Is there a straightforward way to check if something is a mixin?

Question

Raku mixins have two (or more) natures, combining several values in the same container, or values along with roles. However, there is not, as far as I can tell, a straightforward way to check for "mixinity" in a variable that has not been created by you.

This might be a trick

my $foo = 3 but Stringy;
say $foo.^name ~~ /\+/;# OUTPUT: «｢+｣␤»

But is there any other property I'm missing that would allow to look this up directly?

Answer 1

I think you're missing the ^roles and ^parents meta-methods:

my $foo = 3 but Stringy;
dd $foo.^roles;   # (Stringy, Real, Numeric)
dd $foo.^parents; # (Int,)