Why does a function have the word constant at the end even though it does change a variable
<p>My understanding of the keyword 'const' is that it says to the compiler, that the function will not modify any of the variables but in the following example it changes <code>b.d</code>. why?</p>

<pre><code>myClass operator + (myClass b) const { b.d += d; return b; }
</code></pre>
