/* * call-seq: * dvector.delete_at(int) -> number or nil * * Deletes the element at the specified index _int_, returning that element, * or <code>nil</code> if the index is out of range. * * a = Dvector.new(5) {|i| i*3 } * a.delete_at(2) -> 6 * a -> Dvector[0, 3, 9, 12] * a.delete_at(6) -> nil */ VALUE dvector_delete_at_m(VALUE ary, VALUE pos) {