PE>  {
 PE>    temp = a;
 PE>    a = b;
 PE>    b = temp;
 PE>  }

 FM> Couldn't you avoid using the temporary variable by replacing the above
 FM> with
 FM>      {
 FM>        a ^= b;
 FM>        b ^= a;
 FM>        a ^= b;
 FM>      }


There is rarely any point, and a compelling reason NOT to do this - readability.

Any optimising compiler will use temp as a register variable in this
context - declare it 'register' within the inner block if you're concerned
about non-optimising compilers. The xor method would usually be slower
(than two MOV's and one XCHG) in that case.

This is one of those cute tricks you show off at parties, but not
recommended for any real code.


david

--- MaltEd/2 1.0.b6