Fehlerbehandlung

CXX's support for Result<T,E> relies on C++ exceptions, so we can't use that in Chromium. Alternatives:

  • The T part of Result<T, E> can be:

    • Returned via out parameters (e.g. via &mut T). This requires that T can be passed across the FFI boundary - for example T has to be:
      • A primitive type (like u32 or usize)
      • A type natively supported by cxx (like UniquePtr<T>) that has a suitable default value to use in a failure case (unlike Box<T>).
    • Retained on the Rust side, and exposed via reference. This may be needed when T is a Rust type, which cannot be passed across the FFI boundary, and cannot be stored in UniquePtr<T>.
  • The E part of Result<T, E> can be:

    • Returned as a boolean (e.g. true representing success, and false representing failure)
    • Preserving error details is in theory possible, but so far hasn't been needed in practice.