code compiled with boost 1.53, this type: boost::interprocess::rbtree_best_fit<boost::interprocess::null_mutex_family,boost::interprocess::offset_ptr<void,__int64,unsigned __int64,0>,0> has size = 56 member m_header.m_imultiset has size 32 In code compiled with boost 1.55: the same type has size = 72 member m_header.m_imultiset has size 48

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Interprocess: rbtree_best_fit ABI change from 1.53 to 1.55 ?
by Arunski, Kevin 22 Jan '14

22 Jan '14

Hello, I have been using a boost::interprocess::map stored in a managed mapped file segment, using the rb_best_fit allocation algorithm. I have observed that starting in boost 1.55, I cannot interoperate with instances of this allocator that were created by programs compiled by boost 1.53. It appears that the size of a boost::intrusive multiset object has changed, and this changes the representation of the rb_best_fit algorithm within the shared memory region. The toolchain is unchanged between the two programs, in both cases it is Visual Studio 2012 on x64, linked against the release runtime library. The only change is that one was compiled using boost 1.53, while the other was compiled with boost 1.55. Is this the expected behavior? Is there a way to utilize boost interprocess in this way with reasonable certainty that the shared memory representation of it will not change between boost releases?

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vector clock
by Kenneth Adam Miller 22 Jan '14

22 Jan '14

Does boost have either a vector clock or lamport clock of any kind?

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boost multiprecision & STL map - resubmit
by tridiak＠ihug.co.nz 21 Jan '14

21 Jan '14

Ok. Better framed question. The following is compiled on XCode 5.0.1. Clang : Apple LLVM version 5.0 (clang-500.2.79) (based on LLVM 3.3svn) Target: x86_64-apple-darwin12.5.0 Thread model: posix Boost v 1.55.0. Build 2.0-m12. Not sure how to fix it. map complains about constructor ambiguity and I am not sure how to fix it. I am a casual hobbyist programmer and not a C++ expert. Looking at boost headers confuses me. Any help would be appreciated. //--------------------------------------------------------------------- Header File #ifndef boostTest_test_h #define boostTest_test_h #include #include #include using namespace boost::multiprecision; typedef std::map TestMap; #endif //------------------------------------------------------------------------- C++ file #include #include "test.h" int main(int argc, const char * argv[]) { static TestMap tm; std::string s="hello"; int128_t n=128; tm[n]=s;

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odeint - solving an ODE with time-dependent parameter numerically
by Arijit Hazra 21 Jan '14

21 Jan '14

Hello All, I am trying to solve an ode with time-dependent parameters by using boost. I have just started using boost and I think boost library's odeint library is the best option for my problem. Would anyone please explain me how I can solve a Initial Value Problem --a system of ODE --with a time-dependent parameter. e.g. dy1/dt = a1(t) * y2 -b1(t)* y3 -c1(t) y1; dy2/dt = a2(t) * y1 -b2(t)* y1 -c2(t) y3; dy3/dt = a3(t) * y2 -b3(t)* y3 -c3(t) y1; y(0)=c; My idea so far after going through the manuals and help files. is that for fixed time-step if I form a vector of a,b,c and assume a,b,c to be constant over that time-period I can solve using boost library. But this is mathematically less accurate and computationally expensive as far my understanding .For solving an ODE numerically *y*˙(*t*)=*f*(*y*(*t*), *t*) generally the problem is all about function evaluation for explicit methods and Jacobian evaluation for Implicit methods at specific points in *t* and *y*. e.g a step of explicit Euler is *yn*+1=*yn*+(*tn*+1−*tn*)⋅*f*(*yn*,*tn*). For time-dependent parameter, treating it as part of *f*, the function evaluation (respectively, for implicit methods, also treat it as part of the Jacobian evaluation) is the standard procedure. A similar strategy applies to more complicated methods for solving ODEs (multistage methods such as Runge-Kutta, implicit methods for stiff systems, etc.). This strategy is different and mathematically more accurate than assuming parameters are constant over a time step like a multistage method. Would anyone please help me to solve this problem using boost? Thank you in advance. With Best Regards, Arijit Hazra

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Sort boost composite container
by Uthpal Urubail 21 Jan '14

21 Jan '14

I am having below composite container. I am looking to sort the container by member<CA,std::string,&CA::card> at the end. Can some one help me to achieve this? typedef multi_index_container< CA, indexed_by< ordered_unique< composite_key< CA, member<CA,std::string,&CA::name>, member<CA,std::string,&CA::displayName>, member<CA,std::string,&CA::card> > > > > duplicateBook; Regards, UJ

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[BGL] A* implementation
by Knut Krause 21 Jan '14

21 Jan '14

Hi, I'm still considering to use the BGL for my large scale path finding problem. Sadly I don't fully understand the implementation of A* used in boost. Does it use optimizations like bidirectional A* and so on or can I activate those somehow? I think otherwise I'd have to implement my own version of A*. Regards Knut

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Help regarding how to start
by Mihir Thakkar 21 Jan '14

21 Jan '14

I was having a look at the To-Do list & Challenges of BGL. I found few of them already implemented. I would like to contribute, I would appreciate if someone can help from where to find the things which are not yet implemented, (like if boost has an updated To-Do list) I am interested in GUI, mathematics and general algorithms. Thanks!

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Cross compiling boost Windows -> Arm
by Marius Adrian DOBRESCU 21 Jan '14

21 Jan '14

Hello. I have a problem compiling boost with arm-none-linux-gnueabi-g++ on Windows. Shared library dependencies paths seems to be hard-coded with Windows paths: Example: build\bin.v2\libs\filesystem\build\gcc-arm\release\target-os-linux\threading-multi\... I tried to build with --prefix. Not working. Hardcode-dll-paths not working too. Tried to specify an explicit -rpath. The so shared libraries are compiled with hard-coded paths inside, with backslash \\\ and I cannot use them on linux-arm. On stage directory they are hard-coded too. Any idea how can I disable this behavior and what options should I pass to boost and where? I want simple libraries without full rpaths and the build must be done on Windows with gcc-gnueabi. Thanks. Adrian

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[Serialization] 1.49 to 1.55 problems
by John M. Dlugosz 21 Jan '14

21 Jan '14

I did search for "serialization incompatible version" on Google and found issues regarding certain older versions. I checked the release notes as far back as were on the web site, and didn't see anything. I tried building a program with Boost 1.55, and found it would not interoperate with existing programs that were built with Boost 1.49. Taking the error at face value, I need to configure the code to write the old version. How would I do that? —John

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Using BGL for huge grid graphs
by Knut Krause 21 Jan '14

21 Jan '14

Hi, I'm planning on using the BGL on huge graphs the represent a grid where each vertex is a cell connected to it's 8 neighbours. I think something around 2,500,000,000 vertices would be a good number to approach but it would be great if it could handle (a lot) more later. If I got this graph I have to find the shortest path between two vertices. Does anyone here have experiences with graphs that large? Is this even worth a try on "normal" hardware? The edge weights would be stored in the vertices. So if you want to go from (a) to (b) you'd have to pay the cost stored in (b). The graph is not directed either. I read about BGLs CSR graph http://www.boost.org/doc/libs/1_55_0/libs/graph/doc/compressed_sparse_row.h… but since I honestly have no clue how to use BGL yet I thought I'd first hear your opinons. Regards Knut

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Re: [Boost-users] Cannot compile with multiprecision :: eval_*()functions
by Anderson Lebowski 21 Jan '14

21 Jan '14

looks like I went to the wrong track. Yes, merely the pow function works. Thank you very much! On Mon, Jan 20, 2014 at 8:42 AM, John Maddock <john(a)johnmaddock.co.uk>wrote: > I am trying to use eval_pow() and eval_powm() >> > > Those are internal details, you shouldn't really be using them in user > code. > > > My code is like this and I am using Visual Studio 12: >> >> #include <boost/multiprecision/cpp_int.hpp> >> ... >> boost::multiprecision::cpp_int pow("1234567"); >> boost::multiprecision::cpp_int base(3); >> boost::multiprecision::cpp_int result = 0; >> >> boost::multiprecision::default_ops::eval_pow(result, base, pow); >> >> I cannot figure out what's going on wrong when I compile it, the error >> message is like the following, Can anyone shed some light please? >> > > The eval_* functions take *Backends* and not *numbers* as arguments. > > In any case there is (deliberately) no integer pow function which accepts > an arbitrary precision exponent value - even 2^INT_MAX would run the > machine out of memory in a trice. > > What's wrong with: > > result = pow(base, 1234567); > > and let the expression template code handle memory management? > > John. > _______________________________________________ > Boost-users mailing list > Boost-users(a)lists.boost.org > http://lists.boost.org/mailman/listinfo.cgi/boost-users >

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Cannot compile with multiprecision :: eval_*() functions
by Anderson Lebowski 20 Jan '14

20 Jan '14

Hi folks, I am trying to use eval_pow() and eval_powm() My code is like this and I am using Visual Studio 12: #include <boost/multiprecision/cpp_int.hpp> ... boost::multiprecision::cpp_int pow("1234567"); boost::multiprecision::cpp_int base(3); boost::multiprecision::cpp_int result = 0; boost::multiprecision::default_ops::eval_pow(result, base, pow); I cannot figure out what's going on wrong when I compile it, the error message is like the following, Can anyone shed some light please? D:\Develop\C++\boost_1_55_1\boost/multiprecision/detail/number_base.hpp(146): error C2039: 'unsigned_types' : is not a member of 'boost::multiprecision::number<boost::multiprecision::backends::cpp_int_backend<0,0,signed_magnitude,unchecked,std::allocator<boost::multiprecision::limb_type>>,et_on>' 1> D:\Develop\C++\boost_1_55_1\boost/multiprecision/detail/number_base.hpp(191) : see reference to class template instantiation 'boost::multiprecision::detail::canonical_imp<Val,Backend,boost::mpl::int_<1>>' being compiled 1> with 1> [ 1> Val=unsigned char 1> , Backend=double_type 1> ] 1> D:\Develop\C++\boost_1_55_1\boost/multiprecision/detail/integer_ops.hpp(309) : see reference to class template instantiation 'boost::multiprecision::detail::canonical<unsigned char,double_type>' being compiled 1> KeyGen.cpp(152) : see reference to function template instantiation 'void boost::multiprecision::default_ops::eval_powm<boost::multiprecision::cpp_int,int>(Backend &,const Backend &,const Backend &,Integer)' being compiled 1> with 1> [ 1> Backend=boost::multiprecision::cpp_int 1> , Integer=int 1> ] 1>D:\Develop\C++\boost_1_55_1\boost/multiprecision/detail/number_base.hpp(146): error C2146: syntax error : missing ',' before identifier 'unsigned_types' 1>D:\Develop\C++\boost_1_55_1\boost/multiprecision/detail/number_base.hpp(146): error C2065: 'unsigned_types' : undeclared identifier 1>D:\Develop\C++\boost_1_55_1\boost/multiprecision/detail/number_base.hpp(148): error C2977: 'boost::mpl::find_if' : too many template arguments 1> D:\Develop\C++\boost_1_55_1\boost/mpl/find_if.hpp(33) : see declaration of 'boost::mpl::find_if' 1>D:\Develop\C++\boost_1_55_1\boost/multiprecision/detail/number_base.hpp(148): error C2955: 'boost::mpl::find_if' : use of class template requires template argument list 1> D:\Develop\C++\boost_1_55_1\boost/mpl/find_if.hpp(33) : see declaration of 'boost::mpl::find_if' 1>D:\Develop\C++\boost_1_55_1\boost/multiprecision/detail/number_base.hpp(136): error C2039: 'signed_types' : is not a member of 'boost::multiprecision::number<boost::multiprecision::backends::cpp_int_backend<0,0,signed_magnitude,unchecked,std::allocator<boost::multiprecision::limb_type>>,et_on>' 1> D:\Develop\C++\boost_1_55_1\boost/multiprecision/detail/number_base.hpp(191) : see reference to class template instantiation 'boost::multiprecision::detail::canonical_imp<Val,Backend,boost::mpl::int_<0>>' being compiled 1> with 1> [ 1> Val=int 1> , Backend=double_type 1> ] 1> D:\Develop\C++\boost_1_55_1\boost/multiprecision/detail/integer_ops.hpp(310) : see reference to class template instantiation 'boost::multiprecision::detail::canonical<Integer,double_type>' being compiled 1> with 1> [ 1> Integer=int 1> ] 1>D:\Develop\C++\boost_1_55_1\boost/multiprecision/detail/number_base.hpp(136): error C2146: syntax error : missing ',' before identifier 'signed_types' 1>D:\Develop\C++\boost_1_55_1\boost/multiprecision/detail/number_base.hpp(136): error C2065: 'signed_types' : undeclared identifier 1>D:\Develop\C++\boost_1_55_1\boost/multiprecision/detail/number_base.hpp(138): error C2977: 'boost::mpl::find_if' : too many template arguments 1> D:\Develop\C++\boost_1_55_1\boost/mpl/find_if.hpp(33) : see declaration of 'boost::mpl::find_if' 1>D:\Develop\C++\boost_1_55_1\boost/multiprecision/detail/number_base.hpp(138): error C2955: 'boost::mpl::find_if' : use of class template requires template argument list 1> D:\Develop\C++\boost_1_55_1\boost/mpl/find_if.hpp(33) : see declaration of 'boost::mpl::find_if' 1>D:\Develop\C++\boost_1_55_1\boost/multiprecision/detail/integer_ops.hpp(336): error C2780: 'enable_if<boost::multiprecision::backends::is_trivial_cpp_int<boost::multiprecision::backends::cpp_int_backend<MinBits,MaxBits,SignType,Checked,Allocator>>,void>::type boost::multiprecision::backends::eval_right_shift(boost::multiprecision::backends::cpp_int_backend<MinBits,MaxBits,SignType,Checked,Allocator> &,T)' : expects 2 arguments - 1 provided 1> D:\Develop\C++\boost_1_55_1\boost/multiprecision/cpp_int/bitwise.hpp(355) : see declaration of 'boost::multiprecision::backends::eval_right_shift' 1>D:\Develop\C++\boost_1_55_1\boost/multiprecision/detail/integer_ops.hpp(336): error C2780: 'enable_if_c<!boost::multiprecision::backends::is_trivial_cpp_int<boost::multiprecision::backends::cpp_int_backend<MinBits,MaxBits,SignType,Checked,Allocator>>::value,void>::type boost::multiprecision::backends::eval_right_shift(boost::multiprecision::backends::cpp_int_backend<MinBits,MaxBits,SignType,Checked,Allocator> &,boost::multiprecision::double_limb_type)' : expects 2 arguments - 1 provided 1> D:\Develop\C++\boost_1_55_1\boost/multiprecision/cpp_int/bitwise.hpp(298) : see declaration of 'boost::multiprecision::backends::eval_right_shift' 1>D:\Develop\C++\boost_1_55_1\boost/multiprecision/detail/integer_ops.hpp(336): error C2780: 'void boost::multiprecision::default_ops::eval_right_shift(T &,const T &,const V)' : expects 3 arguments - 1 provided 1> D:\Develop\C++\boost_1_55_1\boost/multiprecision/detail/default_ops.hpp(758) : see declaration of 'boost::multiprecision::default_ops::eval_right_shift' ------------------------------ Thanks, -Anderson Lebowski

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Boost.Mock ?
by Mathieu Champlon 20 Jan '14

20 Jan '14

Hello, I initially sent the following message to the boost-dev mailing list, but I'm thinking this might reach more potential users here on boost-users. Would a library for mock objects be of interest ? The documentation can be found here : http://mat007.users.sourceforge.net/boost_mock/ An archive is also available for download there : http://sourceforge.net/projects/mat007.u/files/boost-mock.zip It's been converted from turtle (http://turtle.sourceforge.net/) which was mentioned on the mailing-lists a couple of times in the past. There is a catch in that it needs Boost.Test from the release branch and doesn't compile with the trunk. The changes are minimal though and I can provide a patch if anyone is interested. Is anyone already using the library who would like to see it in Boost ? Or is anyone using another mock object library who wants to give it a go ? Or even better has anyone tried it and decided to user another library who would like to comment on it ? I would be highly interested in any feedback ! Thank you, MAT.

6 9

how to sort boost composite container
by Uthpal Urubail 20 Jan '14

20 Jan '14

I am using below composite container. Finally I am looking to sort

1 0

Question for Boost.Threads and Boost.Test
by young 20 Jan '14

20 Jan '14

According to Boost document, Boost.Test can only be statically linked. Boost.Threads can only be dynamically linked. Then what boost_unit_test_framework-vc100-mt-1_53.lib for? Is it for dynamically linked dll? what libboost_thread-vc100-mt-1_53.lib for? Is it for static library? -- View this message in context: http://boost.2283326.n4.nabble.com/Question-for-Boost-Threads-and-Boost-Tes… Sent from the Boost - Users mailing list archive at Nabble.com.

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[Test] Where to learn about boost::itest::mock_object?
by Mateusz Loskot 20 Jan '14

20 Jan '14

Hi, I'm looking for a simple mocking library to use together with Boost.Test. There is Turtle (aka Boost.Mock) and googlemock. During retrospection of the big thread on Boost.Test future [1], I found this curious post by Gennadiy [2] about mock_object. I had no idea such facility lives in Boost.Test and it looks it's been there for very long time. I can't find any documentation about mock_oboject, only a couple of examples. So, I have a few questions: Is the mock_object an internal feature or is it dedicated (and ready) to use by Boost.Test users? What are basic features of this mocking facility? How does it compare to Turtle or googlemock? [1] http://thread.gmane.org/gmane.comp.lib.boost.devel/234297 [2] http://thread.gmane.org/gmane.comp.lib.boost.devel/234297/focus=234621 [3] find /home/mloskot/dev/boost/_svn/trunk/libs/test -type f | xargs grep mock_object Best regards, -- Mateusz Loskot, http://mateusz.loskot.net

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[Geometry] Registering the Windows RECT structure
by Sean Farrow 19 Jan '14

19 Jan '14

Hi all, Does anybody know whether the Windows RECT structure is known to the boost geometry library. The RECT structure is declared as follows: typedef struct _RECT { LONG left; LONG top; LONG right; LONG bottom; } RECT, *PRECT; Members left The x-coordinate of the upper-left corner of the rectangle. top The y-coordinate of the upper-left corner of the rectangle. right The x-coordinate of the lower-right corner of the rectangle. bottom The y-coordinate of the lower-right corner of the rectangle. If there is no registration, is there an example that shows how to do this? Any help appreciated. Regards Sean.

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[xpressive] Accessing named capture from another scope in the semantic action
by Roger 19 Jan '14

19 Jan '14

Hi! Is it possible access captured group from another scope in the semantic action? Can I write a lazy function somehow and access another scope? The following code results in ”bad_lexical_cast” exception, likely due to the named capture "Year" is an empty string in the "outer scope". const sregex yyyymmdd = (Year=_d>>_d>>_d>>_d) >> (Month= _d>>_d) >> (Day= _d>>_d); sregex rx = yyyymmdd [ tm_year(t) = as<int>(Year) - 1900 /*, … */ ] // bad lexical cast: source type value could not be interpreted as target >> hhmmss [ tm_hour(t) = as<int>(Hour) /*, …*/ ] ; In my case the regex has no recursion, no captured repeated groups, so I can't understand really why I got nested result set. Dumping the nested result tree indicates that the values are captured in another ”scope”. But this is in the match_result<> set, and I can't figure out if there is any equivalent set available inside the semantic action. 20140119190000 #rx day = hour = minute = month = second = year = 20140119 #yyyymmdd day = 19 hour = minute = month = 01 second = year = 2014 190000 #hhmmss day = hour = 19 minute = 00 month = second = 00 year = I’m asking mostly for educational reason. Thanks for any hints! perrog Code: mark_tag Year(1),Month(2),Day(3),Hour(4),Minute(5),Second(6), Micro(7); const sregex yyyymmdd = (Year=_d>>_d>>_d>>_d) >> (Month= _d>>_d) >> (Day= _d>>_d); const sregex hhmmss = (Hour=_d>>_d)>>(Minute=_d>>_d)>>(Second=_d>>_d); bool is_datetime(std::string const& input) { // …don’t need any semantic actions when validating… smatch ignore; sregex rx = yyyymmdd >> hhmmss; return regex_match(input, ignore, rx); } bool get_datetime(std::string const& input, struct tm *time) { local<struct tm*> t(time); function<int tm::*>::type tm_year = { &tm::tm_year }; function<int tm::*>::type tm_hour = { &tm::tm_hour }; // … sregex rx = yyyymmdd [ tm_year(t) = as<int>(Year) - 1900 /*, … */ ] // bad lexical cast: source type value could not be interpreted as target >> hhmmss [ tm_hour(t) = as<int>(Hour) /*, …*/ ] ; smatch ignore; return regex_match(input, ignore, rx); }

2 1