class Foo { has Num $!num; submethod BUILD(Num() :$num) { $!num = $num } method gist { "{self.^name}.new($!num)" } for Num.^methods -> &m { my $name = &m.name; ::?CLASS.^add_method($name, my method (|c) { say "calling: $!num.$name"; my \ret = $!num."$name"(|c); return ::?CLASS.new: :num(ret) if ret ~~ Num; ret }) unless ::?CLASS.^lookup: $name } } my $f = Foo.new: :num(42); say $f; say $f.^name; my $r = $f.log10; say $r; say $r.^name;