title: Why doesn't c = a+++++b work in C?
body: <blockquote>
    <p><strong>Possible Duplicate:</strong><br>
    <a href="https://stackoverflow.com/questions/5341202/please-help-me-understanding-the-error-ab-in-c">Please help me understanding the error a+++++b in C</a>  </p>
  </blockquote>
  
  
  
  <p>In a discussion today the topic of pre/post increment came up.</p>
  
  <p>We tried several combinations of addition and increment:</p>
  
  <pre><code>c = a+++b //works
  c = a++ + ++b //works
  c = a+++ ++b //works
  c = a+++++b // doesn't work, compiler error "error: invalid lvalue in increment
  </code></pre>
  
  <p>Where is the difference? What exactly does that additional whitespace add for the parser so the program compiles?</p>