15. Container functions returning iterators

• Two iterators form a half-open range, closed on the left but open on the right.

• insert( value )

  • uses an iterator to say where to insert a new item

  • returns iterator pointing to new element:

  
          iterator insert( iterator it, T const& x = T() );
  
  

• erase( )

  • uses an iterator to tell it where to erase a new item, or

  • erases a range of items;

  • returns an iterator that points to the next item after the deleted ones.

  
          iterator erase( iterator it );
          iterator erase( iterator first, iterator last );