Re: [boost] [filesystem] adding path equality and path equivalence

From: Jeff Garland (jeff_at_[hidden])
Date: 2004-02-01 12:57:27

On Sun, 1 Feb 2004 16:46:18 -0000, John Maddock wrote
> > Question 2: What if neither exist? Only one exists? My initial thought is
> > that these are likely to be errors, so treat them as such. It could be
> > argued that if either or both don't exist, they can't be equivalent, so
> > return false.
> 
> If only one exists, it's not an error, the two are necessarily
> non-equivalent.  If neither exists, you have a problem ;-)  Probably 
> an error, unless someone has a compelling use case.

How about 2 symbolic links pointing at the same unmounted volume?  I'm
presuming that symbolic links will be followed (perhaps incorrectly) based on
the first statement:   
  "Two paths will be considered equivalent if they resolve to the same
   physical directory or file."

One possibility is that they are equivalent since they point at the same
target.  The other is that it is an error...

> > Windows logic for path equivalent: same device id AND same media volume
> > serial number AND same physical location on disk AND same creation time.

I've recently seen a problem where the creation time between some windows
platforms was off by one second.  I haven't finished tracking it down, but at
first blush it looked like the creation time when measured from a local
Windows XP machine was different from the time reported for that  same file
from a Windows 2K machine mounted across the network.  And now that I think
about it this would never create a problem within the same program anyway :-)

> Wow, I'm impressed, that looks good to me though.

I agree, this looks pretty good.

Jeff