void rehash( size_type count );
Changes the number of buckets to a value
n that is not less than count and satisfies n >= size() / max_load_factor(), then rehashes the container, i.e. puts the elements into appropriate buckets considering that total number of buckets has changed.
|count||-||lower bound for the new number of buckets|
 Return value
Average case linear in the size of the container, worst case quadratic.
rehash(0) may be used to force an unconditional rehash, such as after suspension of automatic rehashing by temporarily increasing max_load_factor().
 See also
| reserves space for at least the specified number of elements and regenerates the hash table |
(public member function)