title: Performance differences between debug and release builds
body: <p>I must admit, that usually I haven't bothered switching between the <em>Debug</em> and <em>Release</em> configurations in my program, and I have usually opted to go for the <em>Debug</em> configuration, even when the programs are actually deployed at the customers place.</p>
  
  <p>As far as I know, the only difference between these configurations if you don't change it manually is that <em>Debug</em> have the <strong><code>DEBUG</code></strong> constant defined, and <em>Release</em> have the <em>Optimize code</em> checked of.</p>
  
  <p>So my questions is actually twofold:</p>
  
  <ol>
  <li><p>Are there much performance differences between these two configurations. Are there any specific type of code that will cause big differences in performance here, or is it actually not that important?</p></li>
  <li><p>Are there any type of code that will run fine under the <em>Debug</em> configuration that might fail under <em>Release</em> configuration, or can you be certain that code that is tested and working fine under the <em>Debug</em> configuration will also work fine under Release configuration.</p></li>
  </ol>