Adding const objects
<p>I have a custom class. Let's call it apple. I overload the addition operator as so:</p>

<pre><code>apple apple::operator+(const apple &amp; other)
{
    return apple
    (
        this-&gt;x + other.x,
        this-&gt;y + other.y,
        this-&gt;z + other.z
    );
}
</code></pre>

<p>and it works great... until i try adding two const apples.</p>

<pre><code>const apple apple1;
const apple apple2;

auto apple3 = apple1 + apple2;
</code></pre>

<p>gives me an error 'no operator "+" matches these operands
            operand types are: const apple  + const apple'</p>

<p>Is there some trick to adding const objects?</p>
