ions">Core constant expression</a>. The macro is necessary to avoid the duplication of the provided expression and currently expands to ~ <code>detail::copy_from_unsized&lt;detail::strlen(CString)&gt;(CString)</code>. (another thanks to <a href="https://github.com/Siapran">Siapran</a> for contributing the implementation for the <code>constexpr length()</code> function.)</li>
</ul>
<h2><a class="anchor" id="autotoc_md13"></a>
v0.7.0</h2>
<ul>
<li>Added <code>constexpr const_string::substr&lt;Pos, [Count]&gt;