へ代入できない
}</span><pre class='rust rust-example-rendered'>
<span class='kw'>struct</span> <span class='ident'>Point</span> {
    <span class='ident'>x</span>: <span class='ident'>i32</span>,
    <span class='ident'>y</span>: <span class='ident'>i32</span>,
}

<span class='kw'>let</span> <span class='kw-2'>mut</span> <span class='ident'>a</span> <span class='op'>=</span> <span class='ident'>Point</span> { <span class='ident'>x</span>: <span class='number'>5</span>, <span class='ident'>y</span>: <