<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en"
lang="en" dir="ltr">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<title>
Set constructors & destructors [C++ Reference]
</title>
<meta name="generator" content="DokuWiki Release 2009-12-25c "Lemming"" />
<meta name="robots" content="index,follow" />
<meta name="date" content="2009-10-09T08:15:36-0700" />
<meta name="keywords" content="stl,set,set_constructors" />
<link rel="search" type="application/opensearchdescription+xml" href="/wiki/lib/exe/opensearch.php" title="C++ Reference" />
<link rel="start" href="/wiki/" />
<link rel="contents" href="/wiki/stl/set/set_constructors?do=index" title="Index" />
<link rel="alternate" type="application/rss+xml" title="Recent Changes" href="/wiki/feed.php" />
<link rel="alternate" type="application/rss+xml" title="Current Namespace" href="/wiki/feed.php?mode=list&ns=stl:set" />
<link rel="edit" title="Edit this page" href="/wiki/stl/set/set_constructors?do=edit" />
<link rel="alternate" type="text/html" title="Plain HTML" href="/wiki/_export/xhtml/stl/set/set_constructors" />
<link rel="alternate" type="text/plain" title="Wiki Markup" href="/wiki/_export/raw/stl/set/set_constructors" />
<link rel="canonical" href="http://www.cppreference.com/wiki/stl/set/set_constructors" />
<link rel="stylesheet" media="all" type="text/css" href="/wiki/lib/exe/css.php?s=all&t=custom1&tseed=1272971091" />
<link rel="stylesheet" media="screen" type="text/css" href="/wiki/lib/exe/css.php?t=custom1&tseed=1272971091" />
<link rel="stylesheet" media="print" type="text/css" href="/wiki/lib/exe/css.php?s=print&t=custom1&tseed=1272971091" />
<script type="text/javascript" charset="utf-8" ><!--//--><![CDATA[//><!--
var NS='stl:set';var JSINFO = {"id":"stl:set:set_constructors","namespace":"stl:set"};
//--><!]]></script>
<script type="text/javascript" charset="utf-8" src="/wiki/lib/exe/js.php?tseed=1272971091" ></script>
<link rel="shortcut icon" href="/wiki/lib/tpl/custom1/images/favicon.png" />
</head>
<body>
<div class="dokuwiki">
<div class="stylehead">
<div class="breadcrumbs">
<span class="bchead">You are here: </span><a href="../../start.html" title="start">C++ Reference</a> » <a href="../../stl/start.html" title="stl:start">C++ Standard Template Library</a> » <a href="../../stl/set/start.html" title="stl:set:start">C++ Sets</a> » <a href="../../stl/set/set.html" title="stl:set:set_constructors">Set constructors & destructors</a> </div>
</div>
<div class="page">
<script src="http://www.google-analytics.com/urchin.js" type="text/javascript">
</script>
<script type="text/javascript">
_uacct = "UA-2828341-1";
urchinTracker();
</script>
<!-- wikipage start -->
<h2><a name="set_constructors_destructors" id="set_constructors_destructors">Set constructors & destructors</a></h2>
<div class="level2">
<p>
Syntax:
</p>
<pre class="c code c++" style="font-family:monospace;"> <span class="co2">#include <set></span>
set<span class="br0">(</span><span class="br0">)</span><span class="sy0">;</span>
set<span class="br0">(</span> <span class="kw4">const</span> set<span class="sy0">&</span> c <span class="br0">)</span><span class="sy0">;</span>
set<span class="br0">(</span> input_iterator start<span class="sy0">,</span> input_iterator end <span class="br0">)</span><span class="sy0">;</span>
set<span class="br0">(</span> input_iterator start<span class="sy0">,</span> input_iterator end<span class="sy0">,</span> <span class="kw4">const</span> key_compare<span class="sy0">&</span> cmp <span class="br0">)</span><span class="sy0">;</span>
explicit set<span class="br0">(</span> <span class="kw4">const</span> key_compare<span class="sy0">&</span> cmp <span class="br0">)</span><span class="sy0">;</span>
~set<span class="br0">(</span><span class="br0">)</span><span class="sy0">;</span></pre>
<p>
Every set has a default constructor, copy constructor, and destructor.
</p>
<p>
The default constructor takes no arguments, creates a new instance of that set,
and runs in <a href="../../complexity.html" class="wikilink1" title="complexity">constant time</a>. The default copy constructor runs in <a href="../../complexity.html" class="wikilink1" title="complexity">linear time</a> and
can be used to create a new set that is a copy of the given set c.
</p>
<p>
The default destructor is called when the set should be destroyed.
</p>
<p>
For example, the following code creates and displays a set of integers:
</p>
<pre class="c code c++" style="font-family:monospace;"> <span class="kw4">const</span> <span class="kw4">int</span> max_nums <span class="sy0">=</span> <span class="nu0">10</span><span class="sy0">;</span>
<span class="kw4">int</span> nums<span class="br0">[</span>max_nums<span class="br0">]</span> <span class="sy0">=</span> <span class="br0">{</span>3<span class="sy0">,</span>1<span class="sy0">,</span>4<span class="sy0">,</span>1<span class="sy0">,</span>5<span class="sy0">,</span>9<span class="sy0">,</span>2<span class="sy0">,</span>6<span class="sy0">,</span>5<span class="sy0">,</span>8<span class="br0">}</span><span class="sy0">;</span>
set<span class="sy0"><</span>int<span class="sy0">></span> digits<span class="sy0">;</span>
<span class="kw1">for</span><span class="br0">(</span> <span class="kw4">int</span> i <span class="sy0">=</span> <span class="nu0">0</span><span class="sy0">;</span> i <span class="sy0"><</span> max_nums<span class="sy0">;</span> <span class="sy0">++</span>i <span class="br0">)</span> digits.<span class="me1">insert</span><span class="br0">(</span>nums<span class="br0">[</span>i<span class="br0">]</span><span class="br0">)</span><span class="sy0">;</span>
<a href="http://www.opengroup.org/onlinepubs/009695399/functions/cout.html"><span class="kw3">cout</span></a> <span class="sy0"><<</span> <span class="st0">"Unique digits are: "</span><span class="sy0">;</span>
<span class="kw1">for</span><span class="br0">(</span> set<span class="sy0"><</span>int<span class="sy0">>::</span><span class="me2">const_iterator</span> iter <span class="sy0">=</span> digits.<span class="me1">begin</span><span class="br0">(</span><span class="br0">)</span><span class="sy0">;</span>
iter <span class="sy0">!=</span> digits.<span class="me1">end</span><span class="br0">(</span><span class="br0">)</span><span class="sy0">;</span>
<span class="sy0">++</span>iter <span class="br0">)</span> <span class="br0">{</span>
<a href="http://www.opengroup.org/onlinepubs/009695399/functions/cout.html"><span class="kw3">cout</span></a> <span class="sy0"><<</span> <span class="sy0">*</span>iter <span class="sy0"><<</span> <span class="st0">' '</span><span class="sy0">;</span>
<span class="br0">}</span>
<a href="http://www.opengroup.org/onlinepubs/009695399/functions/cout.html"><span class="kw3">cout</span></a> <span class="sy0"><<</span> <span class="st0">'<span class="es1">\n</span>'</span><span class="sy0">;</span></pre>
<p>
When run, this code displays:
</p>
<pre class="code">
Unique digits are: 1 2 3 4 5 6 8 9</pre>
</div>
<!-- wikipage stop -->
</div>
<div class="clearer"> </div>
<div class="stylefoot">
<div class="meta">
<div class="user">
</div>
<!--
<div class="doc">
stl/set/set_constructors.txt · Last modified: 10/09/2009 08:15 by 124.255.102.233 </div>
-->
</div>
</div></div></body>
</html>