/*
 *  call-seq:
 *     res.column_values( n )   -> array
 *
 *  Returns an Array of the values from the nth column of each 
 *  tuple in the result.
 *
 */
static VALUE
pgresult_column_values(VALUE self, VALUE index)
{
        int col = NUM2INT( index );
        return make_column_result_array( self, col );
}