Function transfer_ptr 

pub unsafe fn transfer_ptr<T>(ptr: *mut c_void) -> Option<SharedPtr<T>>

Create a SharedPtr by transferring ownership of an existing raw pointer.

Does not increase the reference count - ownership is transferred to SharedPtr.

C++ equivalent: NS::SharedPtr<_Class> TransferPtr(_Class* pObject)

Safety

• The pointer must be a valid Objective-C object.
• The object must have a retain count >= 1.
• The caller transfers ownership and must not release the object.