The type of a "removed" callback function for collections.
typedef void (Ring1_RemovedCallback)(void* element);
A function of this type can be associated with certain collections.
The function is invoked before an element is added to a collection.
A pointer to the element is passed to the function as its single argument.
A "removed" callback function must not mutate the collection it is associated with.
One can safely define a "removed" callback with a more specialized pointer type than
- A pointer to the element.