Raku has this feature by design. While there technically is a general equality operator `eqv`, you rarely see it used. Instead, you use the matching operator, `~~`, which can check equality, or check if a string matches a regex, or check if a number is contained within a range, etc.

    assert user_data == {
        'id': IsPositiveInt,
        'avatar_file': IsStr(regex=r'/[a-z0-9\-]{10}/example\.png'),

Hmm, I'm not convinced. Why not

    assert dirty_check(user_data, {
        'id': IsPositiveInt,
        'avatar_file': IsStr(regex=r'/[a-z0-9\-]{10}/example\.png'),

Edit: Ah, I guess the difference is that dict.__eq__ (and list.__eq__ and so on) recursively tests equality of all child elements. So to support arbitrary nesting I think it really does have to be the equals operator.

this is pretty neat!