[boost] Re: [filesystem] create_directories not thread-safe?

From: David Abrahams (dave_at_[hidden])
Date: 2004-03-09 17:39:35

Beman Dawes <bdawes_at_[hidden]> writes:

>  >This almost goes without saying.
>  >
>  >    create_directory(path p)
>  >
>  >    post: p exists and is a directory
>  >
>  >If the postcondition cannot be satisfied, create_directory _must_ throw.
>  >But if p already exists and is a directory, the postcondition already
>  >holds, so we are free to report the "error" via a different mechanism
>  >(COM, for example, has a conventional "alternate success code" S_FALSE
>  >for such situations).
>
> We have a similar case with remove(), which is reported by remove()
> returning a bool indicating if it actually removed anything.
>
> It would be quite consistent for create_directory() to return a bool
> indicating if it actually had to create the directory.

FWIW, I think that's the right approach.

-- 
Dave Abrahams
Boost Consulting
www.boost-consulting.com