set op(s?) do(es?)n't preserve class inheritance

[grondilu]

The Problem

set union operator (+) does not preserve inheritance from Bag.

Steps to Reproduce

use Test;
plan 1;

class Foo is Bag {}
isa-ok Foo.new("a") (+) Foo.new("b"), Foo, "union of two Foo instances should be a Foo instance";

Environment

• Operating system: fedora 37
• Compiler version: Rakudo™ v2022.12-1118-g03b3b13db

[lizmat]

I think the problem is broader, and probably applies to all set operators.

[lizmat]

Added test with Raku/roast@a647a0ecae I think all set ops are covered now. So closing. Please re-open if I missed something :-)