laptop:~> monk.pl
Benchmark: timing 20 iterations of Atest, Btest, Ctest, Dtest...
     Atest: 17 wallclock secs (16.61 usr +  0.25 sys = 16.86 CPU) @  1.19/s (n=20)
     Btest: 16 wallclock secs (16.73 usr +  0.00 sys = 16.73 CPU) @  1.20/s (n=20)
     Ctest: 17 wallclock secs (16.72 usr +  0.00 sys = 16.72 CPU) @  1.20/s (n=20)
     Dtest: 17 wallclock secs (16.71 usr +  0.02 sys = 16.73 CPU) @  1.20/s (n=20)
        Rate Atest Btest Dtest Ctest
Atest 1.19/s    --   -1%   -1%   -1%
Btest 1.20/s    1%    --   -0%   -0%
Dtest 1.20/s    1%    0%    --   -0%
Ctest 1.20/s    1%    0%    0%    --