/*
 *  call-seq:
 *     dtable.pow!(number)                ->  dtable
 *     dtable.pow!(other)                 ->  dtable
 *     dtable.raised_to!(number)          ->  dtable
 *     dtable.raised_to!(other)           ->  dtable
 *  
 *  When argument is a number, this operation returns a copy of _dtable_ with each entry x replaced by x ** _number_.
 *  When argument is a data array, this operation returns a copy of _dtable_ with each entry x replaced
 *  by x ** the corresponding entry in the _other_ data array.
 */ VALUE dtable_pow_bang(VALUE ary, VALUE arg) {