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Apply Jens' suggested fixes

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[SVN r9263]
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Dave Abrahams
2001-02-18 21:50:57 +00:00
parent 7ee484c614
commit 961c08a82f
1 changed files with 13 additions and 6 deletions
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19
iterator_adaptors.htm
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@@ -542,22 +542,29 @@ int main(int, char*[])
<h4>Example</h4>
<p>The <a href="projection_iterator.htm">Projection Iterator</a> portion of this
library lets you create iterators which, when dereferenced, apply a function to the result of
dereferencing their base iterator. The <a
<p>The <a href="projection_iterator.htm">Projection Iterator</a> adaptor is similar to the <a
href="./transform_iterator.htm">transform iterator adaptor</a> in that
its <tt>operator*()</tt> applies some function to the result of
dereferencing the base iterator and then returns the result. The
difference is that the function must return a reference to some
existing object (for example, a data member within the
<tt>value_type</tt> of the base iterator).
<p>
The <a
href="projection_iterator.htm#projection_iterator_pair_generator">projection_iterator_pair_generator</a> template
is a special two-<a href="../../more/generic_programming.html#type_generator">type generator</a> for mutable and constant versions of a
projection iterator. It is defined as follows:
<blockquote>
<pre>
template &lt;class Function, class Iterator, class ConstIterator&gt;
template &lt;class AdaptableUnaryFunction, class Iterator, class ConstIterator&gt;
struct projection_iterator_pair_generator {
typedef typename AdaptableUnaryFunction::result_type value_type;
typedef projection_iterator_policies&lt;Function&gt; policies;
typedef projection_iterator_policies&lt;AdaptableUnaryFunction&gt; policies;
public:
typedef iterator_adaptor&lt;Iterator,policies,value_type&gt; iterator;
typedef iterator_adaptor&lt;ConstIterator,policies,value_type,
const value_type&amp;,const value_type*&gt; type;
const value_type&amp;,const value_type*&gt; const_iterator;
};
</pre>
</blockquote>