Here&#x27;s a concrete data point in rust 1.5.0 to critique:<p><pre><code>  $ grep &#x27;unsafe {&#x27; src&#x2F;lib* -r |wc -l
  1529
</code></pre>
I&#x27;m skipping src&#x2F;test and src&#x2F;doc and a few other things, so this is likely a mild under-estimate on that front.<p>Docstrings seem to always require a comment leader, so let&#x27;s ignore any lines where the first non-whitespace characters are not &#x27;&#x2F;&#x2F;&#x27;.<p><pre><code>  $ grep &#x27;unsafe {&#x27; src&#x2F;lib* -rh |grep -v &quot;^\s*&#x2F;&#x2F;&quot; |wc -l
  1480
</code></pre>
Inline tests are created using &#x27;mod test&#x27;, so let&#x27;s look:<p><pre><code>  $ grep &#x27;mod test {&#x27; src&#x2F;lib* -rl |wc -l
  6
  $ grep &#x27;unsafe {&#x27; `grep &#x27;mod test {&#x27; src&#x2F;lib* -rl` |wc -l
  13
</code></pre>
So of 1.5k occurrences, 13 lie in modules with inline tests. Let&#x27;s conservatively ignore them all.<p>Final count of non-docstring non-test occurrences of &#x27;unsafe {&#x27; in the 1.5.0 sources: 1463.