span><span class="special">,</span> <span class="identifier">msg</span><span class="special">)</span>
</pre>
<p>
      Both generate a compile time error message if the integral-constant-expression
      <code class="computeroutput"><span class="identifier">x</span></code> is not true. In other words,
      they are the compile time equivalent of the assert macro; this is sometimes
      known as a "compile-time-assertion", but will be called a "static
      assertion" throughout these docs. Note that if th