Benchmark: running foreach, map_it for at least 5 CPU seconds...
   foreach:  6 wallclock secs ( 5.34 usr +  0.00 sys =  5.34 CPU) @ 286.87/s (n=1531)
    map_it:  5 wallclock secs ( 5.15 usr +  0.01 sys =  5.16 CPU) @ 134.77/s (n=695)