It's true that a "checked_as" would come handy from time to time and seems to be in line with the "Rust spirit". But again, since the author seems to be arguing

It's true that a "checked_as" would come handy from time to time and seems to be in line with the "Rust spirit". But again, since the author seems to be arguing in favor of C it seems like an odd complaint. C even makes it tricky to check for integer overflow while Rust has the checked_ family of functions. In C if you get it wrong it's undefined behavior territory baby. Ditto with the tuple thing, C doesn't have tuples and won't let you destructure anything. I guess my overall point is that these complaints seems to pit Rust against some other high level languages like Common Lisp or Haskell but his conclusion is basically "C rulez, Rust droolz".