describe_prepared (PGconn)

    /*
     * call-seq:
     *    conn.describe_prepared( statement_name ) -> PGresult
     *
     * Retrieve information about the prepared statement
     * _statement_name_.
     */
    static VALUE
    pgconn_describe_prepared(VALUE self, VALUE stmt_name)
    {
            PGresult *result;
            VALUE rb_pgresult;
            PGconn *conn = get_pgconn(self);
            char *stmt;
            if(stmt_name == Qnil) {
                    stmt = NULL;
            }
            else {
                    Check_Type(stmt_name, T_STRING);
                    stmt = StringValuePtr(stmt_name);
            }
            result = PQdescribePrepared(conn, stmt);
            rb_pgresult = new_pgresult(result);
            pgresult_check(self, rb_pgresult);
            return rb_pgresult;
    }