From: Robert Bell (belvis_at_[hidden])
Date: 2004-03-09 14:12:10
Jeff Garland wrote:
> On Tue, 09 Mar 2004 11:36:52 -0500, Beman Dawes wrote
>>That's an interesting thought. Of course, it might not be another
>>thread but rather another process that created the directory, and
>>that could be a sign of real trouble.
>>But such a change would allow simpler user code. What is now written:
>> if ( !exists( foo ) ) create_directory( foo );
>> create_directory( foo );
>>What happens when the directory existing really does constitute and
>>error, and create_directory() doesn't throw? Will applications fail
>>in difficult to diagnose ways? Can applications protect themselves
>>against silent failure?
> How about something like:
> void create_directory ( const path& name, bool error_if_exists = false);
> Then the application can decide -- defaulting to nothrow.
I agree; the application must be able to decide if the directory
existing is an error condition or not. However, I don't like the
optional argument. I think I would have a hard time remembering whether
void create_directory(const path& name, bool ok_if_exists = true);
void create_directory(const path& name, bool error_if_exists = false);
create_directory(path, true); // ???
Instead I would prefer two separately named functions, like
create_directory() and create_directory_exists_ok(). (Well, maybe not
these two names exactly, but you get the idea. ;-) )
In the past I've used the word "soft" for this kind of thing:
create_directory -- throws if directory already exists
soft_create_directory -- doesn't throw if directory already exists
>>What happens if the path exists but is not a directory? Presumably
>>that case must still throw.
> Yes, I think so.
Just my $0.02.
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