The reserve() function of unordered_multiset sets the number of buckets in the container (bucket_count) to the most appropriate to contain at least n elements.
If n is greater than the current bucket_count multiplied by the max_load_factor, the container’s bucket_count is increased and a rehash is forced.
If n is lower than that, the function may have no effect.
void reserve( size_type n );
where size_type is an unsigned integral type.
Parameters: This method accepts a mandatory parameter n which is the number of elements requested as minimum capacity.
Returns: It does not returns any value.
Below are the programs to illustrate reserve() method:
The values in unordered_multiset : 7 6 5
The values in unordered_multiset : GeeksforGeeks forGeeks Geeks