---
title: "Platform::IBox Interface | Microsoft Docs"
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---
# Platform::IBox Interface
The [Platform::IBox](../cppcx/platform-ibox-interface.md) interface is the C++ name for the `Windows::Foundation::IReference` interface.  
  
## Syntax  
  
```cpp  
template <typename T>  
interface class IBox  
```  
  
#### Parameters  
 `T`  
 The type of the boxed value.  
  
### Remarks  
 The `IBox<T>` interface is primarily used internally to represent nullable value types, as described in [Value classes and structs (C++/CX)](../cppcx/value-classes-and-structs-c-cx.md). The interface is also used to box value types that are passed to C++ methods that take parameters of type `Object^`. You can explicitly declare an input parameter as `IBox<SomeValueType>`. For an example, see [Boxing](../cppcx/boxing-c-cx.md).  
  
### Requirements  
  
### Members  
 The `Platform::IBox` interface inherits from the [Platform::IValueType](../cppcx/platform-ivaluetype-interface.md) interface. `IBox` has these members:  
  
 **Properties**  
  
|Method|Description|  
|------------|-----------------|  
|[Value](#value)|Returns the unboxed value that was previously stored in this `IBox` instance.|  

## <a name="value"></a> IBox::Value Property
Returns the value that was originally stored in this object.  
  
### Syntax  
  
```cpp  
property T Value {T get();}  
```  
  
### Parameters  
 `T`  
 The type of the boxed value.  
  
### Property Value/Return Value  
 Returns the value that was originally stored in this object.  
  
### Remarks  
 For an example, see [Boxing](../cppcx/boxing-c-cx.md).  
  
  
## See Also  
 [Platform namespace](../cppcx/platform-namespace-c-cx.md)