 will return an error because the channel has already</span>
<span class='comment'>// hung up (or been deallocated)</span>
<span class='kw'>let</span> (<span class='ident'>tx</span>, <span class='ident'>rx</span>) <span class='op'>=</span> <span class='ident'>channel</span>::<span class='op'>&lt;</span><span class='ident'>i32</span><span class='op'>&gt;</span>();
<span class='ident'>drop</span>(<span class='ident'>tx</span>);
<span class='macro'>assert</span><span class='macro'>!</span>(<span class='ident'>