PHP 8.0 Is Released

In Rust ? is the try/error propagation operator. It converts the error to the correct type, if necessary, and returns it.

  let ok = return_result()?;

and

  let ok = match return_result() {
      Ok(ok) => ok,
      Err(err) => return Err(err.into()),
  };

are equivalent

In TypeScript/Kotlin/C#/PHP and many more languages, ?./?[]/?-> is the null conditional operator. Rust doesn't have it in operator form (? works on Option<_> types as if they were a degenerate Result<_, ()> type). instead, you "flatmap" the Options with and_then() (if it's fallible) and map() if it's infallible. Or just use bare pattern matching.

  $country = $session?->user?->getAddress()?->country;

is

  let country = session
      .and_then(|session| session.user)
      .and_then(|user| user.get_address())
      .map(|address| address.country);

Not exactly Rust's, lots of languages have something similar...