---
title: "uuid (C++ Attributes) | Microsoft Docs"
ms.custom: ""
ms.date: "11/04/2016"
ms.reviewer: ""
ms.suite: ""
ms.technology:  
  - "cpp-windows"
ms.tgt_pltfrm: ""
ms.topic: "language-reference"
f1_keywords: 
  - "vc-attr.uuid"
dev_langs: 
  - "C++"
helpviewer_keywords: 
  - "uuid attribute"
ms.assetid: 90562a94-5e28-451b-a4b0-cadda7f66efe
caps.latest.revision: 11
author: "mikeblome"
ms.author: "mblome"
manager: "ghogen"
translation.priority.ht: 
  - "cs-cz"
  - "de-de"
  - "es-es"
  - "fr-fr"
  - "it-it"
  - "ja-jp"
  - "ko-kr"
  - "pl-pl"
  - "pt-br"
  - "ru-ru"
  - "tr-tr"
  - "zh-cn"
  - "zh-tw"
---
# uuid (C++ Attributes)
Specifies the unique ID for a class or interface.  
  
## Syntax  
  
```  
  
      [ uuid(  
   "uuid"  
) ]  
```  
  
#### Parameters  
 *uuid*  
 A 128-bit, unique identifier.  
  
## Remarks  
 If the definition of an interface or class does not specify the `uuid` C++ attribute, then the Visual C++ compiler will provide one. When you specify a `uuid`, you must include the quotes.  
  
 If you do not specify `uuid`, then the compiler will generate the same GUID for interfaces or classes with the same name in different attribute projects on a machine.  
  
 You can use Uuidgen.exe or Guidgen.exe to generate your own unique IDs. (To run either of these tools, click **Start** and click **Run** on the menu. Then enter the name of the required tool.)  
  
 When used in a project that does not also use ATL, specifying the `uuid` attribute is the same as specifying the [uuid](../cpp/uuid-cpp.md) __declspec modifier. To retrieve the `uuid` of a class, you can use [__uuidof](../cpp/uuidof-operator.md)  
  
## Example  
 See the [bindable](../windows/bindable.md) example for a sample use of `uuid`.  
  
## Requirements  
  
### Attribute Context  
  
|||  
|-|-|  
|**Applies to**|**class**, `struct`, `interface`, **union**, `enum`|  
|**Repeatable**|No|  
|**Required attributes**|None|  
|**Invalid attributes**|None|  
  
 For more information about the attribute contexts, see [Attribute Contexts](../windows/attribute-contexts.md).  
  
## See Also  
 [IDL Attributes](../windows/idl-attributes.md)   
 [Interface Attributes](../windows/interface-attributes.md)   
 [Class Attributes](../windows/class-attributes.md)   
 [Typedef, Enum, Union, and Struct Attributes](../windows/typedef-enum-union-and-struct-attributes.md)   
 [uuid](http://msdn.microsoft.com/library/windows/desktop/aa367302)