floats default to NaN... why?

[F i L]

On Saturday, 14 April 2012 at 06:29:40 UTC, Ali Çehreli wrote:
> On 04/13/2012 09:00 PM, F i L wrote:
>
> > default is NaN
>
> Just to complete the picture, character types have invalid 
> initial values as well: 0xFF, 0xFFFF, and 0x0000FFFF for char, 
> wchar, and dchar, respectively.
>
> Ali

That's interesting, but what effect does appending an invalid 
char to a valid one have? Does the resulting string end up being 
"NaS" (Not a String)? Cause if not, I'm not sure that's a fair 
comparison.