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New design proposal for boost::filesystem
by Martin 06 Sep '04

06 Sep '04

Just a thought on the filesystem implementation. Why not separate the path from the filesystem? Let the path be a container for all kind of paths that follow the generic syntax explained in the boost::filesystem documentation. Then use implementation classes that handles root name and conversion to native strings etc. The benefits would be: 1. The path can be used for other things than filesystems (XPath, Win32 registry) 2. Operations can be implemented selectivly for different types (No need for the current messy #ifdefs) bool exists( const path_base<posixfs<std::string> >& aPath); bool exists( const path_base<win32fs<std::wstring> >& aPath); bool exists( const path_base<win32reg<boost::fixed_string<100> > >& aPath); 3. Easy to expand the functionality for specific tasks without touching the boost headers. The implementation could look something like: template <class ImplT> class path_base : private ImplT { public: typedef ImplT::string_type string_type; path_base() : ImplT() {} // all path operations as in current implementation ... private: string_type m_path; }; // // implementation for win32 filesystem // template <class StringT> class win32fs { // root-name ::= root-drive | root-share | root-device // root-drive ::= char ":" // root-share ::= "//" name // root-device ::= name ":" protected: typedef StringT string_type; win32fs() { } string_type make_generic(const string_type::value_type* src); string_type native_file_string(const string_type& m_path) const { return algorithm::replace_all_copy(m_root + m_path, "/", "\\"); } ... private: string_type m_root }; // // implementation of posix filesystem // template <class StringT> class posixfs { win32fs() { } string_type make_generic(const string_type::value_type* src); string_type native_file_string(const string_type& m_path) const { return m_path; } ... } #ifdef BOOST_POSIX typedef path_base<posixfs<std::string>> path; #else ...

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[serialization] request: low-level info about order of serialization
by Joaquín Mª López Muñoz 06 Sep '04

06 Sep '04

I'm slowly designing the addition of serialization support to Boost.MultiIndex, and come up with a need that, AFAIK, the current serialization library does not cover: The serialization of a multi_index_container should ensure that the order in which elements appear is preserved for all indices of the container. This implies serializing the elements and then recording the appropriate rearrangements in each index. I'm writing the code for serializing these rearrangements in an efficient manner as some sort of "diff" sequences, using an algorithm called "longest increasing subsequence" (LIS). The algorithm would greatly benefit for some low-level API by the serialization lib that, given an object reference, would return the order in which that object was serialized. I guess this information is already available internally, as the lib must keep track of previously saved objects. If this requirement is deemed too exotic to provide to the general user, well, I can write something myself without aid from the lib, but I thought I should ask at least :) Thank you, Joaquín M López Muñoz Telefónica, Investigación y Desarrollo

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[request] Sun and IBM users...
by Paul Mensonides 06 Sep '04

06 Sep '04

Can someone test the following preprocessor code on the Sun and IBM preprocessors: #include <boost/preprocessor/detail/split.hpp> #include <boost/preprocessor/punctuation/comma.hpp> #include <boost/preprocessor/punctuation/paren.hpp> #include <boost/preprocessor/tuple/eat.hpp> #define IS_NULLARY(x) \ BOOST_PP_SPLIT(1, IS_NULLARY_C x BOOST_PP_COMMA() 0) \ /**/ #define IS_NULLARY_C() \ ~, 1 BOOST_PP_RPAREN() \ BOOST_PP_TUPLE_EAT(2) BOOST_PP_LPAREN() ~ \ /**/ IS_NULLARY(()) // 1 IS_NULLARY(()abc) // 1 IS_NULLARY(+) // 0 IS_NULLARY(xyz) // 0 #define IS_UNARY(x) IS_NULLARY(IS_UNARY_C x) #define IS_UNARY_C(a) () IS_UNARY((a)) // 1 IS_UNARY((a)abc) // 1 IS_UNARY(+) // 0 IS_UNARY(xyz) // 0 Regards and thanks, Paul Mensonides

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algorithm/string bug
by Llew Sion Goodstadt 06 Sep '04

06 Sep '04

There seems to be a bug somewhere in #include <boost/algorithm/string.hpp> If I am not mistaken, this is the central include file for all the string algorithms. But if, e.g. in replace_example.hpp, you replace the separate declarations of #include <boost/algorithm/string/replace.hpp> #include <boost/algorithm/string/erase.hpp> #include <boost/algorithm/string/case_conv.hpp> with //#include <boost/algorithm/string/replace.hpp> //#include <boost/algorithm/string/erase.hpp> //#include <boost/algorithm/string/case_conv.hpp> #include <boost/algorithm/string.hpp> the file no longer compiles. However, #include <boost/algorithm/string/replace.hpp> //#include <boost/algorithm/string/erase.hpp> //#include <boost/algorithm/string/case_conv.hpp> #include <boost/algorithm/string.hpp> does work. Is there an error in the order of header inclusion? Leo Goodstadt

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Program options possible error?
by Llew Sion Goodstadt 06 Sep '04

06 Sep '04

In <boost/program_options/detail/config_file.hpp> why is BOOST_WORKAROUND used (line 19) before the inclusion of #include <boost/detail/workaround.hpp>? Thanks Leo

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RE: [boost] Re: IOStreams formal review start
by Reece Dunn 06 Sep '04

06 Sep '04

Jonathan Turkanis wrote: >I'm starting to think it would be very useful to have a Flushable concept, >which >would allow components to advertise that they can send all buffered data >downstream at any time. I haven't given it much though yet, but I think it >would >allow OuputFilters to be inserted and removed in the middle of processing a >character sequence, as Dietmar suggested. This would make it possible to write a processor for a PDF file that contains several 'stream' objects, each with different filters (LZW compression, ASCII85 encoding, JPEG images, etc.). Regards, Reece _________________________________________________________________ Express yourself with cool new emoticons http://www.msn.co.uk/specials/myemo

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tru64cxx65 regression tests temporarily disabled
by Markus Schöpflin 06 Sep '04

06 Sep '04

The regular regression tests for Compaq C++ 6.5 on Tru64 V5.1 have been temporarily disabled. They will be reactivated as soon as possible. Markus

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RE: [boost] Re: New design proposal for boost::filesystem
by Reece Dunn 06 Sep '04

06 Sep '04

Vladimir Prus wrote: >Martin wrote: > > > Vladimir Prus <ghost <at> cs.msu.su> writes: > > The current path implementation doesn't > > allow you to handle more than one type (i.e. winfs or posixfs). You >can't > > store a registrypath in a fs::path since it can't handle a hkey.. root. > >Why? Can't I put literal "HKEY_CURRENT_USER" in boost::path? I don't think he's questioning that, but the case where you can use a HKEY handle as the root, for example: // note: not sure on exact calls HKEY hkCU, hkBase; ::OpenKey( null, "HKEY_CURRENT_USER", &hkCU ); ::OpenKey( hkCU, "software\\microsoft\\windows", &hkBase ); boost::fs::path regwin( hkBase ); // oops: error boost::fs::path spyware = regwin / "CurrentVersion" / "Run" / spyware_app; if( exists( spyware )) // does the registry key exist { // display the value std::cout << "removing: " << boost::fs::get_regval( spyware ) << '\n'; boost::fs::delete( spyware ); // delete the registry entry } Also, iterating through registry entries requires different API calls to that of iterating through files. > >> Actually, I think it is very desired to have boost::path usable in more > >> contexts than the filesystem. For example > >> > >> fs::path base("http://my_site.org"); > >> ..... get_file(base / "foo" / "bar") ..... > >> > >> would be great. But I'm just don't sure this requires all that drastic > >> changes. > > > > Why do you think it is a drastic change? > > Changing operations will not take much time since it is only to move the > > things inside "#ifdef BOOST_POSIX" and "#ifdef BOOST_WINDOWS" into > > separate overloads. > >And #ifdef the overloads ;-) I don't think Win32 API calls can be compiled >on Linux. > >I really think that win32/posix distinction should say as it is. For other >types of path, I'm not sure. I *think* that boost::fs::path can accomodate >all of them. Of course, if you stick URL into boost::fs::path, the name >'native_file_path' becomes questionable ;-) Why not have a class like std::char_traits (e.g. boost::fs::path_traits) that abstracts the API used by path. That way, you can have: template< typename CharT > struct posix_path_api { typedef ... file_handle; typedef ... directory_iterator_handle; static bool exists( file_handle ); static void delete( file_handle ); static directory_iterator_handle get_next( directory_iterator_handle ); }; This would then simplify the Win32/posix API problems and allow for internet_api, winregistry_api, etc. to be included, e.g. boost::fs::path< char, internet_api< char > > boostweb( "http://www.boost-consulting.com/boost" ); Regards, Reece _________________________________________________________________ Express yourself instantly with MSN Messenger! Download today - it's FREE! http://messenger.msn.click-url.com/go/onm00200471ave/direct/01/

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warning in boost::program_options
by Rodolfo Schulz de Lima 06 Sep '04

06 Sep '04

Hi, I'm using boost::program_options for the first time and noticed that when compiling a program that uses it using gcc's -Wall, it spits out a warning about an unused function parameter: /usr/include/boost-1_32/boost/program_options/value_semantic.hpp:137: warning: unused parameter 'value_store' Can this be corrected? It's just annoying when using -Werror. Since I've seen warnings in other libraries as well, I wonder why those ones aren't being caught in boost's test summary (on the home page). Just adding -Wall to the compiler option would suffice. Regards, rod

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another warning in boost::program_options
by Rodolfo Schulz de Lima 06 Sep '04

06 Sep '04

Oops... another warning: /usr/include/boost-1_32/boost/program_options/detail/value_semantic.hpp:78: warning: unused parameter 'target_type' There might be others...

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