---
title: "Platform::Metadata Namespace | Microsoft Docs"
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ms.date: "12/30/2016"
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  - "Platform::Metadata Namespace"
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---
# Platform::Metadata Namespace
This namespace contains attributes that modify the declarations of types.  
  
## Syntax  
  
```cpp  
  
namespace Platform {  
   namespace Metadata {  
}}  
```  
  
### Members  
 Although this namespace is intended for internal use, browsers can display the following members of this namespace.  
  
|Name|Remark|  
|----------|------------|  
|Attribute|The base class for attributes.|  
|[Platform::Metadata::DefaultMemberAttribute Attribute](../cppcx/platform-metadata-defaultmemberattribute-attribute.md)|Indicates the preferred function to invoke among several possible overloaded functions.|  
|[Platform::Metadata::FlagsAttribute Attribute](../cppcx/platform-metadata-flagsattribute-attribute.md)Flags|Declares an enumeration as an enumeration of bit fields.<br /><br /> The following example shows how to apply the `Flags` attribute an enumeration.<br /><br /> `[Flags] enum class MyEnumeration { enumA = 1, enumB = 2, enumC = 3}`|  
|[Platform::Metadata::RuntimeClassNameAttribute](../cppcx/platform-metadata-runtimeclassname.md)|Ensures that a private ref class has a valid runtime class name.|  
  
## Inheritance Hierarchy  
 `Platform`  
  
### Requirements  
 **Metadata:** platform.winmd  
  
 **Namespace:** Platform::Metadata  
  
## See Also  
 [Platform Namespace](platform-namespace-c-cx.md)