src/librustdoc/html/templates/sidebar.html

{% if !title.is_empty() %}
    <h2 class="location"> {# #}
        <a href="#">{{title_prefix}}{{title}}</a> {# #}
    </h2>
{% endif %}
<div class="sidebar-elems">
    {% if is_crate %}
        <ul class="block">
            <li><a id="all-types" href="all.html">All Items</a></li> {# #}
        </ul>
    {% endif %}

    {% if self.should_render_blocks() %}
        <section>
            {% for block in blocks %}
                {% if block.should_render() %}
                    {% if !block.heading.name.is_empty() %}
                        <h3><a href="#{{block.heading.href|safe}}">{{block.heading.name}}</a></h3>
                    {% endif %}
                    {% if !block.links.is_empty() %}
                        <ul class="block{% if !block.class.is_empty() +%} {{+block.class}}{% endif %}">
                            {% for link in block.links %}
                                <li><a href="#{{link.href|safe}}">{{link.name}}</a></li>
                            {% endfor %}
                        </ul>
                    {% endif %}
                {% endif %}
            {% endfor %}
        </section>
    {% endif %}
    {% if !path.is_empty() %}
        <h2><a href="{% if is_mod %}../{% endif %}index.html">In {{+ path}}</a></h2>
    {% endif %}
</div>