span class="ident">serial</span>::<span class="ident">Write</span>;

<span class="kw">let</span> <span class="kw-2">mut</span> <span class="ident">serial</span>: <span class="ident">Serial1</span> <span class="op">=</span> {
    <span class="comment">// ..</span>
};

<span class="kw">for</span> <span class="ident">byte</span> <span class="kw">in</span> <span class="string">b&quot;Hello, world!&quot;</span> {
    <span class="comment">// NOTE `block!` blocks until `serial.write()` completes and returns</span