
> field is used.
       <TT
CLASS="LITERAL"
>i</TT
> means that the input/output functions are used.
       <TT
CLASS="LITERAL"
>b</TT
> means that the types are binary-coercible, thus no conversion is required.
      </TD
></TR
></TBODY
></TABLE
></DIV
><P
>   The cast functions listed in <TT
CLASS="STRUCTNAME"
>pg_cast</TT
> must
   always take the cast source type as their first argument type, and
   return the cast destination type as their result type.  A cast
   function can have up to three argument