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    const_cast    [C++ Reference]
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<h2><a name="const_cast" id="const_cast">const_cast</a></h2>
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<p>
Syntax:
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<pre class="c code c++" style="font-family:monospace;">    TYPE const_cast<span class="sy0">&lt;</span>TYPE<span class="sy0">&gt;</span> <span class="br0">&#40;</span>object<span class="br0">&#41;</span><span class="sy0">;</span></pre>
<p>
The const_cast keyword can be used to remove the <a href="../keywords/const.html" class="wikilink1" title="keywords:const">const</a> or <a href="../keywords/volatile.html" class="wikilink1" title="keywords:volatile">volatile</a> property from an object.  The target data type must be the same as the source type, except (of course) that the target type doesn&#039;t have to have the same const qualifier.  The type TYPE must be a pointer or reference type.
</p>

<p>
For example, the following code uses const_cast to remove the <a href="../keywords/const.html" class="wikilink1" title="keywords:const">const</a> qualifier from a object:
</p>
<pre class="c code c++" style="font-family:monospace;">class Foo <span class="br0">&#123;</span>
public<span class="sy0">:</span>
  <span class="kw4">void</span> func<span class="br0">&#40;</span><span class="br0">&#41;</span> <span class="br0">&#123;</span><span class="br0">&#125;</span> <span class="co1">// a non-const member function</span>
<span class="br0">&#125;</span><span class="sy0">;</span>
&nbsp;
<span class="kw4">void</span> someFunction<span class="br0">&#40;</span> <span class="kw4">const</span> Foo<span class="sy0">&amp;</span> f <span class="br0">&#41;</span>  <span class="br0">&#123;</span>
  f.<span class="me1">func</span><span class="br0">&#40;</span><span class="br0">&#41;</span><span class="sy0">;</span>      <span class="co1">// compile error: cannot call a non-const</span>
                 <span class="co1">// function on a const reference</span>
  Foo <span class="sy0">&amp;</span>fRef <span class="sy0">=</span> const_cast<span class="sy0">&lt;</span>Foo<span class="sy0">&amp;&gt;</span><span class="br0">&#40;</span>f<span class="br0">&#41;</span><span class="sy0">;</span>
  fRef.<span class="me1">func</span><span class="br0">&#40;</span><span class="br0">&#41;</span><span class="sy0">;</span>   <span class="co1">// okay</span>
<span class="br0">&#125;</span></pre>
<p>
Related Topics: <a href="../keywords/const.html" class="wikilink1" title="keywords:const">const</a>, <a href="../keywords/dynamic_cast.html" class="wikilink1" title="keywords:dynamic_cast">dynamic_cast</a>, <a href="../keywords/reinterpret_cast.html" class="wikilink1" title="keywords:reinterpret_cast">reinterpret_cast</a>, <a href="../keywords/static_cast.html" class="wikilink1" title="keywords:static_cast">static_cast</a>, <a href="../keywords/casting_comparison.html" class="wikilink1" title="keywords:casting_comparison">A comparison of the C++ casting operators</a>
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