modify variable for both getter and setter
<p>The following property just begs for a value being calculated once for both getter and setter</p>

<p>So instead of:</p>

<pre><code>public bool this[int x, int y]
{
    get
    {
        return this[x * this.width + y];
    }
    set
    {
        this[x * this.width + y] = value;
    }
}
</code></pre>

<p>It be better if we could do this:</p>

<pre><code>public bool this[int x, int y]
{
    int index = x * this.width + y;

    get
    {
        return this[index];
    }
    set
    {
        this[index] = value;
    }
}
</code></pre>

<p>In this case it's not such a big deal and an inline method could be used. But as a principle, is there a way?</p>
