Hi,

At this time, it is my understanding that custom postgres types allow to define the INPUT and OUTPUT functions with signatures, in the case of a custom type PositiveU32:

CREATE  FUNCTION "positiveu32_in"(
	"input" cstring /* core::option::Option<&core::ffi::c_str::CStr> */
) RETURNS PositiveU32 /* core::option::Option<example_extension::PositiveU32> */
IMMUTABLE PARALLEL SAFE
LANGUAGE c /* Rust */
AS 'MODULE_PATHNAME', 'positiveu32_in_wrapper';

and

CREATE  FUNCTION "positiveu32_out"(
	"input" PositiveU32 /* example_extension::PositiveU32 */
) RETURNS cstring /* alloc::ffi::c_str::CString */
IMMUTABLE STRICT PARALLEL SAFE
LANGUAGE c /* Rust */
AS 'MODULE_PATHNAME', 'positiveu32_out_wrapper';

And that is fine if I were to submit queries that provide the column value as a JSON, but since I use diesel, the data is submitted in binary and therefore PostgreSQL searches for a function which accepts a binary signature (to my understanding). Not finding one, it raises the error: no binary input function available for type positiveu32.

How can I make the pgrx sql code generation produce the analogous binary functions? If needed, I am happy to attempt a PR, with some guidance.

It should not be related to this issue, but I feel necessary to specify that in diesel, I serialize the data using serde_cbor in order to serialize it to the same format used by pgrx, or at least that is my understanding.

Best,
Luca