Idempotent partition around median of 5?

[Andrei Alexandrescu via Digitalmars-d]

On 02/04/2016 03:30 PM, Timon Gehr wrote:
> At most 6 comparisons, <=3 swaps, idempotent (optimal number of swaps):

Oh, also: could you let that bad boy run and let it find anything that 
does idempotent partition in 6 compares and 0-7 swaps? Then slowly 
tighten the number of swaps until you find the best balance between 
number of swaps and code size. -- Andrei