September 2005 - Boost-users

Boost Graph Library and Boehm Garbage Collector
by FBSL 08 Sep '08

08 Sep '08

Hello I am having trouble to garbage-collect adjacency_list<>. I have instanciated it with correctly garbage-collected vectors and lists (I have copied vecS and listS definitions, and added Boehm GC's default allocator so that they are garbage-collected). In my application I need to dynamically allocate many graphs, but it does not work, there is a (big) memory leak. Unfortunately, there is no template argument in adjacency_list<> to specify Boehm GC's allocator. Does anyone have a hint ? Snippet code "main.cpp" follows, compiled with Boost Graph Library 1.32, Boehm GC 6.4 and G++ 3.3.5, with command line : $ g++ -o main main.cpp -lgc -lgccpp -- #include <boost/graph/adjacency_list.hpp> #include <gc/gc_allocator.h> #include <gc/gc_cpp.h> #include <iostream> #include <vector> #include <list> using namespace std; using namespace boost; namespace boost { struct collected_vecS {}; struct collected_listS {}; template <class ValueType> struct container_gen<collected_vecS, ValueType> { typedef vector<ValueType,gc_allocator<ValueType> > type; }; template <class ValueType> struct container_gen<collected_listS, ValueType> { typedef list<ValueType,gc_allocator<ValueType> > type; }; template <> struct parallel_edge_traits<collected_vecS> { typedef allow_parallel_edge_tag type; }; template <> struct parallel_edge_traits<collected_listS> { typedef allow_parallel_edge_tag type; }; namespace detail { template <> struct is_random_access<collected_vecS> { enum { value = true }; typedef true_type type; }; } } typedef adjacency_list<collected_vecS, collected_vecS, directedS, no_property, no_property, no_property, collected_listS> graph; int main() { // leaks... while(true){ graph * g=new (UseGC) graph; for(unsigned int i=0; i<100; ++i){ add_vertex(*g); } for(unsigned int i=0; i<100; ++i){ for(unsigned int j=0; j<100; ++j){ add_edge(i,j,*g); } } } }

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BGL: INTERNAL COMPILER ERROR in VC7.1
by Yariv Tal 10 Jun '07

10 Jun '07

This one was already posted by Nicholas Burlett awhile back (see http://lists.boost.org/MailArchives/boost-users/msg06534.php) but I have some new info that may help. The problem: ========= When compiling code that uses the boost.graph library the VC7.1 compiler shouts: c:\boost_1_32_0\boost\mpl\aux_\preprocessed\plain\apply_wrap.hpp(48) : fatal error C1001: INTERNAL COMPILER ERROR As Nicholas already noted, this seems to be due to some compiler problem with the boost.graph out_edge_iterators since it is caused by the following lines in my code: (FilteredGraphGenerator::FilteredGraph is a typedef of a boost::filtered_graph) typedef boost::graph_traits<FilteredGraphGenerator::FilteredGraph> ::out_edge_iterator oedge_iterator; oedge_iterator edgesItr, edgesEnd; boost::tie(edgesItr, edgesEnd) = boost::out_edges(itr->first, m_g.m_filteredGraph); while (edgesItr != edgesEnd) { // do anything! } In fact, it seems to be related to the operator!= between iterators (if the while loop is commented out it compiles). How ever, the error persists even after changing the operator!= to operator== : while (edgesItr == edgesEnd) { // do anything! } ========================================================================== Some findings: =========== * We used to use boost_1_30_0 and the code used to compile PERFECTLY. The problem only appeared after migrating to boost_1_32_0. * Calling directly to the "equal" function in iterator_core_access instead of the operator== works. typedef boost::graph_traits<FilteredGraphGenerator::FilteredGraph> ::out_edge_iterator oedge_iterator; oedge_iterator edgesItr, edgesEnd; boost::tie(edgesItr, edgesEnd) = boost::out_edges(itr->first,m_g.m_filteredGraph); while (boost::iterator_core_access::equal(edgesItr, edgesEnd, boost::mpl::true_())) { // do somthing } * The error message location is at the mpl::apply_wrap2 function. Any relation to the mpl::apply2 function used for declaring the operator== in the BOOST_ITERATOR_FACADE_INTEROP_HEAD macro? Have these functions changed since v1.30.0?

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[BGL] how to actually search with DFS/BFS?
by martin f krafft 22 Nov '06

22 Nov '06

This may seem like a silly question, but how does one actually search with DFS or BFS? Say I want to find the first node for which a predicate returns true in a BFS traversal starting at node N... The function signatures don't have a parameter for "criteria" or "predicate", so I guess it's up for a Visitor to implement such a check. What is not clear to me is how the visitor functions can break out of the search once a condition is true. Thanks, -- martin; (greetings from the heart of the sun.) \____ echo mailto: !#^."<*>"|tr "<*> mailto:" net@madduck invalid/expired pgp subkeys? use subkeys.pgp.net as keyserver! spamtraps: madduck.bogus(a)madduck.net "information superhighway" is just an anagram for "i'm on a huge wispy rhino fart".

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Building boost for 64-bit on AIX
by Patrik Jonsson 17 Aug '06

17 Aug '06

Hi, I'm trying to build boost (1.32.0) on an IBM SP2 under AIX5, using the 64-bit ABI. This is troublesome. I do: bjam "-sTOOLS=gcc" "-sGXX=g++ -maix64 -pthread" --prefix=$HOME --libdir=$HOME/lib64-gcc --includedir=$HOME/include-gcc install But it doesn't work. I get loads of errors like: gcc-Link-action bin/boost/libs/date_time/build/libboost_date_time.so/gcc/debug/shared-linkable-true/libboost_date_time-gcc-d-1_32.so ld: 0711-738 ERROR: Input file bin/boost/libs/date_time/build/libboost_date_time.so/gcc/debug/shared-linkable-true/greg_month.o: XCOFF32 object files are not allowed in 64-bit mode. collect2: ld returned 8 exit status set -e LIBPATH=bin/boost/libs/date_time/build/libboost_date_time.so/gcc/debug/shared-linkable-true:$LIBPATH export LIBPATH "g++" -maix64 -pthread -g -fPIC -shared -o "bin/boost/libs/date_time/build/libboost_date_time.so/gcc/debug/shared-linkable-true/libboost_date_time-gcc-d-1_32.so" "bin/boost/libs/date_time/build/libboost_date_time.so/gcc/debug/shared-linkable-true/greg_month.o" "bin/boost/libs/date_time/build/libboost_date_time.so/gcc/debug/shared-linkable-true/greg_weekday.o" "bin/boost/libs/date_time/build/libboost_date_time.so/gcc/debug/shared-linkable-true/date_generators.o" ...failed gcc-Link-action bin/boost/libs/date_time/build/libboost_date_time.so/gcc/debug/shared-linkable-true/libboost_date_time-gcc-d-1_32.so... ...skipped <@boost!lib64-gcc>libboost_date_time-gcc-d-1_32.so for lack of <@boost!libs!date_time!build/libboost_date_time.so/gcc/debug/shared-linkable-true>libboost_date_time-gcc-d-1_32.so... It seems it's using -maix64 ok when trying to build the library, but not when compiling... Can anyone tell me what the proper way of building boost under these conditions are? Thanks, /Patrik Jonsson

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case insensitive less_than string comparison
by Matthias Kaeppler 07 Mar '06

07 Mar '06

Hi, I am aware that string_algo has an if_iequal functor. Is there also an equivalent for a less-than comparison? I have to compare strings ignoring the case but taking locales into account. Right now I'm calling boost::algorithm::to_lower on two copies of the original strings. I'm not so sure if this is very efficient when I'm comparing thousands of strings. Here's the functor as it is now: struct FileLessNameA : std::binary_function<const File&,const File&,bool> { bool operator() (const File& lhs, const File& rhs) const { std::string path1( lhs.get_name().c_str() ); std::string path2( rhs.get_name().c_str() ); boost::algorithm::to_lower( path1 ); boost::algorithm::to_lower( path2 ); return path1 < path2; } }; Any suggestions for improvements appreciated :) Regards, Matthias -- Matthias Kaeppler

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[date_time] problem adding negative number of months
by Guido Spahn 24 Oct '05

24 Oct '05

Hello, when adding a negative number of months to a date(y, m, d), an exception "Month number is out of range 1..12" is raised if the resulting month m2 belongs to a year y2 < y and m2 > m. For example date(2005, Jan, 1) + months(-1) fails date(2005, Feb, 1) + months(-1) doesn't fail date(2005, Feb, 1) + months(-2) fails date(2005, Feb, 1) + months(-12) doesn't fail date(2005, Feb, 1) + months(-13) doesn't fail date(2005, Feb, 1) + months(-14) fails I checked it only with release 1.33 using the appended code. There is no problem adding or substracting any positive number of months. Hopefully I didn't miss this topic in the mailing list archive. Thanks in advance, Guido #include <boost/date_time/gregorian/gregorian.hpp> int main() { using namespace boost::gregorian; date d(2005, May, 1); for (long m = 0; m >= -40; --m) { try { std::cerr << d << " + (" << m << "): "; std::cerr << d + months(m) << std::endl; } catch (std::exception& e) { std::cerr << "FAILED: " << e.what() << std::endl; } } return 0; }

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Boost Graph Library: Python Bindings
by Yu Huang 17 Oct '05

17 Oct '05

Hi guys, I report a small bug related to bgl.file_kind.adjlist. I tried it using an inputfile in the specified format, but got nothing. And i checked the source code, basic_graph.cpp and found on line 129: case gfk_adjlist: break; which means simply not dealing with it at all. I guess those two guys are so busy to fill some codes in it. Thanks, Yu

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[serialization][any]Do we have serialization support for boost::any?
by Li Lirong 11 Oct '05

11 Oct '05

Hi, Do we have serialization support for boost::any? If not, how is it possible to serialize boost::any? Regards, Lirong

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[Threads]
by lukas 05 Oct '05

05 Oct '05

hi I'm new to boost.threads and have a basic question. During program execution the user has to check the connection to a server. This action should take place in a simple thread. If the user gets bored waiting for responce, he should be able to stop the process and return back to the main application. Is there a proper standard solution? For now I try to yield the thread holding the connection methods. In this case the inner methods all terminate and are not going to be stopped. My first attemp is to stop this inner methods by hand. Is there a better way to do this? kind regards, luke

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[Boost][mpl] vector_c boolean operations
by Noel Belcourt 05 Oct '05

05 Oct '05

Hi, I'm new to the list so this may have been answered elsewhere (like a FAQ for MPL) but I couldn't find it. I've got 2 vector_c types like this typedef vector_c<int, 1,2,1,1,-2,0,1> p1; typedef vector_c<int, 0,3,0,-1,1,3,5> p2; and a resultant type defined as typedef vector_c<int, 1,1,0,1,1,0,1> r; that I want to compare at compile time using logic like this r = p1 || p1 && p2 This pseudo code is what I want to do but I know this doesn't work. Can anyone can suggest a better approach? template <class R, class P1, class P2> struct validate_checkin : boost::mpl::equal< boost::mpl::placeholders::_1, boost::mpl::or_< boost::mpl::placeholders::_2, boost::mpl::and_< boost::mpl::placeholders::_2, boost::mpl::placeholders::_3 >, >, > {}; Regards, -- Noel Belcourt

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