The interface is the C++ name for the Windows::Foundation::IReference interface.
The type of the boxed value.
The IBox<T> interface is primarily used internally to represent nullable value types, as described in Value classes and structs (C++/CX). 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 (C++/CX).
The Platform::IBox interface inherits from the Platform::IValueType interface. IBox has these members:
Returns the unboxed value that was previously stored in this IBox instance.