insert_iterator.html

指导程序员合理、高效的进行标准模板库编程。

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<tt>insert_iterator&amp; operator=(const insert_iterator&amp;)</tt>
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 <A href="trivial.html">Trivial Iterator</A>
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The assignment operator
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<tt>insert_iterator&amp; operator*()</tt>
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 <A href="OutputIterator.html">Output Iterator</A>
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Used to implement the <A href="OutputIterator.html">output iterator</A> expression <tt>*i = x</tt>. <A href="#2">[2]</A>
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<tt>insert_iterator&amp; operator=(const Container::value_type&amp;)</tt>
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 <A href="OutputIterator.html">Output Iterator</A>
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Used to implement the <A href="OutputIterator.html">output iterator</A> expression <tt>*i = x</tt>. <A href="#2">[2]</A>
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<tt>insert_iterator&amp; operator++()</tt>
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 <A href="OutputIterator.html">Output Iterator</A>
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Preincrement.
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<tt>insert_iterator&amp; operator++(int)</tt>
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 <A href="OutputIterator.html">Output Iterator</A>
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Postincrement.
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<tt>output_iterator_tag iterator_category(const insert_iterator&amp;)</tt>
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 <A href="iterator_tags.html">iterator tags</A>
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Returns the iterator's category.
   This is a global function, not a member.
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template&lt;class Container, class Iter)
insert_iterator&lt;Container&gt;
inserter(Container&amp; C, Iter i);
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<tt>insert_iterator</tt>
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See below.
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<h3>New members</h3>
These members are not defined 
in the <A href="OutputIterator.html">Output Iterator</A> requirements,
but are specific to <tt>insert_iterator</tt>.
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Member
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Description
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<tt>insert_iterator(Container&amp; C, Container::iterator i)</tt>
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Constructs an <tt>insert_iterator</tt> that inserts objects in <tt>C</tt>.
   If <tt>Container</tt> is a <A href="Sequence.html">Sequence</A>, then each object will be 
   inserted immediately  before the element pointed to by <tt>i</tt>.  
   If <tt>C</tt> is a <A href="SortedAssociativeContainer.html">Sorted Associative Container</A>, then the first
   insertion will use <tt>i</tt> as a hint for beginning the search.
   The iterator <tt>i</tt> must be a dereferenceable or past-the-end
   iterator in <tt>C</tt>.
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template&lt;class Container, class Iter)
insert_iterator&lt;Container&gt;
inserter(Container&amp; C, Iter i);
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Equivalent to <tt>insert_iterator&lt;Container&gt;(C, i)</tt>.  <A href="#2">[2]</A>
   This is a global function, not a member function.
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<h3>Notes</h3>
<P><A name="1">[1]</A>
Note the difference between assignment through a
<tt><A href="Container.html">Container</A>::iterator</tt> and assignment through an
<tt>insert_iterator&lt;<A href="Container.html">Container</A>&gt;</tt>.  If <tt>i</tt> is a valid
<tt><A href="Sequence.html">Sequence</A>::iterator</tt>, then it points to some particular
element in the <A href="Container.html">container</A>; the expression <tt>*i = t</tt> 
replaces that element with <tt>t</tt>, and does not change the total number
of elements in the <A href="Container.html">container</A>.  If <tt>ii</tt> is a valid
<tt>insert_iterator&lt;<A href="Container.html">container</A>&gt;</tt>, however, then 
the expression <tt>*ii = t</tt> is equivalent, for some <tt><A href="Container.html">container</A></tt>
<tt>c</tt> and some valid <tt><A href="Container.html">container</A>::iterator j</tt>, to the 
expression <tt>c.insert(j, t)</tt>.  That is, it does not overwrite
any of <tt>c</tt>'s elements and it does change <tt>c</tt>'s size.
<P><A name="2">[2]</A>
Note how assignment through an <tt>insert_iterator</tt> is implemented.
In general, unary <tt>operator*</tt> must be defined so that it returns a
proxy object, where the proxy object defines <tt>operator=</tt> to perform
the insert operation.  In this case, for the sake of simplicity, the
proxy object is the <tt>insert_iterator</tt> itself.  That is, <tt>*i</tt> simply
returns <tt>i</tt>, and <tt>*i = t</tt> is equivalent to <tt>i = t</tt>.  You should not,
however, rely on this behavior.  It is an implementation detail,
and it is not guaranteed to remain the same in future versions.
<P><A name="3">[3]</A>
This function exists solely for the sake of convenience:
since it is a non-member function, the template parameters may be
inferred and the type of the <tt>insert_iterator</tt> need not be declared
explicitly.  One easy way to reverse a range and insert it
into a <A href="Sequence.html">Sequence</A> <tt>S</tt>, for example, is
<tt><A href="reverse_copy.html">reverse_copy</A>(first, last, inserter(S, S.begin()))</tt>.
<h3>See also</h3>
<A href="front_insert_iterator.html">front_insert_iterator</A>, <A href="back_insert_iterator.html" tppabs="http://www.sgi.com/Technology/STL/back_insert_iterator.shtml">back_insert_iterator</A>, <A href="OutputIterator.html" tppabs="http://www.sgi.com/Technology/STL/OutputIterator.shtml">Output Iterator</A>,
<A href="Sequence.html">Sequence</A>, <A href="Iterators.html" tppabs="http://www.sgi.com/Technology/STL/Iterators.shtml">Iterator overview</A>

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