Added isInstanceOf() partially applied function to class instances

lib/class.js

@@ -255,6 +255,10 @@ var extend = ( function( extending )
                     this.__construct.apply( this, ( args || arguments ) );
                     args = null;
                 }
+
+                // attach any instance properties/methods (done after
+                // constructor to ensure they are not overridden)
+                attachInstanceOf( this );
             };
 
             return __self;
@@ -286,6 +290,7 @@ function setupProps( func, abstract_methods )
 {
     attachAbstract( func, abstract_methods );
     attachExtend( func );
+    attachInstanceOf( func );
 }
 
 
@@ -384,3 +389,19 @@ function attachExtend( func )
     });
 }
 
+
+/**
+ * Attaches partially applied isInstanceOf() method to class instance
+ *
+ * @param  {Object}  instance  class instance to attach method to
+ *
+ * @return  {undefined}
+ */
+function attachInstanceOf( instance )
+{
+    util.defineSecureProp( instance, 'isInstanceOf', function( type )
+    {
+        return exports.isInstanceOf( type, instance );
+    });
+}
+

test/test-class.js

@@ -112,4 +112,11 @@ assert.ok(
     "Class is not an instance of its instance"
 );
 
+assert.ok(
+    ( ( inst.isInstanceOf instanceof Function )
+        && ( inst.isInstanceOf( Foo ) === true )
+        && ( inst.isInstanceOf( inst ) === false )
+    ),
+    "Class instance contains partially applied isInstanceOf method"
+);