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<div class="section boost_icl_examples_std_copy" lang="en">
<div class="titlepage"><div><div><h3 class="title">
<a name="boost_icl.examples.std_copy"></a><a class="link" href="std_copy.html" title="Std copy">Std copy</a>
</h3></div></div></div>
<p>
The standard algorithm <a href="http://www.cplusplus.com/reference/algorithm/copy/" target="_top"><code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">copy</span></code></a>
can be used to fill interval containers from standard containers of intervals
or interval value pairs (segments). Because intervals do not represent <span class="emphasis"><em><span class="bold"><strong>elements</strong></span></em></span> but <span class="emphasis"><em><span class="bold"><strong>sets</strong></span></em></span>,
that can be empty or contain more than one element, the usage of <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">copy</span></code>
differs from what we are familiar with using <span class="emphasis"><em>containers of elements</em></span>.
</p>
<div class="itemizedlist"><ul type="disc">
<li>
Use <code class="computeroutput"><span class="identifier">icl</span><span class="special">::</span><span class="identifier">inserter</span></code> from <code class="computeroutput"><span class="preprocessor">#include</span>
<span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">icl</span><span class="special">/</span><span class="identifier">iterator</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span></code> instead of <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">inserter</span></code>
to call insertions on the target interval container.
</li>
<li>
As shown in the examples above and below this point, most of the time we
will not be interested to <code class="computeroutput"><span class="identifier">insert</span></code>
segments into <code class="computeroutput"><a class="link" href="../../boost/icl/interval_map.html" title="Class template interval_map">interval_maps</a></code>
but to <a class="link" href="../function_reference/addition.html" title="Addition"><span class="emphasis"><em><span class="bold"><strong>add</strong></span></em></span></a> them, in order to generate
the desired aggregation results. You can use <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">copy</span></code>
with an <code class="computeroutput"><span class="identifier">icl</span><span class="special">::</span><span class="identifier">adder</span></code> instead of an <code class="computeroutput"><span class="identifier">icl</span><span class="special">::</span><span class="identifier">inserter</span></code>
to achieve this.
</li>
</ul></div>
<p>
</p>
<p>
</p>
<pre class="programlisting"><span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">iostream</span><span class="special">></span>
<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">vector</span><span class="special">></span>
<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">algorithm</span><span class="special">></span>
<span class="preprocessor">#include</span> <span class="special"><</span><span class="identifier">boost</span><span class="special">/</span><span class="identifier">icl</span><span class="special">/</span><span class="identifier">interval_map</span><span class="special">.</span><span class="identifier">hpp</span><span class="special">></span>
<span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">std</span><span class="special">;</span>
<span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">;</span>
<span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">icl</span><span class="special">;</span>
<span class="comment">// 'make_segments' returns a vector of interval value pairs, which
</span><span class="comment">// are not sorted. The values are taken from the minimal example
</span><span class="comment">// in section 'interval combining styles'.
</span><span class="identifier">vector</span><span class="special"><</span><span class="identifier">pair</span><span class="special"><</span><span class="identifier">discrete_interval</span><span class="special"><</span><span class="keyword">int</span><span class="special">>,</span> <span class="keyword">int</span><span class="special">></span> <span class="special">></span> <span class="identifier">make_segments</span><span class="special">()</span>
<span class="special">{</span>
<span class="identifier">vector</span><span class="special"><</span><span class="identifier">pair</span><span class="special"><</span><span class="identifier">discrete_interval</span><span class="special"><</span><span class="keyword">int</span><span class="special">>,</span> <span class="keyword">int</span><span class="special">></span> <span class="special">></span> <span class="identifier">segment_vec</span><span class="special">;</span>
<span class="identifier">segment_vec</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="identifier">make_pair</span><span class="special">(</span><span class="identifier">discrete_interval</span><span class="special"><</span><span class="keyword">int</span><span class="special">>::</span><span class="identifier">right_open</span><span class="special">(</span><span class="number">2</span><span class="special">,</span><span class="number">4</span><span class="special">),</span> <span class="number">1</span><span class="special">));</span>
<span class="identifier">segment_vec</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="identifier">make_pair</span><span class="special">(</span><span class="identifier">discrete_interval</span><span class="special"><</span><span class="keyword">int</span><span class="special">>::</span><span class="identifier">right_open</span><span class="special">(</span><span class="number">4</span><span class="special">,</span><span class="number">5</span><span class="special">),</span> <span class="number">1</span><span class="special">));</span>
<span class="identifier">segment_vec</span><span class="special">.</span><span class="identifier">push_back</span><span class="special">(</span><span class="identifier">make_pair</span><span class="special">(</span><span class="identifier">discrete_interval</span><span class="special"><</span><span class="keyword">int</span><span class="special">>::</span><span class="identifier">right_open</span><span class="special">(</span><span class="number">1</span><span class="special">,</span><span class="number">3</span><span class="special">),</span> <span class="number">1</span><span class="special">));</span>
<span class="keyword">return</span> <span class="identifier">segment_vec</span><span class="special">;</span>
<span class="special">}</span>
<span class="comment">// 'show_segments' displays the source segements.
</span><span class="keyword">void</span> <span class="identifier">show_segments</span><span class="special">(</span><span class="keyword">const</span> <span class="identifier">vector</span><span class="special"><</span><span class="identifier">pair</span><span class="special"><</span><span class="identifier">discrete_interval</span><span class="special"><</span><span class="keyword">int</span><span class="special">>,</span> <span class="keyword">int</span><span class="special">></span> <span class="special">>&</span> <span class="identifier">segments</span><span class="special">)</span>
<span class="special">{</span>
<span class="identifier">vector</span><span class="special"><</span><span class="identifier">pair</span><span class="special"><</span><span class="identifier">discrete_interval</span><span class="special"><</span><span class="keyword">int</span><span class="special">>,</span> <span class="keyword">int</span><span class="special">></span> <span class="special">>::</span><span class="identifier">const_iterator</span> <span class="identifier">iter</span> <span class="special">=</span> <span class="identifier">segments</span><span class="special">.</span><span class="identifier">begin</span><span class="special">();</span>
<span class="keyword">while</span><span class="special">(</span><span class="identifier">iter</span> <span class="special">!=</span> <span class="identifier">segments</span><span class="special">.</span><span class="identifier">end</span><span class="special">())</span>
<span class="special">{</span>
<span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"("</span> <span class="special"><<</span> <span class="identifier">iter</span><span class="special">-></span><span class="identifier">first</span> <span class="special"><<</span> <span class="string">","</span> <span class="special"><<</span> <span class="identifier">iter</span><span class="special">-></span><span class="identifier">second</span> <span class="special"><<</span> <span class="string">")"</span><span class="special">;</span>
<span class="special">++</span><span class="identifier">iter</span><span class="special">;</span>
<span class="special">}</span>
<span class="special">}</span>
<span class="keyword">void</span> <span class="identifier">std_copy</span><span class="special">()</span>
<span class="special">{</span>
<span class="comment">// So we have some segments stored in an std container.
</span> <span class="identifier">vector</span><span class="special"><</span><span class="identifier">pair</span><span class="special"><</span><span class="identifier">discrete_interval</span><span class="special"><</span><span class="keyword">int</span><span class="special">>,</span> <span class="keyword">int</span><span class="special">></span> <span class="special">></span> <span class="identifier">segments</span> <span class="special">=</span> <span class="identifier">make_segments</span><span class="special">();</span>
<span class="comment">// Display the input
</span> <span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"input sequence: "</span><span class="special">;</span> <span class="identifier">show_segments</span><span class="special">(</span><span class="identifier">segments</span><span class="special">);</span> <span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"\n\n"</span><span class="special">;</span>
<span class="comment">// We are going to 'std::copy' those segments into an interval_map:
</span> <span class="identifier">interval_map</span><span class="special"><</span><span class="keyword">int</span><span class="special">,</span><span class="keyword">int</span><span class="special">></span> <span class="identifier">segmap</span><span class="special">;</span>
<span class="comment">// Use an 'icl::inserter' from <boost/icl/iterator.hpp> to call
</span> <span class="comment">// insertion on the interval container.
</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">copy</span><span class="special">(</span><span class="identifier">segments</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(),</span> <span class="identifier">segments</span><span class="special">.</span><span class="identifier">end</span><span class="special">(),</span>
<span class="identifier">icl</span><span class="special">::</span><span class="identifier">inserter</span><span class="special">(</span><span class="identifier">segmap</span><span class="special">,</span> <span class="identifier">segmap</span><span class="special">.</span><span class="identifier">end</span><span class="special">()));</span>
<span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"icl::inserting: "</span> <span class="special"><<</span> <span class="identifier">segmap</span> <span class="special"><<</span> <span class="identifier">endl</span><span class="special">;</span>
<span class="identifier">segmap</span><span class="special">.</span><span class="identifier">clear</span><span class="special">();</span>
<span class="comment">// When we are feeding data into interval_maps, most of the time we are
</span> <span class="comment">// intending to compute an aggregation result. So we are not interested
</span> <span class="comment">// the std::insert semantincs but the aggregating icl::addition semantics.
</span> <span class="comment">// To achieve this there is an icl::add_iterator and an icl::adder function
</span> <span class="comment">// provided in <boost/icl/iterator.hpp>.
</span> <span class="identifier">std</span><span class="special">::</span><span class="identifier">copy</span><span class="special">(</span><span class="identifier">segments</span><span class="special">.</span><span class="identifier">begin</span><span class="special">(),</span> <span class="identifier">segments</span><span class="special">.</span><span class="identifier">end</span><span class="special">(),</span>
<span class="identifier">icl</span><span class="special">::</span><span class="identifier">adder</span><span class="special">(</span><span class="identifier">segmap</span><span class="special">,</span> <span class="identifier">segmap</span><span class="special">.</span><span class="identifier">end</span><span class="special">()));</span> <span class="comment">//Aggregating associated values
</span> <span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"icl::adding : "</span> <span class="special"><<</span> <span class="identifier">segmap</span> <span class="special"><<</span> <span class="identifier">endl</span><span class="special">;</span>
<span class="comment">// In this last case, the semantics of 'std::copy' transforms to the
</span> <span class="comment">// generalized addition operation, that is implemented by operator
</span> <span class="comment">// += or + on itl maps and sets.
</span><span class="special">}</span>
<span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
<span class="special">{</span>
<span class="identifier">cout</span> <span class="special"><<</span> <span class="string">">> Interval Container Library: Example std_copy.cpp <<\n"</span><span class="special">;</span>
<span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"-----------------------------------------------------------\n"</span><span class="special">;</span>
<span class="identifier">cout</span> <span class="special"><<</span> <span class="string">"Using std::copy to fill an interval_map:\n\n"</span><span class="special">;</span>
<span class="identifier">std_copy</span><span class="special">();</span>
<span class="keyword">return</span> <span class="number">0</span><span class="special">;</span>
<span class="special">}</span>
<span class="comment">// Program output:
</span><span class="comment">/*---------------------------------------------------------
>> Interval Container Library: Example std_copy.cpp <<
-----------------------------------------------------------
Using std::copy to fill an interval_map:
input sequence: ([2,4),1)([4,5),1)([1,3),1)
icl::inserting: {([1,5)->1)}
icl::adding : {([1,2)->1)([2,3)->2)([3,5)->1)}
---------------------------------------------------------*/</span>
</pre>
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