dirMatches := best.isDir() == other.isDir()
				suffixMatches := strings.HasSuffix(best.name, slashSeparator) == strings.HasSuffix(other.name, slashSeparator)

				// Simple case. Both are same type with same suffix.
				if dirMatches && suffixMatches {
					toMerge = append(toMerge, otherIdx)
					continue
				}

				if !dirMatches {

// ReadWriter stores pointers to a [Reader] and a [Writer].
// It implements [io.ReadWriter].
type ReadWriter struct {
	*Reader
	*Writer
}

// NewReadWriter allocates a new [ReadWriter] that dispatches to r and w.
func NewReadWriter(r *Reader, w *Writer) *ReadWriter {
	return &ReadWriter{r, w}