Indeed. That was because smart-matching in Perl was symmetric. The smart-matching in Raku (formerly known as Perl 6) is asymmetric and customizable. If you w

Indeed. That was because smart-matching in Perl was symmetric. The smart-matching in Raku (formerly known as Perl 6) is asymmetric and customizable. If you write: a ~~ b you are effectively executing: b.ACCEPTS(a) In other words, the right hand side of the smart-match is responsible for accepting the left hand side. So as a developer of a class, you can add your own ACCEPTS (multi-)method to govern how your class will handle smart-matching.