I wonder if this is *really* what you want!
A little credit, please. Yes, it's *really* what I want.
Ah, please accept my apologies. You by default always have as much credit as is humanly possible from me! I guessed that you might have wanted a little more than you asked for. This was simply because I have made the mistake of choosing the simpler requirement set when actually later I realized I wanted the path processing. Sorry.
I suspect that you probably want to determine the common effective prefix of the paths after canonicalisation.
No, the paths are known to be already canonicalized (with a 'z' ;->)
I'll try and remember to use 'z'!
Not particularly elegant, but this does work:
path x("/foo/bar"); path y("/foo/baar");
auto result = std::mismatch(x.begin(), x.end(), y.begin());
path prefix; for (auto itr = x.begin(); itr != result.first; ++itr) prefix /= *itr;
std::cout << prefix << std::endl;
I think this code doesn't "work" because it meets the stated requirements exactly! I think the requirements are normally greater than those we
first
think of when looking at the problem.
A. you didn't know my requirements ;-), and
True, but I would have felt bad if I had spotted a potential issue, stayed silent and then found out that I could have saved you some time.
B. for such an operation requiring the input paths to be canonical beforehand might in fact be the most appropriate interface.
I can see an argument for that. I wasn't attempting to suggest that there was one obvious correct idiom. I was really aiming to link to the previous discussion and the supplied implementation for a solution. I think on most observations I perceive similar improvements to be possible. My only real disagreement is with labelling Boost.Filesystem as frustrating. For the most part it helps me avoid writing tedious code. I like the idea of improving the iteration scheme and making it more like a container.
-- Dave Abrahams BoostPro Computing Software Development Training http://www.boostpro.com Clang/LLVM/EDG Compilers C++ Boost
Regards, Neil Groves