- Boost-users - lists.boost.org

[range, iterator?] compiler error going from 1.34 to 1.37
by Martin Livesey 19 Jan '09

19 Jan '09

We are upgrading our legacy code to use boost 1.37 from version 1.34 and have hit a slight hitch. The following (massively simplified) code no longer compiles. I tried it on more than one compiler and the error messages aren't too useful in helping to determine the issue. (The target compiler will be VS 2k8). Any assistance would be appreciated. Thanks in advance. #include "tchar.h" #include <boost/iterator/filter_iterator.hpp> #include <boost/range/iterator_range.hpp> #include <list> class A{}; class B { public: typedef std::list<A>::iterator iterator; iterator begin() { return bs.begin(); } iterator end() { return bs.end(); } private: typedef std::list<A> List; List bs; }; template <class Predicate> struct FilteredRange { typedef boost::filter_iterator<Predicate, B::iterator> iterator_type; typedef boost::iterator_range<iterator_type> range_type; }; template <typename Predicate> typename FilteredRange<Predicate>::range_type getFilteredRange(B *list) { return boost::make_iterator_range(boost::make_filter_iterator<Predicate>(list->begin(), list->end()), boost::make_filter_iterator<Predicate>(list->end(), list->end())); } class C { public: bool operator()(const A &a) const {return true;} }; int _tmain(int argc, _TCHAR* argv[]) { getFilteredRange<C>(new B).size(); return 0; }

2 1

[boost-users][function] how to
by Igor R 19 Jan '09

19 Jan '09

Hello, function<void(Base *)> funcB; function <void(Derived *)> funcD; Is it possible to convert somehow funcD --> funcB ? Thanks.

2 3

Boost::interprocess sharing string
by Federico Golfrè Andreasi 19 Jan '09

19 Jan '09

Hi ! I have a problem sharing a string within a shared memory segment using named objects. (Boost.interporcess 1.36.0) I attach here the code of the two programs: one writes the string and the other read it. In the reader a segmentation fault is throw. Where am I wrong? Thank you very much Federico

2 1

[proto] applying proto to real problems
by Michael Marcin 19 Jan '09

19 Jan '09

I haven't used proto before and as I read the documentation everything makes sense but I can't figure out how to apply the information there to solve my problems. I think if I can figure out how to solve a simplified example from my actual problem I can figure out the rest. // typical 3d vector template< typename T > struct vec3 { T x,y,z; }; // typical 3d dot product template< typename T > T dot_product( const vec3<T>& a, const vec3<T>& b ) { return a.x*b.x + a.y*b.y + a.z*b.z; } // typical 16.16 fixed point number struct fixed { boost::int32_t data; }; // typical multiplication for this fixed point number fixed operator*( fixed lhs, fixed rhs ) { fixed result = { static_cast<boost::int32_t> ( ( boost::int64_t(lhs.data)*rhs.data ) >> 16 ) }; return result; } // however using the typical dot product with // fixed numbers is too lossy and inefficient // so we have to specialize dot_product for // these fixed point numbers to do this template<> fixed dot_product( const vec3<fixed>& a, const vec3<fixed>& b ) { fixed result = { static_cast<boost::int32_t> ( ( boost::int64_t(a.x.data) * b.x.data + boost::int64_t(a.y.data) * b.y.data + boost::int64_t(a.z.data) * b.z.data ) >> 16 ) }; return result; } What I want to be able to do is to make the typical dot product generate code that is equivalent to the specialized dot product when instantiated with T = fixed. This seems like something proto should handle easily from the description of the library but I just don't get proto yet. Thanks, -- Michael Marcin

3 2

Comparing is_pointer with true_
by jean-louis.a.leroy＠fortis.com 19 Jan '09

19 Jan '09

Hello. I need to compare is_const<T> with true_ or false_. I don't find an easy way to do it. I have tried: void foo(mpl::true_) { cout << "true" << endl; } void foo(mpl::false_) { cout << "false" << endl; } int _tmain(int argc, _TCHAR* argv[]) { foo(is_same< mpl::true_, is_pointer<void*>() >()); foo(is_same< mpl::true_, is_pointer<void*>::type() >()); foo(is_convertible< is_pointer<void*>(), mpl::true_ >()); foo(is_base_of< mpl::true_, is_pointer<void*>() >()); return 0; } (in case you wonder why I don't simply pass is_pointer to foo(), here's why: I have a function object that is called twice with a bool_ template argument; the first time it handles all non-pointer types and in a second pass it handles the pointer types; in fact I'm trying to implement the equivalent of b1 == b2, where b1 and b2 are bools). I understand that is_pointer<T> derives either from true_type or false_type. Thus it's normal that is_same fails. But what of the others? Jean-Louis = = = = = = = = = = = = = = = = = = = = = = = = = Fortis disclaimer : http://www.fortis.be/legal/disclaimer.htm Privacy policy related to banking activities of Fortis: http://www.fortis.be/legal/privacy_policy.htm = = = = = = = = = = = = = = = = = = = = = = = = =

2 3

Re: [Boost-users] problems installing boost -- explorer.exe
by Marks, Joseph 19 Jan '09

19 Jan '09

For what it's worth, I have had a similar problem with the "7z" or 7-zip program. I had to re-install this program this morning, as it was "acting" up. I don't know what you're using for zips -- WinZip, 7-zip, j-zip, or some other program, but the problem *could* be with that software; then again, it might not. ADMG Joseph

1 0

problems installing boost -- explorer.exe Application error
by Paul Epstein 19 Jan '09

19 Jan '09

I have been trying to install the latest version of Boost from sourceforge.net. I have a Windows Vista operating system. I downloaded the boost.zip file and the boost-jam.zip file. I was able to extract the boost-jam file without problems. However, whenever I try and extract the boost.zip file to a folder I created I get the message: explorer.exe - Application Error The exception unknown software exception (0xc000000d) occurred in the application at 0x75afc02c. I tried ending the process explorer.exe, but when I kill that process, I am unable to do the extracting. I know this is a basic problem. I doubt that the issue is specifically Boost-related but since the problem arose in a boost-context, I'm hopefully on topic. Many thanks for your help. Paul Epstein

2 1

Building iostreams with zlib support on Windows XP in mingw-msys
by e m 19 Jan '09

19 Jan '09

I use bjam like so: bjam toolset=gcc link=static runtime-link=static threading=single \ --with-iostreams --with-filesystem \ -sNO_COMPRESSION=0 -sNO_ZLIB=0 -sZLIB_SOURCE=C:/zlib123 \ --build-type=release install -------------------------------------------------- But, I do not believe that zlib is being built or linked in to iostreams. The only libs I get in C:/Boost/lib after bjam are these: libboost_filesystem-mgw34-s.lib libboost_system-mgw34-s.lib libboost_iostreams-mgw34-s.lib However, the output from bjam does not indicate any errors with iostreams or zlib. -------------------------------------------------- When I try to compile the zlib example from here: http://www.boost.org/doc/libs/1_37_0/libs/iostreams/doc/classes/zlib.html#e… I get these errors: C:/Users/e4m/AppData/Local/Temp/ccSscQ9O.o:zlib_test.cpp:(.text$_ZN5boost9iostreams6detail22zlib_decompressor_implISaIcEED2Ev[boost::iostreams::detail::zlib_decompressor_impl<std::allocator<char> >::~zlib_decompressor_impl()]+0x58): undefined reference to `boost::iostreams::detail::zlib_base::reset(bool, bool)' C:/Users/e4mAppData/Local/Temp/ccSscQ9O.o:zlib_test.cpp:(.text$_ZN5boost9iostreams6detail22zlib_decompressor_implISaIcEED2Ev[boost::iostreams::detail::zlib_decompressor_impl<std::allocator<char> >::~zlib_decompressor_impl()]+0x6a): undefined reference to `boost::iostreams::detail::zlib_base::~zlib_base()' ... ... ... -------------------------------------------------- I am trying to compile the example like this: g++ -static -O3 zlib_test.cpp -o zlib_test.exe -Ic://Boost/include/boost-1_37/ c://Boost/lib/libboost_iostreams-mgw34-s.lib -------------------------------------------------- Here is the example source code as I have modified it slightly while experimenting: #include <fstream> #include <iostream> #include <boost/iostreams/filtering_streambuf.hpp> #include <boost/iostreams/copy.hpp> #include <boost/iostreams/filter/zlib.hpp> //#include "C:/boost_1_37_0/boost_1_37_0/libs/iostreams/src/zlib.cpp" #define BOOST_IOSTREAMS_NO_LIB int main() { using namespace std; using namespace boost::iostreams; ifstream file("hello.z", ios_base::in | ios_base::binary); filtering_streambuf<input> in; in.push(zlib_decompressor()); in.push(file); boost::iostreams::copy(in, cout); return 0; } -------------------------------------------------- I've googled a lot for the last week trying to figure out what I'm doing wrong, to no avail... Can someone help me? Thanks, e

3 3

[fusion - I think!] Multiple nested range traversal.
by Robert Jones 19 Jan '09

19 Jan '09

I recently asked a question on here about traversal of multiple indices, which produced a luke-warm reaction, mainly because I wasn't really asking the right question! So here's another try. Consider a bit of code like this for ( unsigned i=0; i!=3; ++i ) for ( unsigned j=2; j!=5;++j ) for ( unsigned k=4;k!=10;++k ) f( i, j, k ); I'd guess this comes up pretty often, and by generalising it to * an arbitrary number of ranges, of arbitrary types * f() implemented as a lambda or bind function would have quite wide applicability. I've considered writing an implemetation, which has dragged me into examining fusion and mpl in some detail, but doing so does not seem to me be trivial at all. Is there already something in Boost which does this? Thanks, Rob.

2 2

[boost-users][serialization]
by Igor R 19 Jan '09

19 Jan '09

Hello, I've just started to use serialization in my project. When I try to save some struct into archive: boost::archive::xml_oarchive archive = ....; archive << BOOST_SERIALIZATION_NVP(descriptor_); ...the following error occures (boost 1.36.0, MSVC9.0SP): boost/serialization/level.hpp(54) : error C2039: 'basic_traits' : is not a member of 'boost::serialization::boost::serialization' What does it mean in terms of my code, i.e. where should I look for an error? Thank you.

1 1