[thedracle]

> when exceptions would add no overhead

Isn't the overhead for C++ exceptions quite significant, especially if an exception is thrown?

Exception handling can also increase the size of the binary because of the additional data needed to handle stack unwinding and exception dispatch.

I think a number of optimizations are made quite a bit more complex by exception handling as well.

[tialaramex]

The argument for the Exception price is that we told you Exceptions were for Exceptional situations. This argument feels reasonable until you see it in context as a library author.

Suppose I'm writing a Clown Redemption library. It's possible to Dingle a Clown during redemption, but if the Clown has already dingled that's a problem so... should I raise an exception? Alice thinks obviously I should raise an exception for that, she uses a lot of Clowns, the Clown Redemption library helps her deliver high quality Clown software and it's very fast, she has never dingled a Clown and she never plans to, the use of exceptions suits Alice well because she can completely ignore the problem.

Unfortunately Bob's software handles primarily dingling Clowns, for Bob it's unacceptable to eat an exception every single damn time one of the Clowns has already been dingled, he demands an API in which there's just a return value from the dingling function which tells you if this clown was already dingled, so he can handle that appropriately - an exception is not OK because it's expensive.

Alice and Bob disagree about how "exceptional" the situation is, and I'm caught in the middle, but I have to choose whether to use exceptions. I can't possibly win here.

[alphanullmeric]

Like I said, this argument doesn’t work because you can use options in c++ but you can’t use exceptions in rust. So when there’s an occasion where you want to avoid the overhead of an option or result in rust - well too bad.

[dureuill]

Yes you can. They're called panics

[kllrnohj]

Exceptions cost performance when thrown whereas return values always cost performance.

If all you care about is outright performance, having the option for exceptions is easily the superior choice. The binary does get bigger but those are cold pages so who cares (since exceptions are exceptional, right?)