January 2007 - Boost-users - lists.boost.org

[spirit][phoenix] calling stack::pop
by Jeffrey Holle 21 Jan '07

21 Jan '07

I'm writing a parser using spirit 1.84. I'd like use phoenix to call a method of an attribute in my definition class. Within my definition class I have: typedef stack<int> Parents; Parents parents_; I've attempted to call the pop method of this container using: [phoenix::bind(&definition::Parents::pop)] I get an error saying that an undefined reference to pop was made. If I change the syntax to: [phoenix::bind(&definition::Parents::pop)()] The error messages are much worst. Is there a way to do such a thing using phoenix?

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Directory size (via boost::filesystem) problem
by Daniel Wyatt 21 Jan '07

21 Jan '07

Okay so i just wrote this quick program to test boost::filesystem's features out. It's supposed to find the size of a directory (the sum of the size of the files in it) and optionally recurse all subdirectories: #include <cstdio> #include <cstdlib> #include <iostream> #include <sstream> #include <boost/filesystem/operations.hpp> using namespace std; using namespace boost::filesystem; void Usage(char *Path) { printf("Usage: %s <Directory> [-r]\n", Path); exit(EXIT_FAILURE); } unsigned long DirSize(const string Directory, bool Recurse = false) { long Size = 0; directory_iterator itDir; directory_iterator itEnd; path Path; Path = Directory; itDir = directory_iterator(Path); for (; itDir != itEnd; itDir++) { if (is_directory(*itDir)) { if (Recurse) Size += DirSize(itDir->string(), true); continue; } Size += file_size(*itDir); } return Size; } string UnitString(unsigned long Bytes) { const char *Units[] = {"bytes", "KiB", "MiB", "GiB", "TiB", "PiB"}; const unsigned int UnitsMax = 6; double Size = (double)Bytes; unsigned int i = 0; stringstream ss; for (i = 0; i < UnitsMax && Size >= 1024.0; i++) Size /= 1024.0; ss.precision(2); ss << fixed << Size; ss << " " << Units[i]; return ss.str(); } int main(int argc, char *argv[]) { bool Recurse = false; if (argc != 2 && argc != 3) Usage(argv[0]); if (argc == 3) Recurse = true; if (argc == 3 && stricmp(argv[2], "-r") != 0) Usage(argv[0]); if (!exists(argv[1])) { printf("Directory '%s' does not exist\n\n", argv[1]); Usage(argv[0]); } if (!is_directory(argv[1])) { printf("'%s' is not a directory\n\n", argv[1]); Usage(argv[0]); } printf("Size of directory '%s': %s\n", argv[1], UnitString(DirSize(argv[1], Recurse)).c_str()); return EXIT_SUCCESS; } Its not too pretty but ignore that please. It works for the most part. It gives perfect results for nearly all directories. One exception i've noticed on my system is "C:\Program Files". It gives me "419.15 MiB" but it should be giving me something more like "8.40 GiB". I figure an unsigned long is large enough, isn't it? Do i need to use an unsigned long long or is there something else wrong here??? Thanks, Daniel Wyatt

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Re: [Boost-users] BoostCon 2007 Program Committee progress report
by Moshe Matitya 21 Jan '07

21 Jan '07

Moshe Matitya wrote: > > Beman Dawes wrote: > > > > The conference dates (May 14-16) are firm, and other > arrangements are > > moving forward. See http://www.boost.org/more/BoostCon07.html > > That page says that the conference dates are May 14-18. Can we nail down the conference dates? Beman's message from last week says that the dates are May 14-16, but the web site continues to say that they're May 14-18. It this a three-day or a five-day conference? Moshe

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[Fusion] fusion::traits::is_sequence <-> mpl::is_sequence?
by Sohail Somani 21 Jan '07

21 Jan '07

Hi, If I am trying to make a fusion sequence mpl compatible, do I need to specialize mpl::is_sequence as well? I had expected that the following should be true: BOOST_MPL_ASSERT(( fusion::traits::is_sequence<myseq> )); BOOST_MPL_ASSERT(( mpl::is_sequence<myseq> )); But the compilation fails on the second line. I've also defined begin using the fusion extension mechanism for this sequence. Thanks! Sohail

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[fusion][mpl] Get type from fusion sequence using mpl::at_c
by Chris Weed 21 Jan '07

21 Jan '07

Hi, I am trying to get the type of the first element in a fusion vector using mpl::at_c. This seems simple enough. // Here is the code #include <boost/fusion/sequence/container/vector.hpp> #include <boost/mpl/at.hpp> int main() { typedef boost::fusion::vector<int,int> VectorType; typedef boost::mpl::at_c<VectorType,0>::type value0; return 0; } This won't compile on vc-8.0, and I get the following error message: ...patience... ...found 467 targets... ...updating 2 targets... msvc.compile.c++ bin\msvc-8.0\debug\example2.obj example2.cpp using native typeof boost\boost/mpl/begin_end.hpp(35) : error C2903: 'apply' : symbol is neither a class template nor a function template boost\boost/mpl/aux_/at_impl.hpp(33) : see reference to class template instantiation 'boost::mpl::begin<Sequence>' being compiled with [ Sequence=VectorType ] boost\boost/mpl/at.hpp(45) : see reference to class template instantiation 'boost::mpl::at_impl<Tag>::apply<Sequence,N>' being compiled with [ Tag=boost::fusion::fusion_sequence_tag, Sequence=VectorType, N=boost::mpl::long_<0> ] examples\example2.cpp(11) : see reference to class template instantiation 'boost::mpl::at_c<Sequence,N>' being compiled with [ Sequence=VectorType, N=0 ] boost\boost/mpl/begin_end.hpp(35) : error C2027: use of undefined type 'boost::mpl::begin_impl<boost::fusion::fusion_sequence_tag>' boost\boost/mpl/begin_end.hpp(35) : error C2059: syntax error : '<' boost\boost/mpl/begin_end.hpp(35) : error C2039: 'type' : is not a member of '`global namespace'' boost\boost/mpl/begin_end.hpp(35) : error C2238: unexpected token(s) preceding ';' boost\boost/mpl/aux_/at_impl.hpp(33) : error C2039: 'type' : is not a member of 'boost::mpl::begin<Sequence>' with [ Sequence=VectorType ] boost\boost/mpl/aux_/at_impl.hpp(34) : error C2146: syntax error : missing ',' before identifier 'type' boost\boost/mpl/aux_/at_impl.hpp(34) : error C2065: 'type' : undeclared identifier boost\boost/mpl/aux_/at_impl.hpp(35) : error C2955: 'boost::mpl::advance' : use of class template requires template argument list boost\boost/mpl/advance.hpp(60) : see declaration of 'boost::mpl::advance' boost\boost/mpl/aux_/at_impl.hpp(35) : error C2039: 'type' : is not a member of 'boost::mpl::advance' boost\boost/mpl/advance.hpp(60) : see declaration of 'boost::mpl::advance' boost\boost/mpl/aux_/at_impl.hpp(35) : error C2146: syntax error : missing ';' before identifier 'iter_' boost\boost/mpl/aux_/at_impl.hpp(35) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int boost\boost/mpl/aux_/at_impl.hpp(35) : error C4430: missing type specifier - int assumed. Note: C++ does not support default-int boost\boost/mpl/aux_/at_impl.hpp(37) : error C2065: 'iter_' : undeclared identifier boost\boost/mpl/aux_/at_impl.hpp(37) : error C2955: 'boost::mpl::deref' : use of class template requires template argument list boost\boost/mpl/deref.hpp(35) : see declaration of 'boost::mpl::deref' boost\boost/mpl/aux_/at_impl.hpp(37) : error C2371: 'boost::mpl::at_impl<Tag>::apply<Sequence,N>::type' : redefinition; different basic types with [ Tag=boost::fusion::fusion_sequence_tag, Sequence=VectorType, N=boost::mpl::long_<0> ] boost\boost/mpl/aux_/at_impl.hpp(35) : see declaration of 'boost::mpl::at_impl<Tag>::apply<Sequence,N>::type' with [ Tag=boost::fusion::fusion_sequence_tag, Sequence=VectorType, N=boost::mpl::long_<0> ] call "C:\Program Files\Microsoft Visual Studio 8\VC\vcvarsall.bat" x86 >nul cl /Zm800 -nologo -TP /Z7 /Od /Ob0 /W3 /GR /MDd /Zc:forScope /Zc:wchar_t /wd4675 /EHs @"bin\msvc-8.0\debug\example2.obj.rsp" -c -Fo"bin\msvc-8.0\debug\example2.obj" ...failed msvc.compile.c++ bin\msvc-8.0\debug\example2.obj... ...skipped <pbin\msvc-8.0\debug>example2.exe for lack of <pbin\msvc-8.0\debug>example2.obj... ...failed updating 1 target... ...skipped 1 target...

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Newbie question conerning interprocess stuff
by Wolfgang Hottgenroth 20 Jan '07

20 Jan '07

Hi, I'm a complete newbie with boost and have a question concerning the interprocess stuff. I took the piece of code to share a vector in shared memory between two processes from the quick-start guide as a start point and it compiled and ran immediately with success for me. Then I tried to replace the vector by a map: #include <boost/interprocess/managed_shared_memory.hpp> #include <boost/interprocess/containers/map.hpp> #include <boost/interprocess/allocators/allocator.hpp> using namespace std; int main () { boost::interprocess::shared_memory_object::remove("MySharedMemory"); boost::interprocess::managed_shared_memory segment(boost::interprocess::create_only, "MySharedMemory" ,65536); //segment size in bytes typedef pair<const int, int> MyPair; typedef boost::interprocess::allocator<MyPair, boost::interprocess::managed_shared_memory::segment_manager> ShmemAllocator; typedef boost::interprocess::map<int, int, less<int>, ShmemAllocator> MyMap; const ShmemAllocator alloc_inst (segment.get_segment_manager()); MyMap *mymap = segment.construct<MyMap>("MyMap")(alloc_inst); // mymap->insert(make_pair(1,10)); // mymap->insert(make_pair(2,20)); // mymap->insert(make_pair(3,30)); // mymap->insert(make_pair(4,40)); // mymap->insert(make_pair(5,50)); return 0; } and I wasn't able to compile it any more. (I've put the error message and the sources on the web, find it here: http://www.hottis.de/boost/) I think it is the segment.construct line, although I don't find a direct hint in the error message from the compiler, but if I comment out this line, the compiler is happy. Has any one any hint for me? Thank you very much, Wolfgang

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[statechart] - delay of handlinmg a specific event?
by Oliver.Kowalke＠qimonda.com 20 Jan '07

20 Jan '07

Hello, Is it possible to delay the handling of an event? If I've three states X, Y and Z; initial state is X. State Y is entered if X receives event y1. State Z is entered if X receives event z1. X is entered if Y receives event y2. Y is entered if Z receives event z2. If Y is entered then it executes a function which will generate event y2 during ist processing (function will be executed in another thread - thread passes event y2 to state machine). It is possible that event z1 is passed to the state machine before event y2. How can I delay processing of event z1 until y2 event handling has taken place? Regards, Oliver

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Easy linking question
by Mark Wyszomierski 19 Jan '07

19 Jan '07

Hi, I compiled for visual studio 2005 (vc8). In my boost lib folder I have a serialization library named: libboost_serialization-vc80-mt-gd-1_33_1.lib everything was working fine until I changed my code generation runtime library from: Multi-threaded Debug DLL (/MDd) to: Multi-threaded Debug (/MTd) Now when I compile I get a linking error saying my app cannot find the lib called: libboost_serialization-vc80-mt-sgd-1_33_1.lib (there is an 's' before the 'gd' which is the difference). I don't have this lib anywhere in my boost folder. What happened! Thanks, Mark

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boost::apply_visitor(const& visitor, ...) - why const?
by cdr＠encapsule.com 19 Jan '07

19 Jan '07

Hello, Why does boost::apply_visitor take a const reference to the visitor object? This forces me to write a boost::static_visitor-derived visitor that looks like this: class my_visitor_t : public boost::static_visitor<> { template <typename T> void operator()(T const& t) const { // do something ... } }; ... when what I would really like to do is something like this: class my_visitor_t : public boost::static_visitor<> { my_visitor(my_data & _data) : data(_data) {} void operator()(int const& i) // NOT const { // data.blah.blah = // blah } template <typename T> void operator()(T const& t) // NOT const { // data.foo() } my_data & data }; So I might have several different instances of a given a my_variant_t: my_variant_t v1; my_variant_t v2; my_variant_t v3; my_data_t my_data; my_visitor_t my_visitor(my_data); boost::apply_visitor(my_visitor, v1); boost::apply_visitor(my_visitor, v2); // and so on... ... BUT, the fact that I must make the visitor operator() const makes this impossible and is inconsistent with the way that I'm used to leveraging visitors in the BGL. Would someone be kind enough to comment on the rationale behind this? What am I missing here? - Thanks Chris

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crash on test_no_rtti
by Miguel Silvestre 19 Jan '07

19 Jan '07

Hi! I'm tryingto compile and test the test_no_rtti for deriving pointers of derived classes. I'm getting a crash in the file dbgheap.c line 266 when the boost tries to do this: return dynamic_cast<T>(u); on file smart_cast.hpp line 76. I'm using VC-80 compiler. In the attach I send the file (a little bit modified, since I'm looking for this to compile :S). Any sugestion please???? -- Miguel Silvestre

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