> An obvious case is when using optional as a global.
Well, ok, although I think we were doing fine storing such values in unique_ptr. Now you're going to come back and say that you can't ever afford a double indirection when accessing globals, and if so, fine. But you still could have very easily written your own wrapper that suits your needs without demanding that std::optional be relaxed to the point where it cannot provide compile-time safety guarantees.
> Other cases are when you’ve checked the optional once at the top of a basic block to be used multiple times after.
Disagree. The way optional types are supposed to work (and the way I have used them in real code) is that you check it once, and in doing so, you obtain a reference to the stored value (assuming it the check passes). Further accesses to the value thus do not require checks. The type system is thus used to model whether the check has been done or not, and helps you write code that does the minimal number of checks required.
You seem to think everyone else in this thread is an idiot, but I promise you I have written real code with very strict optional types (similar to kj::Maybe) without introducing unnecessary branches.
Well, ok, although I think we were doing fine storing such values in unique_ptr. Now you're going to come back and say that you can't ever afford a double indirection when accessing globals, and if so, fine. But you still could have very easily written your own wrapper that suits your needs without demanding that std::optional be relaxed to the point where it cannot provide compile-time safety guarantees.
> Other cases are when you’ve checked the optional once at the top of a basic block to be used multiple times after.
Disagree. The way optional types are supposed to work (and the way I have used them in real code) is that you check it once, and in doing so, you obtain a reference to the stored value (assuming it the check passes). Further accesses to the value thus do not require checks. The type system is thus used to model whether the check has been done or not, and helps you write code that does the minimal number of checks required.
You seem to think everyone else in this thread is an idiot, but I promise you I have written real code with very strict optional types (similar to kj::Maybe) without introducing unnecessary branches.