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<div class="sect1" title="Constness">
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<a name="sec-refptr-constness"></a>Constness</h2></div></div></div>
<p>
The use of the <code class="literal">const</code> keyword in C++ is not always clear. You
might not realise that <span class="type">const Something*</span> declares a pointer to a
<span class="type">const Something</span>, The pointer can be changed, but not the
<span class="type">Something</span> that it points to.
</p>
<p>
Therefore, the <code class="classname">RefPtr</code> equivalent of
<span class="type">Something*</span> for a method parameter is <span class="type">const
Glib::RefPtr<Something>&</span>, and the equivalent of
<span class="type">const Something*</span> is <span class="type">const Glib::RefPtr<const
Something>&</span>.
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<p>
The <code class="literal">const ... &</code> around both is just for efficiency, like
using <code class="classname">const std::string&</code> instead of
<code class="classname">std::string</code> for a method parameter to avoid unnecessary
copying.
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