// generics/GenericCast.java
// (c)2017 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
import java.util.*;
import java.util.stream.*;

class FixedSizeStack<T> {
 private final int size;
 private Object[] storage;
 private int index = 0;
 FixedSizeStack(int size) {
 this.size = size;
 storage = new Object[size];
 }
 public void push(T item) {
 if(index < size)
 storage[index++] = item;
 }
 @SuppressWarnings("unchecked")
 public T pop() {
 return index == 0 ? null : (T)storage[--index];
 }
 @SuppressWarnings("unchecked")
 Stream<T> stream() {
 return (Stream<T>)Arrays.stream(storage);
 }
}

public class GenericCast {
 static String[] letters =
 "ABCDEFGHIJKLMNOPQRS".split("");
 public static void main(String[] args) {
 FixedSizeStack<String> strings =
 new FixedSizeStack<>(letters.length);
 Arrays.stream("ABCDEFGHIJKLMNOPQRS".split(""))
 .forEach(strings::push);
 System.out.println(strings.pop());
 strings.stream()
 .map(s -> s + " ")
 .forEach(System.out::print);
 }
}
/* Output:
S
A B C D E F G H I J K L M N O P Q R S
*/