You personally don&#x27;t have to write the macro: cargo makes it super easy to use ones others have written, e.g. <a href="https:&#x2F;&#x2F;crates.io&#x2F;crates&#x2F;maplit&#x2F;" rel="nofollow">https:&#x2F;&#x2F;crates.io&#x2F;crates&#x2F;maplit&#x2F;</a>.