Google Git
Sign in
nest-open-source / nest-cam / 4320010 / boost / 62d1066a6d52d5ac4e10c106f0eab14c820be0ce / . / boost / libs / algorithm / doc / html / the_boost_algorithm_library / CXX11 / any_of.html
blob: f14065d74032f8821b21c65bc86fecbd998823b2 [file] [log] [blame]
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=US-ASCII">
<title>any_of</title>
<link rel="stylesheet" href="../../../../../../doc/src/boostbook.css" type="text/css">
<meta name="generator" content="DocBook XSL Stylesheets V1.78.1">
<link rel="home" href="../../index.html" title="The Boost Algorithm Library">
<link rel="up" href="../../algorithm/CXX11.html" title="C++11 Algorithms">
<link rel="prev" href="../../algorithm/CXX11.html" title="C++11 Algorithms">
<link rel="next" href="none_of.html" title="none_of">
</head>
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
<table cellpadding="2" width="100%"><tr>
<td valign="top"><img alt="Boost C++ Libraries" width="277" height="86" src="../../../../../../boost.png"></td>
<td align="center"><a href="../../../../../../index.html">Home</a></td>
<td align="center"><a href="../../../../../../libs/libraries.htm">Libraries</a></td>
<td align="center"><a href="http://www.boost.org/users/people.html">People</a></td>
<td align="center"><a href="http://www.boost.org/users/faq.html">FAQ</a></td>
<td align="center"><a href="../../../../../../more/index.htm">More</a></td>
</tr></table>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="../../algorithm/CXX11.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../algorithm/CXX11.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="none_of.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
</div>
<div class="section">
<div class="titlepage"><div><div><h3 class="title">
<a name="the_boost_algorithm_library.CXX11.any_of"></a><a class="link" href="any_of.html" title="any_of">any_of</a>
</h3></div></div></div>
<p>
The header file 'boost/algorithm/cxx11/any_of.hpp' contains four variants
of a single algorithm, <code class="computeroutput"><span class="identifier">any_of</span></code>.
The algorithm tests the elements of a sequence and returns true if any of
the elements has a particular property.
</p>
<p>
The routine <code class="computeroutput"><span class="identifier">any_of</span></code> takes
a sequence and a predicate. It will return true if the predicate returns
true for any element in the sequence.
</p>
<p>
The routine <code class="computeroutput"><span class="identifier">any_of_equal</span></code>
takes a sequence and a value. It will return true if any element in the sequence
compares equal to the passed in value.
</p>
<p>
Both routines come in two forms; the first one takes two iterators to define
the range. The second form takes a single range parameter, and uses Boost.Range
to traverse it.
</p>
<h5>
<a name="the_boost_algorithm_library.CXX11.any_of.h0"></a>
<span class="phrase"><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>
</h5>
<p>
The function <code class="computeroutput"><span class="identifier">any_of</span></code> returns
true if the predicate returns true any item in the sequence. There are two
versions; one takes two iterators, and the other takes a range.
</p>
<p>
</p>
<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>
<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>
<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>
<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>
<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>
<span class="special">}}</span>
</pre>
<p>
</p>
<p>
The function <code class="computeroutput"><span class="identifier">any_of_equal</span></code>
is similar to <code class="computeroutput"><span class="identifier">any_of</span></code>, but
instead of taking a predicate to test the elements of the sequence, it takes
a value to compare against.
</p>
<p>
</p>
<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>
<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>
<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>
<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>
<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>
<span class="special">}}</span>
</pre>
<p>
</p>
<h5>
<a name="the_boost_algorithm_library.CXX11.any_of.h1"></a>
<span class="phrase"><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>
</h5>
<p>
Given the container <code class="computeroutput"><span class="identifier">c</span></code> containing
<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>
<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>,
then
</p>
<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>
<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>
<span class="keyword">using</span> <span class="identifier">boost</span><span class="special">::</span><span class="identifier">algorithm</span><span class="special">;</span>
<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>
<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>
<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>
<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>
<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>
<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>
<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>
</pre>
<p>
</p>
<h5>
<a name="the_boost_algorithm_library.CXX11.any_of.h2"></a>
<span class="phrase"><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
Requirements</a>
</h5>
<p>
<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
output iterators.
</p>
<h5>
<a name="the_boost_algorithm_library.CXX11.any_of.h3"></a>
<span class="phrase"><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>
</h5>
<p>
All of the variants of <code class="computeroutput"><span class="identifier">any_of</span></code>
and <code class="computeroutput"><span class="identifier">any_of_equal</span></code> run in
<span class="emphasis"><em>O(N)</em></span> (linear) time; that is, they compare against each
element in the list once. If any of the comparisons succeed, the algorithm
will terminate immediately, without examining the remaining members of the
sequence.
</p>
<h5>
<a name="the_boost_algorithm_library.CXX11.any_of.h4"></a>
<span class="phrase"><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
Safety</a>
</h5>
<p>
All of the variants of <code class="computeroutput"><span class="identifier">any_of</span></code>
and <code class="computeroutput"><span class="identifier">any_of_equal</span></code> take their
parameters by value or const reference, and do not depend upon any global
state. Therefore, all the routines in this file provide the strong exception
guarantee.
</p>
<h5>
<a name="the_boost_algorithm_library.CXX11.any_of.h5"></a>
<span class="phrase"><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>
</h5>
<div class="itemizedlist"><ul class="itemizedlist" style="list-style-type: disc; ">
<li class="listitem">
The routine <code class="computeroutput"><span class="identifier">any_of</span></code> is
part of the C++11 standard. When compiled using a C++11 implementation,
the implementation from the standard library will be used.
</li>
<li class="listitem">
<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
empty ranges, no matter what is passed to test against.
</li>
<li class="listitem">
The second parameter to <code class="computeroutput"><span class="identifier">any_of_value</span></code>
is a template parameter, rather than deduced from the first parameter
(<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
flexibility for callers, and takes advantage of built-in comparisons
for the type that is pointed to by the iterator. The function is defined
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>
evaluates to true (where <code class="computeroutput"><span class="identifier">iter</span></code>
is an iterator to each element in the sequence)
</li>
</ul></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 &#169; 2010-2012 Marshall Clow<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>
<hr>
<div class="spirit-nav">
<a accesskey="p" href="../../algorithm/CXX11.html"><img src="../../../../../../doc/src/images/prev.png" alt="Prev"></a><a accesskey="u" href="../../algorithm/CXX11.html"><img src="../../../../../../doc/src/images/up.png" alt="Up"></a><a accesskey="h" href="../../index.html"><img src="../../../../../../doc/src/images/home.png" alt="Home"></a><a accesskey="n" href="none_of.html"><img src="../../../../../../doc/src/images/next.png" alt="Next"></a>
</div>
</body>
</html>