[boost] Re: [Filesystem] i18n

From: Alf P. Steinbach (alf_p_steinbach_at_[hidden])
Date: 2005-03-31 11:35:09

Beman Dawes wrote:
> ... with the following errors I can't see any way to know if the path
> actually exists or not:
> 
>   [EACCES] Search permission is denied for a component of the path
> prefix. 
> 
>   [EIO] An error occurred while reading from the file system.
> 
>   [ELOOP] A loop exists in symbolic links encountered during
> resolution   of the path argument.
> 
>   [ENAMETOOLONG] The length of the path argument exceeds {PATH_MAX} or
>   a pathname component is longer than {NAME_MAX}.
> 
> If you agree with that analysis, then it looks like exists() should be
> changed to throw on those last four errors.

Looks to me that 'exists()' must yield a tri-state result if its going
to be kept with existing name.

Some questions cannot be answered with only yes or no.

An alternative to tri-state is to split the thing into two or more
functions.  I vaguely remember seeing some documentation about this
where the current interface seemed obscure to me, the client code
programmer having to keep in mind a table of possible combinations of
results and what they would mean.  Sorry I'm too lazy to look into this
again, but if that vague recollection is correct, then I suggest that
the elements in that table indicate the functions that _should_ be there.