Re: Pointers in custom types

Will Harrower <wjh105@doc.ic.ac.uk> writes:
> I'm writing a custom type in C that needs to manage two byte arrays
> (among other things). I have attempted to implement this using something
> similar to the following struct (along with corresponding input and
> output functions):

> typedef struct example {
>     bytea* first;
>     bytea* second;
> } example;

You can't do that; the value of a datatype has to be a single chunk of
memory, and it has to be independent of exactly where it's stored
because it will get copied around without modification.

            regards, tom lane