src/test/singlenode_regress/sql/create_cast.sql

--
-- CREATE_CAST
--

-- Create some types to test with
CREATE TYPE casttesttype;

CREATE FUNCTION casttesttype_in(cstring)
   RETURNS casttesttype
   AS 'textin'
   LANGUAGE internal STRICT IMMUTABLE;
CREATE FUNCTION casttesttype_out(casttesttype)
   RETURNS cstring
   AS 'textout'
   LANGUAGE internal STRICT IMMUTABLE;

CREATE TYPE casttesttype (
   internallength = variable,
   input = casttesttype_in,
   output = casttesttype_out,
   alignment = int4
);

-- a dummy function to test with
CREATE FUNCTION casttestfunc(casttesttype) RETURNS int4 LANGUAGE SQL AS
$$ SELECT 1; $$;

SELECT casttestfunc('foo'::text); -- fails, as there's no cast

-- Try binary coercion cast
CREATE CAST (text AS casttesttype) WITHOUT FUNCTION;
SELECT casttestfunc('foo'::text); -- doesn't work, as the cast is explicit
SELECT casttestfunc('foo'::text::casttesttype); -- should work
DROP CAST (text AS casttesttype); -- cleanup

-- Try IMPLICIT binary coercion cast
CREATE CAST (text AS casttesttype) WITHOUT FUNCTION AS IMPLICIT;
SELECT casttestfunc('foo'::text); -- Should work now

-- Try I/O conversion cast.
SELECT 1234::int4::casttesttype; -- No cast yet, should fail

CREATE CAST (int4 AS casttesttype) WITH INOUT;
SELECT 1234::int4::casttesttype; -- Should work now

DROP CAST (int4 AS casttesttype);

-- Try cast with a function

CREATE FUNCTION int4_casttesttype(int4) RETURNS casttesttype LANGUAGE SQL AS
$$ SELECT ('foo'::text || $1::text)::casttesttype; $$;

CREATE CAST (int4 AS casttesttype) WITH FUNCTION int4_casttesttype(int4) AS IMPLICIT;
SELECT 1234::int4::casttesttype; -- Should work now