amp;Foo = &amp;a;</span>
<span class='kw'>let</span> <span class='ident'>b</span> <span class='op'>=</span> <span class='ident'>TraitObject</span> {
    <span class='comment'>// データを保存</span>
    <span class='ident'>data</span>: <span class='kw-2'>&amp;</span><span class='ident'>a</span>,
    <span class='comment'>// メソッドを保存</span>
    <span class='ident'>vtable</span>: <span class='kw-2'>&amp;</span><span class='ident'>Foo_for_String_vtable</span>
};

<span class='comment'>// let 