count.xml Amend the code example and add return type (#4291)

Return type of Counter::count() should either be compatible with Countable::count(): int, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice

language/predefined/countable/count.xml

@@ -38,10 +38,13 @@
    <programlisting role="php">
 <![CDATA[
 <?php
-class Counter implements Countable {
+
+class Counter implements Countable
+{
     private $count = 0;
 
-    public function count() {
+    public function count(): int
+    {
         return ++$this->count;
     }
 }
@@ -51,6 +54,7 @@ $counter = new Counter;
 for ($i = 0; $i < 10; ++$i) {
     echo "I have been count()ed " . count($counter) . " times\n";
 }
+
 ?>
 ]]>
    </programlisting>