erase

Erases items at the position or selected items.

  void erase(iterator position);

  size_type erase(const key_type& x);

  void erase(iterator first, iterator last);  

The first erase function erases the item pointed to by position from the container. The second erases all items in the container that compare equal to x and returns the number of elements erased. The third erase erases the range (first, last) from the container.

swap(hash_set& y);

Swaps the contents of *this with y in constant time.

clear();

Erases all elements from the container.