Benchmark: timing 15000 iterations of mine-elegant, mine-less-elegant, original, yours-arg2...
mine-elegant:  7 wallclock secs ( 5.19 usr +  0.00 sys =  5.19 CPU) @ 2890.17/s (n=15000)
mine-less-elegant:  4 wallclock secs ( 3.19 usr +  0.01 sys =  3.20 CPU) @ 4687.50/s (n=15000)
  original:  6 wallclock secs ( 5.06 usr +  0.02 sys =  5.08 CPU) @ 2952.76/s (n=15000)
yours-arg2: 32 wallclock secs (25.06 usr +  0.08 sys = 25.14 CPU) @ 596.66/s (n=15000)