home | login | register | DMCA | contacts | help | donate |      

A B C D E F G H I J K L M N O P Q R S T U V W X Y Z
А Б В Г Д Е Ж З И Й К Л М Н О П Р С Т У Ф Х Ц Ч Ш Щ Э Ю Я


my bookshelf | genres | recommend | rating of books | rating of authors | reviews | new | форум | collections | читалки | авторам | add
fantasy
space fantasy
fantasy is horrors
heroic
prose
  military
  child
  russian
detective
  action
  child
  ironical
  historical
  political
western
adventure
adventure (child)
child's stories
love
religion
antique
Scientific literature
biography
business
home pets
animals
art
history
computers
linguistics
mathematics
religion
home_garden
sport
technique
publicism
philosophy
chemistry
close

Loading...


Description

Insert_iterator is an iterator adaptor that functions as an Output Iterator: assignment through an insert_iterator inserts an object into a Container. Specifically, if ii is an insert_iterator, then ii keeps track of a Container c and an insertion point p; the expression *ii = x performs the insertion c.insert(p, x). [1]

There are two different Container concepts that define this expression: Sequence, and Sorted Associative Container. Both concepts define insertion into a container by means of c.insert(p, x), but the semantics of this expression is very different in the two cases.

For a Sequence S, the expression S.insert(p, x) means to insert the value ximmediately before the iterator p. That is, the two-argument version of insert allows you to control the location at which the new element will be inserted. For a Sorted Associative Container, however, no such control is possible: the elements in a Sorted Associative Container always appear in ascending order of keys. Sorted Associative Containers define the two-argument version of insert as an optimization. The first argument is only a hint: it points to the location where the search will begin.

If you assign through an insert_iterator several times, then you will be inserting several elements into the underlying container. In the case of a Sequence, they will appear at a particular location in the underlying sequence, in the order in which they were inserted: one of the arguments to insert_iterator's constructor is an iterator p, and the new range will be inserted immediately before p.

In the case of a Sorted Associative Container, however, the iterator in the insert_iterator's constructor is almost irrelevant. The new elements will not necessarily form a contiguous range; they will appear in the appropriate location in the container, in ascending order by key. The order in which they are inserted only affects efficiency: inserting an already-sorted range into a Sorted Associative Container is an O(N) operation.


insert_iterator < Container > | Standard Template Library Programmer`s Guide | Example







Loading...