On Fri, May 15, 2009 at 5:10 AM, Andre Merzky <andre@...> wrote:

Quoting [Beman Dawes] (May 12 2009):

...

Ticket #2925 complains that "boost::filesystem cannot atomically copy file if target exists" ...

...

The proposed solution is to add an option to copy_file():

    enum class copy_option { fail_if_exists, overwrite_if_exists };

    void copy_file( const Path & from_path, const Path & to_path,       copy_option option=copy_option::fail_if_exists );

The implementation would be atomic on both POSIX and Windows.

Comments?

Makes sense.

OK, fix committed to trunk. It will go in branches/release once sufficient regression tests have cycled.

I would suggest to check the complete lib for similar problems.  I think most operational and convenience functions are prone to similar problems.

Hum... "most" is too strong; many of the operational functions are implemented as a single operating system API call. I really don't want to spend time analyzing and fixing the V2 codebase. Instead, I've added an item to the V3 do-list to do an atomicity review. I'm planning to spend a lot of time on Filesystem.V3 this summer, and release a V3 beta as the code firms up. Thanks, --Beman