WeakRef::CopyTo Method
The new home for Visual Studio documentation is Visual Studio 2017 Documentation on docs.microsoft.com.
The latest version of this topic can be found at WeakRef::CopyTo Method.
Assigns a pointer to an interface, if available, to the specified pointer variable.
Syntax
HRESULT CopyTo(
REFIID riid,
_Deref_out_ IInspectable** ptr
);
template<
typename U
>
HRESULT CopyTo(
_Deref_out_ U** ptr
);
HRESULT CopyTo(
_Deref_out_ IWeakReference** ptr
);
Parameters
U
Pointer an IInspectable interface. An error is emitted if U is not derived from IInspectable.
riid
An interface ID. An error is emitted if riid is not derived from IWeakReference.
ptr
A doubly-indirect pointer to IInspectable or IWeakReference.
Return Value
S_OK if successful; otherwise, an HRESULT that describes the failure. For more information, see Remarks.
Remarks
A return value of S_OK means that this operation succeeded, but doesn't indicate whether the weak reference was resolved to a strong reference. If S_OK is returned, test that parameter p is a strong reference; that is, parameter p isn't equal to nullptr.
Starting in the Windows 10 SDK, this method does not set the WeakRef instance to nullptr if the weak reference could not be obtained, so you should avoid error checking code that checks the WeakRef for nullptr. Instead, check ptr for nullptr.
Requirements
Header: client.h
Namespace: Microsoft::WRL