If instead we use the other constructor, it's possible for the API to register errors into a return value; I would use that instead of an exception, since exception throwing is pretty slow, and it's especially not ideal in a loop like this

I agree, but I'm not much of a c++ programmer. Is there an example I can borrow from?

Cribbing from the internet, if I do this:

    boost::system::error_code ec;

    for (fs::recursive_directory_iterator it{path, ec}, end; it != end;
         it.increment(ec)) {
      LOG(WARNING) << "SEPH: examinging " << it->path() << "\n";
      if (fs::is_symlink(it->path())) {
        results.push_back(it->path().string());
      } else if (fs::is_directory(it->path())) {
        results.push_back(it->path().string());
      }
    }

It stops on the first permission denied error. Obviously not the behavior we want.

As I understand it, there are a couple of things. The first issue, is that we want the non-throw form -- to get this, we pass in an error receiver. The second issue, is that short form of the for loop uses ++ which has causes an exception if the iterate is passed in, thus the 3 part for loop.

I've also opted to pass in fs::directory_options::skip_permission_denied since otherwise the iteration stops on the first permission error.

I opted to ignore the errors, half because I didn't know how to read them, and half because all we'd do is INFO log them.

For my future self, these links had some okay explanations, and some possible helpers if we wanted to make a class for it.

• https://stackoverflow.com/questions/73101565/how-to-use-recursive-directory-iterator-without-exceptions-in-c
• https://stackoverflow.com/questions/70382262/recursive-directory-iterators-skip-permission-denied-option-appears-to-be-ignor
• https://stackoverflow.com/questions/67776830/c-directory-item-iteration-without-exceptions