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  24. </div>
  25. <div class="section">
  26. <div class="titlepage"><div><div><h3 class="title">
  27. <a name="boost_icl.examples.std_copy"></a><a class="link" href="std_copy.html" title="Std copy">Std copy</a>
  28. </h3></div></div></div>
  29. <p>
  30. 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>
  31. can be used to fill interval containers from standard containers of intervals
  32. 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>,
  33. 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>
  34. differs from what we are familiar with using <span class="emphasis"><em>containers of elements</em></span>.
  35. </p>
  36. <div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
  37. <li class="listitem">
  38. 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>
  39. <span class="special">&lt;</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">&gt;</span></code> instead of <code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">inserter</span></code>
  40. to call insertions on the target interval container.
  41. </li>
  42. <li class="listitem">
  43. As shown in the examples above and below this point, most of the time
  44. we will not be interested to <code class="computeroutput"><span class="identifier">insert</span></code>
  45. segments into <code class="computeroutput"><a class="link" href="../../boost/icl/interval_map.html" title="Class template interval_map">interval_maps</a></code>
  46. 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
  47. 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>
  48. 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>
  49. to achieve this.
  50. </li>
  51. </ul></div>
  52. <p>
  53. </p>
  54. <pre class="programlisting"><span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">iostream</span><span class="special">&gt;</span>
  55. <span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">vector</span><span class="special">&gt;</span>
  56. <span class="preprocessor">#include</span> <span class="special">&lt;</span><span class="identifier">algorithm</span><span class="special">&gt;</span>
  57. <span class="preprocessor">#include</span> <span class="special">&lt;</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">&gt;</span>
  58. <span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">std</span><span class="special">;</span>
  59. <span class="keyword">using</span> <span class="keyword">namespace</span> <span class="identifier">boost</span><span class="special">;</span>
  60. <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>
  61. <span class="comment">// 'make_segments' returns a vector of interval value pairs, which</span>
  62. <span class="comment">// are not sorted. The values are taken from the minimal example</span>
  63. <span class="comment">// in section 'interval combining styles'.</span>
  64. <span class="identifier">vector</span><span class="special">&lt;</span><span class="identifier">pair</span><span class="special">&lt;</span><span class="identifier">discrete_interval</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&gt;,</span> <span class="keyword">int</span><span class="special">&gt;</span> <span class="special">&gt;</span> <span class="identifier">make_segments</span><span class="special">()</span>
  65. <span class="special">{</span>
  66. <span class="identifier">vector</span><span class="special">&lt;</span><span class="identifier">pair</span><span class="special">&lt;</span><span class="identifier">discrete_interval</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&gt;,</span> <span class="keyword">int</span><span class="special">&gt;</span> <span class="special">&gt;</span> <span class="identifier">segment_vec</span><span class="special">;</span>
  67. <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">&lt;</span><span class="keyword">int</span><span class="special">&gt;::</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>
  68. <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">&lt;</span><span class="keyword">int</span><span class="special">&gt;::</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>
  69. <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">&lt;</span><span class="keyword">int</span><span class="special">&gt;::</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>
  70. <span class="keyword">return</span> <span class="identifier">segment_vec</span><span class="special">;</span>
  71. <span class="special">}</span>
  72. <span class="comment">// 'show_segments' displays the source segements.</span>
  73. <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">&lt;</span><span class="identifier">pair</span><span class="special">&lt;</span><span class="identifier">discrete_interval</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&gt;,</span> <span class="keyword">int</span><span class="special">&gt;</span> <span class="special">&gt;&amp;</span> <span class="identifier">segments</span><span class="special">)</span>
  74. <span class="special">{</span>
  75. <span class="identifier">vector</span><span class="special">&lt;</span><span class="identifier">pair</span><span class="special">&lt;</span><span class="identifier">discrete_interval</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&gt;,</span> <span class="keyword">int</span><span class="special">&gt;</span> <span class="special">&gt;::</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>
  76. <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>
  77. <span class="special">{</span>
  78. <span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"("</span> <span class="special">&lt;&lt;</span> <span class="identifier">iter</span><span class="special">-&gt;</span><span class="identifier">first</span> <span class="special">&lt;&lt;</span> <span class="string">","</span> <span class="special">&lt;&lt;</span> <span class="identifier">iter</span><span class="special">-&gt;</span><span class="identifier">second</span> <span class="special">&lt;&lt;</span> <span class="string">")"</span><span class="special">;</span>
  79. <span class="special">++</span><span class="identifier">iter</span><span class="special">;</span>
  80. <span class="special">}</span>
  81. <span class="special">}</span>
  82. <span class="keyword">void</span> <span class="identifier">std_copy</span><span class="special">()</span>
  83. <span class="special">{</span>
  84. <span class="comment">// So we have some segments stored in an std container.</span>
  85. <span class="identifier">vector</span><span class="special">&lt;</span><span class="identifier">pair</span><span class="special">&lt;</span><span class="identifier">discrete_interval</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">&gt;,</span> <span class="keyword">int</span><span class="special">&gt;</span> <span class="special">&gt;</span> <span class="identifier">segments</span> <span class="special">=</span> <span class="identifier">make_segments</span><span class="special">();</span>
  86. <span class="comment">// Display the input</span>
  87. <span class="identifier">cout</span> <span class="special">&lt;&lt;</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">&lt;&lt;</span> <span class="string">"\n\n"</span><span class="special">;</span>
  88. <span class="comment">// We are going to 'std::copy' those segments into an interval_map:</span>
  89. <span class="identifier">interval_map</span><span class="special">&lt;</span><span class="keyword">int</span><span class="special">,</span><span class="keyword">int</span><span class="special">&gt;</span> <span class="identifier">segmap</span><span class="special">;</span>
  90. <span class="comment">// Use an 'icl::inserter' from &lt;boost/icl/iterator.hpp&gt; to call </span>
  91. <span class="comment">// insertion on the interval container.</span>
  92. <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>
  93. <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>
  94. <span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"icl::inserting: "</span> <span class="special">&lt;&lt;</span> <span class="identifier">segmap</span> <span class="special">&lt;&lt;</span> <span class="identifier">endl</span><span class="special">;</span>
  95. <span class="identifier">segmap</span><span class="special">.</span><span class="identifier">clear</span><span class="special">();</span>
  96. <span class="comment">// When we are feeding data into interval_maps, most of the time we are</span>
  97. <span class="comment">// intending to compute an aggregation result. So we are not interested</span>
  98. <span class="comment">// the std::insert semantincs but the aggregating icl::addition semantics.</span>
  99. <span class="comment">// To achieve this there is an icl::add_iterator and an icl::adder function </span>
  100. <span class="comment">// provided in &lt;boost/icl/iterator.hpp&gt;.</span>
  101. <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>
  102. <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>
  103. <span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"icl::adding : "</span> <span class="special">&lt;&lt;</span> <span class="identifier">segmap</span> <span class="special">&lt;&lt;</span> <span class="identifier">endl</span><span class="special">;</span>
  104. <span class="comment">// In this last case, the semantics of 'std::copy' transforms to the </span>
  105. <span class="comment">// generalized addition operation, that is implemented by operator</span>
  106. <span class="comment">// += or + on itl maps and sets.</span>
  107. <span class="special">}</span>
  108. <span class="keyword">int</span> <span class="identifier">main</span><span class="special">()</span>
  109. <span class="special">{</span>
  110. <span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"&gt;&gt; Interval Container Library: Example std_copy.cpp &lt;&lt;\n"</span><span class="special">;</span>
  111. <span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"-----------------------------------------------------------\n"</span><span class="special">;</span>
  112. <span class="identifier">cout</span> <span class="special">&lt;&lt;</span> <span class="string">"Using std::copy to fill an interval_map:\n\n"</span><span class="special">;</span>
  113. <span class="identifier">std_copy</span><span class="special">();</span>
  114. <span class="keyword">return</span> <span class="number">0</span><span class="special">;</span>
  115. <span class="special">}</span>
  116. <span class="comment">// Program output:</span>
  117. <span class="comment">/*---------------------------------------------------------
  118. &gt;&gt; Interval Container Library: Example std_copy.cpp &lt;&lt;
  119. -----------------------------------------------------------
  120. Using std::copy to fill an interval_map:
  121. input sequence: ([2,4),1)([4,5),1)([1,3),1)
  122. icl::inserting: {([1,5)-&gt;1)}
  123. icl::adding : {([1,2)-&gt;1)([2,3)-&gt;2)([3,5)-&gt;1)}
  124. ---------------------------------------------------------*/</span>
  125. </pre>
  126. <p>
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  130. <td align="left"></td>
  131. <td align="right"><div class="copyright-footer">Copyright &#169; 2007-2010 Joachim
  132. Faulhaber<br>Copyright &#169; 1999-2006 Cortex Software
  133. GmbH<p>
  134. Distributed under the Boost Software License, Version 1.0. (See accompanying
  135. 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>)
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