alt Hacker NewsIt's not just arbitrary renaming (Rust Result vs C++ Expected is fine) -- it's choosing a conflicting name for an extremely common abstract data type. If they wanted to call it "Elephant," great, but Optional is a well-known concept and Result/Expected isn't the same thing.
(I don't really object to the idea of skipping a real Optional<T> type in a language in favor of just Result<T, ()>.)
I would guess the two languages have little overlap in who they appeal to, and this is a bit closer to C semantics which is their north star. In C for functions that don’t return a value you often return a null for success or a return code that is a defined error code, which is exactly how Optional works in C3 (but you don’t write the word Optional in the function head). If you need to return a value in C you often pass an out param pointer and then still return either null or a defined error value. The improvement is you just write ‘type?’ for the return type to enable this and you don’t need an out param, but you still need the define (faultdef).