Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]

Groups > comp.lang.c++ > #8996

Re: C++ and directories

Show all headers | View raw

On Wed, 17 Aug 2011 13:02:34 +0000, Juha Nieminen wrote:

>>>   Anyways, is there a reason why the C++ standard couldn't include a
>>> library similar to boost::filesystem?
>> 
>> A third-party library has more leeway. It's up to the third-party
>> developer whether "it sort-of works, on common platforms" is good enough.
>> If e.g. an OS vendor complains that the interface is a poor match for
>> their OS's filesystem semantics, the boost developers can just say
>> "tough luck". But the ISO standardisation process is rather more involved.
> 
>   Not everything even in the current standard is something that *must*
> work on every system in existence.
> 
>   For example, where does the output of std::cout (or printf from that
> matter) go?

It doesn't have to "go" anywhere. An implementation can discard anything
written to cout/cerr and consider cin as being initially at EOF.

However, on most platforms which actually have files, there's enough
commonality to make it worth defining a basic interface. Even on systems
which don't have files, stringstream still works.

>   I think a file system library is feasible even for the C++ standard,
> especially if it includes means to check that the target architecture
> has proper support.

Unlike streams, filesystems differ greatly in their semantics. E.g.
single root (Unix) versus multiple drives and UNC paths (Windows), the
types of object which can exist on a filesystem, whether links are
supported and whether they're transparent (hard links) or a distinct type
(symbolic links), whether filenames are composed of bytes (Unix) or
characters (Windows), whether filenames are case-sensitive, whether a file
can be renamed or deleted while it is open, what information is stored
about a file, whether files are versioned (VMS), ...

The differences just between Unix and Windows are enough that even fairly
trivial cases end up requiring #ifdef'd code to handle the differences.
And once you move beyond the most common platforms, you're usually on your
own.

Back to comp.lang.c++ | Previous | Next — Previous in thread | Next in thread | Find similar | Unroll thread

Thread

C++ and directories "Edward Hvarregaard" <edwardh@shaw.ca> - 2011-08-15 17:49 -0700
  Re: C++ and directories Ian Collins <ian-news@hotmail.com> - 2011-08-16 12:55 +1200
    Re: C++ and directories jt@toerring.de (Jens Thoms Toerring) - 2011-08-16 11:15 +0000
  Re: C++ and directories Nobody <nobody@nowhere.com> - 2011-08-16 11:57 +0100
    Re: C++ and directories Juha Nieminen <nospam@thanks.invalid> - 2011-08-16 11:42 +0000
      Re: C++ and directories Marc <marc.glisse@gmail.com> - 2011-08-16 11:49 +0000
      Re: C++ and directories jt@toerring.de (Jens Thoms Toerring) - 2011-08-16 11:58 +0000
      Re: C++ and directories Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-08-16 16:02 +0000
      Re: C++ and directories Nobody <nobody@nowhere.com> - 2011-08-17 13:09 +0100
        Re: C++ and directories Juha Nieminen <nospam@thanks.invalid> - 2011-08-17 13:02 +0000
          Re: C++ and directories Nobody <nobody@nowhere.com> - 2011-08-17 18:11 +0100
          Re: C++ and directories "Paul" <pchristor@yahoo.co.uk> - 2011-08-18 20:38 +0100
            Re: C++ and directories Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-08-23 01:03 -0700
          Re: C++ and directories Nick Keighley <nick_keighley_nospam@hotmail.com> - 2011-08-23 01:06 -0700
  Re: C++ and directories Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-08-16 15:24 +0000
  Re: C++ and directories "Bo Persson" <bop@gmb.dk> - 2011-08-17 12:39 +0200
    Re: C++ and directories Jorgen Grahn <grahn+nntp@snipabacken.se> - 2011-08-17 11:39 +0000
  Re: C++ and directories "Edward Hvarregaard" <edwardh@shaw.ca> - 2011-08-22 10:06 -0700

csiph-web