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<div class="section" title="Useful functions">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_bimap.the_tutorial.useful_functions"></a><a class="link" href="useful_functions.html" title="Useful functions">Useful functions</a>
</h3></div></div></div>
<div class="toc"><dl>
<dt><span class="section"><a href="useful_functions.html#boost_bimap.the_tutorial.useful_functions.projection_of_iterators">Projection
of iterators</a></span></dt>
<dt><span class="section"><a href="useful_functions.html#boost_bimap.the_tutorial.useful_functions.replace_and_modify">replace
and modify</a></span></dt>
<dt><span class="section"><a href="useful_functions.html#boost_bimap.the_tutorial.useful_functions.retrieval_of_ranges">Retrieval
of ranges</a></span></dt>
</dl></div>
<div class="section" title="Projection of iterators">
<div class="titlepage"><div><div><h4 class="title">
<a name="boost_bimap.the_tutorial.useful_functions.projection_of_iterators"></a><a class="link" href="useful_functions.html#boost_bimap.the_tutorial.useful_functions.projection_of_iterators" title="Projection of iterators">Projection
of iterators</a>
</h4></div></div></div>
<p>
Iterators can be projected to any of the three views of the bimap. A bimap
provides three member functions to cope with projection: <code class="computeroutput"><span class="identifier">project_left</span></code>, <code class="computeroutput"><span class="identifier">project_right</span></code>
and <code class="computeroutput"><span class="identifier">project_up</span></code>, with projects
iterators to the <span class="emphasis"><em>left map view</em></span>, the <span class="emphasis"><em>right
map view</em></span> and the <span class="emphasis"><em>collection of relations view</em></span>.
These functions take any iterator from the bimap and retrieve an iterator
over the projected view pointing to the same element.
</p>
<p>
Here is an example that uses projection:
</p>
<p>
<a href="../../../../example/projection.cpp" target="_top">Go to source code</a>
</p>
<p>
</p>
<p>
</p>
<pre class="programlisting"><span class="keyword">typedef</span> <span class="identifier">bimap</span><span class="special">&lt;</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">,</span><span class="identifier">multiset_of</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">,</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">greater</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&gt;</span> <span class="special">&gt;</span> <span class="special">&gt;</span> <span class="identifier">bm_type</span><span class="special">;</span>
<span class="identifier">bm_type</span> <span class="identifier">bm</span><span class="special">;</span>
<span class="identifier">bm</span><span class="special">.</span><span class="identifier">insert</span><span class="special">(</span> <span class="identifier">bm_type</span><span class="special">::</span><span class="identifier">value_type</span><span class="special">(</span><span class="string">"John"</span> <span class="special">,</span><span class="number">34</span><span class="special">)</span> <span class="special">);</span>
<span class="identifier">bm</span><span class="special">.</span><span class="identifier">insert</span><span class="special">(</span> <span class="identifier">bm_type</span><span class="special">::</span><span class="identifier">value_type</span><span class="special">(</span><span class="string">"Peter"</span><span class="special">,</span><span class="number">24</span><span class="special">)</span> <span class="special">);</span>
<span class="identifier">bm</span><span class="special">.</span><span class="identifier">insert</span><span class="special">(</span> <span class="identifier">bm_type</span><span class="special">::</span><span class="identifier">value_type</span><span class="special">(</span><span class="string">"Mary"</span> <span class="special">,</span><span class="number">12</span><span class="special">)</span> <span class="special">);</span>
<span class="comment">// Find the name of the next younger person after Peter
</span>
<span class="identifier">bm_type</span><span class="special">::</span><span class="identifier">left_const_iterator</span> <span class="identifier">name_iter</span> <span class="special">=</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">left</span><span class="special">.</span><span class="identifier">find</span><span class="special">(</span><span class="string">"Peter"</span><span class="special">);</span>
<span class="identifier">bm_type</span><span class="special">::</span><span class="identifier">right_const_iterator</span> <span class="identifier">years_iter</span> <span class="special">=</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">project_right</span><span class="special">(</span><span class="identifier">name_iter</span><span class="special">);</span>
<span class="special">++</span><span class="identifier">years_iter</span><span class="special">;</span>
<span class="identifier">std</span><span class="special">::</span><span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"The next younger person after Peter is "</span> <span class="special">&lt;&lt;</span> <span class="identifier">years_iter</span><span class="special">-&gt;</span><span class="identifier">second</span><span class="special">;</span>
</pre>
<p>
</p>
<p>
</p>
</div>
<div class="section" title="replace and modify">
<div class="titlepage"><div><div><h4 class="title">
<a name="boost_bimap.the_tutorial.useful_functions.replace_and_modify"></a><a class="link" href="useful_functions.html#boost_bimap.the_tutorial.useful_functions.replace_and_modify" title="replace and modify">replace
and modify</a>
</h4></div></div></div>
<p>
These functions are members of the views of a bimap that are not founded
in their standard counterparts.
</p>
<p>
The <code class="computeroutput"><span class="identifier">replace</span></code> family member
functions performs in-place replacement of a given element as the following
example shows:
</p>
<p>
<a href="../../../../example/tutorial_modify_and_replace.cpp" target="_top">Go to source
code</a>
</p>
<p>
</p>
<p>
</p>
<pre class="programlisting"><span class="keyword">typedef</span> <span class="identifier">bimap</span><span class="special">&lt;</span> <span class="keyword">int</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="special">&gt;</span> <span class="identifier">bm_type</span><span class="special">;</span>
<span class="identifier">bm_type</span> <span class="identifier">bm</span><span class="special">;</span>
<span class="identifier">bm</span><span class="special">.</span><span class="identifier">insert</span><span class="special">(</span> <span class="identifier">bm_type</span><span class="special">::</span><span class="identifier">value_type</span><span class="special">(</span><span class="number">1</span><span class="special">,</span><span class="string">"one"</span><span class="special">)</span> <span class="special">);</span>
<span class="comment">// Replace (1,"one") with (1,"1") using the right map view
</span><span class="special">{</span>
<span class="identifier">bm_type</span><span class="special">::</span><span class="identifier">right_iterator</span> <span class="identifier">it</span> <span class="special">=</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">right</span><span class="special">.</span><span class="identifier">find</span><span class="special">(</span><span class="string">"one"</span><span class="special">);</span>
<span class="keyword">bool</span> <span class="identifier">successful_replace</span> <span class="special">=</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">right</span><span class="special">.</span><span class="identifier">replace_key</span><span class="special">(</span> <span class="identifier">it</span><span class="special">,</span> <span class="string">"1"</span> <span class="special">);</span>
<span class="identifier">assert</span><span class="special">(</span> <span class="identifier">successful_replace</span> <span class="special">);</span>
<span class="special">}</span>
<span class="identifier">bm</span><span class="special">.</span><span class="identifier">insert</span><span class="special">(</span> <span class="identifier">bm_type</span><span class="special">::</span><span class="identifier">value_type</span><span class="special">(</span><span class="number">2</span><span class="special">,</span><span class="string">"two"</span><span class="special">)</span> <span class="special">);</span>
<span class="comment">// Fail to replace (1,"1") with (1,"two") using the left map view
</span><span class="special">{</span>
<span class="identifier">assert</span><span class="special">(</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span> <span class="special">==</span> <span class="number">2</span> <span class="special">);</span>
<span class="identifier">bm_type</span><span class="special">::</span><span class="identifier">left_iterator</span> <span class="identifier">it</span> <span class="special">=</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">left</span><span class="special">.</span><span class="identifier">find</span><span class="special">(</span><span class="number">1</span><span class="special">);</span>
<span class="keyword">bool</span> <span class="identifier">successful_replace</span> <span class="special">=</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">left</span><span class="special">.</span><span class="identifier">replace_data</span><span class="special">(</span> <span class="identifier">it</span><span class="special">,</span> <span class="string">"two"</span> <span class="special">);</span>
<span class="line_callout_bug"><a class="co" name="boost_bimap9co" href="useful_functions.html#boost_bimap9"><img src="../../../../../../doc/src/images/callouts/1.png" alt="1" border="0"></a></span><span class="identifier">assert</span><span class="special">(</span> <span class="special">!</span> <span class="identifier">successful_replace</span> <span class="special">);</span>
<span class="identifier">assert</span><span class="special">(</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span> <span class="special">==</span> <span class="number">2</span> <span class="special">);</span>
<span class="special">}</span>
</pre>
<p>
</p>
<p>
</p>
<p>
</p>
<div class="calloutlist"><table border="0" summary="Callout list"><tr>
<td width="5%" valign="top" align="left"><p><a name="boost_bimap9"></a><a href="#boost_bimap9co"><img src="../../../../../../doc/src/images/callouts/1.png" alt="1" border="0"></a> </p></td>
<td valign="top" align="left"><p> <code class="computeroutput"><span class="identifier">it</span></code> is still valid here,
and the bimap was left unchanged </p></td>
</tr></table></div>
<p>
</p>
<p>
</p>
<p>
<code class="computeroutput"><span class="identifier">replace</span></code> functions performs
this substitution in such a manner that:
</p>
<div class="itemizedlist"><ul class="itemizedlist" type="disc">
<li class="listitem">
The complexity is constant time if the changed element retains its original
order with respect to all views; it is logarithmic otherwise.
</li>
<li class="listitem">
Iterator and reference validity are preserved.
</li>
<li class="listitem">
The operation is strongly exception-safe, i.e. the <code class="computeroutput"><span class="identifier">bimap</span></code>
remains unchanged if some exception (originated by the system or the
user's data types) is thrown.
</li>
</ul></div>
<p>
<code class="computeroutput"><span class="identifier">replace</span></code> functions are powerful
operations not provided by standard STL containers, and one that is specially
handy when strong exception-safety is required.
</p>
<p>
The observant reader might have noticed that the convenience of replace
comes at a cost: namely the whole element has to be copied <span class="emphasis"><em>twice</em></span>
to do the updating (when retrieving it and inside <code class="computeroutput"><span class="identifier">replace</span></code>).
If elements are expensive to copy, this may be quite a computational cost
for the modification of just a tiny part of the object. To cope with this
situation, Boost.Bimap provides an alternative updating mechanism: <code class="computeroutput"><span class="identifier">modify</span></code> functions.
</p>
<p>
<code class="computeroutput"><span class="identifier">modify</span></code> functions accepts
a functor (or pointer to function) taking a reference to the data to be
changed, thus eliminating the need for spurious copies. Like <code class="computeroutput"><span class="identifier">replace</span></code> functions, <code class="computeroutput"><span class="identifier">modify</span></code>
functions does preserve the internal orderings of all the indices of the
<code class="computeroutput"><span class="identifier">bimap</span></code>. However, the semantics
of modify functions are not entirely equivalent to replace functions. Consider
what happens if a collision occurs as a result of modifying the element,
i.e. the modified element clashes with another with respect to some unique
view. In the case of <code class="computeroutput"><span class="identifier">replace</span></code>
functions, the original value is kept and the method returns without altering
the container, but <code class="computeroutput"><span class="identifier">modify</span></code>
functions cannot afford such an approach, since the modifying functor leaves
no trace of the previous value of the element. Integrity constraints thus
lead to the following policy: when a collision happens in the process of
calling a modify functions, the element is erased and the method returns
false. This difference in behavior between <code class="computeroutput"><span class="identifier">replace</span></code>
and <code class="computeroutput"><span class="identifier">modify</span></code> functions has
to be considered by the programmer on a case-by-case basis.
</p>
<p>
Boost.Bimap defines new placeholders named <code class="computeroutput"><span class="identifier">_key</span></code>
and <code class="computeroutput"><span class="identifier">_data</span></code> to allow a sounder
solution. You have to include <code class="computeroutput"><span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">bimap</span><span class="special">/</span><span class="identifier">support</span><span class="special">/</span><span class="identifier">lambda</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span></code>
to use them.
</p>
<p>
<a href="../../../../example/tutorial_modify_and_replace.cpp" target="_top">Go to source
code</a>
</p>
<p>
</p>
<p>
</p>
<pre class="programlisting"><span class="keyword">typedef</span> <span class="identifier">bimap</span><span class="special">&lt;</span> <span class="keyword">int</span><span class="special">,</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span> <span class="special">&gt;</span> <span class="identifier">bm_type</span><span class="special">;</span>
<span class="identifier">bm_type</span> <span class="identifier">bm</span><span class="special">;</span>
<span class="identifier">bm</span><span class="special">.</span><span class="identifier">insert</span><span class="special">(</span> <span class="identifier">bm_type</span><span class="special">::</span><span class="identifier">value_type</span><span class="special">(</span><span class="number">1</span><span class="special">,</span><span class="string">"one"</span><span class="special">)</span> <span class="special">);</span>
<span class="comment">// Modify (1,"one") to (1,"1") using the right map view
</span><span class="special">{</span>
<span class="identifier">bm_type</span><span class="special">::</span><span class="identifier">right_iterator</span> <span class="identifier">it</span> <span class="special">=</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">right</span><span class="special">.</span><span class="identifier">find</span><span class="special">(</span><span class="string">"one"</span><span class="special">);</span>
<span class="keyword">bool</span> <span class="identifier">successful_modify</span> <span class="special">=</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">right</span><span class="special">.</span><span class="identifier">modify_key</span><span class="special">(</span> <span class="identifier">it</span> <span class="special">,</span> <span class="identifier">_key</span> <span class="special">=</span> <span class="string">"1"</span> <span class="special">);</span>
<span class="identifier">assert</span><span class="special">(</span> <span class="identifier">successful_modify</span> <span class="special">);</span>
<span class="special">}</span>
<span class="identifier">bm</span><span class="special">.</span><span class="identifier">insert</span><span class="special">(</span> <span class="identifier">bm_type</span><span class="special">::</span><span class="identifier">value_type</span><span class="special">(</span><span class="number">2</span><span class="special">,</span><span class="string">"two"</span><span class="special">)</span> <span class="special">);</span>
<span class="comment">// Fail to modify (1,"1") to (1,"two") using the left map view
</span><span class="special">{</span>
<span class="identifier">assert</span><span class="special">(</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span> <span class="special">==</span> <span class="number">2</span> <span class="special">);</span>
<span class="identifier">bm_type</span><span class="special">::</span><span class="identifier">left_iterator</span> <span class="identifier">it</span> <span class="special">=</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">left</span><span class="special">.</span><span class="identifier">find</span><span class="special">(</span><span class="number">1</span><span class="special">);</span>
<span class="keyword">bool</span> <span class="identifier">successful_modify</span> <span class="special">=</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">left</span><span class="special">.</span><span class="identifier">modify_data</span><span class="special">(</span> <span class="identifier">it</span><span class="special">,</span> <span class="identifier">_data</span> <span class="special">=</span> <span class="string">"two"</span> <span class="special">);</span>
<span class="line_callout_bug"><a class="co" name="boost_bimap10co" href="useful_functions.html#boost_bimap10"><img src="../../../../../../doc/src/images/callouts/1.png" alt="1" border="0"></a></span><span class="identifier">assert</span><span class="special">(</span> <span class="special">!</span> <span class="identifier">successful_modify</span> <span class="special">);</span>
<span class="identifier">assert</span><span class="special">(</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">size</span><span class="special">()</span> <span class="special">==</span> <span class="number">1</span> <span class="special">);</span>
<span class="special">}</span>
</pre>
<p>
</p>
<p>
</p>
<p>
</p>
<div class="calloutlist"><table border="0" summary="Callout list"><tr>
<td width="5%" valign="top" align="left"><p><a name="boost_bimap10"></a><a href="#boost_bimap10co"><img src="../../../../../../doc/src/images/callouts/1.png" alt="1" border="0"></a> </p></td>
<td valign="top" align="left"><p> <code class="computeroutput"><span class="identifier">it</span></code> is not longer valid
and <code class="computeroutput"><span class="special">(</span><span class="number">1</span><span class="special">,</span><span class="string">"1"</span><span class="special">)</span></code> is removed from the bimap </p></td>
</tr></table></div>
<p>
</p>
<p>
</p>
</div>
<div class="section" title="Retrieval of ranges">
<div class="titlepage"><div><div><h4 class="title">
<a name="boost_bimap.the_tutorial.useful_functions.retrieval_of_ranges"></a><a class="link" href="useful_functions.html#boost_bimap.the_tutorial.useful_functions.retrieval_of_ranges" title="Retrieval of ranges">Retrieval
of ranges</a>
</h4></div></div></div>
<p>
Standard <code class="computeroutput"><span class="identifier">lower_bound</span></code> and
<code class="computeroutput"><span class="identifier">upper_bound</span></code> functions can
be used to lookup for all the elements in a given range.
</p>
<p>
Suppose we want to retrieve the elements from a <code class="computeroutput"><span class="identifier">bimap</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">,</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&gt;</span></code> where the left value is in the range
<code class="computeroutput"><span class="special">[</span><span class="number">20</span><span class="special">,</span><span class="number">50</span><span class="special">]</span></code>
</p>
<p>
</p>
<p>
</p>
<pre class="programlisting"><span class="keyword">typedef</span> <span class="identifier">bimap</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">,</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&gt;</span> <span class="identifier">bm_type</span><span class="special">;</span>
<span class="identifier">bm_type</span> <span class="identifier">bm</span><span class="special">;</span>
<span class="comment">// ...
</span>
<span class="identifier">bm_type</span><span class="special">::</span><span class="identifier">left_iterator</span> <span class="identifier">iter_first</span> <span class="special">=</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">left</span><span class="special">.</span><span class="identifier">lower_bound</span><span class="special">(</span><span class="number">20</span><span class="special">);</span>
<span class="identifier">bm_type</span><span class="special">::</span><span class="identifier">left_iterator</span> <span class="identifier">iter_second</span> <span class="special">=</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">left</span><span class="special">.</span><span class="identifier">upper_bound</span><span class="special">(</span><span class="number">50</span><span class="special">);</span>
<span class="comment">// range [iter_first,iter_second) contains the elements in [20,50]
</span></pre>
<p>
</p>
<p>
</p>
<p>
Subtle changes to the code are required when strict inequalities are considered.
To retrieve the elements greater than 20 and less than 50, the code has
to be rewritten as
</p>
<p>
</p>
<p>
</p>
<pre class="programlisting"><span class="identifier">bm_type</span><span class="special">::</span><span class="identifier">left_iterator</span> <span class="identifier">iter_first</span> <span class="special">=</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">left</span><span class="special">.</span><span class="identifier">upper_bound</span><span class="special">(</span><span class="number">20</span><span class="special">);</span>
<span class="identifier">bm_type</span><span class="special">::</span><span class="identifier">left_iterator</span> <span class="identifier">iter_second</span> <span class="special">=</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">left</span><span class="special">.</span><span class="identifier">lower_bound</span><span class="special">(</span><span class="number">50</span><span class="special">);</span>
<span class="comment">// range [iter_first,iter_second) contains the elements in (20,50)
</span></pre>
<p>
</p>
<p>
</p>
<p>
To add to this complexity, the careful programmer has to take into account
that the lower and upper bounds of the interval searched be compatible:
for instance, if the lower bound is 50 and the upper bound is 20, the iterators
<code class="computeroutput"><span class="identifier">iter_first</span></code> and <code class="computeroutput"><span class="identifier">iter_second</span></code> produced by the code above
will be in reverse order, with possibly catastrophic results if a traversal
from <code class="computeroutput"><span class="identifier">iter_first</span></code> to <code class="computeroutput"><span class="identifier">iter_second</span></code> is tried. All these details
make range searching a tedious and error prone task.
</p>
<p>
The range member function, often in combination with lambda expressions,
can greatly help alleviate this situation:
</p>
<p>
</p>
<p>
</p>
<pre class="programlisting"><span class="keyword">typedef</span> <span class="identifier">bimap</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">,</span><span class="identifier">std</span><span class="special">::</span><span class="identifier">string</span><span class="special">&gt;</span> <span class="identifier">bm_type</span><span class="special">;</span>
<span class="identifier">bm_type</span> <span class="identifier">bm</span><span class="special">;</span>
<span class="comment">// ...
</span>
<span class="line_callout_bug"><a class="co" name="boost_bimap11co" href="useful_functions.html#boost_bimap11"><img src="../../../../../../doc/src/images/callouts/1.png" alt="1" border="0"></a></span><span class="identifier">bm_type</span><span class="special">::</span><span class="identifier">left_range_type</span> <span class="identifier">r</span><span class="special">;</span>
<span class="line_callout_bug"><a class="co" name="boost_bimap12co" href="useful_functions.html#boost_bimap12"><img src="../../../../../../doc/src/images/callouts/2.png" alt="2" border="0"></a></span><span class="identifier">r</span> <span class="special">=</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">left</span><span class="special">.</span><span class="identifier">range</span><span class="special">(</span> <span class="number">20</span> <span class="special">&lt;=</span> <span class="identifier">_key</span><span class="special">,</span> <span class="identifier">_key</span> <span class="special">&lt;=</span> <span class="number">50</span> <span class="special">);</span> <span class="comment">// [20,50]
</span>
<span class="identifier">r</span> <span class="special">=</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">left</span><span class="special">.</span><span class="identifier">range</span><span class="special">(</span> <span class="number">20</span> <span class="special">&lt;</span> <span class="identifier">_key</span><span class="special">,</span> <span class="identifier">_key</span> <span class="special">&lt;</span> <span class="number">50</span> <span class="special">);</span> <span class="comment">// (20,50)
</span>
<span class="identifier">r</span> <span class="special">=</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">left</span><span class="special">.</span><span class="identifier">range</span><span class="special">(</span> <span class="number">20</span> <span class="special">&lt;=</span> <span class="identifier">_key</span><span class="special">,</span> <span class="identifier">_key</span> <span class="special">&lt;</span> <span class="number">50</span> <span class="special">);</span> <span class="comment">// [20,50)
</span></pre>
<p>
</p>
<p>
</p>
<p>
</p>
<div class="calloutlist"><table border="0" summary="Callout list">
<tr>
<td width="5%" valign="top" align="left"><p><a name="boost_bimap11"></a><a href="#boost_bimap11co"><img src="../../../../../../doc/src/images/callouts/1.png" alt="1" border="0"></a> </p></td>
<td valign="top" align="left"><p> <code class="computeroutput"><span class="identifier">range_type</span></code> is a handy
typedef equal to <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span><span class="special">&lt;</span><span class="identifier">iterator</span><span class="special">,</span><span class="identifier">iterator</span><span class="special">&gt;</span></code>. <code class="computeroutput"><span class="identifier">const_range_type</span></code>
is provided too, and it is equal to <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">pair</span><span class="special">&lt;</span><span class="identifier">const_iterator</span><span class="special">,</span><span class="identifier">const_iterator</span><span class="special">&gt;</span></code> </p></td>
</tr>
<tr>
<td width="5%" valign="top" align="left"><p><a name="boost_bimap12"></a><a href="#boost_bimap12co"><img src="../../../../../../doc/src/images/callouts/2.png" alt="2" border="0"></a> </p></td>
<td valign="top" align="left"><p> _key is a Boost.Lambda placeholder.
To use it you have to include <code class="computeroutput"><span class="special">&lt;</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">bimap</span><span class="special">/</span><span class="identifier">support</span><span class="special">/</span><span class="identifier">lambda</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">&gt;</span></code>
</p></td>
</tr>
</table></div>
<p>
</p>
<p>
</p>
<p>
<code class="computeroutput"><span class="identifier">range</span></code> simply accepts predicates
specifying the lower and upper bounds of the interval searched. Please
consult the reference for a detailed explanation of the permissible predicates
passed to range.
</p>
<p>
One or both bounds can be omitted with the special unbounded marker:
</p>
<p>
</p>
<p>
</p>
<pre class="programlisting"><span class="identifier">r</span> <span class="special">=</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">left</span><span class="special">.</span><span class="identifier">range</span><span class="special">(</span> <span class="number">20</span> <span class="special">&lt;=</span> <span class="identifier">_key</span><span class="special">,</span> <span class="identifier">unbounded</span> <span class="special">);</span> <span class="comment">// [20,inf)
</span>
<span class="identifier">r</span> <span class="special">=</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">left</span><span class="special">.</span><span class="identifier">range</span><span class="special">(</span> <span class="identifier">unbounded</span> <span class="special">,</span> <span class="identifier">_key</span> <span class="special">&lt;</span> <span class="number">50</span> <span class="special">);</span> <span class="comment">// (-inf,50)
</span>
<span class="line_callout_bug"><a class="co" name="boost_bimap13co" href="useful_functions.html#boost_bimap13"><img src="../../../../../../doc/src/images/callouts/1.png" alt="1" border="0"></a></span><span class="identifier">r</span> <span class="special">=</span> <span class="identifier">bm</span><span class="special">.</span><span class="identifier">left</span><span class="special">.</span><span class="identifier">range</span><span class="special">(</span> <span class="identifier">unbounded</span> <span class="special">,</span> <span class="identifier">unbounded</span> <span class="special">);</span> <span class="comment">// (-inf,inf)
</span></pre>
<p>
</p>
<p>
</p>
<p>
</p>
<div class="calloutlist"><table border="0" summary="Callout list"><tr>
<td width="5%" valign="top" align="left"><p><a name="boost_bimap13"></a><a href="#boost_bimap13co"><img src="../../../../../../doc/src/images/callouts/1.png" alt="1" border="0"></a> </p></td>
<td valign="top" align="left"><p> This is equivalent to std::make_pair(s.begin(),s.end()) </p></td>
</tr></table></div>
<p>
</p>
<p>
</p>
<p>
<a href="../../../../example/tutorial_range.cpp" target="_top">Go to source code</a>
</p>
</div>
</div>
<table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
<td align="left"></td>
<td align="right"><div class="copyright-footer">Copyright © 2006 -2007 Matias Capeletto<p>
Distributed under the Boost Software License, Version 1.0. (See accompanying
file LICENSE_1_0.txt or copy at <a href="http://www.boost.org/LICENSE_1_0.txt" target="_top">http://www.boost.org/LICENSE_1_0.txt</a>)
</p>
</div></td>
</tr></table>
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