postgresql 7.1.1 and textout and textin

hello,

trying to migrate production servers form 7.0.2 to 7.1.1 now I need to
compile an function written in c and when compiling using following
includes:

#include <postgres.h>
#include <utils/builtins.h>
#include <utils/palloc.h>
#include <string.h>

I get following compile errors:

c:82: warning: passing arg 1 of `textout' from incompatible pointer type

line 82: src = textout( src_string );

c:238: warning: passing arg 1 of `textin' from incompatible pointer type

line 238: return( (text *)textin( ret ) );

function I'm trying to port is this one:
http://www.ca.postgresql.org/mhonarc/pgsql-sql/1998-06/msg00119.html

any points to convert textout and textin to 7.1 ?

thanks from barcelona!

jaume.