Different attribute for checks vs coercions?

[falsifian]

If I'm debugging someone's code and see:

my $average_score :of(WholeNum) = compute_average_score();

it would be nice to be able to tell immediately whether WholeNum is a check or a coercion, without having to look it up. This could, for example, help me understand whether some strange behaviour I'm seeing must be the fault of compute_average_score or if the coercion could be involved.

Why not use different attributes for checks and coercions? E.g.

my $average_score :of(PositiveInteger) :via(RoundToInteger) = ...;

I see two advantages:

1. Someone reading the code can immediately tell whether something's a check or a coercion.
2. Checks and coercions can be cleanly combined: just use both attributes.

Is there any disadvantage?

Just a casual perl user here; read the spec and thought it looks quite nice except for this. I don't have experience with large perl codebases so treat this suggestion appropriately :)