Idempotent partition around median of 5?

[Xinok via Digitalmars-d]

On Thursday, 4 February 2016 at 20:30:57 UTC, Timon Gehr wrote:
> At most 6 comparisons, <=3 swaps, idempotent (optimal number of 
> swaps):
>
> void partition5(ref int[5] a){
>   if(a[0]<a[1]){
> ...

Great, we can all go home!

I was curious so I did a crude measurement: when compiled for 
64-bit with all optimizations turned on (-release -O -inline 
-boundscheck=off), the machine code for this function is about 
3KB in size.