Rate        split1       substr1         subst subst_inplace
split1        2.93/s            --          -72%         -100%         -100%
substr1       10.3/s          253%            --          -99%          -99%
subst          901/s        30682%         8623%            --          -24%
subst_inplace 1179/s        40176%        11313%           31%            --
ok 1
ok 2
ok 3
1..3