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

Re: [Boost-users] [coroutine] Is there a max number of coroutines that can be created?
by José 11 Jul '14

11 Jul '14

2 1

[coroutine] Is there a max number of coroutines that can be created?
by José 11 Jul '14

11 Jul '14

3 2

[logging] Setting log level works if set_filter called from main, but not if called from a function in a static library
by Hickman, Steve (AdvTech) 10 Jul '14

10 Jul '14

To make setting the log level at runtime easy, I created the following routine: -----Utiliites.hpp namespace Utilities { void setLogLevel(const std::string &level); }; ------Utilities.cpp ----- #include "Utilities.hpp" #include <boost/log/core.hpp> #include <boost/log/expressions.hpp> namespace logging = boost::log; #define SET_IF_LOG_LEVEL(lvlVar, levelVal) \ if (lvlVar.compare( #levelVal ) == 0) \ { \ logging::core::get()->set_filter \ ( \ logging::trivial::severity >= logging::trivial:: ## levelVal \ ); \ } void Utilities::setLogLevel(const std::string &level) { // default is debug std::string lvl = (level.length() > 0)?level:"debug"; Utilities::lowerCase(lvl); // just to make sure we're consistent if (lvl.compare("disabled") == 0) boost::log::core::get()->set_logging_enabled(false); SET_IF_LOG_LEVEL(lvl,trace); SET_IF_LOG_LEVEL(lvl,debug); SET_IF_LOG_LEVEL(lvl,info); SET_IF_LOG_LEVEL(lvl,warning); SET_IF_LOG_LEVEL(lvl,error); SET_IF_LOG_LEVEL(lvl,fatal); } -------------------main.cpp ------------------------------ #include <boost/log/core.hpp> #include <boost/log/expressions.hpp> namespace logging = boost::log; int main(int argc, char** argv) { if (argc > 1) { Utilities::setLogLevel(argv[1]); } //logging::core::get()->set_filter // ( // logging::trivial::severity >= logging::trivial::debug // ); BOOST_LOG_TRIVIAL(trace) << "Utilities unit test main starting " << std::endl; } ------------------------ Utilities.cpp is compiled as part of a static library that is linked to my main routine. If I call this function from my main routine, it appears to have no effect. I still get every logging message no matter what level I attempt to set. However, if I call logging::core::get()->set_filter() from my main routine (passing an appropriate level) it works as expected. I'm not certain what's happening here. Is it possible that logging::core::get() isn't actually dealing with a singleton? That the pointer returned by get() when called from my library is not the same as the pointer returned by the same call in my main routine? And, regardless of what is happening, how do I fix this? I'm using Visual Studio 2012 building Debug Win32 console application. Running on Windows 7 64bit. Steve Hickman System Architect, Flight Deck of the Future 480-236-8367

1 0

[log] , [smart_ptr] global logger declaration issues tons of warnings
by Valerii Valeev 10 Jul '14

10 Jul '14

Hello, global logger declaration as follows BOOST_LOG_INLINE_GLOBAL_LOGGER_DEFAULT(mylog_master, boost::log::sources::severity_logger<boost::log::trivial::severity_level>); issues a lots of warnings (see below) pointing to some smart_ptr code. If anyone could advice - does it look like my problem or something else – it would be greatly appreciated. Cheers, Valerii. Warning text: In file included from /usr/local/boost-1.55.0/include/boost/smart_ptr/make_shared_object.hpp:17, from /usr/local/boost-1.55.0/include/boost/log/sources/global_logger_storage.hpp:21, from /usr/local/boost-1.55.0/include/boost/log/common.hpp:24, from mylog.cpp:10: /usr/local/boost-1.55.0/include/boost/smart_ptr/detail/sp_forward.hpp: In function ‘T&& boost::detail::sp_forward(T&) [with T = const char*]’: /usr/local/boost-1.55.0/include/boost/smart_ptr/make_shared_object.hpp:218: instantiated from ‘typename boost::detail::sp_if_not_array<T>::type boost::make_shared(Arg1&&, Args&& ...) [with T = boost::log::v2s_mt_posix::sources::aux::logger_holder<boost::log::v2s_mt_posix::sources::severity_logger<boost::log::v2s_mt_posix::trivial::severity_level> >, Arg1 = const char*, Args = unsigned int, mylog_master::logger_type]’ /usr/local/boost-1.55.0/include/boost/log/sources/global_logger_storage.hpp:141: instantiated from ‘static boost::shared_ptr<boost::log::v2s_mt_posix::sources::aux::logger_holder_base> boost::log::v2s_mt_posix::sources::aux::logger_singleton<TagT>::construct_logger() [with TagT = mylog_master]’ /usr/local/boost-1.55.0/include/boost/log/sources/global_logger_storage.hpp:121: instantiated from ‘static void boost::log::v2s_mt_posix::sources::aux::logger_singleton<TagT>::init_instance() [with TagT = mylog_master]’ /usr/local/boost-1.55.0/include/boost/log/detail/singleton.hpp:45: instantiated from ‘static StorageT& boost::log::v2s_mt_posix::aux::lazy_singleton<DerivedT, StorageT>::get() [with DerivedT = boost::log::v2s_mt_posix::sources::aux::logger_singleton<mylog_master>, StorageT = boost::shared_ptr<boost::log::v2s_mt_posix::sources::aux::logger_holder<boost::log::v2s_mt_posix::sources::severity_logger<boost::log::v2s_mt_posix::trivial::severity_level> > >]’ /usr/local/boost-1.55.0/include/boost/log/sources/global_logger_storage.hpp:112: instantiated from ‘static typename TagT::logger_type& boost::log::v2s_mt_posix::sources::aux::logger_singleton<TagT>::get() [with TagT = mylog_master]’ ../../include/myproject/mylog.hpp:20: instantiated from here /usr/local/boost-1.55.0/include/boost/smart_ptr/detail/sp_forward.hpp:30: warning: returning reference to temporary mylog.hpp:20 is the line where global logger is declared: BOOST_LOG_INLINE_GLOBAL_LOGGER_DEFAULT(mylog_master, boost::log::sources::severity_logger<boost::log::trivial::severity_level>); And my platform / compiler: $ gcc -v Using built-in specs. Target: x86_64-redhat-linux Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla --enable-bootstrap --enable-shared --enable-threads=posix --enable-checking=release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-gnu-unique-object --enable-languages=c,c++,objc,obj-c++,java,fortran,ada --enable-java-awt=gtk --disable-dssi --with-java-home=/usr/lib/jvm/java-1.5.0-gcj-1.5.0.0/jre --enable-libgcj-multifile --enable-java-maintainer-mode --with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libjava-multilib --with-ppl --with-cloog --with-tune=generic --with-arch_32=i686 --build=x86_64-redhat-linux Thread model: posix gcc version 4.4.7 20120313 (Red Hat 4.4.7-3) (GCC)

1 0

Limitations of BOOST_COROUTINES_V2 (pass by reference)
by Mueller-Roemer, Johannes Sebastian 09 Jul '14

09 Jul '14

Hi, aside from the fact that the new coroutines are - apparently intentionally - only unidirectional now (currently not much of an issue for me), I noticed that it is apparently no longer possible to yield values by reference as shown in the following example: #include <fstream> #include <string> #include <iostream> #include <boost/coroutine/all.hpp> using type = std::string; auto lines_from_file(char const * fname) -> boost::coroutines::coroutine<type>::pull_type { using namespace boost::coroutines; return coroutine<type>::pull_type{ [fname](coroutine<type>::push_type& yield) { std::string line; std::ifstream stream(fname); while(stream) std::getline(stream, line), yield(line); }, attributes(fpu_not_preserved) }; } int main(int, char**) { auto lines = lines_from_file("test.txt"); unsigned count = 0; for(auto& line : lines) std::cout << std::setw(4) << ++count << ": " << line << "\n"; } If one changes type to std::string const & the example no longer compiles. If I use the old BOOST_COROUTINES_V1 API boost::coroutines::coroutine<std::string const &()> works just fine. Is this limitation also intentional (why?) or is this an unintentional regression? Regards Johannes S. Mueller-Roemer -- Johannes S. Mueller-Roemer, MSc Wiss. Mitarbeiter - Interactive Engineering Technologies (IET) Fraunhofer-Institut für Graphische Datenverarbeitung IGD Fraunhoferstr. 5 | 64283 Darmstadt | Germany Tel +49 6151 155-606 | Fax +49 6151 155-139 johannes.mueller-roemer(a)igd.fraunhofer.de | www.igd.fraunhofer.de

4 9

Boost.python with custom (Anaconda) python installation on Mac OSX
by Gianluca Meneghello 09 Jul '14

09 Jul '14

Dear all, Sorry for asking a probably basic question, I have been trying to use boost. python with Anaconda python (https://store.continuum.io/cshop/anaconda/) on Mac OSX without success. My current installation works with the standard OSX python, for example by running the test in boost_1_55_0/libs/python/example/quickstart using the following command: $/usr/bin/python test_extending.py where /usr/bin/python is the default OSX python. In contrast the command: $python test_extending.py where python is the custom Anaconda one fails with Trying: from extending import * Expecting nothing Fatal Python error: PyThreadState_Get: no current thread Abort trap: 6 I understand this is due to boost linking the wrong python --- i.e. the system python instead of the Anaconda one - -- but I cannot make up my mind on how to change this, despite the fact that the project-config.jam file created by bootstrap.sh seems to correctly point to the anaconda installation. Please let me know if I can provide more details. Thanks in advance for your help, gianluca

1 0

[ptr_container] usage of auto_type
by Olaf Peter 09 Jul '14

09 Jul '14

Hello, I have the following code fragment: typedef boost::ptr_vector<T> vector_t; typedef message_vector_t::auto_type auto_t; .... vector_t v; { auto_t x(new T) // do something with x v.push_back(x.release()); // here rise my question } according http://www.boost.org/doc/libs/1_53_0/libs/ptr_container/doc/examples.html #6 Do I have to release x all the time? E.g. I want to use it in the loop, where at the end I have to push_back the value, where for my understanding x goes out of scope and hence is released automatically. After studying the header, there is no push_back for auto_type (which is static_move_ptr), but for std::auto_ptr (which is imo deprecated in C++11) and T (which converts it into an auto_type again). Is it correct or do I miss something?

2 1

Wrapper to C++ Lists using Python Boost
by Kv Gopalkrishnan 09 Jul '14

09 Jul '14

Hi all I am relatively new to python boost and am trying to wrap a list of pairs using an iterator. In the Public section I have namespace sky{ class FindNextMask{ public: FindNextMask() {}; FindNextMask(int i):iter(i){} bool operator()(const pair<int,string>& p)const{ if (iter <= p.first) return true; else return false; } private: int iter; }; Then in another class say S class S { private: list<pair<int,string> > A; } I am unable to find a solution to this. Any help in this context would be appreciated. I know to write wrappers for pairs and vectors but I do not understand how to extend this to C++ lists and connect it with iterators and operators. class_<std::vector<std::pair<double, double> > >("VectorOfPairs") .def(vector_indexing_suite<std::vector<std::pair<double,double> > >()); class_<std::pair<double, double> >("DoublePair") // Wrapper for a pair only .def_readwrite("first", &std::pair<double, double>::first) .def_readwrite("second", &std::pair<double, double>::second); Kind Regards K.V.

1 0

boost::function performance issues with C++11
by 饭桶 09 Jul '14

09 Jul '14

Hi, Does anyone know why -std=c++11 causes so much difference on boost::function? I was planed to understand if there any performance issues with big size of parameters. So I wrote a function that takes a vector as parameter, like func2 shows. I know it's better to use a pointer or reference as function parameter. I just want to evaluate the performance, so let's keep the vector as parameter. However, I found that it's quite slow when compiled with -std=c++11. In detail, it takes 173874 milliseconds with C++11, while it takes 3676 seconds without C++11. About 50 times slower!! How can that be? In my opinion, I thought boost::function should had the same performance with std::function. So I decided to try std::function in C++11 directly, Finally, it takes about 29233 milliseconds. That's till 8 times slows! Can anyone tell me what happend here? int func2(std::vector<int> i){ total += i.size(); return i.size(); } const int T = 1000000; s = boost::chrono::system_clock::now(); for (int i = 0; i < T; ++i) call(boost::bind(&func2, v)); e = boost::chrono::system_clock::now(); In case you need to know my enviorment, my OS is Arch, compiler is gcc 4.9.0, and optimizations are default. The execution time (ms) of three versions I tried: boost::function with C++11 : 173874 boost::function without C++11 : 3676 std::function in C++11 : 29233 Any thoughts are appreciated! Thanks, Athrun

6 12

Determine if boost was compiled with c++11
by Chris Stankevitz 08 Jul '14

08 Jul '14

Hello, My project uses cmake, gcc with c++11 support, and boost compiled libraries. Apparently my project must use only boost libraries that were created with c++11. The consequences of not doing this are random crashes. Is there a way I can determine whether or not boost was compiled with a c++11 compiler? I would like to verify, at configure time, that a c++11 version of boost is being used. Thank you, Chris

1 0

Re: [Boost-users] DateTime without serialization
by Macumber, Daniel 08 Jul '14

08 Jul '14

Thanks John, BOOST_SERIALIZATION_NO_LIB worked for me. I assume that some include I am using was inadvertently triggering the auto link with serialization even though I was not using that functionality. Thanks for the help! Dan -----Original Message----- Date: Mon, 07 Jul 2014 18:27:00 +0100 From: John Maddock <boost.regex(a)virgin.net> To: boost-users(a)lists.boost.org Subject: Re: [Boost-users] DateTime without serialization Message-ID: <53BAD864.3090800(a)virgin.net> Content-Type: text/plain; charset=ISO-8859-1; format=flowed > Hello, I am using the DateTime library's to/from string > functionality but not the DateTime serialization > functionality. However, when I build my program boost > auto linking keeps trying to link against the serialization > library. Is there a way I can build and link against DateTime > without auto linking against serialization? I am using visual > studio 2013 and boost 1.55. Define BOOST_SERIALIZATION_NO_LIB to disable auto-linking of serialization. However... you should need to #include the date_time serialization code in order to use iostream output? John.

1 0

Re: [Boost-users] boost::function performance issues with C++11
by Seeger, Steven D. (GSFC-444.0)[Embedded Flight Systems, Inc] 08 Jul '14

08 Jul '14

>Right, there are 1000 integers in the vector. If something, say STL, is bottleneck for boost::bind with C++ 11, it >should also be a bottleneck without C++11. And they should have the same performance. However, the fact shows >that C++11 mode has some additional overhead. I wanna figure that out. What if you try with just 1 integer? Does the difference in time stay proportionally the same? Steven

4 4

[spirit] qi xml parser
by Michael Powell 07 Jul '14

07 Jul '14

Hello, I am building out a general use xml parser including attributes, arbitrary number of elements, and so on. So far so good, makes sense parsing names and so forth. However, how do you handle element content? Which could either be a string, or zero or more other elements (basically of the same rule as the enclosing element rule). It would seem you need a terminus, the empty element tag. In such a way that populates the parent (initial) element, and its children (of the same element kind). I'll be adapting structs to capture the results. I am also using a couple of helpful references, for instance: http://www.w3.org/TR/xml11/ http://stackoverflow.com/questions/9473843/boost-spirit-how-to-extend-xml-p… Also not sure quite how to capture the adapted parts at strategic rule opportunities. My domain model will look something like this, keeping it simple as possible: struct xattribute { std::string name; std::string value; }; typedef std::vector<xattribute> xattribute_vector; struct xelement; typedef std::vector<xelement> xelement_vector; struct xelement { std::string name; std::string content; xattribute_vector attributes; xelement_vector children; }; Thanks... Best regards, Michael Powell

2 6

DateTime without serialization
by Macumber, Daniel 07 Jul '14

07 Jul '14

Hello, I am using the DateTime library's to/from string functionality but not the DateTime serialization functionality. However, when I build my program boost auto linking keeps trying to link against the serialization library. Is there a way I can build and link against DateTime without auto linking against serialization? I am using visual studio 2013 and boost 1.55. Thanks, Dan Sent with Good (www.good.com)

3 2

BOOST_OS_UNIX not working
by Troy Heron 07 Jul '14

07 Jul '14

Hello, I've just decided to give Boost.Predef a test drive for the first time and have found a problem using BOOST_OS_UNIX. See the test snippet here: http://pastebin.com/4dLDAhEV This is the output I get using both g++ 4.9.0 and clang++ 3.4.2: BOOST_OS_UNIX: 0 BOOST_OS_LINUX: 1 unix: 1 __unix: 1 _XOPEN_SOURCE: 700 _POSIX_SOURCE: 1 Everything that is defined that should be to make BOOST_OS_UNIX be defined. I haven't seen this mentioned anywhere before. I guess this a bug? I haven't looked at predef headers yet. Thanks, Troy

2 1

How to Wrap a List of pairs with Python Boost
by Kv Gopalkrishnan 07 Jul '14

07 Jul '14

Hi all I am quiet new to python boost and am stuck with a problem with C++ STL lists. I have a data type that is something like this list<pair<int,string> > gap_ls; Which is under the private section. I would like to wrap this like one can do using a vector like this class_<std::vector<std::pair<double, double> > >("VectorOfPairs") .def(vector_indexing_suite<std::vector<std::pair<double,double> > >()); and for pairs I had this class_<std::pair<double, double> >("DoublePair") .def_readwrite("first", &std::pair<double, double>::first) .def_readwrite("second", &std::pair<double, double>::second); But how do I write a wrapper for list<pair<int,string> >gap_ls; Any advice in this context would be appreciated. Kind Regards K.V.

1 0

Re: [Boost-users] Boost-users Digest, Vol 3844, Issue 1
by Seeger, Steven D. (GSFC-444.0)[Embedded Flight Systems, Inc] 05 Jul '14

05 Jul '14

>Date: Sun, 29 Jun 2014 13:21:21 -0300 >From: Agust?n K-ballo Berg? <kaballo86(a)hotmail.com> >To: boost-users(a)lists.boost.org >Subject: Re: [Boost-users] [fusion] maps and arrays >Message-ID: <BLU436-SMTP192734464D2B326EAF70973A7050(a)phx.gbl> >Content-Type: text/plain; charset="ISO-8859-1"; format=flowed >I missed the part where `for_each` was invoking the callable on each >element of the array, that is not how it is supposed to be. You are >right that making a recursive callable is the correct way to obtain that >behavior. Hi Agustin I'm sorry for taking so long to reply to you. I've been swamped. I really appreciate you taking the time to have this discussion with me and helping me to see that the behavior I was experiencing before with the for_each stepping into each array item is not correct. I should remember in the future to try and understand from the documentation what something is doing and not just by empirically testing it. >Without any other information on the error you get, I'm betting that >this is due to adding support for C++11 (not-so) perfect forwarding: > void foo(std::array<int, 2> const&){} > template <typename T> > void bar(T&& v){ foo(std::forward<T>(v)); } > foo({3,4}); // ok > bar({3,4}); // error: {3,4} has no type If I get some time I will play with this. I think that it is a bug that I cannot use braced initializer in c++11 with 1.55 like I could in 1.53. In the meantime I am adding a comment and referencing this discussion to my bug report to show that it is not a bug. I imagine they are not interested in the 1.53 issue we may have uncovered. Regards, Steven

1 0

skip list in boost
by David Frank 05 Jul '14

05 Jul '14

Hi, I found this email thread about submitting skip list implementation to boost: Boost mailing page: Re: [boost] Review managers wanted for augmented data structures Boost mailing page: Re: [boost] Review managers wanted f... Boost : Date view Thread view Subject view Author view Subject: Re: [boost] Review managers wanted for augmented data structures From: Vadim Stadnik (vadimst... View on lists.boost.org Preview by Yahoo But, I do not see it in the current version of boost, I'm wondering if it is somewhere I missed? Thanks, David

2 2

[Graph] Newbie on A*
by Sensei 04 Jul '14

04 Jul '14

Dear all, I am fiddling with the A* example on cities in order to learn how to use the A* search. Obviously, I cannot make it work :) The main goal is this, but I'm way too far from this: make A* fail when the path is longer, **not costlier**, than a constant. But right now I'd just like to have A* working on a graph. :) In order to see the different results, I've paired it with a Dijkstra search, and my A* heuristics is quite simple: constant. Dijkstra works fine, but A* stops at the first node, and the target isn't reached (but a path is available). What am I doing wrong? Forgive me if I'm making a stupid mistake bu I'm completely a newbie! If you need the graph, here's the link: https://dl.dropboxusercontent.com/u/15635416/g.txt Thanks! #include <cstdio> #include <cstdlib> #include <iostream> #include <utility> #include <algorithm> #include <numeric> #include <deque> #include <unordered_set> #include <vector> #include <fstream> #include <list> #include <boost/graph/graph_traits.hpp> #include <boost/graph/compressed_sparse_row_graph.hpp> #include <boost/graph/dijkstra_shortest_paths.hpp> #include <boost/graph/breadth_first_search.hpp> #include <boost/graph/depth_first_search.hpp> #include <boost/pending/indirect_cmp.hpp> #include <boost/range/irange.hpp> #include <boost/property_map/property_map.hpp> #include <boost/graph/astar_search.hpp> // Properties: weights are int typedef boost::property<boost::edge_weight_t, int> edge_weight; // The graph itself as a compressed sparse row matrix typedef boost::compressed_sparse_row_graph<boost::bidirectionalS, boost::no_property, edge_weight> boost_graph; // Vertex iterator typedef boost::graph_traits<boost_graph>::vertex_iterator vertex_iterator; // Edge iterator typedef boost::graph_traits<boost_graph>::edge_iterator edge_iterator; // Adjacent nodes iterator typedef boost::graph_traits<boost_graph>::adjacency_iterator adjacency_iterator; typedef boost::graph_traits<boost_graph>::out_edge_iterator outward_iterator; typedef boost::graph_traits<boost_graph>::in_edge_iterator inward_iterator; // Property maps typedef boost::property_map<boost_graph, boost::vertex_index_t>::type index_map; //typedef boost::property_map<boost_graph, boost::vertex_name_t> name_map; // Property iterators typedef boost::iterator_property_map<std::size_t*, index_map, std::size_t, std::size_t&> predecessor_map; typedef boost::iterator_property_map<std::size_t*, index_map, std::size_t, std::size_t&> distance_map; bool isValid(std::size_t index) { return (index >= 0) && (index <= 12); } // **************************************************************************** // A* heuristics template <class graph_type> class astar_heuristic : public boost::astar_heuristic<graph_type, std::size_t> { public: typedef typename boost::graph_traits<graph_type>::vertex_descriptor vertex_type; astar_heuristic(vertex_type goal) : goal_(goal) { }; std::size_t operator()(vertex_type u) { return 3; } private: vertex_type goal_; }; // Class to be used to terminate the A* algorithm class exit_astar { public: exit_astar(bool found) { }; }; // A* visitor that terminates when we find the goal template <class vertex_type> class astar_visitor : public boost::default_astar_visitor { public: astar_visitor(vertex_type goal) : goal_(goal) { }; template <class Graph> void examine_vertex(vertex_type u, Graph& g) { //std::cout << "EXAM: " << u << std::endl; if (u == goal_) throw exit_astar(true); } private: vertex_type goal_; }; // **************************************************************************** int main(int argc, const char * argv[]) { std::vector<std::pair<std::size_t, std::size_t>> graph_edges; std::vector<int> edge_weight; int n_nodes; int read_a, read_b, read_w; n_nodes = -1; std::ifstream igraph("/Users/senseiwa/Documents/Projects/scratch/tbb/g.txt"); while(igraph >> read_a >> read_b >> read_w) { if (read_a > n_nodes) n_nodes = read_a; if (read_b > n_nodes) n_nodes = read_b; read_a--; read_b--; graph_edges.push_back(std::make_pair(read_a, read_b)); edge_weight.push_back(read_w); } std::cout << "+++ READ # NODES: " << n_nodes << std::endl; // Create the graph boost_graph graph(boost::edges_are_unsorted_multi_pass, graph_edges.begin(), graph_edges.end(), edge_weight.data(), n_nodes); std::cout << "Graph statistics: " << std::endl; std::cout << "Nodes: " << boost::num_vertices(graph) << std::endl; std::cout << "Edges: " << graph_edges.size() << std::endl; edge_iterator ei, ee; std::size_t source_node = std::stoul(argv[1]); std::size_t destination_node = std::stoul(argv[2]); std::cout << ">> SOURCE NODE " << source_node << std::endl; std::cout << "Degrees in/out: " << source_node << std::endl; std::cout << boost::in_degree(boost::vertex(source_node, graph), graph) << std::endl; std::cout << boost::out_degree(boost::vertex(source_node, graph), graph) << std::endl; std::cout << "Degrees in/out: " << destination_node << std::endl; std::cout << boost::in_degree(boost::vertex(destination_node, graph), graph) << std::endl; std::cout << boost::out_degree(boost::vertex(destination_node, graph), graph) << std::endl; std::vector<std::size_t> preds(boost::num_vertices(graph)); std::vector<std::size_t> dists(boost::num_vertices(graph)); index_map idx_map = boost::get(boost::vertex_index, graph); predecessor_map pred_map(preds.data(), idx_map); distance_map dist_map(dists.data(), idx_map); boost::dijkstra_shortest_paths(graph, source_node, boost::distance_map(dist_map).predecessor_map(pred_map)); typedef std::vector<boost_graph::edge_descriptor> path_type; path_type spath; std::cout << ">> SOURCE NODE " << source_node << std::endl; std::cout << ">> DESTINATION NODE " << destination_node << std::endl; // ******* DIJKSTRA ******************************************************** std::size_t v = destination_node; // We want to start at the destination and work our way back to the source for(std::size_t u = pred_map[v]; // Start by setting 'u' to the destintaion node's predecessor u != v; // Keep tracking the path until we get to the source v = u, u = pred_map[v]) // Set the current vertex to the current predecessor, and the predecessor to one level up { std::pair<boost_graph::edge_descriptor, bool> edgePair = boost::edge(u, v, graph); boost_graph::edge_descriptor edge = edgePair.first; spath.push_back(edge); } // Write shortest path int totalDistance = 0; for(path_type::reverse_iterator pathIterator = spath.rbegin(); pathIterator != spath.rend(); ++pathIterator) { std::cout << boost::source(*pathIterator, graph) << " - " << boost::target(*pathIterator, graph) << " = " << boost::get(boost::edge_weight, graph, *pathIterator) << std::endl; totalDistance += boost::get(boost::edge_weight, graph, *pathIterator); } std::cout << "Shortest Dijkstra path from " << source_node << " to " << destination_node << " cost " << totalDistance << std::endl; // ******* A* ************************************************************** // A* search predecessor and cost std::vector<std::size_t> p(boost::num_vertices(graph)); std::vector<std::size_t> d(boost::num_vertices(graph)); try { // A* parameter interface astar_search(graph, source_node, astar_heuristic<boost_graph>(destination_node), boost::predecessor_map(&p[0]).distance_map(&d[0]).visitor(astar_visitor<std::size_t>(destination_node))); } catch(exit_astar fg) { std::list<std::size_t> shortest_path; for(std::size_t v = source_node; ; v = p[v]) { shortest_path.push_front(v); if(p[v] == v) break; } auto spi = shortest_path.begin(); std::cout << "node " << source_node << std::endl; for(++spi; spi != shortest_path.end(); ++spi) std::cout << "node " << *spi << std::endl; std::cout << "Shortest A* path from " << source_node << " to " << destination_node << " cost " << d[destination_node] << std::endl; std::cout << shortest_path.size() << std::endl; return 0; } std::cout << "Didn't find a path from " << source_node << "to" << destination_node << "!" << std::endl; return 0; } +++ READ # NODES: 200 Graph statistics: Nodes: 200 Edges: 4000 >> SOURCE NODE 1 Degrees in/out: 1 0 35 Degrees in/out: 192 39 1 >> SOURCE NODE 1 >> DESTINATION NODE 192 1 - 47 = 2 47 - 91 = 3 91 - 120 = 1 120 - 175 = 1 175 - 192 = 10 Shortest Dijkstra path from 1 to 192 cost 17 node 1 Shortest A* path from 1 to 192 cost 17 1

2 2

Re: [Boost-users] Boost-users Digest, Vol 3847, Issue 2
by Jorge Bellon 04 Jul '14

04 Jul '14

Buenos días Vicenç, Te envío la respuesta del desarrollador de la librería. Tiene sentido lo que dice. La única pega, quizás, sería que, en caso de no haber memoria disponible, tardaríamos al menos tanto tiempo como el "round-trip latency" antes de darnos cuenta... Un saludo, Jorge > Message: 1 > Date: Thu, 03 Jul 2014 20:08:33 +0200 > From: Ion Gazta?aga <igaztanaga(a)gmail.com> > To: boost-users(a)lists.boost.org > Subject: Re: [Boost-users] [Interprocess] Managed segment placement > Message-ID: <53B59C21.9040901(a)gmail.com> > Content-Type: text/plain; charset=UTF-8; format=flowed > > El 03/07/2014 10:24, Jorge Bellon escribi?: > > Hi Ion, > > Thank you for the info. > > > > The use case would be to manage a memory pool allocated on a remote node. > > > > This would be used by a run-time library for distributed programming. It > > would allocate a memory region and manage this memory from another node, > > so that we can perform operations with that piece of memory (allocate > > portions, transfer data, etc.) without the intervention of the local > > node. > > Why can't you put the manager in the remote node? The manager also needs > to allocate memory for indexes that track the position of named/unique > objects and that memory comes from the memory region also used to > construct objects. If you don't need named objects you can use a null > index to minimize used memory. > > Do you need to shared this remote node memory between processes? If you > only use remote memory from a single process you can speed things a bit > using raw pointers: > > typedef basic_managed_external_buffer < > char, > rbtree_best_fit<null_mutex_family, void* >, > null_index > > > my_managed_external_buffer; > > If you want to serialize objects then you should use offset_ptr<void> > instead of void*. > > I still miss the point of separating the manager (which is placed in the > beginning of the memory region) and the rest of the region. > > Best, > > Ion WARNING / LEGAL TEXT: This message is intended only for the use of the individual or entity to which it is addressed and may contain information which is privileged, confidential, proprietary, or exempt from disclosure under applicable law. If you are not the intended recipient or the person responsible for delivering the message to the intended recipient, you are strictly prohibited from disclosing, distributing, copying, or in any way using this message. If you have received this communication in error, please notify the sender and destroy and delete any copies you may have received. http://www.bsc.es/disclaimer

1 0

Re: [Boost-users] [atomic] ThreadSanitizer reports a data race when using the code from "reference counting" example
by Adam Romanek 04 Jul '14

04 Jul '14

On 01.07.2014 10:49, Andrey Semashev wrote: > On Tue, Jul 1, 2014 at 12:41 PM, Adam Romanek wrote: >> On 01.07.2014 10:36, Andrey Semashev wrote: >>> >>> On Tue, Jul 1, 2014 at 12:20 PM, Andrey Semashev >>> wrote: >>>> >>>> On Tue, Jul 1, 2014 at 11:20 AM, Adam Romanek >>>> wrote: >>>>> >>>>> Andrey, >>>>> >>>>> If you don't mind, please have a look at the conversation that I started >>>>> on >>>>> boost-users list [1] a few days back. Since you're the maintainer of >>>>> Boost.Atomic I'd like to know your opinion on this issue. Or maybe I >>>>> should >>>>> repost this on boost-dev list? >>>> >>>> >>>> I don't follow users list, mostly because I can't even keep up with >>>> the developers list. So it's better to reach me on the dev list. >>>> >>>> The code in the StackOverflow topic indeed contains a potential >>>> problem. The fetch_sub(release) operation prevents previous operations >>>> from sinking past it and atomic_thread_fence(acquire) prevents the >>>> following operations from floating above it. However, these two >>>> barriers themselves can be reordered creating a window where >>>> operations before fetch_sub(release) and after >>>> atomic_thread_fence(acquire) may overlap. I believe, this is permitted >>>> on both the compiler and hardware levels. This doesn't mean that's >>>> what is actually happening and being flagged by TSan; it is still >>>> possible that some TSan bug is exposed. The fact that replacing >>>> atomic_thread_fence(acquire) with fetch_add(acquire) speaks in favor >>>> of the bug suspicion. >>> >>> >>> Actually, no, fetch_add(acquire) is significantly different from the >>> fence. It operates on the same object as the previous >>> fetch_sub(release), so it must observe its effects and cannot be >>> reordered. >>> >> >> After reading your first response I thought you're suggesting that the >> "reference counting" example in Boost.Atomic docs is broken. But hopefully >> we agree that it's fine, right? :) > > The example in the docs is indeed not correct. I believe, it should be > corrected to use acq_rel memory order in intrusive_ptr_release. The > fence can be removed then. I'll fix it as soon as I have some time. > >> So I guess this is a false positive from TSan, as suggested by others on SO. >> I'll ask this on TSan's mailing list, lets see what they say. > > Ok, let me know if there are other considerations from TSan devs. > See above for my private conversation with Andrey Semashev on this topic (he does not follow the boost-users mailing list). Andrey says that the "reference counting example" from Boost.Atomic docs is broken. What do you think about this? WBR, Adam Romanek

2 2

[msm] more than 10 states causes long compilation error
by Raj Sambasivan 04 Jul '14

04 Jul '14

Hi, I get a long compilation error when i include the last line, i tried including #define BOOST_MPL_CFG_NO_PREPROCESSED_HEADERS #define BOOST_MPL_LIMIT_VECTOR_SIZE 30 // or whatever you need #define BOOST_MPL_LIMIT_MAP_SIZE 30 but still have the same problem, compilation error is at the bottom. any help? struct transition_table: boost::mpl::vector< Row<Empty, NewOrderRequest, PendingNew, handleNewOrderRequest>, Row<PendingNew, AckedResponse, Acked, handleAckedResponse>, Row<PendingNew, OrderRejectedResponse, OrderRejected, handleOrderRejectedResponse>, Row<PendingNew, CancelRequest, PendingCancel, handleCancelRequest>, Row<PendingCancel, CanceledResponse, Canceled, handleCanceledResponse >, Row<PendingCancel, CancelRejected, CancelRejected, handleCancelRejectedResponse>, Row<PendingReplace, ReplacedResponse, Replaced, handleReplacedResponse >, Row<PendingReplace, ReplaceRejected, ReplaceRejected, handleReplaceRejectedResponse>, Row<Acked, CancelRequest, PendingCancel, handleCancelRequest>, Row<Acked, FilledResponse, Filled, handleFilledResponse> > { }; compilation error (truncated) g++ -I/boost_1_55_0/ -c -Wall test.cpp In file included from test.cpp:1: In file included from ./Order.H:11: In file included from /boost_1_55_0/boost/msm/back/state_machine.hpp:28: In file included from /boost_1_55_0/boost/fusion/include/as_set.hpp:10: */boost_1_55_0/boost/fusion/container/set/convert.hpp:24:30: **error: * *implicit* * instantiation of undefined template 'boost::fusion::detail::as_set<11>'* typedef typename gen:: * ^* */boost_1_55_0/boost/msm/back/state_machine.hpp:1164:50: note: *in instantiation of template class 'boost::fusion::result_of::as_set<boost::mpl::s_item<Filled, boost::mpl::s_item<ReplaceRejected, boost::mpl::s_item<Replaced, boost::mpl::s_item<CancelRejected, boost::mpl::s_item<Canceled, boost::mpl::s_item<OrderRejected, boost::mpl::s_item<Acked, boost::mpl::s_item<PendingReplace, boost::mpl::s_item<PendingCancel, boost::mpl::s_item<PendingNew, boost::mpl::s_item<Empty, boost::mpl::set0<mpl_::na> > > > > > > > > > > > >' requested here typedef typename ::boost::fusion::result_of::as_set<state_list>::typ... * ^* *test.cpp:5:37: note: *in instantiation of template class 'boost::msm::back::state_machine<<anonymous>::order_, boost::parameter::void_, boost::parameter::void_, boost::parameter::void_, boost::parameter::void_>' requested here std::cout << " -> " << state_names[o.current_state()[0]] << std::endl; * ^* */boost_1_55_0/boost/fusion/container/set/detail/as_set.hpp:26:12: note: * template is declared here struct as_set; * ^* In file included from test.cpp:1: In file included from ./Order.H:11: In file included from /boost_1_55_0/boost/msm/back/state_machine.hpp:28: In file included from /boost_1_55_0/boost/fusion/include/as_set.hpp:10: */boost_1_55_0/boost/fusion/container/set/convert.hpp:25:26: **error: * *'apply'* * following the 'template' keyword does not refer to a template* template apply<typename result_of::begin<Sequence>::type>::type * ^~~~~* *test.cpp:5:38: **error: **expected ']'* *...*

2 2

[Interprocess] Managed segment placement
by Jorge Bellon 03 Jul '14

03 Jul '14

Good morning, I'm using Boost::Interprocess' managed external buffer for my application. I would like to know whether it is possible or not to instantiate the segment manager object in a different place other than the buffer itself, so that the whole buffer is used exclusively for data. Thanks in advance, Jorge WARNING / LEGAL TEXT: This message is intended only for the use of the individual or entity to which it is addressed and may contain information which is privileged, confidential, proprietary, or exempt from disclosure under applicable law. If you are not the intended recipient or the person responsible for delivering the message to the intended recipient, you are strictly prohibited from disclosing, distributing, copying, or in any way using this message. If you have received this communication in error, please notify the sender and destroy and delete any copies you may have received. http://www.bsc.es/disclaimer

2 3

[interceptors] How to intercept when a function is called
by Michael Powell 03 Jul '14

03 Jul '14

Hello, I don't know if there is a first or second class library in Boost to do with this already. Or at least a C++ mechanism I could leverage. Basically, I want to hook or intercept when a function call is made. I do not want to change the underlying call, although I suppose that hook could be done as well. For now, I just want a callback when that function calls is made. For instance, a vector push_back listener. I want to listen when items are push_back-ed onto the vector. The items should still land in the vector. I just want the notification when that occurs. I've dug around for different "callback" flavors, but these just seem to be wrappers to an underlying method pointer, bound function, along these lines. I can do that easy enough but it doesn't buy me the interception when the push back is actually called. The tricky part with push_back as well, is that it comes in two flavors, so there needs to be a stand in lambda, something to declare the actual kind of argument(s) I want. Then there's the matter of Variadics. But for now I am not concerned with either of these. Thank you... Best regards, Michael Powell

4 5

How to judge matched rule when looping with sregex_token_iterator in boost.xpressive?
by Li Dong 03 Jul '14

03 Jul '14

Dear all, I would like to use boost.xpressive to parse some string like “a+b:c”, and I wrote the following snippet: sregex reOp = as_xpr('+') | '-' | '*' | '/'; sregex reDelim = as_xpr(':'); sregex reField = +_w; sregex reSimpleToken = reOp | reDelim | reField; string str = "a+b:c"; sregex_token_iterator cur(str.begin(), str.end(), reSimpleToken), end; for (; cur != end; ++cur) { cout << *cur << endl; } which will print: a + b : c but I would also want to know which rule is matched for the sequent operations, for example ‘a’, ‘b’ and ‘c' are matched by reField, and ‘+’ is matched by ‘reOp’. I am very new to boost.xpressive, so if this is not the good way, correct me please. Any help is appreciated! Best, Li

1 0