October 2009 - Boost-users - lists.preview.boost.org

[fusion] vector slicing (sort of)
by Jean-Louis Leroy 26 Oct '09

26 Oct '09

I am a bit surprised that this compiles: vector<char, int> v2; vector<char> v1(v2); v1 = v2; J-L

3 3

[Boost.Test]: output_test_stream and wchar_t (i.e. woutput_test_stream)?
by Boris Dušek 25 Oct '09

25 Oct '09

Hi, I am using Boost.Test and wanted to use the output_test_stream, however found out that it's stream of chars and my app uses strictly wchar_t. I also found that the output_test_stream inherits from basic_wrap_stringstream<char>::wrapped_stream - is there any plan to templatize output_test_stream itself? For now I have resorted to simply using std::wstringstream as a workaround. Thanks, Boris

2 1

function calling convensions
by Sean Farrow 25 Oct '09

25 Oct '09

Hi: I need to use the stdcall calling convension for a dll that I'm writing. When ever I do this with boost, I get the following errors: ... Creating library d:\Work\Access For Everyone\GHG\TPProductsZW\Debug\TPProductsZW.lib and object d:\Work\Access For Everyone\GHG\TPProductsZW\Debug\TPProductsZW.exp TPProductsZW.obj : error LNK2019: unresolved external symbol "class boost::system::error_category const & __stdcall boost::system::get_system_category(void)" (?get_system_category@system@boost@@YGABVerror_category@12@XZ) referenced in function "void __cdecl boost::system::`dynamic initializer for 'system_category''(void)" (??__Esystem_category@system@boost@@YAXXZ) TPProductsZW.obj : error LNK2019: unresolved external symbol "class boost::system::error_category const & __stdcall boost::system::get_generic_category(void)" (?get_generic_category@system@boost@@YGABVerror_category@12@XZ) referenced in function "void __cdecl boost::system::`dynamic initializer for 'generic_category''(void)" (??__Egeneric_category@system@boost@@YAXXZ) d:\Work\Access For Everyone\GHG\TPProductsZW\Debug\TPProductsZW.dll : fatal error LNK1120: 2 unresolved externals Does anyone know how to solve this issue? I'm building statically, and using visual studio c++ 2008, I'm also using __declspec(dllexport) Regards Sean. Results

2 1

[Proto] Bug in 1.40 : uncomplete type in matches
by joel 25 Oct '09

25 Oct '09

I just switched from 39 to 40 and my proto code that was working doesn't anymore. I define a grammar that matches any terminal, any nary functions except for address_of and comma like this : struct grammar : bp::or_< bp::terminal< block<bp::_,bp::_> > , meta::lambda_term< boost::is_arithmetic > , bp::and_< bp::nary_expr< bp::_, bp::vararg< grammar > > , bp::not_< meta::low_level<bp::_> > , bp::not_< meta::stream<bp::_,bp::_> > > > {}; where lambda_term is : template< template<class> class Lambda > struct lambda_term : boost::proto::and_< boost::proto::terminal<boost::proto::_> , boost::proto::if_<Lambda<boost::proto::_value>()> > {}; When i compile any code that instanciate my grammar, i got : /usr/local/include/boost-1_40/boost/proto/matches.hpp:304: error: invalid use of incomplete type ‘struct boost::proto::op::address_of<boost::proto::wildcardns_::_>’ While I got no error in 1.39 Do I miss some include of core proto file that wasn't needed before ? -- ___________________________________________ Joel Falcou - Assistant Professor PARALL Team - LRI - Universite Paris Sud XI Tel : (+33)1 69 15 66 35

1 1

[exception] array tags
by Diederick C. Niehorster 25 Oct '09

25 Oct '09

Hi, I have just discovered boost::exception and am very happy I did. One thing i would like to do, but haven't yet figure out: I have a matrix class for which I want to throw exceptions when out_of_range requests are made. One of the extra tags I want to attach is the dimensions of the matrix and it would be neat if i can put those in an array. Defining the tag is no problem, getting the info in there is: defining: typedef boost::error_info<struct tag_std_range_size,size_t[2]> std_range_size; I have tried: << std_range_size({m_nRows, m_nCols}); size_t a[2] = {m_nRows, m_nCols}; << std_range_size(a); and desperately even << std_range_size() = {m_nRows, m_nCols}; which doesn't make much sense Can I do such a thing, should I use something else than a plain array or do i have to resort to two separate tags for nRows adn nCols respectively? Thank you for your help and advice! Best, Diederick

3 11

GIL documentation
by Valmor de Almeida 24 Oct '09

24 Oct '09

Hello, Is there a printable version of the flash video tutorial at http://opensource.adobe.com/gil/presentation/index.htm for the Generic Image Library? Thanks, -- Valmor

1 0

Re: [Boost-users] Boost-users Digest, Vol 2158, Issue 1
by Ben 24 Oct '09

24 Oct '09

> Ahhh - so try > > ar >> static_cast<A* &>(a2p); > > Robert Ramey > > troy d. straszheim wrote: >> Ben wrote: >>> { >>> std::ifstream ifs(fname); >>> boost::archive::binary_iarchive ar(ifs); >>> ar >> static_cast<A*>(a2p); >>> } >> >> You're trying to write to an rvalue. Note that >> >> int *ip = 0; >> static_cast<int*>(ip) = 0; // lvalue required as >> // left operand of assignment >> >> doesn't compile either... Wow, that was silly of me. Thanks for the quick response. Any clue to the main question I had (repeated below) about serializing classes with references? I don't think it's an rvalue thing, as the problem occurs even in the save_construct_data bit. Generally, I'm trying to copy what the documentation says to do. Best, Ben Date: Fri, 23 Oct 2009 15:27:48 -0700 From: Ben <midfield(a)gmail.com> To: boost-users(a)lists.boost.org Subject: [Boost-users] [serialization] Serializing a reference Message-ID: <9157df230910231527x686ff3b4n16ec1e9eabc9515(a)mail.gmail.com> Content-Type: text/plain; charset=ISO-8859-1 Hello Boost Experts -- And now for my real question. Again, g++ 4.2.1, OS X 10.6.1, boost 1.40. I'm trying to follow the instructions in the document for serializing classes with reference members, which suggests I serialize them as pointers. First, a program which works, that uses pointers and not references: #include <iostream> #include <fstream> #include <boost/archive/binary_oarchive.hpp> #include <boost/archive/binary_iarchive.hpp> struct A { int v; template<class Ar> void serialize(Ar & ar, const unsigned int ver) { ar & v; } }; struct B { A *ap; B(A *ap_) : ap(ap_) {} template<class Ar> void serialize(Ar & ar, const unsigned int ver) {} }; template<class Ar> void save_construct_data(Ar & ar, const B * b, const unsigned int ver) { ar << b->ap; } template<class Ar> void load_construct_data(Ar & ar, B * b, const unsigned int ver) { A * ap_; ar >> ap_; ::new(b)B(ap_); } int main(int ac, char ** argv) { A a; a.v = 10; B * b1p; b1p = new B(&a); const char * fname = "test.bin"; { std::ofstream ofs(fname); boost::archive::binary_oarchive ar(ofs); ar << b1p; } B * b2p; { std::ifstream ifs(fname); boost::archive::binary_iarchive ar(ifs); ar >> b2p; } std::cout << b2p->ap->v << std::endl; return 0; } What I would really like to do is to modify this program so that class B has a reference to class A instead of a pointer. The documentation suggests I do the following: "This raises the question of how and where the objects being referred to are stored and how are they created. Also there is the question about references to polymorphic base classes. Basically, these are the same questions that arise regarding pointers. This is no surprise as references are really a special kind of pointer. We address these questions by serializing references as though they were pointers." The example given after this serializes the address of the referenced object, similar to the above. My translation of that code is: #include <iostream> #include <fstream> #include <boost/archive/binary_oarchive.hpp> #include <boost/archive/binary_iarchive.hpp> struct A { int v; template<class Ar> void serialize(Ar & ar, const unsigned int ver) { ar & v; } }; struct B { A &a; B(A &a_) : a(a_) {} template<class Ar> void serialize(Ar & ar, const unsigned int ver) {} }; template<class Ar> void save_construct_data(Ar & ar, const B * b, const unsigned int ver) { ar << (&(b->a)); } template<class Ar> void load_construct_data(Ar & ar, B * b, const unsigned int ver) { A * ap_; ar >> ap_; ::new(b)B(*ap_); } int main(int ac, char ** argv) { A a; a.v = 10; B * b1p; b1p = new B(a); const char * fname = "test.bin"; { std::ofstream ofs(fname); boost::archive::binary_oarchive ar(ofs); ar << b1p; } B * b2p; { std::ifstream ifs(fname); boost::archive::binary_iarchive ar(ifs); ar >> b2p; } std::cout << b2p->a.v << std::endl; return 0; } This however fails to compile, with the message: Compilation started at Fri Oct 23 15:25:29 make -k debug make all "CXX_FLAGS = -g -fno-inline -m64 -I. -I.. -I/opt/local/include -Wall -Wextra -Wpointer-arith -Wcast-align -Wwrite-strings -Wconversion -Woverloaded-virtual -Wno-sign-compare -Wno-unused -fno-nonansi-builtins" \ "LD_FLAGS = -g -m64" g++ -g -fno-inline -m64 -I. -I.. -I/opt/local/include -Wall -Wextra -Wpointer-arith -Wcast-align -Wwrite-strings -Wconversion -Woverloaded-virtual -Wno-sign-compare -Wno-unused -fno-nonansi-builtins -c test.cc -o test.o test.cc: In function 'void save_construct_data(Ar&, const B*, unsigned int) [with Ar = boost::archive::binary_oarchive]': /opt/local/include/boost/serialization/serialization.hpp:148: instantiated from 'void boost::serialization::save_construct_data_adl(Archive&, const T*, unsigned int) [with Archive = boost::archive::binary_oarchive, T = B]' /opt/local/include/boost/archive/detail/oserializer.hpp:179: instantiated from 'void boost::archive::detail::pointer_oserializer<Archive, T>::save_object_ptr(boost::archive::detail::basic_oarchive&, const void*) const [with Archive = boost::archive::binary_oarchive, T = B]' test.cc:60: instantiated from here test.cc:27: error: no match for 'operator<<' in 'ar << (A*)b->B::a' /opt/local/include/boost/archive/detail/interface_oarchive.hpp:63: note: candidates are: Archive& boost::archive::detail::interface_oarchive<Archive>::operator<<(T&) [with T = A*, Archive = boost::archive::binary_oarchive] make[1]: *** [test.o] Error 1 make[1]: Target `all' not remade because of errors. make: *** [debug] Error 2 Compilation exited abnormally with code 2 at Fri Oct 23 15:25:30 What am I doing wrong? Best regards, Ben

1 0

compiling boost with mpi support
by Sean Farrow 24 Oct '09

24 Oct '09

Hi: I'm looking to compile boost with mpi support. I am using visual c++ 2008, what mpi libraries are supported. Where should I place the mpi library I wish to wrap, any pointers appreciated. Sean.

2 2

[serialization] Question about pointers and casting
by Ben 24 Oct '09

24 Oct '09

Dear Boost Experts -- I'm using g++ 4.2.1, OS X 10.6.1, boost 1.40, although I have also seen this on linux. In attempting to understand how boost::serialization works, I've stumbled across the following curiosity. The following program compiles and runs fine (I've eliminated diagnostic output which verifies the serialization.) #include <iostream> #include <fstream> #include <boost/archive/binary_oarchive.hpp> #include <boost/archive/binary_iarchive.hpp> struct A { int v; template<class Ar> void serialize(Ar & ar, const unsigned int ver) { ar & v; } }; int main(int ac, char ** argv) { A a; a.v = 10; A * a1p = &a; const char * fname = "test.bin"; { std::ofstream ofs(fname); boost::archive::binary_oarchive ar(ofs); ar << a1p; } A * a2p; { std::ifstream ifs(fname); boost::archive::binary_iarchive ar(ifs); ar >> a2p; } return 0; } However, if I add a static_cast<A*> to either a1p or a2p (which are already declared to be type A*) in the serialization / deserialization lines, it fails to compile: #include <iostream> #include <fstream> #include <boost/archive/binary_oarchive.hpp> #include <boost/archive/binary_iarchive.hpp> struct A { int v; template<class Ar> void serialize(Ar & ar, const unsigned int ver) { ar & v; } }; int main(int ac, char ** argv) { A a; a.v = 10; A * a1p = &a; const char * fname = "test.bin"; { std::ofstream ofs(fname); boost::archive::binary_oarchive ar(ofs); ar << static_cast<A*>(a1p); } A * a2p; { std::ifstream ifs(fname); boost::archive::binary_iarchive ar(ifs); ar >> static_cast<A*>(a2p); } return 0; } Compilation started at Fri Oct 23 14:31:17 make -k debug make all "CXX_FLAGS = -g -fno-inline -m64 -I. -I.. -I/opt/local/include -Wall -Wextra -Wpointer- arith -Wcast-align -Wwrite-strings -Wconversion -Woverloaded-virtual -Wno-sign-compare -Wno- unused -fno-nonansi-builtins" \ "LD_FLAGS = -g -m64" g++ -g -fno-inline -m64 -I. -I.. -I/opt/local/include -Wall -Wextra -Wpointer-arith -Wcast-align - Wwrite-strings -Wconversion -Woverloaded-virtual -Wno-sign-compare -Wno-unused -fno- nonansi-builtins -c test.cc -o test.o test.cc: In function 'int main(int, char**)': test.cc:25: error: no match for 'operator<<' in 'ar << a1p' /opt/local/include/boost/archive/detail/interface_oarchive.hpp:63: note: candidates are: Archive& boost::archive::detail::interface_oarchive<Archive>::operator<<(T&) [with T = A*, Archive = boost::archive::binary_oarchive] test.cc:33: error: no match for 'operator>>' in 'ar >> a2p' /opt/local/include/boost/archive/detail/interface_iarchive.hpp:60: note: candidates are: Archive& boost::archive::detail::interface_iarchive<Archive>::operator>>(T&) [with T = A*, Archive = boost::archive::binary_iarchive] make[1]: *** [test.o] Error 1 make[1]: Target `all' not remade because of errors. make: *** [debug] Error 2 Compilation exited abnormally with code 2 at Fri Oct 23 14:31:18 This completely boggles my mind. My limited understanding suggests the compiler should not be able to distinguish between the two programs! I can put the cast on either one of the two pointers and it fails, and using an old style cast to A* also fails. I seem to not understand what boost::serialization is doing generally, so I was hoping the answer to this question (which is obviously a theoretical curiosity and of no practical value) would lead to further insight. Best regards, Ben

3 2

boost.thread query
by Sean Farrow 23 Oct '09

23 Oct '09

Hi: I am considering using boost.threadfir a project and was wondering whether the function passed to boost.thread has to be of any pargicular type i.e void return. Secondly, if I don't call thread.join, will the thread continue executing? I'm terminating the thread with a windows event. Finally, is there a terminate function? Any help appreciated. Sean.

2 1