Re: Warning: Unreachable code detected

"throw" is one in a class of statements considered "jump statements".
This means, anything that occurs after a jump statement is considered
unreachable. This will occur for "break", "return", "goto", and "continue"
as well.  In C# you'll get warning CS0162 for each of the cases in the
following:
 while (true)
 {
  switch ((int)source)
  {
   case 1:
    return;
    break;
   case 2:
    goto label;
    break;
   case 3:
    continue;
    break;
   case 4:
    throw new Exception();
    break;
   case 5:
    break;
    break;
  }
 }
label:
 return;

There's nothing you can do short of re-arranging the code.  But, I would
consider it the same as the other jump statements (including break) as
being one of 5 statements that can appear at the end of a case block.
I.e. I wouldn't re-arrange the code and risk making it confusing and
harder to maintain just because you want to always end your case blocks
with a "break;".