Comment by benrazdev

Technically, with generics, you could get a Result that is almost as good as Rust, but it is unidiomatic and awkward to write:

    type Result[T, E any] struct {
        Val   T
        Err   E
        IsErr bool
    }

    type Payload string

    type ProgError struct {
        Prog   string
        Code   int
        Reason string
    }

    func DoStuff(x int) Result[Payload, ProgError] {
        if x > 8 {
            return Result[Payload, ProgError]{Err: ProgError{Prog: "ls", code: 1, "no directory"}}
        }
        return Result[Payload, ProgError]{Val: "hello"}
    }