an <code class="docutils literal notranslate"><span class="pre">&lt;output_variable&gt;</span></code> a given string's length in bytes.
Note that this means if <code class="docutils literal notranslate"><span class="pre">&lt;string&gt;</span></code> contains multi-byte characters, the
result stored in <code class="docutils literal notranslate"><span class="pre">&lt;output_variable&gt;</span></code> will <em>not</em> be the number of characters.</p>
<div class="highlight-cmake notranslate" id="substring"><di