Trait for forthcoming singletons

camo-image-proxy.php

@@ -12,4 +12,11 @@
  * @package         Camo_Image_Proxy
  */
 
-// Your code starts here.
+namespace Camo_Image_Proxy;
+
+define( __NAMESPACE__ . '\PLUGIN_PATH', dirname( __FILE__ ) );
+
+/**
+ * Trait for singletons
+ */
+require_once PLUGIN_PATH . '/inc/trait-singleton.php';

inc/trait-singleton.php

+<?php
+/**
+ * Trait file for Singletons.
+ *
+ * @package Camo_Image_Proxy
+ */
+
+namespace Camo_Image_Proxy;
+
+/**
+ * Make a class into a singleton.
+ */
+trait Singleton {
+	/**
+	 * Existing instance.
+	 *
+	 * @var object
+	 */
+	protected static $instance;
+
+	/**
+	 * Get class instance.
+	 *
+	 * @return object
+	 */
+	public static function instance() {
+		if ( ! isset( static::$instance ) ) {
+			static::$instance = new static();
+			static::$instance->setup();
+		}
+		return static::$instance;
+	}
+
+	/**
+	 * Setup the singleton.
+	 */
+	public function setup() {
+		// Silence.
+	}
+}