BUG #13919: Cast error when table is empty.

The following bug has been logged on the website:

Bug reference:      13919
Logged by:          Eaden McKee
Email address:      mail@eaden.net
PostgreSQL version: 9.4.1
Operating system:   Any
Description:

When trying to change the type of column I received the error :

PG::DatatypeMismatch: ERROR:  column "date_of_birth" cannot be cast
automatically to type date
HINT:  Specify a USING expression to perform the conversion.

I totally understand the error. However, there are no rows in the table, so
it IS possible to automatically to cast 0 strings into 0 dates.

If there are no rows, can the column type just be changed?