RE: [boost] Filesystem attributes

From: Stewart, Robert (stewart_at_[hidden])
Date: 2002-03-05 12:59:33

From: Jan Langer [mailto:jan_at_[hidden]]
> 
> On Sun, 3 Mar 2002, Dietmar Kuehl wrote:
> >
> >The opaque type would be useful for users only as a key to 
> corresponding
> >property maps accessing the various file attributes.
> 
> yes, thats exactly what string should do in a posix impl.. in your
> implementation the dir_it always called stat to retrieve the file
> attributes but i think this is not needed.

I'm not certain about Posix, but with the standard library (by way of C) you
can use a FILE *, and on *nix systems you can use an integer file descriptor
to refer to a file.  The point is that a string, however long, must be
compared through much of its length to determine whether it matches another,
thus making comparisons and lookups slower.

Dietmar's opaque type provides something akin to a FILE * or a file
descriptor which makes lookups quick.

Rob
Susquehanna International Group, LLP
http://www.sig.com