import java.util.ArrayList;
import java.util.Arrays;
import java.util.Iterator;
import java.util.List;
import com.github.fracpete.javautils.enumerate.Enumerated;
import static com.github.fracpete.javautils.Enumerate.enumerate;

...

String[] array = new String[]{"a", "b", "c"};
List<String> list = new ArrayList<>(Arrays.asList(array));

// Array
System.out.println("\nWrapping Array:");
for (Enumerated<String> e: enumerate(array))
  System.out.println(e.index + ": " + e.value);

// Iterable
System.out.println("\nWrapping Iterable:");
for (Enumerated<String> e: enumerate(list))
  System.out.println(e.index + ": " + e.value);

// Iterable (start=1)
System.out.println("\nWrapping Iterable (start = 1):");
for (Enumerated<String> e: enumerate(list, 1))
  System.out.println(e.index + ": " + e.value);

// Iterable (start=0, step = -1)
System.out.println("\nWrapping Iterable (start = 0, step = -2):");
for (Enumerated<String> e: enumerate(list, 0, -2))
  System.out.println(e.index + ": " + e.value);

// Iterator
System.out.println("\nWrapping Iterator:");
Iterator<String> iter = list.iterator();
for (Iterator<Enumerated<String>> it = enumerate(iter); it.hasNext(); ) {
  Enumerated<String> e = it.next();
  System.out.println(e.index + ": " + e.value);
}

import java.util.HashMap;
import java.util.Map;
import com.github.fracpete.javautils.struct.MapStruct;
import com.github.fracpete.javautils.struct.Struct2;
import static com.github.fracpete.javautils.Struct.pairs;
import static com.github.fracpete.javautils.Struct.struct;

...

public static Struct2<Integer,Integer> return2int(Integer value) {
  return struct(value, value * value);
}

public static void main(String[] args) throws Exception {
  System.out.println("\nSimple struct");
  int value = 12;
  System.out.println("value=" + value);
  Struct2<Integer,Integer> i2 = return2int(value);
  System.out.println("container: " + i2);
  System.out.println("value1: " + i2.value1);
  System.out.println("value2: " + i2.value2);

  System.out.println("\nMap key/value pairs");
  Map<String,String> map = new HashMap<>();
  map.put("C", "Hello");
  map.put("B", "World");
  map.put("A", "Sup!");
  for (MapStruct<String,String> s: pairs(map))
    System.out.println("k=" + s.key + ", v=" + s.value);
}