Benchmark: timing 10000 iterations of split_anonymous, split_simple...

split_anonymous: 19 wallclock secs (19.05 CPU) @ 525.02/s (n=10000)
split_simple: 16 wallclock secs (15.77 CPU) @ 634.32/s (n=10000)

                 Rate split_anonymous    split_simple
split_anonymous 525/s              --            -17%
split_simple    634/s             21%              --