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

[multi-array] Is default initialization guaranteed?
by Eugenio Bargiacchi 15 Mar '14

15 Mar '14

Hello, I'm trying to figure out whether boost::multi_array does guarantee any initialization on its elements, since I can't find an explicit mention of this in the docs. I've noticed that all constructors of boost_multi array call the function allocate_space(), which is defined as follows: void allocate_space() { typename Allocator::const_pointer no_hint=0; base_ = allocator_.allocate(this->num_elements(),no_hint); this->set_base_ptr(base_); allocated_elements_ = this->num_elements(); std::uninitialized_fill_n(base_,allocated_elements_,T()); } Thus, std::uninitialized_fill_n should set all values to their default ones, right? For example, a boost::multi_array containing doubles is guaranteed to be zeroed at constructions, am I correct? Or are there cases where there's no guarantee of initialization, and that is why the documentation does not mention it? Thanks in advance. Best regards, Eugenio Bargiacchi

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Boost Log
by Manuel Torres 14 Mar '14

14 Mar '14

Hello, I am using Boost Log 1.55 with MinGW 32-bits (GCC v.4.8.1) under Windows 7 64-bits and it seems that the "AutoFlush" parameter is not working when a settings file is used. I thought it might have to do with the "Asynchronous" parameter but, after setting four sinks with the combinations of "AutoFlush" and "Asynchronous", I got the same result: the log files are only created after the application is closed. I would appreciate if someone could help. This is the settings file I am testing with: [Core] DisableLogging=false Filter="%Severity% < 6" [Sinks.ConsoleSink] Destination=Console Format="[%TimeStamp%] <%Severity%> %Channel%: %Message%" Asynchronous=true AutoFlush=true [Sinks.TextFileSink0] Destination=TextFile FileName="0_%Y%m%d%H%M%S_Node_%N.log" Format="[%TimeStamp%] <%Severity%> %Channel%: %Message%" Asynchronous=true AutoFlush=true Target="../log" RotationSize=1000000 RotationTimePoint="00:00:00" MaxSize=10000000 [Sinks.TextFileSink1] Destination=TextFile FileName="1_%Y%m%d%H%M%S_Node_%N.log" Format="[%TimeStamp%] <%Severity%> %Channel%: %Message%" Asynchronous=true AutoFlush=false Target="../log" RotationSize=1000000 RotationTimePoint="00:00:00" MaxSize=10000000 [Sinks.TextFileSink2] Destination=TextFile FileName="2_%Y%m%d%H%M%S_Node_%N.log" Format="[%TimeStamp%] <%Severity%> %Channel%: %Message%" Asynchronous=false AutoFlush=true Target="../log" RotationSize=1000000 RotationTimePoint="00:00:00" MaxSize=10000000 [Sinks.TextFileSink3] Destination=TextFile FileName="3_%Y%m%d%H%M%S_Node_%N.log" Format="[%TimeStamp%] <%Severity%> %Channel%: %Message%" Asynchronous=false AutoFlush=false Target="../log" RotationSize=1000000 RotationTimePoint="00:00:00" MaxSize=10000000

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[asio] resolver::cancel() problem
by Matthew Edwards 14 Mar '14

14 Mar '14

In my application (and a separate test program) it seems as though the cancel() function on the resolver does not work as intended. For async resolves, the cancel functionality should abort them immediately and pass an 'operation aborted' error code to the callback handler. In my tests, I will resolve an invalid domain (this causes the resolve to take a few seconds, to demonstrate the problem), sleep for 100ms, then call cancel on the resolver object. No cancelling actually occurs, and the callback is simply triggered after a few seconds with a "No host found" error code, not the expected operation aborted. Has anyone experienced this before, or know how I might be using the resolver incorrectly?

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[Graph] Guarantee on bidirectional graphs
by Sensei 14 Mar '14

14 Mar '14

Dear all, I am implementing my custom algorithm for path discovery (as in a recent post), and I'd like to know one simple thing. My graph is a bidirectional sparse compressed row graph, and I need to represent a *directed* graph with that (I need in and out edges). So, is the order of nodes in an edge guaranteed to generate the correct in/out adjacent nodes? I do not care about ordering of nodes, just distinguishing nodes that belong to in and out edges. For instance, given a directed graph that has node 4 with two out edges to 5 and 6, and 4 in edges from 1, 2, and 3, am I guaranteed that, even if the graph is bidirectional, the in and out edges will be unaffected and won't be swapped? Moreover, when I dump the indices of out edges, the results seem to be right, but when I dump the in edges, results are erroneous. I must be doing something really wrong... And one more thing: I have tried my code with just using the stream output as in http://programmingexamples.net/wiki/CPP/Boost/BGL/DirectedGraph, just using std::cout << neighbors_out.first << std::endl; clang complains: main.cpp:165:19: error: invalid operands to binary expression ('ostream' (aka 'basic_ostream<char>') and 'boost::detail::csr_out_edge_iterator<boost::compressed_sparse_row_graph<boost::bidirectionalS, boost::no_property, boost::no_property, boost::no_property, unsigned long, unsigned long> >') std::cout << neighbors_out.first << std::endl; ~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~ while if I use the following, it compiles just fine (but as I said, the output is wrong): std::cout << neighbors_out.first->idx << std::endl; See the snippet for an example. Thanks & Cheers! typedef boost::compressed_sparse_row_graph<boost::bidirectionalS> boost_graph; typedef boost::graph_traits<boost_graph>::vertex_iterator vertex_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; // ... std::vector<std::pair<std::size_t, std::size_t>> results; results.push_back(std::make_pair( 0, 1)); results.push_back(std::make_pair( 0, 3)); results.push_back(std::make_pair( 1, 4)); results.push_back(std::make_pair( 2, 4)); results.push_back(std::make_pair( 3, 4)); results.push_back(std::make_pair( 4, 5)); results.push_back(std::make_pair( 4, 6)); results.push_back(std::make_pair( 5, 7)); results.push_back(std::make_pair( 7, 8)); results.push_back(std::make_pair( 8, 9)); results.push_back(std::make_pair( 8, 11)); results.push_back(std::make_pair( 8, 12)); results.push_back(std::make_pair( 9, 10)); results.push_back(std::make_pair(12, 10)); // Create the graph boost_graph graph(boost::edges_are_unsorted_multi_pass, results.begin(), results.end(), 13); std::cout << "Outward adjacents" << std::endl; std::pair<outward_iterator, outward_iterator> neighbors_out; neighbors_out = boost::out_edges(boost::vertex(4, graph), graph); for(; neighbors_out.first != neighbors_out.second; ++neighbors_out.first) { std::cout << neighbors_out.first->idx << std::endl; } std::cout << "Inward adjacents" << std::endl; std::pair<inward_iterator, inward_iterator> neighbors_in; neighbors_in = boost::in_edges(boost::vertex(4, graph), graph); for(; neighbors_in.first != neighbors_in.second; ++neighbors_in.first) { std::cout << neighbors_in.first->idx << std::endl; } == OUTPUT == Outward adjacents 5 6 Inward adjacents 2 3 4

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cpp_rational memory bloat with repeated construction and destruction
by W Randolph Franklin 14 Mar '14

14 Mar '14

Hi, My application, overlay, constructs and destroys millions of cpp_rational variables. As overlay executes, its memory continually grows. My variables don't have that many digits, but each time that they are constructed or destroyed, they are slightly wider or narrower. W/o studying the cpp_rational source, I surmise that it uses a heap that gets badly fragmented. Apart from the space, each single allocation is probably taking ever more time. That's annoying because overlay otherwise would take linear time. What should I do? Are there easy ways to control this problem? Are other rational implementations better? Boost gives me a choice of several. Are there better implementations outside boost? ----- Not that it's relevant, but FYI, my application is to overlay two planar graphs, intersecting all the edges to find the output faces. There might be 100,000 edges. Roundoff error is a serious problem that causes topological impossibilities. The idea is to use rationals to prevent roundoff. Upon reading each input float, I use a continued fraction approximation to convert it to the closest rational justified by the number of significant digits. That entails constructing and destroying variables of varying widths as the approximation converges. This is probably what is thrashing the memory. However if I don't do that, the values start by having perhaps 20 digits, which doubles each time as line equations are computed and lines intersected. Perhaps I could restructure my code to avoid that. However IMHO, it is quite well structured now, and making it ugly to be fast would be a pity. Help? Thanks.

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Indirectly 'recursive' type erasure
by Samuel Christie 13 Mar '14

13 Mar '14

I'm trying to create a type erasure concept for a type that has a member function which can return a custom collection of itself. Having had little luck with the general formulation, I tried simplifying it to: BOOST_TYPE_ERASURE_MEMBER((has_collection), collection, 0); typedef any< mpl::vector< copy_constructible<>, typeid_<>, relaxed, has_collection<vector<_self>()> > > test; class Test { public: vector<test> collection(); }; However, I get conversion errors if the Test::collection method returns either vector<Test> or vector<test>; it only seems to match if I have it literally return vector<_self>, which implies to me that I'm not understanding what I'm doing, and that _self isn't getting substituted in this case. What do I need to do in order to be able to return types that are dependent on the erasure type? My actual code uses a more indirect relationship, with the collection method returning a custom erased collection type that has an erased iterator that can dereference to the equivalent of Test. However, since there is still a form of cyclic dependency, I'm not really sure what I can do about it. I've tried using a custom struct based concept that had direct template arguments in the place of 'boost type erasure member', but I think I understand that technique even less, and it didn't seem to help much. It looked like there might be something useful under the Associated Types section of the type erasure documentation, but I couldn't quite figure it out. Any assistance would be most helpful. Thanks, -sc

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[Coroutine] Assertion when coroutine is not run
by Brian Ravnsgaard Riis 13 Mar '14

13 Mar '14

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi, I've been toying with Boost.Coroutine lately. For starters I have tried to implement a message parser using the library. For this purpose I have two coroutine<char>::push_type in a containing class. These are initialized at class construction with a lambda. One coroutine parses the message header, the other the body. This all worked fine. Until I had a test case where I was only interested in the message header, so I never called the message-body-coroutine. At object destruction I get a this assertion: replyparser: /usr/local/include/boost/coroutine/detail/push_coroutine_object.hpp:167: void boost::coroutines::detail::push_coroutine_object<char, <lambda at src/replyparser.cpp:303:22>, boost::coroutines::detail::standard_stack_allocator, std::allocator<boost::coroutines::push_coroutine<char> >, boost::coroutines::pull_coroutine<char> >::run() [X = char, Y = <lambda at src/replyparser.cpp:303:22>, Z = boost::coroutines::detail::standard_stack_allocator, V = std::allocator<boost::coroutines::push_coroutine<char> >, W = boost::coroutines::pull_coroutine<char>]: Assertion `hldr_from->data' failed. The message-body coroutine is really simple; it just takes the characters and stuffs them into a std::string until the string size is equal to the expected length of the body (parsed from the header): [&](coroutine<char>::pull_type& c) { content.push_back(c.get()); while(content.size() != contentLength) { c(); content.push_back(c.get()); } validResult = true; } This works just fine when I parse the message body, but when I (choose to) ignore the message body, so the coroutine is never called, I get the above assertion. I have a feeling I'm missing some obvious detail about this. Of course I would normally not skip the message body, but there is a chance the length is 0, i.e. there *is* no message body. I'd prefer to have no assertions in that case. What am I doing wrong? /Brian Riis -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJTHQlPAAoJEFES4N8QrEodJ+MH/1z+N+YnXrCm3xPnp7wAlM+w 3RZkeNOOJ0h67nmBHRJXj3A3+t/Hy+FZV/SUBDMtCwx/zIH5fZZtsBaw89frAsdI SPmLiwG6NgBoBSV8Pih4gD+k4LvTbYh5AQLF2ssB/WAVZODk92iz4sNrNFVwThFn S68NStkEyyXElrCzkd3w0QQD8sD2OGWAW0YlHLGhUXlsouWRyd9VKAbEXdrTKLVQ I0ciL87AzOKsfrfV89U1eQh5uHEgg8ZcDa459ieqeOISXhNJI/ba8rv6mkXGEseB U7wRr7M1XMdHolPiFlUEKrUocdAPLS/AjeVfcGkJSzc2bhka08qu4EMTgqkOhtY= =G1Y2 -----END PGP SIGNATURE-----

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managed shared memory with basic_string
by Sean K 12 Mar '14

12 Mar '14

I am new to boost so please pardon if this question has already been asked. I was able to build a shared memory IPC client and server using "int" primitive type successfully. I need to send a fixed number of "char" (primitive type). At first I tried to define a struct of a fixed char struct { char data[1024]; } dataset; typedef dataset mychararray; and use this like how this example shows for 'int" http://en.highscore.de/cpp/boost/interprocesscommunication.html#interproces… But for some reason it did not compile due to the boost::interprocess::managed_shared_memory.construct () not accepting that kind of datatype. So, I looked at the basic_string implementation based on these two web sites. http://prakharprakhar.blogspot.com/2009/12/boost-shared-memory-vector.html http://en.highscore.de/cpp/boost/interprocesscommunication.html#interproces… (basic_string variant) I am built a reader and writer separate app. The reader will look for content. If it does not find it, it will wait or sleep and try again, etc. If it finds something it will try to print the basic_string content that I sent over. I thought I had it correctly built but obviously it is not since the reader server crashes or cores when it tries to access the p.first content. Below are the two programs (along with the build.sh which compiles each). I am testing this as a 32 bit app on a 64 bit redhat5 and 32 bit centos6. You will notice in the strreader.cc that when I try to access the basic_string, that it crashes. I ran the reader (server) within the 32 bit eclipse debugger, and the memory addresses and content of the p BStringPair looks fine. Anybody have some ideas or can anybody try this and see what you can tell what is wrong. strreader.cc #include <iostream> #include <boost/interprocess/managed_shared_memory.hpp> #include <boost/thread/thread.hpp> #include <boost/interprocess/containers/vector.hpp> #include <boost/interprocess/allocators/allocator.hpp> #include <iostream> #include <string> #include <cstdlib> using namespace std; using namespace boost::interprocess; int main() { typedef boost::interprocess::allocator<char, boost::interprocess::managed_shared_memory::segment_manager> ShmemAllocator; typedef basic_string<char, std::char_traits<char>, ShmemAllocator> BString; typedef std::pair<BString *, std::size_t> BStringPair; int count = 0; shared_memory_object::remove("Highscore"); while (true) { managed_shared_memory segment(open_or_create, "Highscore", 65536); if (segment.get_num_named_objects() > 0){ BStringPair p = segment.find<BString> ("str"); printf("stuff in memory\n"); if (p.first ){ // THIS IS WHERE IT CRASHES!!! //printf("%s \n",(p.first->c_str()) ); //int strlen = p.first->size(); } printf("p.second: %d \n", p.second); } shared_memory_object::remove("Highscore"); //printf("one: %s", one.first); //printf("two: %s", two.first); int msecs = 2000; boost::this_thread::sleep(boost::posix_time::milliseconds(msecs)); printf("sleeping...\n"); } return 0; } build.sh for the reader g++ -m32 -fPIC -Xlinker -zmuldefs strreader.cc -o strreader -I/common/COTS/boost_1_42_0/include -L/common/COTS/boost_1_42_0/lib -lboost_thread -lboost_system -pthread strwriter.cpp #include <iostream> #include <boost/interprocess/managed_shared_memory.hpp> #include <boost/thread/thread.hpp> #include <boost/interprocess/containers/vector.hpp> #include <boost/interprocess/containers/string.hpp> #include <boost/interprocess/allocators/allocator.hpp> #include <iostream> #include <string> #include <cstdlib> using namespace std; using namespace boost::interprocess; int main() { typedef boost::interprocess::allocator<char, boost::interprocess::managed_shared_memory::segment_manager> ShmemAllocator; typedef boost::interprocess::basic_string<char, std::char_traits<char>, ShmemAllocator> BString; try { shared_memory_object::remove("Highscore"); printf("cleared out memory\n"); managed_shared_memory segment(open_or_create, "Highscore", 65536); printf("initialized managed shared memory \n"); ShmemAllocator allocInst (segment.get_segment_manager()); BString bstrData(segment.get_segment_manager()); bstrData = "hello"; std::string data = "Hello"; //BString bstrToSend(data.begin(), data.end()); //BString bstrToSend(data.c_str()); BString *mystring = segment.construct<BString> ("str")(bstrData); //mystring="Hello"; printf("inserted mystring into shmvector \n"); } catch (boost::interprocess::bad_alloc e) { printf("we caught bad alloc\n"); printf("explanation: %s", e.what()); throw; } catch (...) { printf("caught unknown exception\n"); throw; } printf("wrote number"); return 0; } build.sh for the writer: g++ -m32 -fPIC -Xlinker -zmuldefs strwriter.cpp -o strwriter -I/common/COTS/boost_1_42_0/include -L/common/COTS/boost_1_42_0/lib -lboost_thread -lboost_system -pthread -- Sean

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[Boost.Preprocessor] Why BOOST_PP_SEQ_CAT with a sequence of comma separated pair is a missuse ?
by Albert 11 Mar '14

11 Mar '14

Hello, I tried to use the BOOST_PP_SEQ_CAT with a sequence of parenthesized comma-separated pair of token. It works fine with visual 2010 but fails with gcc. I first think that there were a problem in the specific gcc implementation part. That's why I opened the issue 9633 : https://svn.boost.org/trac/boost/ticket/9633 But, it has recently been closed for invalidity, the corrector telling that it is not a valid use. I have not read the entire help of the PP library but as far as I understand the sequence definition given in A.4.5.1. (http://www.boostpro.com/mplbook/preprocessor.html) as "any string of nonempty parenthesized /macro arguments/." and the definition of macro arguments in A.2.3, I fail to see why the sequence could be incorrect. Specially when I read the end of the paragraph : " It /is/ possible to pass either string of tokens above as part of a single macro argument, provided it is parenthesized: FOO(*(*std::pair<int,int>*)*) // one argument FOO(*(*{ int x = 1, y = 2; return x+y; }*)*) // one argument " I fail to see where in the dedicated entry for BOOST_PP_SEQ_CAT (http://www.boost.org/doc/libs/1_55_0/libs/preprocessor/doc/ref/seq_cat.html) there is a rule I violated. So my questions are : => why the code I proposed is invalid ? => Is the workaround proposed with BOOST_PP_SEQ_FOR_EACH is also a missused and may fail according to evolutions of the library ? Thanks in advance for your answers. The code : #include <boost\preprocessor\seq\cat.hpp> #define SOME_SEQUENCE (('a',1)) (('b',2)) (('c',3)) (('d',4)) (('e',5)) struct dummy { dummy& operator()(char,int) {return *this;} }; int main() { dummy() BOOST_PP_SEQ_CAT(SOME_SEQUENCE); // Visual 2010 generates dummy() ('a',1)('b',2)('c',3)('d',4)('e',5); // gcc fails with compiler errors due to the comma I suppose return 0; }

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boost::serialization - Serialization (non intrusive) of a map containing in and structure.
by Brian Davis 11 Mar '14

11 Mar '14

I am using boost 1.41.0 and MS VS 2008. I have been having trouble serializing a map which contains a int (key) and structure value. I create a simple test app to aid in the discussion. I am attempting to perform a non intrusive serialization of the structure. I had in the past been able to serialize a map of <int,string> successfully, but now that the map is <int, non_intrusive> where non_intrusive is the name of my strut, I get an error: 2>Windows-6.1\install\include\boost-1_41\boost/serialization/access.hpp(109) : error C2039: 'serialize' : is not a member of 'non_intrusive' and the line in boost is: template<class Archive, class T> static void serialize( Archive & ar, T & t, const unsigned int file_version ){ t.serialize(ar, file_version); // serialize( ar, t, file_version ); } Where if I change the line t.serialize(ar, file_version); to serialize( ar, t, file_version ); and then it compiles. Which of course I know I should not do, but only did so to see if I could get it to call my template specialization for my serialize code of my strut with out having to perform in intrusive serialization and agian was just a test to see if boost would call my serialize function. I have revered this so fear not... this is not the problem. namespace boost { namespace serialization { template<class Archive> void serialize( Archive& ar, non_intrusive& ni ){ ar & ni.a; } which is of course wrapped in the boost::serialization namespace... full example below I am guessing I have not done something correctly and I have been successful in the past as I said serializing structures, vectors, and maps. This is the first time I tried to serialize a map with a struct. I also converted my code (not the example) to use a vector of std::pair<int, non_intrusive> and got the same error. Here is the full program listing any help would be appreciated: //------------------------------------------------------------------------------------------- #include <string> #include <fstream> #include <algorithm> #include <boost/filesystem.hpp> #include <boost/filesystem/fstream.hpp> #include <boost/serialization/utility.hpp> #include <boost/archive/xml_oarchive.hpp> #include <boost/archive/xml_iarchive.hpp> #include <boost/serialization/string.hpp> #include <boost/serialization/map.hpp> struct non_intrusive{ int id; std::string name; }; typedef std::map<int, non_intrusive> a_map_t; namespace boost { namespace serialization { // Not sure if I need to do this bit, but I have seen references to this // syntax on the web. template<class Archive> void serialize( Archive& ar, std::pair<int, non_intrusive> & ni_pair ){ ar & std::pair<int, non_intrusive>( ni_pair ); } template<class Archive> void serialize( Archive& ar, non_intrusive& ni ){ ar & ni.a; } }} void save ( const a_map_t& map_var, const std::string& file_name ) { boost::filesystem::path file_path = file_name; boost::filesystem::path pathstr = file_path.remove_leaf(); if( pathstr != "" ) boost::filesystem::create_directory( pathstr ); std::ofstream ofs( file_name.c_str(), std::ios_base::out | std::ios_base::trunc); boost::archive::xml_oarchive xml(ofs); xml << BOOST_SERIALIZATION_NVP( map_var ); } // +---------------------------------------------------------------------- a_map_t load(const std::string& file_name) { a_map_t map_var; // std::ifstream ifs(file_name.c_str(), std::fstream::binary | std::fstream::in); std::ifstream ifs(file_name.c_str() ); if( !ifs ) { non_intrusive od; od.id = -1; od.name = "unknown device"; map_var.insert( a_map_t::value_type( 0, od ) ); save( map_var, file_name ); }else { boost::archive::xml_iarchive xml(ifs); xml >> BOOST_SERIALIZATION_NVP( map_var ); } return map_var; } // +---------------------------------------------------------------------- int main( void ){ a_map_t map; map = load("map.xml"); save(map, "map.xm" ); }

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error with static assert and floating-point detection
by Philipp Kraus 11 Mar '14

11 Mar '14

Hello, I try to use Boost Static Assert to define a template parameter only for double & floats. I use the call BOOST_STATIC_ASSERT( !boost::is_integral<T>::value ) I get in a class the error: error: no member named 'is_integral' in namespace 'boost' BOOST_STATIC_ASSERT( !boost::is_integral<T>::value ) My question is, how can I check the template parameter so that only floating-point types are allowed? How can I avoid the error? Thanks Phil

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boost::asio::io_service::poll_once vs EPOLLET
by Jason Aubrey 11 Mar '14

11 Mar '14

The conditional define of boost::asio::io_service that uses epoll always seems to use edge triggered (ET) flag instead of level triggered (LT). This makes me think poll_once should be avoided due to Scenario 1 below. Can anyone confirm this? Given: 1) 2 sockets (A and B) added to epoll interface for receiving only 2) 2 UDP messages arrive in the same moment on socket A 3) epoll_wait returns a ready socket (socket A) Scenario 1: Using ET with poll_once: 4) If io_service::poll_once is called 1 of 2 messages are read 5) epoll_wait(ET) blocks until another message is received Result: Bad, starvation if another message is not received Scenario 2: Using ET with poll: 4) If io_service::poll is called 2 of 2 messages are read 5) epoll_wait(ET) blocks until another message is received? Result: Good, all messages processed without A/B fairness (unfair since read was greedy) Scenario 3: Using LT with poll_once: 4) If io_service::poll_once is called 1 of 2 messages are read 5) epoll_wait(LT) returns a ready socket (socket A) 6) If io_service::poll_once is called 1 of 1 messages are read Result: Good, all messages processed with A/B fairness I don't think Scenario 3 is currently supported by boost::asio::io_service. Jason

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[Serialization] Avoiding multiple de-serialization
by beet 11 Mar '14

11 Mar '14

Dear Boost-Community, I have a large, "directed" tree-like data structure (i.e., no cycles), holding boost::shared_ptr's either to container-objects or "leaf-objects", i.e. individual objects not holding other objects. All shared_ptr's hold base-pointers, i.e. the leaf-objects share a common base type, but not much else. I would now like to collect statistics on some of the leaf-objects during the program run. In order to do this, I'm storing boost::shared_ptr's to the leaf objects in a container outside of the tree. Getting access to the leaf objects would otherwise be very inefficient, as the tree can have virtually any geometry (except for cycles), and I do not know the geometry in advance. The tree is repeatedly (de-)serialized, and I would like to also (de-)serialize the top-level container, so I still have easy access to the leaf-objects after de-serialization. However, it is not clear to me what happens to the leaf-objects after de-serialization of both the tree and the external container. Will the leaf-objects be de-serialized twice ? Or might there be different leaf-objects in the external container and in the tree ? Thanks for any insight you may provide. Best Regards, beet

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Composer issue with boost::log::sinks::event_log on VS2010
by Konrad Rybacki 11 Mar '14

11 Mar '14

Hello, I use basic_event_log_backend according to documentation<http://www.boost.org/doc/libs/1_55_0/libs/log/doc/html/log/detailed/sink_ba…>- I add formatters to events with event_composer: sinks::event_log::event_composer composer( sinks::event_log::direct_event_id_mapping<int>("EventId") ); composer[MSG1] % expr::attr<WORD>("Tag1"); composer[MSG2] % expr::attr<DWORD>("Tag2"); composer[MSG3] % expr::attr<std::string>("Tag3"); backend->set_event_composer(composer); Unfortunately event log entries in event viewer are incomplete - i.e. there are still "%n" placeholders instead of their values. From what I have found while inspecting the code with debugger it seems that event_map_reference& operator% (FormatterT const& fmt)is never hit - so m_EventMap in composer is empty. I added a method that works the same way as mentioned operator: template< typename FormatterT > event_map_reference& add_formatter(FormatterT const &fmt) { m_Composer = m_Owner.add_formatter(m_ID, m_Composer, formatter_type(fmt)); return *this; } and call it explicitly, so the code looks like that: composer[MSG1].add_formatter(expr::attr<WORD>("Tag1")); composer[MSG2].add_formatter(expr::attr<DWORD>("Tag2")); composer[MSG3].add_formatter(expr::attr<std::string>("Tag3")); Now m_EventMap has three items - and I get empty strings instead of "%n" in event viewer. I pass the tag values with boost macro, i.e.: BOOST_LOG_SCOPED_THREAD_TAG("Tag3", std::string("value")); I am using Visual Studio 2010 compiler. Any ideas? Regards, Konrad.

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Customizing locale of stream for Boost.Serialization seems to fail
by Christophe Fuzier 11 Mar '14

11 Mar '14

Hi, I have a problem with Boost.Serialization. I have posted a question on a forum but have not got any answer until now. Here is the reproduction of my post (note: I'm using Boost 1.48, patch level 0). I need to use Boost.Serialization to serialize floating-point numbers. Since NaN and infinites cannot natively be read from an input stream, I am trying to use the facets in boost/math/special_functions. I have tested them on my platform using code similar to the examples we can find here: http://www.boost.org/doc/libs/1_50_0/libs/math/doc/sf_and_dist/html/math_to… However, the following code still fails to properly unserialize non-finite floating point values (an exception is thrown with description "input stream error"). #include <limits> #include <locale> #include <sstream> #include <boost/archive/xml_iarchive.hpp> #include <boost/archive/xml_oarchive.hpp> #include <boost/math/special_functions/nonfinite_num_facets.hpp> #include <boost/serialization/nvp.hpp> struct Data { float f; Data() : f(std::numeric_limits<float>::quiet_NaN()) {} template <class Archive> void serialize(Archive & ar, unsigned const) { ar & BOOST_SERIALIZATION_NVP(f); } }; void test() { using namespace boost::archive; Data d; std::ostringstream oss; xml_oarchive oar(oss); oar << BOOST_SERIALIZATION_NVP(d); //std::cout << oss.str() << std::endl; std::istringstream iss(oss.str()); std::locale const new_loc(iss.getloc(), new boost::math::nonfinite_num_get<char>); iss.imbue(new_loc); xml_iarchive iar(iss); iar >> BOOST_SERIALIZATION_NVP(d); std::cout << d.f << std::endl; } Am I doing something wrong? Is there a problem with my Boost version or my platform? Is there a better solution? Any help would be greatly appreciated. <END OF POST> Thank you in advance for any suggestion. Christophe Fuzier

1 1

Re: [Boost-users] Problems with Boost 1.41
by Ксения Сафина 10 Mar '14

10 Mar '14

Thank you, Ben My platform is x86_64. I have any experience with Boost and c++ language at all so I'm sorry for asking questions like this. The errors like "Threading support unavaliable: it has been explicitly disabled with BOOST_DISABLE_THREADS" are not clear for me. I mean I have any ideas about where do they come from. gcc -v gives me "Using built-in specs. COLLECT_GCC=gcc COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/4.7/lto-wrapper Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu/Linaro 4.7.3-1ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-4.7/README.Bugs --enable-languages=c,c++,go,fortran,objc,obj-c++ --prefix=/usr --program-suffix=-4.7 --enable-shared --enable-linker-build-id --libexecdir=/usr/lib --without-included-gettext --enable-threads=posix --with-gxx-include-dir=/usr/include/c++/4.7 --libdir=/usr/lib --enable-nls --with-sysroot=/ --enable-clocale=gnu --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-gnu-unique-object --enable-plugin --with-system-zlib --enable-objc-gc --with-cloog --enable-cloog-backend=ppl --disable-cloog-version-check --disable-ppl-version-check --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --with-tune=generic --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu Thread model: posix gcc version 4.7.3 (Ubuntu/Linaro 4.7.3-1ubuntu1) " Is there something wrong with these options? Ksenia > >Date: Mon, 10 Mar 2014 11:42:02 +0800 >From: Ben Pope < benpope81(a)gmail.com > >To: boost-users(a)lists.boost.org >Subject: Re: [Boost-users] Problems with Boost 1.41 >Message-ID: < lfjcb4$kvb$1(a)ger.gmane.org > >Content-Type: text/plain; charset=UTF-8; format=flowed > >On Sunday, March 09, 2014 06:05 PM, ?????? ?????? wrote: >> Hi everyone, >> >> I'm trying to build this >> http://vina.scripps.edu/manual.html#build program using Boost 1.41. >> >> 'make' command gives me a large amount of errors: > >snip > >> error: #error >> "Threading support unavaliable: it has been explicitly disabled with >> BOOST_DISABLE_THREADS" > >snip > >> error: #error >> "Sorry, no boost threads are available for this platform." > >snip > >> Could anyone help me to understand what do these all errors mean? > >I think the error messages are quite clear. > >> I'm on Ubuntu 13.04, gcc version is 4.7.3 (Ubuntu/Linaro 4.7.3-1ubuntu1) > >I hesitate to ask, but what architecture is your platform? > >Boost 1.41 was tested with gcc 4.4.1 on Ubuntu (and some older >compilers), the platform is not mentioned, but it's probably x86 or >x86_64. It's possible that you need to modify the compiler >configuration to accept the newer gcc and/or libstdc++. > >Ben > >Date: Sun, 09 Mar 2014 14:05:41 +0400 >From: ?????? ?????? < cat7mail.ru(a)mail.ru > >To: boost-users(a)lists.boost.org >Subject: [Boost-users] Problems with Boost 1.41 >Message-ID: < 1394359541.299650432(a)f329.i.mail.ru > >Content-Type: text/plain; charset="utf-8" > > Hi everyone, > >I'm trying to build this http://vina.scripps.edu/manual.html#build ?program using Boost 1.41. > >'make' ?command gives me a large amount of errors: >? >noraneko@noraneko-K53SJ:~/Programs/autodock_vina_1_1_2/build/linux/release$ make/usr/bin/g++ -static -pthread -ansi -Wno-long-long -O3 -DNDEBUG -I /usr/local/include -I ../../../src/lib -o main.o -c ../../../src/main/main.cpp >In file included from /usr/local/include/boost/thread/detail/platform.hpp:17:0, >from /usr/local/include/boost/thread/thread.hpp:12, >from ../../../src/main/main.cpp:32: >/usr/local/include/boost/config/requires_threads.hpp:29:4: error: #error "Threading support unavaliable: it has been explicitly disabled with BOOST_DISABLE_THREADS" >In file included from /usr/local/include/boost/thread/thread.hpp:12:0, >from ../../../src/main/main.cpp:32: >/usr/local/include/boost/thread/detail/platform.hpp:67:9: error: #error "Sorry, no boost threads are available for this platform." >In file included from ../../../src/main/main.cpp:32:0: >/usr/local/include/boost/thread/thread.hpp:19:2: error: #error "Boost threads unavailable on this platform" >In file included from /usr/local/include/boost/thread/detail/thread.hpp:11:0, >from /usr/local/include/boost/thread/thread.hpp:22, >from ../../../src/main/main.cpp:32: >/usr/local/include/boost/thread/mutex.hpp:18:2: error: #error "Boost threads unavailable on this platform" >In file included from /usr/local/include/boost/thread/detail/thread.hpp:13:0, >from /usr/local/include/boost/thread/thread.hpp:22, >from ../../../src/main/main.cpp:32: >/usr/local/include/boost/thread/detail/thread_heap_alloc.hpp:19:2: error: #error "Boost threads unavailable on this platform" >In file included from /usr/local/include/boost/thread/detail/thread_group.hpp:9:0, >from /usr/local/include/boost/thread/thread.hpp:24, >from ../../../src/main/main.cpp:32: >/usr/local/include/boost/thread/shared_mutex.hpp:18:2: error: #error "Boost threads unavailable on this platform" >In file included from /usr/local/include/boost/thread/thread.hpp:22:0, >from ../../../src/main/main.cpp:32: >/usr/local/include/boost/thread/detail/thread.hpp:40:9: error: expected class-name before ?{? token >/usr/local/include/boost/thread/detail/thread.hpp:68:9: error: expected class-name before ?{? token >/usr/local/include/boost/thread/detail/thread.hpp:88:9: error: expected class-name before ?{? token >/usr/local/include/boost/thread/detail/thread.hpp:113:17: error: ?mutex? in namespace ?boost? does not name a type >/usr/local/include/boost/thread/detail/thread.hpp:114:9: error: ?thread_data_ptr? in namespace ?boost::detail? does not name a type >/usr/local/include/boost/thread/detail/thread.hpp:118:49: error: expected ?)? before ?data? >/usr/local/include/boost/thread/detail/thread.hpp:120:9: error: ?thread_data_ptr? in namespace ?boost::detail? does not name a type >In file included from /usr/local/include/boost/thread/thread.hpp:22:0, >from ../../../src/main/main.cpp:32: >/usr/local/include/boost/thread/detail/thread.hpp:134:23: error: ?thread_data_ptr? in namespace ?boost::detail? does not name a type >/usr/local/include/boost/thread/detail/thread.hpp:139:23: error: ?thread_data_ptr? in namespace ?boost::detail? does not name a type >/usr/local/include/boost/thread/detail/thread.hpp:319:17: error: ?thread_data_base? in namespace ?boost::detail? does not name a type >/usr/local/include/boost/thread/detail/thread.hpp:320:9: error: ?native_handle_type? does not name a type >/usr/local/include/boost/thread/detail/thread.hpp: In constructor ?boost::thread::thread(F, typename boost::disable_if<boost::is_convertible<T&, boost::detail::thread_move_t<T> >, boost::thread::dummy*>::type)?: >/usr/local/include/boost/thread/detail/thread.hpp:189:13: error: class ?boost::thread? does not have any field named ?thread_info? >/usr/local/include/boost/thread/detail/thread.hpp: In constructor ?boost::thread::thread(boost::detail::thread_move_t<T>)?: >/usr/local/include/boost/thread/detail/thread.hpp:197:13: error: class ?boost::thread? does not have any field named ?thread_info? >/usr/local/include/boost/thread/detail/thread.hpp: In constructor ?boost::thread::thread(boost::detail::thread_move_t<boost::thread>)?: >/usr/local/include/boost/thread/detail/thread.hpp:204:13: error: ?thread_info? was not declared in this scope >/usr/local/include/boost/thread/detail/thread.hpp:204:28: error: ?class boost::thread? has no member named ?thread_info? >/usr/local/include/boost/thread/detail/thread.hpp:205:16: error: ?class boost::thread? has no member named ?thread_info? >/usr/local/include/boost/thread/detail/thread.hpp: In constructor ?boost::thread::thread(F, A1)?: >/usr/local/include/boost/thread/detail/thread.hpp:237:13: error: class ?boost::thread? does not have any field named ?thread_info? >/usr/local/include/boost/thread/detail/thread.hpp: In constructor ?boost::thread::thread(F, A1, A2)?: >/usr/local/include/boost/thread/detail/thread.hpp:243:13: error: class ?boost::thread? does not have any field named ?thread_info? >/usr/local/include/boost/thread/detail/thread.hpp: In constructor ?boost::thread::thread(F, A1, A2, A3)?: >/usr/local/include/boost/thread/detail/thread.hpp:250:13: error: class ?boost::thread? does not have any field named ?thread_info? >.... >/usr/local/include/boost/thread/detail/thread_group.hpp: In member function ?void boost::thread_group::remove_thread(boost::thread*)?: >/usr/local/include/boost/thread/detail/thread_group.hpp:55:13: error: ?lock_guard? is not a member of ?boost? >/usr/local/include/boost/thread/detail/thread_group.hpp:55:31: error: ?shared_mutex? was not declared in this scope >/usr/local/include/boost/thread/detail/thread_group.hpp:55:51: error: ?m? was not declared in this scope >/usr/local/include/boost/thread/detail/thread_group.hpp:55:52: error: ?guard? was not declared in this scope >/usr/local/include/boost/thread/detail/thread_group.hpp: In member function ?void boost::thread_group::join_all()?: >/usr/local/include/boost/thread/detail/thread_group.hpp:65:13: error: ?shared_lock? is not a member of ?boost? >/usr/local/include/boost/thread/detail/thread_group.hpp:65:32: error: ?shared_mutex? was not declared in this scope >/usr/local/include/boost/thread/detail/thread_group.hpp:65:52: error: ?m? was not declared in this scope >/usr/local/include/boost/thread/detail/thread_group.hpp:65:53: error: ?guard? was not declared in this scope >/usr/local/include/boost/thread/detail/thread_group.hpp: In member function ?void boost::thread_group::interrupt_all()?: >/usr/local/include/boost/thread/detail/thread_group.hpp:77:13: error: ?shared_lock? is not a member of ?boost? >/usr/local/include/boost/thread/detail/thread_group.hpp:77:32: error: ?shared_mutex? was not declared in this scope >/usr/local/include/boost/thread/detail/thread_group.hpp:77:52: error: ?m? was not declared in this scope >/usr/local/include/boost/thread/detail/thread_group.hpp:77:53: error: ?guard? was not declared in this scope >/usr/local/include/boost/thread/detail/thread_group.hpp: In member function ?size_t boost::thread_group::size() const?: >/usr/local/include/boost/thread/detail/thread_group.hpp:89:13: error: ?shared_lock? is not a member of ?boost? >/usr/local/include/boost/thread/detail/thread_group.hpp:89:32: error: ?shared_mutex? was not declared in this scope >/usr/local/include/boost/thread/detail/thread_group.hpp:89:52: error: ?m? was not declared in this scope >/usr/local/include/boost/thread/detail/thread_group.hpp:89:53: error: ?guard? was not declared in this scope >make: *** [main.o] Error 1 > >Could anyone help me to understand what do these all errors mean?? > >I'm on Ubuntu 13.04, gcc version is 4.7.3 (Ubuntu/Linaro 4.7.3-1ubuntu1)? > >Ksenia

2 5

Problems with Boost 1.41
by Ксения Сафина 10 Mar '14

10 Mar '14

Hi everyone, I'm trying to build this http://vina.scripps.edu/manual.html#build program using Boost 1.41. 'make' command gives me a large amount of errors: noraneko@noraneko-K53SJ:~/Programs/autodock_vina_1_1_2/build/linux/release$ make/usr/bin/g++ -static -pthread -ansi -Wno-long-long -O3 -DNDEBUG -I /usr/local/include -I ../../../src/lib -o main.o -c ../../../src/main/main.cpp In file included from /usr/local/include/boost/thread/detail/platform.hpp:17:0, from /usr/local/include/boost/thread/thread.hpp:12, from ../../../src/main/main.cpp:32: /usr/local/include/boost/config/requires_threads.hpp:29:4: error: #error "Threading support unavaliable: it has been explicitly disabled with BOOST_DISABLE_THREADS" In file included from /usr/local/include/boost/thread/thread.hpp:12:0, from ../../../src/main/main.cpp:32: /usr/local/include/boost/thread/detail/platform.hpp:67:9: error: #error "Sorry, no boost threads are available for this platform." In file included from ../../../src/main/main.cpp:32:0: /usr/local/include/boost/thread/thread.hpp:19:2: error: #error "Boost threads unavailable on this platform" In file included from /usr/local/include/boost/thread/detail/thread.hpp:11:0, from /usr/local/include/boost/thread/thread.hpp:22, from ../../../src/main/main.cpp:32: /usr/local/include/boost/thread/mutex.hpp:18:2: error: #error "Boost threads unavailable on this platform" In file included from /usr/local/include/boost/thread/detail/thread.hpp:13:0, from /usr/local/include/boost/thread/thread.hpp:22, from ../../../src/main/main.cpp:32: /usr/local/include/boost/thread/detail/thread_heap_alloc.hpp:19:2: error: #error "Boost threads unavailable on this platform" In file included from /usr/local/include/boost/thread/detail/thread_group.hpp:9:0, from /usr/local/include/boost/thread/thread.hpp:24, from ../../../src/main/main.cpp:32: /usr/local/include/boost/thread/shared_mutex.hpp:18:2: error: #error "Boost threads unavailable on this platform" In file included from /usr/local/include/boost/thread/thread.hpp:22:0, from ../../../src/main/main.cpp:32: /usr/local/include/boost/thread/detail/thread.hpp:40:9: error: expected class-name before ‘{’ token /usr/local/include/boost/thread/detail/thread.hpp:68:9: error: expected class-name before ‘{’ token /usr/local/include/boost/thread/detail/thread.hpp:88:9: error: expected class-name before ‘{’ token /usr/local/include/boost/thread/detail/thread.hpp:113:17: error: ‘mutex’ in namespace ‘boost’ does not name a type /usr/local/include/boost/thread/detail/thread.hpp:114:9: error: ‘thread_data_ptr’ in namespace ‘boost::detail’ does not name a type /usr/local/include/boost/thread/detail/thread.hpp:118:49: error: expected ‘)’ before ‘data’ /usr/local/include/boost/thread/detail/thread.hpp:120:9: error: ‘thread_data_ptr’ in namespace ‘boost::detail’ does not name a type In file included from /usr/local/include/boost/thread/thread.hpp:22:0, from ../../../src/main/main.cpp:32: /usr/local/include/boost/thread/detail/thread.hpp:134:23: error: ‘thread_data_ptr’ in namespace ‘boost::detail’ does not name a type /usr/local/include/boost/thread/detail/thread.hpp:139:23: error: ‘thread_data_ptr’ in namespace ‘boost::detail’ does not name a type /usr/local/include/boost/thread/detail/thread.hpp:319:17: error: ‘thread_data_base’ in namespace ‘boost::detail’ does not name a type /usr/local/include/boost/thread/detail/thread.hpp:320:9: error: ‘native_handle_type’ does not name a type /usr/local/include/boost/thread/detail/thread.hpp: In constructor ‘boost::thread::thread(F, typename boost::disable_if<boost::is_convertible<T&, boost::detail::thread_move_t<T> >, boost::thread::dummy*>::type)’: /usr/local/include/boost/thread/detail/thread.hpp:189:13: error: class ‘boost::thread’ does not have any field named ‘thread_info’ /usr/local/include/boost/thread/detail/thread.hpp: In constructor ‘boost::thread::thread(boost::detail::thread_move_t<T>)’: /usr/local/include/boost/thread/detail/thread.hpp:197:13: error: class ‘boost::thread’ does not have any field named ‘thread_info’ /usr/local/include/boost/thread/detail/thread.hpp: In constructor ‘boost::thread::thread(boost::detail::thread_move_t<boost::thread>)’: /usr/local/include/boost/thread/detail/thread.hpp:204:13: error: ‘thread_info’ was not declared in this scope /usr/local/include/boost/thread/detail/thread.hpp:204:28: error: ‘class boost::thread’ has no member named ‘thread_info’ /usr/local/include/boost/thread/detail/thread.hpp:205:16: error: ‘class boost::thread’ has no member named ‘thread_info’ /usr/local/include/boost/thread/detail/thread.hpp: In constructor ‘boost::thread::thread(F, A1)’: /usr/local/include/boost/thread/detail/thread.hpp:237:13: error: class ‘boost::thread’ does not have any field named ‘thread_info’ /usr/local/include/boost/thread/detail/thread.hpp: In constructor ‘boost::thread::thread(F, A1, A2)’: /usr/local/include/boost/thread/detail/thread.hpp:243:13: error: class ‘boost::thread’ does not have any field named ‘thread_info’ /usr/local/include/boost/thread/detail/thread.hpp: In constructor ‘boost::thread::thread(F, A1, A2, A3)’: /usr/local/include/boost/thread/detail/thread.hpp:250:13: error: class ‘boost::thread’ does not have any field named ‘thread_info’ .... /usr/local/include/boost/thread/detail/thread_group.hpp: In member function ‘void boost::thread_group::remove_thread(boost::thread*)’: /usr/local/include/boost/thread/detail/thread_group.hpp:55:13: error: ‘lock_guard’ is not a member of ‘boost’ /usr/local/include/boost/thread/detail/thread_group.hpp:55:31: error: ‘shared_mutex’ was not declared in this scope /usr/local/include/boost/thread/detail/thread_group.hpp:55:51: error: ‘m’ was not declared in this scope /usr/local/include/boost/thread/detail/thread_group.hpp:55:52: error: ‘guard’ was not declared in this scope /usr/local/include/boost/thread/detail/thread_group.hpp: In member function ‘void boost::thread_group::join_all()’: /usr/local/include/boost/thread/detail/thread_group.hpp:65:13: error: ‘shared_lock’ is not a member of ‘boost’ /usr/local/include/boost/thread/detail/thread_group.hpp:65:32: error: ‘shared_mutex’ was not declared in this scope /usr/local/include/boost/thread/detail/thread_group.hpp:65:52: error: ‘m’ was not declared in this scope /usr/local/include/boost/thread/detail/thread_group.hpp:65:53: error: ‘guard’ was not declared in this scope /usr/local/include/boost/thread/detail/thread_group.hpp: In member function ‘void boost::thread_group::interrupt_all()’: /usr/local/include/boost/thread/detail/thread_group.hpp:77:13: error: ‘shared_lock’ is not a member of ‘boost’ /usr/local/include/boost/thread/detail/thread_group.hpp:77:32: error: ‘shared_mutex’ was not declared in this scope /usr/local/include/boost/thread/detail/thread_group.hpp:77:52: error: ‘m’ was not declared in this scope /usr/local/include/boost/thread/detail/thread_group.hpp:77:53: error: ‘guard’ was not declared in this scope /usr/local/include/boost/thread/detail/thread_group.hpp: In member function ‘size_t boost::thread_group::size() const’: /usr/local/include/boost/thread/detail/thread_group.hpp:89:13: error: ‘shared_lock’ is not a member of ‘boost’ /usr/local/include/boost/thread/detail/thread_group.hpp:89:32: error: ‘shared_mutex’ was not declared in this scope /usr/local/include/boost/thread/detail/thread_group.hpp:89:52: error: ‘m’ was not declared in this scope /usr/local/include/boost/thread/detail/thread_group.hpp:89:53: error: ‘guard’ was not declared in this scope make: *** [main.o] Error 1 Could anyone help me to understand what do these all errors mean? I'm on Ubuntu 13.04, gcc version is 4.7.3 (Ubuntu/Linaro 4.7.3-1ubuntu1) Ksenia

2 1

[boost::thread] Starting thread at specific time
by Kyle Ketterer 09 Mar '14

09 Mar '14

Hello all, I am working on an application which I originally wrote as a console app and am now transforming into a Windows service. Basically, looking for a little advice. My goal is to have an independent service which starts at a specific time and only runs for a set amount of hours. The code I am currently contemplating looks like this: ---------------------------------------------------------------- int start_hour = 18; //6pm time_t t = time(0); //current time struct tm* now = localtime ( &t ); //total time the app should run for boost::posix_time::time_duration run_duration ( 10, 0, 0, 0 ); //current time relative duration boost::posix_time::time_duration start_duration ( now->tm_hour, now->tm_min, now->tm_sec ); //get duration until service start boost::posix_time::time_duration diff = boost::posix_time::hours(start_hour) - boost::posix_time::milliseconds (start_duration.total_milliseconds() ); //dont start thread until designated start time boost::thread thr ( &ServiceWorkerThread ); //sleep this thread until ready to start boost::this_thread::sleep( boost::posix_time::milliseconds( diff.total_milliseconds() ) ); if ( thr.timed_join( run_duration ) ) { //do stuff } ------------------------------------------------------------- Basically, I am trying to make use of the time_duration class to achieve this. Based on the code above, I want to run the service for 10 hours, but not start it until the correct hour. Somewhere near the end of the service entry I will restart the service and the service *should* until the correct time and only execute for X hours. I am looking for further suggestions/improvements based on the above. Thanks!

4 4

boost::geometry::index::rtree with different CoordinateSystem
by Ola Martin Lykkja 08 Mar '14

08 Mar '14

Hi, I am trying to build a rtree index with a collection if waypoint (about 30.000) each represented by longitude and latitude. When I use Cartesian coordinates rtree.query works as expected. However the results are slightly wrong because of my use of longitude,latitude in the cartesian domain. I then tried to refine the datatypes to use spherical_equatorial and geographic CoordinateSystem. Now I encounter two problems: a) With geographic, it does not compile. b) With spherical_equatorial query(nearest) gives clearly wrong results. Do you have any clues on what I am doing wrong? Attached is two images illustrating the query results. Search target is dot with label on it. I am using boost 1.55.0 on Linux with g++ 4.4.3 (same result with 4.6.3). typedef bg::model::point<double, 2, bg::cs::cartesian> geo_point; typedef bg::model::point<double, 2, bg::cs::spherical_equatorial<bg::degree> > geo_point_with_wrong_results; typedef bg::model::point<double, 2, bg::cs::geographic<bg::degree> > geo_point_does_not_compile; typedef std::pair<geo_point, unsigned int> geo_vg_value; void test() { iterate_over_all_waypoints (wp) { geo_point pt(wp->on, wp->lat); rtree.insert(std::make_pair(pt, wp->id)); } std::vector<geo_vg_value> result; geo_point here(targetLat, targetLat); rtree.query(bgi::nearest(here, 20), std::back_inserter(result)); } Kind regards, Ola Martin

2 1

don't give template arguments to make_iterator_range
by Matei David 07 Mar '14

07 Mar '14

Hi, I recently came across an issue with make_iterator_range(), which is used to externally construct iterator_range objects. The problem is that if a template argument is explicitly specified, gcc 4.8.2 refuses to compile the code. In the meantime, clang 3.4 compiles it without warnings. This runs contrary to the intuition that specifying a template argument can only help (speed up) compilation. You might want to make a note about this in the documentation to Boost Range: "Don't give an explicit template argument to make_iterator_range! If you do, the program will be ill-formed!" The heavily simplified problem is explained here: http://stackoverflow.com/questions/22258054/c-inconsistency-between-gcc-and… The internal Boost Range details are the following. As described here: http://www.boost.org/doc/libs/1_55_0/libs/range/doc/html/range/reference/ut… make_iterator_range has 5 overloads, all of which are template functions. Consider the 1st and 4th overloads: template <typename It> iterator_range<It> make_iterator_range(It, It); template <typename R> iterator_range<typename range_iterator<R>::type> make_iterator_range(Range&, typename range_difference<R>::type, typename range_difference<R>::type); The problem occurs if I write something like: Some_Iterator it; auto r = make_iterator_range<Some_Iterator>(it, it); Specifically, when gcc encounters this call to make_iterator_range, for a reason I don't fully understand (but others do, see the reply on SO), it does not eliminate the 2nd overload listed above from consideration, and instead it tries to instantiate the bogus type range_iterator<R> with R=Some_Iterator. I say "bogus" because the template argument of range_iterator is meant to be a range, not an iterator. In turn, this triggers a compilation error. In the meantime, clang happily eliminates the 2nd overload, probably based on the fact that it needs 3 arguments, not 2 as are given in the call. The problem disappears if I don't give an explicit template argument: auto r = make_iterator_range(it, it); even though the correct overload is indeed the first one, with argument Some_Iterator. Apparently giving an explicit template argument at that point makes the program ill-formed. I don't fully understand why, but see the SO comments. M

1 0

first time user
by Pubudu Bandara 07 Mar '14

07 Mar '14

I have downloaded boost and did build the boost libraries according to http://www.boost.org/doc/libs/1_55_0/more/getting_started/windows.html and configured VS2008 as well. but when i'm trying to use #include <boost/thread.hpp> it gives following set of compilation errors. 1>C:\Program Files\boost_1_55_0\boost/smart_ptr/detail/sp_counted_base_w32.hpp(74) : error C3861: '_InterlockedIncrement': identifier not found 1>C:\Program Files\boost_1_55_0\boost/smart_ptr/detail/sp_counted_base_w32.hpp(93) : error C3861: '_InterlockedCompareExchange': identifier not found 1>C:\Program Files\boost_1_55_0\boost/smart_ptr/detail/sp_counted_base_w32.hpp(101) : error C3861: '_InterlockedDecrement': identifier not found 1>C:\Program Files\boost_1_55_0\boost/smart_ptr/detail/sp_counted_base_w32.hpp(110) : error C3861: '_InterlockedIncrement': identifier not found 1>C:\Program Files\boost_1_55_0\boost/smart_ptr/detail/sp_counted_base_w32.hpp(115) : error C3861: '_InterlockedDecrement': identifier not found 1>C:\Program Files\boost_1_55_0\boost/smart_ptr/detail/spinlock_w32.hpp(62) : error C3861: '_InterlockedExchange': identifier not found 1>C:\Program Files\boost_1_55_0\boost/thread/win32/thread_data.hpp(130) : error C3861: '_InterlockedIncrement': identifier not found 1>C:\Program Files\boost_1_55_0\boost/thread/win32/thread_data.hpp(135) : error C3861: '_InterlockedDecrement': identifier not found 1>C:\Program Files\boost_1_55_0\boost/thread/win32/basic_timed_mutex.hpp(52) : error C3861: '_InterlockedExchange': identifier not found 1>C:\Program Files\boost_1_55_0\boost/thread/win32/basic_timed_mutex.hpp(100) : error C3861: '_InterlockedCompareExchange': identifier not found 1>C:\Program Files\boost_1_55_0\boost/thread/win32/basic_timed_mutex.hpp(118) : error C3861: '_InterlockedCompareExchange': identifier not found 1>C:\Program Files\boost_1_55_0\boost/thread/win32/basic_timed_mutex.hpp(147) : error C3861: '_InterlockedDecrement': identifier not found 1>C:\Program Files\boost_1_55_0\boost/thread/win32/basic_timed_mutex.hpp(210) : error C3861: '_InterlockedDecrement': identifier not found 1>C:\Program Files\boost_1_55_0\boost/thread/win32/basic_timed_mutex.hpp(225) : error C3861: '_InterlockedExchangeAdd': identifier not found 1>C:\Program Files\boost_1_55_0\boost/thread/win32/basic_timed_mutex.hpp(248) : error C3861: '_InterlockedCompareExchange': identifier not found 1>C:\Program Files\boost_1_55_0\boost/thread/win32/condition_variable.hpp(68) : error C3861: '_InterlockedIncrement': identifier not found 1>C:\Program Files\boost_1_55_0\boost/thread/win32/condition_variable.hpp(73) : error C3861: '_InterlockedDecrement': identifier not found 1>C:\Program Files\boost_1_55_0\boost/thread/win32/condition_variable.hpp(110) : error C3861: '_InterlockedIncrement': identifier not found 1>C:\Program Files\boost_1_55_0\boost/thread/win32/condition_variable.hpp(115) : error C3861: '_InterlockedDecrement': identifier not found 1>C:\Program Files\boost_1_55_0\boost/thread/win32/once.hpp(183) : error C3861: '_InterlockedCompareExchange': identifier not found 1>C:\Program Files\boost_1_55_0\boost/thread/win32/once.hpp(202) : error C3861: '_InterlockedIncrement': identifier not found 1>C:\Program Files\boost_1_55_0\boost/thread/win32/once.hpp(205) : error C3861: '_InterlockedExchange': identifier not found 1>C:\Program Files\boost_1_55_0\boost/thread/win32/once.hpp(218) : error C3861: '_InterlockedExchange': identifier not found 1>C:\Program Files\boost_1_55_0\boost/thread/win32/once.hpp(741) : error C3861: '_InterlockedIncrement': identifier not found help me on this issue. -- Pubudu Bandara Undergraduate Department of Computer Science and Engineering University of Moratuwa

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boost::tribool "if ( someTriboolVar == indeterminate )" semantics is confusing
by Peter Hackett 06 Mar '14

06 Mar '14

I started using tribool recently. I just discovered that I was using it incorrectly. I had code that did something like: tribool triboolVar1 = indeterminate; if ( triboolVar1 == indeterminate ) { cout << "triboolVar1 is indeterminate" << endl; } else { cout << "triboolVar1 is NOT indeterminate" << endl; } I was expecting this to print "triboolVar1 is indeterminate". However it prints "triboolVar1 is NOT indeterminate". I ended up looking through "include/boost/logic/tribool.hpp" and after a bit of head scratching, I think I understand why this doesn't do what I expect: The above "if" line is "really" (pseudo-code): if ( operator==(tribool triboolVar1,tribool indeterminate) ) { where operator== returns a tribool, and (I think) tribool::operator safe_bool() const { return value == true_value? &dummy::nonnull : 0; } is used to turn the tribool into a bool. And give that operator== says: ... if (indeterminate(x) || indeterminate(y)) return indeterminate; ... Then clearly no matter what the value of triboolVar1 is, the "if" code will be false. I haven't had any schooling in what (I'm assuming) might be called something like "Multi-Level-Logic", but: Shouldn't an "indeterminate" value equal another "indeterminate" value? -- Peter Hackett Member of Technical Staff IC Manage http://icmanage.com phone (408) 358-8191 x6012

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Boost Serialization Difference in Archive Versions
by Lynn Gilbert 06 Mar '14

06 Mar '14

Hope everyone is doing well. I'm having an issue with boost serialization. I have serialized a file on my ODroid U2 using Boost v1.53. I'm trying to deserialize the file on a computer which only has Boost v1.46; however, line 7 below causes the following error: CMyClass Exception thrown: unsupported version Code: 1 void CMyClass::enableDeserialize(std::string file, bool binary) { 2 filename = file ; 3 isBinary = binary ; 4 ifs = new std::ifstream(file.c_str()) ; 5 try { 6 if (isBinary) { 7 CMyClass::ib = new boost::archive::binary_iarchive(*ifs) ; 8 } else { 9 CMyClass::ia = new boost::archive::text_iarchive(*ifs) ; 10 } 11 } catch (boost::archive::archive_exception e) { 12 std::cout << "CMyClass Exception thrown: " << e.what() << std::endl ; 13 } 14 } The boost archive version for v1.53 (version I serialized with) is 10 and the boost archive version for v1.46 (the version I'm trying to deserialize with) is 9. Boost documentation hasn't helped me determine the differences between the 2 archive versions. I've only been able to find answers for how to deserialize an older archive. Please note, I don't do anything with BOOST_CLASS_VERSION. CMyClass hasn't changed at all. I can't imagine boost can handle the deserialization of a newer archive so I don't feel like I'm missing that answer. What I need to know if if there is a way I can serialize in v1.53 based on boost archive version 9 instead of 10. I'm hoping the new version of boost will still allow me to serialize at an older version. Then, I should be able to deserialize the archive just fine. Any advice you could provide is much appreciated! -- Lynn Coddington Gilbert Partner, Robotic Paradigm Systems www.roboticparadigmsystems.com www.facebook.com/RoboticParadigmSystems lynn(a)roboticparadigmsystems.com 678-428-0935

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\boost\cstdint.hpp(129) : error C2059: syntax error : '::'
by Uthpal Urubail 05 Mar '14

05 Mar '14

I am trying use boost in my application. I am getting compiler error, if I try to include headers after one of the application include file where uint64_t is defined. #if defined(OS_WIN) && !defined(uint64_t) #define uint64_t unsigned __int64 #endif Error: Can some one help me find the better solution to resolve these type of issues? Regards, UJ

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CMake and Boost
by Koteswara Rao Ruvva 05 Mar '14

05 Mar '14

Hello All, I built boost libraries with the option build-type=complete and created libraries for various options, like gcc54-mt, gcc45-mt-d, gcc45-mt-s, gcc-54mt-sd etc. I have similar ones for intel toolchain too. Now, how do I force CMake to link to the correct library file out of many versions? Do I have to specify the full library name? Or can I specify the build type, like debug, multi-threading etc and leave the CMake to choose the right file to link? Is there such an option? I'm building on Linux under gcc and intel compilers and keeping both gcc and intel library files in one folder. Thank you all for being there to help the community. --Kotesh

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relocation R_X86_64_32 against
by Koteswara Rao Ruvva 04 Mar '14

04 Mar '14

Hello All, I'm a newbie to this mailing list. I am trying to build static boost libraries and link to my libraries. I used ./bjam debug link=static cxxflags="-std=c++0x" stage to build the boost libraries. When I build my libraries (shared or static) with linking to boost libraries, I get the following error: libboost_regex.a(instances.o): relocation R_X86_64_32 against `.bss' can not be used when making a shared object; recompile with -fPIC libboost_regex.a: could not read symbols: Bad value Then I tried adding -fPIC while building my boost libraries. Didn't help. Any suggestions. Thank you Kotesh

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Boost qi parser
by Uthpal Urubail 04 Mar '14

04 Mar '14

{ name = "new" sub_name = "SUBTITLE" values = { 1, 2, 3; } input_values = { 1, 2, 3; 5, 5, 6 10, 12, 3} type = input intval = 100 } Can some one help me to write the parser for the above format? I am trying something like below and this doesn’t seem to work for me. template <typename Iterator> struct keys_and_values : qi::grammar<Iterator, mapDef()> { keys_and_values() : keys_and_values::base_type(query) { using namespace qi; query = '{' >> *lit(' ') >> pair >> *(lit(' ') >> *lit(' ') >> pair) >> *lit(' ') >> '}'; pair = key >> -(*lit(' ') >> "=" >> *lit(' ') >> value); key = +char_("a-zA-Z0-9_") ; value = +char_("a-zA-Z0-9") | lexeme[('{' >> +char_("\"@+*.( , ) $ a-zA-Z0-9_ -") >> '}')] | lexeme[('"' >> +char_("\"@+*.( , ) $ a-zA-Z0-9_ -") >> '"')]; } qi::rule<Iterator, mapDef()> query; qi::rule<Iterator, std::pair<std::string, std::string>()> pair; qi::rule<Iterator, std::string()> key, value; }; Any help would be highly appriciated. Regards, UJ

3 5

[Boost.Log] logging only in a debug build
by Sean Farrow 03 Mar '14

03 Mar '14

Hi, Is there a way with Boost.Log to have logging code emitted in a debug build but completely removed for release. The only way I can come up with is to have #if defs and #endif's scattered throughout the code. Has anyone come up with a better way? Any help appreciated. Kind Regards Sean.

2 3

[BGL] Shared nodes on path
by Sensei 03 Mar '14

03 Mar '14

Dear all, I have a simple question about the most efficient way of finding shared nodes between a path and a graph. Let me be more explicit. I have an oriented graph G, and a very simple graph P, which is actually a simple oriented path (n0 -> n1 -> ... -> nK). I need to find *all* the possible shared paths between P and G with the same length as P. For instance, being P = n1 -> n2 -> n3 -> n4 -> n5 -> n6 we may find that the G and P share only two sub-paths n1 -> n2 -> n3 n5 -> n6 I'd like to find all sub-graphs that connect the two paths, for instance having n1 -> n2 -> n3 -> n10 -> n5 -> n6 n1 -> n2 -> n3 -> n42 -> n5 -> n6 with the constraint that the solution must be a path with the same length as P, therefore a solution as these n1 -> n2 -> n3 -> n9 -> n8 -> n5 -> n6 n1 -> n2 -> n3 -> n5 -> n6 would not be acceptable. I know I can do it manually, but I think a BGL-aware solution is quite better that a manual search :) Thanks & Cheers!

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