The clone_from implementation for IdMap drops the values present in the map and then begins cloning values from the other map. If a .clone() call pancics, then the afformentioned dropped elements can be freed again.
get_or_insert
get_or_insert reserves space for a value, before calling the user provided insertion function f. If the function f panics then uninitialized or previously freed memory can be dropped.
remove_set
When removing a set of elements, ptr::drop_in_place is called on each of the element to be removed. If the Drop impl of one of these elements panics then the previously dropped elements can be dropped again.
References
The clone_from implementation for IdMap drops the values present in the map and then begins cloning values from the other map. If a .clone() call pancics, then the afformentioned dropped elements can be freed again.
get_or_insert
get_or_insert reserves space for a value, before calling the user provided insertion function f. If the function f panics then uninitialized or previously freed memory can be dropped.
remove_set
When removing a set of elements, ptr::drop_in_place is called on each of the element to be removed. If the Drop impl of one of these elements panics then the previously dropped elements can be dropped again.
References