I'm using C++17 (or perhaps C++14 with the filesystem TS) to work with some files: Check their size; open them for reading or for writing etc.
Now, when doing this fails, I typically get an exception: "file not found" or "permission denied". But this doesn't tell me which file wasn't found nor which permission was denied. Thus I can't tell whether the file I tried to open is in a non-existent directory, or whether the directory exists but the file doesn't. Or - whether I have no permission to check the file, or no permission to access its containing directory.
Obviously, it's important for a user of a (console) application to know exactly what's the (filesystem-related) problem is.
Is there an idiomatic way or making these errors more specific, or should I just roll my own wrappers / pre-call validator functions to take care of this?
PS - Yes, I realize there can be race conditions in which a path passes validation, but then someone creates a file or changes permission; and that there may also be locking issues to consider. You may ignore this in your answer (or not ignore it if you want to address that too.)