title: c/c++ using else instead of if not
body: <p>Encountered a bit of weird-looking code and it got me wondering if there's any practical application to it, or if it's just a random oddity.</p>
  
  <p>The code essentially looks like this:</p>
  
  <pre><code>#ifdef PREPROCESSOR_CONDITION
      if (runtime_condition) {
      } else
  #endif
      {
          //expression
      }
  </code></pre>
  
  <p>I included the macro bit, though I doubt it has any bearing. There's no code that runs when runtime_condition is true, only the else block. I figure this ought to be completely identical to using if(!runtime_condition) and no else block (which would have been more straightforward), but maybe there's some kind of compiler-optimizey thing happening? </p>
  
  <p>Or, you know, it could be that there used to be something in the if block that got deleted and nobody bothered to change the expression.</p>