Issuing a count() on a Collection should throw an exception

src/Collection/Collection.php

@@ -17,6 +17,7 @@
 use ArrayIterator;
 use InvalidArgumentException;
 use IteratorIterator;
+use LogicException;
 use Serializable;
 use Traversable;
 
@@ -71,6 +72,20 @@ public function unserialize($collection)
         $this->__construct(unserialize($collection));
     }
 
+    /**
+     * Throws an exception.
+     *
+     * Issuing a count on a Collection can have many side effects, some making the
+     * Collection unusable after the count operation.
+     *
+     * @return void
+     * @throws \LogicException
+     */
+    public function count()
+    {
+        throw new LogicException('You cannot issue a count on a Collection.');
+    }
+
     /**
      * Returns an array that can be used to describe the internal state of this
      * object.

tests/TestCase/Collection/CollectionTest.php

@@ -611,6 +611,19 @@ public function testInvalidConstructorArgument()
         new Collection('Derp');
     }
 
+    /**
+     * Tests that issuing a count will throw an exception
+     *
+     * @expectedException \LogicException
+     * @return void
+     */
+    public function testCollectionCount()
+    {
+        $data = [1, 2, 3, 4];
+        $collection = new Collection($data);
+        $collection->count();
+    }
+
     /**
      * Tests take method
      *