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  26 <div class="titlepage"><div><div><h3 class="title">
  27 <a name="the_boost_algorithm_library.CXX11.any_of"></a><a class="link" href="any_of.html" title="any_of">any_of</a>
  28 </h3></div></div></div>
  29 <p>
  30         The header file 'boost/algorithm/cxx11/any_of.hpp' contains four variants
  31         of a single algorithm, <code class="computeroutput"><span class="identifier">any_of</span></code>.
  32         The algorithm tests the elements of a sequence and returns true if any of
  33         the elements has a particular property.
  34       </p>
  35 <p>
  36         The routine <code class="computeroutput"><span class="identifier">any_of</span></code> takes
  37         a sequence and a predicate. It will return true if the predicate returns
  38         true for any element in the sequence.
  39       </p>
  40 <p>
  41         The routine <code class="computeroutput"><span class="identifier">any_of_equal</span></code>
  42         takes a sequence and a value. It will return true if any element in the sequence
  43         compares equal to the passed in value.
  44       </p>
  45 <p>
  46         Both routines come in two forms; the first one takes two iterators to define
  47         the range. The second form takes a single range parameter, and uses Boost.Range
  48         to traverse it.
  49       </p>
  50 <h5>
  51 <a name="the_boost_algorithm_library.CXX11.any_of.h0"></a>
  52         <span><a name="the_boost_algorithm_library.CXX11.any_of.interface"></a></span><a class="link" href="any_of.html#the_boost_algorithm_library.CXX11.any_of.interface">interface</a>
  53       </h5>
  54 <p>
  55         The function <code class="computeroutput"><span class="identifier">any_of</span></code> returns
  56         true if the predicate returns true any item in the sequence. There are two
  57         versions; one takes two iterators, and the other takes a range.
  58       </p>
  59 <p>
  60 </p>
  61 <pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">algorithm</span> <span class="special">{</span>
  62 <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">InputIterator</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Predicate</span><span class="special">&gt;</span>
  63         <span class="keyword">bool</span> <span class="identifier">any_of</span> <span class="special">(</span> <span class="identifier">InputIterator</span> <span class="identifier">first</span><span class="special">,</span> <span class="identifier">InputIterator</span> <span class="identifier">last</span><span class="special">,</span> <span class="identifier">Predicate</span> <span class="identifier">p</span> <span class="special">);</span>
  64 <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">Range</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">Predicate</span><span class="special">&gt;</span>
  65         <span class="keyword">bool</span> <span class="identifier">any_of</span> <span class="special">(</span> <span class="keyword">const</span> <span class="identifier">Range</span> <span class="special">&amp;</span><span class="identifier">r</span><span class="special">,</span> <span class="identifier">Predicate</span> <span class="identifier">p</span> <span class="special">);</span>
  66 <span class="special">}}</span>
  67 </pre>
  68 <p>
  69       </p>
  70 <p>
  71         The function <code class="computeroutput"><span class="identifier">any_of_equal</span></code>
  72         is similar to <code class="computeroutput"><span class="identifier">any_of</span></code>, but
  73         instead of taking a predicate to test the elements of the sequence, it takes
  74         a value to compare against.
  75       </p>
  76 <p>
  77 </p>
  78 <pre class="programlisting"><span class="keyword">namespace</span> <span class="identifier">boost</span> <span class="special">{</span> <span class="keyword">namespace</span> <span class="identifier">algorithm</span> <span class="special">{</span>
  79 <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">InputIterator</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">V</span><span class="special">&gt;</span>
  80         <span class="keyword">bool</span> <span class="identifier">any_of_equal</span> <span class="special">(</span> <span class="identifier">InputIterator</span> <span class="identifier">first</span><span class="special">,</span> <span class="identifier">InputIterator</span> <span class="identifier">last</span><span class="special">,</span> <span class="identifier">V</span> <span class="keyword">const</span> <span class="special">&amp;</span><span class="identifier">val</span> <span class="special">);</span>
  81 <span class="keyword">template</span><span class="special">&lt;</span><span class="keyword">typename</span> <span class="identifier">Range</span><span class="special">,</span> <span class="keyword">typename</span> <span class="identifier">V</span><span class="special">&gt;</span>
  82         <span class="keyword">bool</span> <span class="identifier">any_of_equal</span> <span class="special">(</span> <span class="keyword">const</span> <span class="identifier">Range</span> <span class="special">&amp;</span><span class="identifier">r</span><span class="special">,</span> <span class="identifier">V</span> <span class="keyword">const</span> <span class="special">&amp;</span><span class="identifier">val</span> <span class="special">);</span>
  83 <span class="special">}}</span>
  84 </pre>
  85 <p>
  86       </p>
  87 <h5>
  88 <a name="the_boost_algorithm_library.CXX11.any_of.h1"></a>
  89         <span><a name="the_boost_algorithm_library.CXX11.any_of.examples"></a></span><a class="link" href="any_of.html#the_boost_algorithm_library.CXX11.any_of.examples">Examples</a>
  90       </h5>
  91 <p>
  92         Given the container <code class="computeroutput"><span class="identifier">c</span></code> containing
  93         <code class="computeroutput"><span class="special">{</span> <span class="number">0</span><span class="special">,</span> <span class="number">1</span><span class="special">,</span>
  94         <span class="number">2</span><span class="special">,</span> <span class="number">3</span><span class="special">,</span> <span class="number">14</span><span class="special">,</span> <span class="number">15</span> <span class="special">}</span></code>,
  95         then
  96 </p>
  97 <pre class="programlisting"><span class="keyword">bool</span> <span class="identifier">isOdd</span> <span class="special">(</span> <span class="keyword">int</span> <span class="identifier">i</span> <span class="special">)</span> <span class="special">{</span> <span class="keyword">return</span> <span class="identifier">i</span> <span class="special">%</span> <span class="number">2</span> <span class="special">==</span> <span class="number">1</span><span class="special">;</span> <span class="special">}</span>
  98 <span class="keyword">bool</span> <span class="identifier">lessThan10</span> <span class="special">(</span> <span class="keyword">int</span> <span class="identifier">i</span> <span class="special">)</span> <span class="special">{</span> <span class="keyword">return</span> <span class="identifier">i</span> <span class="special">&lt;</span> <span class="number">10</span><span class="special">;</span> <span class="special">}</span>
  99
 100 <span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">algorithm</span><span class="special">;</span>
 101 <span class="identifier">any_of</span> <span class="special">(</span> <span class="identifier">c</span><span class="special">,</span> <span class="identifier">isOdd</span> <span class="special">)</span> <span class="special">--&gt;</span> <span class="keyword">true</span>
 102 <span class="identifier">any_of</span> <span class="special">(</span> <span class="identifier">c</span><span class="special">.</span><span class="identifier">begin</span> <span class="special">(),</span> <span class="identifier">c</span><span class="special">.</span><span class="identifier">end</span> <span class="special">(),</span> <span class="identifier">lessThan10</span> <span class="special">)</span> <span class="special">--&gt;</span> <span class="keyword">true</span>
 103 <span class="identifier">any_of</span> <span class="special">(</span> <span class="identifier">c</span><span class="special">.</span><span class="identifier">begin</span> <span class="special">()</span> <span class="special">+</span> <span class="number">4</span><span class="special">,</span> <span class="identifier">c</span><span class="special">.</span><span class="identifier">end</span> <span class="special">(),</span> <span class="identifier">lessThan10</span> <span class="special">)</span> <span class="special">--&gt;</span> <span class="keyword">false</span>
 104 <span class="identifier">any_of</span> <span class="special">(</span> <span class="identifier">c</span><span class="special">.</span><span class="identifier">end</span> <span class="special">(),</span> <span class="identifier">c</span><span class="special">.</span><span class="identifier">end</span> <span class="special">(),</span> <span class="identifier">isOdd</span> <span class="special">)</span> <span class="special">--&gt;</span> <span class="keyword">false</span>  <span class="comment">// empty range</span>
 105 <span class="identifier">any_of_equal</span> <span class="special">(</span> <span class="identifier">c</span><span class="special">,</span> <span class="number">3</span> <span class="special">)</span> <span class="special">--&gt;</span> <span class="keyword">true</span>
 106 <span class="identifier">any_of_equal</span> <span class="special">(</span> <span class="identifier">c</span><span class="special">.</span><span class="identifier">begin</span> <span class="special">(),</span> <span class="identifier">c</span><span class="special">.</span><span class="identifier">begin</span> <span class="special">()</span> <span class="special">+</span> <span class="number">3</span><span class="special">,</span> <span class="number">3</span> <span class="special">)</span> <span class="special">--&gt;</span> <span class="keyword">false</span>
 107 <span class="identifier">any_of_equal</span> <span class="special">(</span> <span class="identifier">c</span><span class="special">.</span><span class="identifier">begin</span> <span class="special">(),</span> <span class="identifier">c</span><span class="special">.</span><span class="identifier">begin</span> <span class="special">(),</span> <span class="number">99</span> <span class="special">)</span> <span class="special">--&gt;</span> <span class="keyword">false</span>  <span class="comment">// empty range</span>
 108 </pre>
 109 <p>
 110       </p>
 111 <h5>
 112 <a name="the_boost_algorithm_library.CXX11.any_of.h2"></a>
 113         <span><a name="the_boost_algorithm_library.CXX11.any_of.iterator_requirements"></a></span><a class="link" href="any_of.html#the_boost_algorithm_library.CXX11.any_of.iterator_requirements">Iterator
 114         Requirements</a>
 115       </h5>
 116 <p>
 117         <code class="computeroutput"><span class="identifier">any_of</span></code> and <code class="computeroutput"><span class="identifier">any_of_equal</span></code> work on all iterators except
 118         output iterators.
 119       </p>
 120 <h5>
 121 <a name="the_boost_algorithm_library.CXX11.any_of.h3"></a>
 122         <span><a name="the_boost_algorithm_library.CXX11.any_of.complexity"></a></span><a class="link" href="any_of.html#the_boost_algorithm_library.CXX11.any_of.complexity">Complexity</a>
 123       </h5>
 124 <p>
 125         All of the variants of <code class="computeroutput"><span class="identifier">any_of</span></code>
 126         and <code class="computeroutput"><span class="identifier">any_of_equal</span></code> run in
 127         <span class="emphasis"><em>O(N)</em></span> (linear) time; that is, they compare against each
 128         element in the list once. If any of the comparisons succeed, the algorithm
 129         will terminate immediately, without examining the remaining members of the
 130         sequence.
 131       </p>
 132 <h5>
 133 <a name="the_boost_algorithm_library.CXX11.any_of.h4"></a>
 134         <span><a name="the_boost_algorithm_library.CXX11.any_of.exception_safety"></a></span><a class="link" href="any_of.html#the_boost_algorithm_library.CXX11.any_of.exception_safety">Exception
 135         Safety</a>
 136       </h5>
 137 <p>
 138         All of the variants of <code class="computeroutput"><span class="identifier">any_of</span></code>
 139         and <code class="computeroutput"><span class="identifier">any_of_equal</span></code> take their
 140         parameters by value or const reference, and do not depend upon any global
 141         state. Therefore, all the routines in this file provide the strong exception
 142         guarantee.
 143       </p>
 144 <h5>
 145 <a name="the_boost_algorithm_library.CXX11.any_of.h5"></a>
 146         <span><a name="the_boost_algorithm_library.CXX11.any_of.notes"></a></span><a class="link" href="any_of.html#the_boost_algorithm_library.CXX11.any_of.notes">Notes</a>
 147       </h5>
 148 <div class="itemizedlist"><ul class="itemizedlist" type="disc">
 149 <li class="listitem">
 150             The routine <code class="computeroutput"><span class="identifier">any_of</span></code> is
 151             part of the C++11 standard. When compiled using a C++11 implementation,
 152             the implementation from the standard library will be used.
 153           </li>
 154 <li class="listitem">
 155             <code class="computeroutput"><span class="identifier">any_of</span></code> and <code class="computeroutput"><span class="identifier">any_of_equal</span></code> both return false for
 156             empty ranges, no matter what is passed to test against.
 157           </li>
 158 <li class="listitem">
 159             The second parameter to <code class="computeroutput"><span class="identifier">any_of_value</span></code>
 160             is a template parameter, rather than deduced from the first parameter
 161             (<code class="computeroutput"><span class="identifier">std</span><span class="special">::</span><span class="identifier">iterator_traits</span><span class="special">&lt;</span><span class="identifier">InputIterator</span><span class="special">&gt;::</span><span class="identifier">value_type</span></code>) because that allows more
 162             flexibility for callers, and takes advantage of built-in comparisons
 163             for the type that is pointed to by the iterator. The function is defined
 164             to return true if, for any element in the sequence, the expression <code class="computeroutput"><span class="special">*</span><span class="identifier">iter</span> <span class="special">==</span> <span class="identifier">val</span></code>
 165             evaluates to true (where <code class="computeroutput"><span class="identifier">iter</span></code>
 166             is an iterator to each element in the sequence)
 167           </li>
 168 </ul></div>
 169 </div>
 170 <table xmlns:rev="http://www.cs.rpi.edu/~gregod/boost/tools/doc/revision" width="100%"><tr>
 171 <td align="left"></td>
 172 <td align="right"><div class="copyright-footer">Copyright &#169; 2010-2012 Marshall Clow<p>
 173         Distributed under the Boost Software License, Version 1.0. (See accompanying
 174         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>)
 175       </p>
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