Date: Sat, 19 Nov 1994 04:46:56 -0500
From: davis AT amy DOT tch DOT harvard DOT edu ("John E. Davis")
To: dolan AT fnoc DOT navy DOT mil, gordon AT spot DOT colorado DOT edu
Subject: Re: printf or floating point error?????
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu

>A cast does not say "convert this value on the right to this type and
>assign it to the recipient on the left", a cast says "for right now,
>the bit pattern contained in the piece of _storage_ at the location
>indicated by the object being cast IS this type, use it as this type
>and pass the appropriate value under that interpretation into the
>recipient on the left", not at all the same thing, it turns out.

I do not think that this statement is correct. 
Consider:

   float x, y;
   long i = 10;
   
   /* assume sizeof (float) == sizeof (long) */
   
   x = (float) i;
   y = *(float *) &i;
   
Here `x' will have the value of 10.0 whereas `y' has the bit pattern that you
are suggesting above.  `y' will will almost certainly not be 10.0 and `x' will
not have the bit pattern of `i'.  That is, the float cast above will
definitely modify the bit pattern of i.

--John