Does a view not define a composite type?

I have a view: “reporting_helpers.customers_by_state_ranked"

I try to define a function with this signature:

CREATE OR REPLACE FUNCTION reporting.formatted_cust_by_state_bold(c "reporting_helpers.customers_by_state_ranked")
RETURNS "reporting_helpers.customers_by_state_ranked"

I am told “ERROR: type reporting_helpers.customers_by_state_ranked does not exist”

I am confused.