object_getIndexedIvars(_:)
Returns a pointer to any extra bytes allocated with a instance given object.
Declaration
func object_getIndexedIvars(_ obj: Any?) -> UnsafeMutableRawPointer?Parameters
- obj:
An Objective-C object.
Return Value
A pointer to any extra bytes allocated with obj. If obj was not allocated with any extra bytes, then dereferencing the returned pointer is undefined.
Discussion
This function returns a pointer to any extra bytes allocated with the instance (as specified by class_createInstance(_:_:) with extraBytes>0). This memory follows the object’s ordinary ivars, but may not be adjacent to the last ivar.
The returned pointer is guaranteed to be pointer-size aligned, even if the area following the object’s last ivar is less aligned than that. Alignment greater than pointer-size is never guaranteed, even if the area following the object’s last ivar is more aligned than that.
In a garbage-collected environment, the memory is scanned conservatively.