rust/src/librustdoc/html/templates/type_layout_size.html

{% if is_unsized %}
  (unsized)
{% else %}
  {% if size == 1 %}
    1 byte
  {% else %}
    {{ size +}} bytes
  {% endif %}
  {% if is_uninhabited %}
    {# +#} (<a href="https://doc.rust-lang.org/stable/reference/glossary.html#uninhabited">uninhabited</a>)
  {% endif %}
{% endif %}