private static string GetWindowsRoot()

in SharpGenTools.Sdk/Internal/Roslyn/PathUtilities.cs [201:264]
43 lines of code
13 McCabe index (conditional complexity)

        private static string GetWindowsRoot(string path)
        {
            // Windows
            int length = path.Length;
            if (length >= 1 && IsDirectorySeparator(path[0]))
            {
                if (length < 2 || !IsDirectorySeparator(path[1]))
                {
                    //  It was of the form:
                    //          \     
                    //          \f
                    // in this case, just return \ as the root.
                    return path.Substring(0, 1);
                }

                // First consume all directory separators.
                int i = 2;
                i = ConsumeDirectorySeparators(path, length, i);

                // We've got \\ so far.  If we have a path of the form \\x\y\z
                // then we want to return "\\x\y" as the root portion.
                bool hitSeparator = false;
                while (true)
                {
                    if (i == length)
                    {
                        // We reached the end of the path. The entire path is
                        // considered the root.
                        return path;
                    }

                    if (!IsDirectorySeparator(path[i]))
                    {
                        // We got a non separator character.  Just keep consuming.
                        i++;
                        continue;
                    }

                    if (!hitSeparator)
                    {
                        // This is the first separator group we've hit after some server path.  
                        // Consume them and keep going.
                        hitSeparator = true;
                        i = ConsumeDirectorySeparators(path, length, i);
                        continue;
                    }

                    // We hit the second separator.  The root is the path up to this point.
                    return path.Substring(0, i);
                }
            }
            else if (length >= 2 && path[1] == VolumeSeparatorChar)
            {
                // handles c: and c:\
                return length >= 3 && IsDirectorySeparator(path[2])
                    ? path.Substring(0, 3)
                    : path.Substring(0, 2);
            }
            else
            {
                // No path root.
                return "";
            }
        }