Hey, I&#x27;m not the one claiming that Rust solves the expression problem. :)<p><pre><code>  &gt; where it provides stronger abstractions, their cost may 
  &gt; be higher than in other languages
</code></pre>
What is this referring to? I can&#x27;t think of anything in Rust that matches this description, unless you&#x27;re referring to something like e.g. devirtualization via JIT compilation. Rust&#x27;s abstractions are actually supremely impressive IMO; just yesterday I was marvelling at how `(0..x).fold(0, |sum, i| sum + i)` (which involves an external iterator, a generic function, and a closure) gets compiled down to the closed-form `((x - 1) * (x - 2) &#x2F; 2) + x - 1` (which admittedly slightly misses Gauss&#x27; famous `(x * (x + 1)) &#x2F; 2`, but that might just be nitpicking :P ).