Scott McMurray wrote:

On Fri, Feb 6, 2009 at 21:22, Kenny Riddile <kfriddile@yahoo.com> wrote:

...

Is there any existing functionality for getting a relative path from a full path, where the desired relative path is relative to an arbitrary directory path? If not, I'm assuming I would just have to walk up both full paths until I find their intersection...etc

There isn't yet, though I have a ticket filed requesting one: https://svn.boost.org/trac/boost/ticket/1976 Please add your use case to that ticket.

The v3 lib under discussion has a read_symlink function which will allow a non-naïve implementation. In the mean time, if you're in windows you can try the implementation in the ticket. _______________________________________________ Unsubscribe & other changes: http://lists.boost.org/mailman/listinfo.cgi/boost

Thanks. The use case proposed on your ticket is literally identical to mine (persisting relative paths to allow checking output files in subversion).

On Fri, Feb 6, 2009 at 22:32, Kenny Riddile <kfriddile@yahoo.com> wrote:

Also, may I suggest the name "as_relative_to" for the member function if this is added to the library? as_relative_to would be a const member method that take the desired base path as its only parameter and returns the desired relative path.

The problem I see with that is that to handle symlinks elegantly, "uncomplete" will need to look at the filesystem, not just the path elements, which, following as I understand the way things are organized, prevents it from being part of the path class itself. (This is the same problem that keeps coming up: ./foo/bar/.. doesn't have to be ./foo when symlinks are involved.) In any case, it's the inverse function to complete, so it should be the same kind of beast. (It seems p.has_root_path() ? complete(relative(p)) : relative(complete(p)) should be equivalent to p, assuming compatible root_name()s in the first branch.) As I mention in the ticket, I really like the idea of calling the function relative, but I'm worried about conceptual conflict with the relative_path() decomposition function (which I don't really like, since if complete uses initial_path, it seems like relative would be to initial_path, not to the root of the path in question, though the member/nonmember may be enough to disambiguate).