PHP如何实现定义对象类型的常量

repeat:
	switch (Z_TYPE_P(val)) {
		case IS_LONG:
		case IS_DOUBLE:
		case IS_STRING:
		case IS_BOOL:
		case IS_RESOURCE:
		case IS_NULL:
			break;
		case IS_OBJECT:
			if (!val_free) {
				if (Z_OBJ_HT_P(val)->get) {
					val_free = val = Z_OBJ_HT_P(val)->get(val TSRMLS_CC);
					goto repeat;
				} else if (Z_OBJ_HT_P(val)->cast_object) {
					ALLOC_INIT_ZVAL(val_free);
					if (Z_OBJ_HT_P(val)->cast_object(val, val_free, IS_STRING TSRMLS_CC) == SUCCESS) {
						val = val_free;
						break;
					}
				}
			}
			/* no break */
		default:
			zend_error(E_WARNING,"Constants may only evaluate to scalar values");
			if (val_free) {
				zval_ptr_dtor(&val_free);
			}
			RETURN_FALSE;
	}

Class Test{
   public $name='呵呵';
   public function __toString(){
     return $this->name;
   }
}

$t=new Test();
define('TT',$t);
echo TT;