Benchmark: running enum, list for at least 5 CPU seconds...
      enum:  5 wallclock secs ( 3.55 usr +  1.74 sys =  5.29 CPU) @ 501.89/s (n=2655)
      list:  5 wallclock secs ( 5.32 usr +  0.00 sys =  5.32 CPU) @ 1668.23/s (n=8875)

       Rate enum list
enum  502/s   -- -70%
list 1668/s 232%   --