- Boost-users - lists.boost.org

[heap] How to orderly traverse a priority queue and update a given element?
by Francisco Lopes 27 Feb '13

27 Feb '13

I'm looking for a good data structure that can *maintain* its elements sorted. Currently I'm trying Boost.Heap<http://www.boost.org/doc/libs/1_53_0/doc/html/heap.html> . I frequently need to orderly traverse the data structure, find a element based on some property and update its priority when it matches. Boost.Heap priority queues provide ordered and non-ordered iterators. Element updates occurs through a element handle, a handle can be obtained from a ordinary non-ordered iterator, but not directly from a ordered one as in the following example: #include <iostream>#include <algorithm>#include <boost/heap/fibonacci_heap.hpp> using namespace boost::heap; int main(){ fibonacci_heap<int> fib_heap; fib_heap.push(1); fib_heap.push(2); fib_heap.push(3); for(auto i = fib_heap.ordered_begin(); i != fib_heap.ordered_end(); ++i) { auto h = fibonacci_heap<int>::s_handle_from_iterator(i); if(*h == 3) { fib_heap.increase(h, *h + 2); break; } } std::for_each(fib_heap.ordered_begin(), fib_heap.ordered_end(), [](const int &e) { std::cout << e << std::endl; });} How can I orderly traverse the queue and update an element in the traversal? Note that I leave traversal after the update. (Suggestions of alternative libraries for such purpose are welcome)

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Errors compiling for Linux Ubuntu
by Michael Powell 26 Feb '13

26 Feb '13

Hello, Unless my compiler tool chain is off, I am just getting a ton of errors compiling Boost 1.53.0 for Linux Ubuntu. Ultimately, we'll want to cross-compile down to Arch Linux / ARM as well if it makes a difference (and it will). Errors saying failed updating 57 targets, skipped 10150 targets. I am building with all libraries and setting my prefix to /opt/boost_1_53_0. Then I run the ./b2 install. I am basically following the Linux instructions, but apparently, what am I missing? Thank you. Regards, Michael

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Boost.MSM cc1plus.exe:: error: out of memory allocating 65532
by RaRi 26 Feb '13

26 Feb '13

Hi all, I'm using boost.msm from the boost 1.53.0 library. I have together 8 submachines and almost 50 states distributed between the differente submachines. The number of events is 44. Unfortunately I got the following compilation error: * cc1plus.exe:: error: out of memory allocating 65532* First of all I have observed the memory allocation while the compilation phase: It exceeded 2Gm memory and than I've received that error. So, my solution was to switch to an 64 bit system with 8 GB memory. But to hell, I still got this error. My system environment is configured as follows: Operating system : Windows 7 64-Bit MinGW32, gcc v.4.72 Is this an gcc bug or do I have to extend to 16 GB? But I don't think so, as the failue is always reported after almost 2 Gb memory allocation while the compilation phase... Thank you for your help in advance, BR, Rafael -- View this message in context: http://boost.2283326.n4.nabble.com/Boost-MSM-cc1plus-exe-error-out-of-memor… Sent from the Boost - Users mailing list archive at Nabble.com.

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[units] Creating a velocity unit
by Ryan 26 Feb '13

26 Feb '13

Boost Community, I'm trying to create a custom velocity unit. I would like to create a unit that is in nautical miles per hour to represent my speed value. If I use pound_force.hpp as an example of units with more than one dimension I can create the following. BOOST_UNITS_DEFINE_BASE_UNIT_WITH_CONVERSIONS(metric, nautical_mile_per_hour, "nautical mile per hour", "nmi h^-1", factor, si::velocity, ???); If this is the right track, what id would I use and how do I know that it is unique? This seems forced. I would rather define this unit in terms of meters per second. Nautical miles is already in terms of meters and hours is also defined as a scale of seconds. Can I somehow use these two already defined units to create the new unit? How would I do this? Ryan

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[PBGL] distributed property map problem
by bminano 26 Feb '13

26 Feb '13

Hello, I am having a problem trying to initialize the distributed property map in parallel code. I get a memory access violation when running this part of code: BGL_FORALL_EDGES(e, g, Graph) { remote_key k(rank, index); put(values, k, 0.1); index++; } I followed the distributed_property_map_test, but I cannot figure where is the problem. It fails at the first edge. The distributed map is defined as follows: typedef boost::parallel::distributed_property_map<mpi_process_group, remote_key_to_global, EdgeIndexMap> ValueMap; ValueMap values(g.process_group(), remote_key_to_global(), eindex); values.set_reduce(rank_accumulate_reducer<double>()); Where eindex is a local map with the local indices of the edges. Please, could someone help me? -- View this message in context: http://boost.2283326.n4.nabble.com/PBGL-distributed-property-map-problem-tp… Sent from the Boost - Users mailing list archive at Nabble.com.

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[fusion, phoenix, spirit2] C++ orientation
by Michael Powell 26 Feb '13

26 Feb '13

Hello, It's been a little while since I've gone into much depth in C++. Been in the C# world for recent years and have a fairly advanced view of that world, through concepts like push-oriented dependency injection, pull-oriented inversion of control (less preferred), functional style programming using anonymous actions, functions, lambdas, and so on. I am working on a project now where we are adopting C++ into the mix, and I would like to get a much better sense for Spirit (likely Spirit2) for purposes of how to run sequences of complex data through various calculations, finds, counts, etc, probably needing to dynamically parse these calculations. Our data will be a series of spiked tuples (one or more) of n-dimensional packed values, and we'll probably need to dynamically parse calculations on the n-dimensions to determine did we satisfy the solution. I don't know if that makes any sense to anyone. It's all very conceptual, very abstract, at this stage of the game. I know, or have a sense, exactly how I might do it in C#, .NET 4, and so on. A little less so what's available in C++, much less boost, spirit, phoenix, fusion, etc. Any insight where to begin would be helpful. Regards, Michael

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[Regex] MSVC 2008 (VC9) fails to compile regex_raw_buffer.hpp on 1_49
by Larry 26 Feb '13

26 Feb '13

I get an error just including regex.hpp in a program that used to work on earlier VC versions. 1>c:\boost\include\boost-1_49\boost\regex\v4\regex_raw_buffer.hpp(184) : error C2665: 'operator new' : none of the 6 overloads could convert all the argument types 1> c:\program files (x86)\microsoft visual studio 9.0\vc\include\new(57): could be 'void *operator new(size_t,void *) throw()' 1> c:\program files (x86)\microsoft visual studio 9.0\vc\include\new(86): or 'void *operator new(size_t,const std::nothrow_t &) throw()' 1> while trying to match the argument list '(const char [64], long)' 1>c:\boost\include\boost-1_49\boost\regex\v4\perl_matcher_non_recursive.hpp(110) : error C2059: syntax error : '*' inline raw_storage::raw_storage(size_type n) { start = end = static_cast<pointer>(::operator new(n)); <--- offending line for first error BOOST_REGEX_NOEH_ASSERT(start) last = start + n; } struct save_state_init { saved_state** stack; save_state_init(saved_state** base, saved_state** end) : stack(base) { *base = static_cast<saved_state*>(get_mem_block()); *end = reinterpret_cast<saved_state*>(reinterpret_cast<char*>(*base)+BOOST_REGEX_BLOCKSIZE); --(*end); (void) new (*end)saved_state(0); <---- offending line for second error ........... I looked to see if this was a known failure but apparently missed it if it was already covered. It is probably not a Boost problem. The earlier versions were compiled on 32 bit systems and this is a 64 bit system (Win7). I assume I have probably missed some configuration item to make this work. I am fairly certain I did compile this before under VC9 on a 32 bit system (Vista). (Boost was built from source on this system and this compiler.) Any pointers for resolution would be appreciated. Larry

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Boost user's guide or getting started guide?
by John Lilley 25 Feb '13

25 Feb '13

Greetings! I feel that many questions I have about Boost.Geometry are really questions about the "Boost way and true path". Is there a good place to get started with Boost.Geometry specifically or Boost in general? I feel that I am locking in some basic understanding of how all of these templates fit together, what are Ranges, what are "concepts" etc. Where do I RTFM? Thanks, john

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nest mpl::lambda
by Niitsuma Hirotaka 25 Feb '13

25 Feb '13

I would like to use mpl::lambda in nest. In this case works fine. --------- typedef boost::mpl::lambda<boost::mpl::max<boost::mpl::_1,boost::mpl::_2> > my_max; typedef boost::mpl::fold< boost::mpl::vector_c<int,1,7,0,-2,5,-1> , boost::mpl::int_<6> //, boost::mpl::max<boost::mpl::_1,boost::mpl::_2> , my_max >::type r2; BOOST_MPL_ASSERT(( boost::is_same< r2, boost::mpl::integral_c<int, 7> > )); --------- However --------- typedef boost::mpl::lambda< boost::mpl::fold< boost::mpl::_1 ,boost::mpl::front<boost::mpl::_1> ,my_max >::type >::type my_max_types; typedef my_max_types::apply<boost::mpl::vector_c<int,1,7,0,-2,5,-1> >::type r3; BOOST_MPL_ASSERT(( boost::is_same< r3, boost::mpl::integral_c<int, 7> > )); ///error => becomes boost::mpl::integral_c<int, 1> --------- How to define such nest lambda in mpl?

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Re: [Boost-users] [parallel graph] error building parallel BGL
by The Maschine 25 Feb '13

25 Feb '13

Hi ./b2 libs/graph_parallel/example No it didnt work. Tasos ####### "typeinfo for boost::mpi::exception", referenced from: typeinfo for boost::exception_detail::error_info_injector<boost::mpi::exception>in dijkstra_shortest_paths.o "vtable for boost::mpi::exception", referenced from: boost::mpi::exception::exception(boost::mpi::exception const&)in dijkstra_shortest_paths.o NOTE: a missing vtable usually means the first non-inline virtual member function has no definition. ld: symbol(s) not found for architecture x86_64 collect2: ld returned 1 exit status "g++" -L"/usr/local/Cellar/open-mpi/1.6.3/lib" -o "bin.v2/libs/graph_parallel/example/darwin-4.2.1/debug/dijkstra_shortest_paths" "bin.v2/libs/graph_parallel/example/darwin-4.2.1/debug/dijkstra_shortest_paths.o" "bin.v2/libs/system/build/darwin-4.2.1/debug/libboost_system.dylib" "bin.v2/libs/graph_parallel/build/darwin-4.2.1/debug/libboost_graph_parallel.dylib" "bin.v2/libs/serialization/build/darwin-4.2.1/debug/libboost_serialization.dylib" -lm -lmpi -lmpi_cxx -g ...failed darwin.link bin.v2/libs/graph_parallel/example/darwin-4.2.1/debug/dijkstra_shortest_paths... ...failed updating 2 targets...

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