Smartmatch is experimental at backwards_replace.pl line 43.
String Length: 2500
                   Rate    pure_regex for_smartmatch reverse_regex rindex_substr
pure_regex        752/s            --          -100%         -100%         -100%
for_smartmatch 190934/s        25277%             --          -35%          -46%
reverse_regex  292322/s        38753%            53%            --          -18%
rindex_substr  356174/s        47240%            87%           22%            --