title: Why does C++ accept multiple prefixes but not postfixes for a variable
body: <p>While looking into <a href="https://stackoverflow.com/questions/11679258/can-you-have-a-incrementor-and-a-decrementor-on-the-same-variable-in-the-same-st#comment15483521_11679258">Can you have a incrementor and a decrementor on the same variable in the same statement in c</a></p>
  
  <p>I  discovered that you can have several prefix increment/decrement operators on a single variable, but only one postfix</p>
  
  <p>ex:</p>
  
  <pre><code>++--++foo; // valid
  foo++--++; // invalid
  --foo++;   // invalid
  </code></pre>
  
  <p>Why is this?</p>