">chunk_extensions</span><span class="special">::</span><span class="identifier">parse</span></code></a> to parse the extensions
                  into a structured container for easier access. The implementation
                  type-erases the callback without requiring a dynamic allocation.
                  For this reason, the callback object is passed by a non-constant
                  reference.
                </p>
                <p>
                  The function object will be called with this 