Re: [boost] Review Request: Filesystem Library

From: Victor A. Wagner, Jr. (vawjr_at_[hidden])
Date: 2002-08-03 01:39:24

At Friday 2002/08/02 21:23, you wrote:
>From: "Beman Dawes" <bdawes_at_[hidden]>
>
> > Again, the function remove_all() is provided to meet the need for a
> > function which does not throw an exception if the target doesn't exist.
> >
> > It seems to me people are advocating something that is already provided.
>Am
> > I missing something?
>
>Yes. Using the other function is dangerous. It provides a false sense of
>security by working in all testcases, then throws an exception in the field
>when some other process gets in and deletes the file before we get a
>chance. Precondition checking should usually not be done with exceptions in
>the first place, and I think this is a particularly bad use for it.
>[deleted]
>This example is much worse, since the problem will almost never show up
>during testing, and even if it did, there's absolutely no test you can make
>to check whether the file will actually exist by the time you try to delete
>it.

It means that if the OS won't tell you whether it actually deleted the 
file, the program won't know for sure.
You might not even be able to tell then (not all OS's report with 
one-to-one correspondence with the truth).

>-----------------------------------------------------------
>            David Abrahams * Boost Consulting
>dave_at_[hidden] * http://www.boost-consulting.com

Victor A. Wagner Jr.      http://rudbek.com
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