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

[gil] channel_convert question
by Christian Henning 05 May '07

05 May '07

Hi there, what's the difference between the following two lines? float red_1 = channel_convert< bits32f >( 1.f ); float red_2 = channel_convert< bits32f >( (bits32f) 1.f ); The first gives me garbage whereas the second gives the correct result. Regards, Christian

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[gil][bind] How to bind gil::at_c ?
by Christian Henning 05 May '07

05 May '07

Hi there my compiler doesn't like binding the gil::at_c function. I'm using MSVC 7.1 SP1. Please correct if I'm wrong but I think you need to supply a function pointer cast for overloaded function when using this compiler. But for some reasons I cannot make it happen. template < typename CHANNEL > void set_zero( CHANNEL c ) { c = 0; } int main() { rgb8_image_t src; bmp_read_image( ".\\flower.bmp", src ); typedef channel_type<rgb8_pixel_t>::type return_t; add_reference<return_t>::type (*AA)( rgb8_pixel_t& ) = &gil::at_c<0>; for_each( view( src ).begin() , view( src ).end() , bind( &set_zero, bind( AA, _1 ))); return 0; } compiler error is: \gil\repos\gil_2\libs\gil\toolbox\test.cpp(74) : error C2440: 'initializing' : cannot convert from 'overloaded-function' to 'boost::add_reference<T>::type (__cdecl *)(boost::gil::rgb8_pixel_t &)' with [ T=boost::gil::bits8 ] None of the functions with this name in scope match the target type Thanks ahead, Christian

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Re: [Boost-users] [BoostCon07][testing] Session reminder.
by David Abrahams 04 May '07

04 May '07

on Fri May 04 2007, Stefan Seefeld <seefeld-AT-sympatico.ca> wrote: > David Abrahams wrote: > >> Okay, here are some issues I think ought to be solved, in no >> particular order, some (much) more important than others: > > David, > > I'm happy to see you bring up much the same points I mentioned. > Here is one I haven't yet got to, and would like to explore a bit > further: > >> * generating XML by parsing the jam log is fragile and prevents the >> use of multiple build processes (-jN). This one should be almost >> embarassingly easy to fix. > > I think there is more to this than only the ability to run tests in > parallel. For example, it would help to robustify the testing > harness if the 'test database' could be inspected without actually > executing any test. By that I mean the ability to: > > * See all tests, as part of the test database structure (i.e. their > organization into test suites) > > * See meta data associated with tests, such as > > - what kind of test > - expected outcome, per platform > - dependencies, prerequisites, etc. How would that help with robustness? -- Dave Abrahams Boost Consulting www.boost-consulting.com Don't Miss BoostCon 2007! ==> http://www.boostcon.com

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Boost serialization w/gcc 3.2.3 on CentOS 4.4?
by matthew.garman＠gmail.com 04 May '07

04 May '07

We've got an in-house infrastructure that uses the boost::serialization library (from boost 1.33). Thus far, all our development has been done using gcc 3.4.5 and 3.4.6 on CentOS 4.3 and 4.4 (respectively). (Note that CentOS is practically the same as Red Hat Enterprise Linux.) Now we are forced to integrate with a 3rd party proprietary library that was built with gcc 3.2. So I installed the gcc32 package: % gcc32 --version gcc32 (GCC) 3.2.3 20030502 (Red Hat Linux 3.2.3-47.3) Copyright (C) 2002 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. If I build my program with gcc 3.2 and link against boost built with gcc 3.4, my program segfaults as soon as the first boot::serialization method is called. So I tried to rebuild boost using gcc 3.2. I did this by running the configure script, then modifying the "BJAM_CONFIG" variable of the top-level Makefile: BJAM_CONFIG= -sPYTHON_ROOT=/usr -sPYTHON_VERSION=2.3 \ -sGXX=g++32 -sGCC=gcc32 Then I ran make. First thing I noticed is that there were a *lot* of warnings, although the library did build. Same thing when building my own program: lots of warnings surrounding the boost stuff, but it does build. Also, when linking, I get this warning: /usr/bin/ld: warning: libstdc++.so.6, needed by /usr/local/lib/libboost_serialization-gcc.so, may conflict with libstdc++.so.5 Unfortunately, the program still crashes when it gets to the boost::serialization stuff. I looked at the Boost compatibility matrix, and as far as I can tell, gcc 3.2 is supported (though I definitely could have misread something!). So my hunch is that I've got a problem with my build process... but I'm not sure where. I know I've left out some details; please let me know what other info I need to provide. Suggestions or general "things to try" are welcome as well! Thanks, Matt

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xml serialization : compilation fails
by Cyril 04 May '07

04 May '07

Hello all, I have a problem while attempting to serialize a simple object using xml (text works fine !). This is my code : // SomeData.h #include <boost/serialization/utility.hpp> #include <boost/serialization/base_object.hpp> class OBJECTS_API InternalData { public: InternalData(); virtual ~InternalData(); virtual int getInternals() const = 0; private: friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { } }; class OBJECTS_API RealData : public InternalData { public: RealData(int internals=0); int getInternals() const; private: int _internals; friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { ar & BOOST_SERIALIZATION_BASE_OBJECT_NVP(InternalData) & BOOST_SERIALIZATION_NVP(_internals); } }; class OBJECTS_API SomeData { public: SomeData(int internals=0); ~SomeData(); InternalData* getInternals() const; private: InternalData* _data; static InternalData* createData(int internals); friend class boost::serialization::access; template<class Archive> void serialize(Archive & ar, const unsigned int version) { //ar.register_type(static_cast<RealData*>(0)); ar & BOOST_SERIALIZATION_NVP(_data); } }; ////////////////// // somewhere else const SomeData data(4); boost::archive::xml_oarchive xoa(archive); //archive is a file stream xoa << data; //////////////////// This fails to compile because : // basic_xml_oarchive.hpp // Anything not an attribute and not a name-value pair is an // error and should be trapped here. template<class T> void save_override(T & t, BOOST_PFTO int) { // If your program fails to compile here, its most likely due to // not specifying an nvp wrapper around the variable to // be serialized. BOOST_STATIC_ASSERT(0 == sizeof(T)); } I can't see why my code isn't correct according to that constraint. Any help ? Thanks in advance.

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spirit and gcc-3.3 and 64 bit
by Jörg Becker 04 May '07

04 May '07

Hi there, I have a problem compiling the following parser with gcc-3.3 in a 64 bit environment: the compiler consumes a lot of cpu time, but never returns. On my old 32 bit box I could compile a similar parser without problems. Also I can compile this parser with gcc-3.3 -m32. With gcc-4.1 I can build a 64 bit version but due to company restrictions I have to use the gcc-3.3. Thanks for any suggestions. Jörg ----------------------- parser definition my_parser.h ----------------------- #ifndef my_parser_h #define my_parser_h #include <boost/spirit/core.hpp> #include <boost/spirit/attribute.hpp> // closure struct my_closure : boost::spirit::closure< my_closure, bool > { member1 match; }; struct my_parser : public boost::spirit::grammar < my_parser, my_closure::context_t > { my_parser () {} template <typename ScannerT> struct definition { definition ( my_parser const& self ) { top = boost::spirit::str_p( "a" )[ self.match = phoenix::arg1 ]; } typedef boost::spirit::rule< ScannerT, my_closure::context_t > rule_t; boost::spirit::rule< ScannerT > top; boost::spirit::rule< ScannerT > const& start () const { return top; } }; }; #endif // my_parser_h ------------------ test program ------------------ #include "my_parser.h" int main () { my_parser parser; bool match = false; boost::spirit::parse_info<> info = parse( "a and b or c", parser[ phoenix::var( match ) = phoenix::arg1 ], boost::spirit::space_p ); if ( info.full ) { return match; } else { return -1; } }

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Re: [Boost-users] [Serialisation] One last GUID question - I hope.
by Pavlo Korzhyk 04 May '07

04 May '07

.... > "The macro BOOST_CLASS_EXPORT_GUID associates a string literal with a > class. In the above example we've used a string rendering of the class > name. If a object of such an "exported" class is serialized through a > pointer and is otherwise unregistered, the "export" string is included > in the archive. When the archive is later read, the string literal is > used to find the class which should be created by the serialization > library. ****This permits each class to be in a separate header file > along with its string identifier****. There is no need to maintain a .... > Is the document misleading here, or have I missed something?? It says that the class declaration may be placed in a separate header, but that doesn't mean BOOST_CLASS_EXPORT_GUID must be placed to that header too :) When you create a separate header for the class, usually you also create a separate .cpp for it. Place BOOST_CLASS_EXPORT there and everything will work fine. WBR, Pavlo Korzhyk ICQ#155870780

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[fusion][bind] How to bind a fusion sequence?
by Christian Henning 03 May '07

03 May '07

Hi there, I have a problem ( compilation error ) using a fusion map with boost bind. Not sure if that is the intended usage. So, please show some mercy when I'm doing something totally stupid. Basically, I have a std::vector of a fusion::map instances. And I would like to find a fusion::map instance with a special value. Here is the code: #include <vector> #include <algorithm> #include <functional> #include <boost/bind.hpp> #include <boost/fusion/algorithm.hpp> #include <boost/fusion/sequence.hpp> #include <boost/fusion/iterator.hpp> using namespace std; using namespace boost; namespace fields { struct _id_; struct _name_; struct _birthday_; struct _address_id_; } typedef fusion::map< fusion::pair< fields::_id_ , string > , fusion::pair< fields::_name_ , string > , fusion::pair< fields::_birthday_ , string > , fusion::pair< fields::_address_id_, string > > table_type; int main() { table_type table; vector< table_type > vec; find_if( vec.begin() , vec.end() , bind( equal_to< string >() , bind( &fusion::at_key< fields::_id_ >, _1 ) , string( "Hallo" ))); return 0; } Does that makes sense? If yes, how would I do it? I'm using MSVC 7.1 and the first couple of compiler errors are: Compiling... test.cpp test.cpp(43) : error C2783: 'result_of::at_key<const Sequence,Key>::type boost::fusion::at_key(const Sequence &)' : could not deduce template argument for 'Sequence' c:\boost\boost\fusion\sequence\intrinsic\at_key.hpp(50) : see declaration of 'boost::fusion::at_key' test.cpp(43) : error C2783: 'lazy_disable_if<boost::is_const<Sequence>,boost::fusion::result_of::at_key<Sequence,Key>>::type boost::fusion::at_key(Sequence &)' : could not deduce template argument for 'Sequence' c:\boost\boost\fusion\sequence\intrinsic\at_key.hpp(43) : see declaration of 'boost::fusion::at_key' test.cpp(43) : error C2784: 'boost::_bi::bind_t<R,boost::_mfi::dm<R,T>,_bi::list_av_1<A1>::type> boost::bind(R T::* ,A1)' : could not deduce template argument for 'overloaded function type' from 'overloaded function type' c:\boost\boost\bind.hpp(1616) : see declaration of 'boost::bind' [snip] Thanks for your patients, Christian

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Re: [Boost-users] [BoostCon07][testing] Session reminder.
by Anthony Williams 03 May '07

03 May '07

"Gennadiy Rozental" <gennadiy.rozental(a)thomson.com> writes: [snipped lots of sensible stuff] > VI Boost release > > The boost release is done automatically every predefined period of time > (like three month). It requires NO testing, NO branching and NO > merging/reverting. It's done by single script (a bit oversimplification, but > close) that does these tasks: > > 1. It iterates through all components and check any component that was > released since previous boost release. > Very important: The component should NOT depend on older version of > component that is being released. For example if library A depends on > version 1.23 of library B and version 1.24 of library B was released, > library A won't become part of the next boost release. Here I don't understand. Suppose Boost release X contains library A version 1.4, and library B version 1.23, and library A depends on library B. The developer of library B then releases a new version (1.24), and the author of library A doesn't. The next Boost release (Y) comes along, and now library A is no longer part of the Boost release? That strikes me as a bad plan --- the contents of Boost will vary from release to release as developers update their libraries at different rates. As an alternative, how about this: if library A depends on version xyz of library B, then library B is pinned at version xyz for Boost releases until library A is updated. If library A is not updated for n consecutive Boost releases, library A is dropped from Boost as unmaintained. How about this, also: a library developer can only release their library if it is built against the latest released version of all its dependent libraries. That way if a core library is updated, all other libraries will have to use the new version before they can release. Anthony -- Anthony Williams Just Software Solutions Ltd - http://www.justsoftwaresolutions.co.uk Registered in England, Company Number 5478976. Registered Office: 15 Carrallack Mews, St Just, Cornwall, TR19 7UL

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Boost Sandbox has moved to Subversion
by Doug Gregor 03 May '07

03 May '07

The Boost Sandbox has now moved from Sourceforge CVS to Subversion hosted at OSL. The Boost Sandbox CVS at Sourceforge is now closed and should no longer be used. The Subversion URL for the Sandbox is: http://svn.boost.org/svn/boost/sandbox/ For anyone requiring write access to the sandbox, please read http:// svn.boost.org/trac/boost/wiki/BoostSubversion and follow the directions there. The Subversion URL for read/write access to the sandbox is: https://svn.boost.org/svn/boost/sandbox/ More information about the Boost Subversion repository is available at http://svn.boost.org - Doug

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