Benchmark: timing 500000 iterations of case1, case2...
     case1:  3 wallclock secs ( 3.76 usr +  0.00 sys =  3.76 CPU) @ 132978.72/s (n=500000)
     case2:  4 wallclock secs ( 4.11 usr +  0.00 sys =  4.11 CPU) @ 121654.50/s (n=500000)
          Rate case2 case1
case2 119332/s    --   -9%
case1 131234/s   10%    --