[boost] [outcome] expected vs. result

Niall, I am trying to summarize differences between `expected` and `result<T>`. So far, I have identified the following: 1. API/ABI stability guarantees. 2. `result` has empty state - `expected` does not. 3. `result` uses error_code_extended for more error details in the ring-buffer. 4. No ordering (operator<) for `result` Is the above list complete? Regards, &rzej;