You couldn't or wouldn't. but why have a read statement like cin>> which looks so nice and clean when you then have to go and check everything with flags and boolean casts on stateful objects.

I agree. It's lunacy. just be explicit and use functions or equivalent like literally every other language.

Well in a language like Haskell you could solve this with monads and do-notation. The general idiom in Haskell is to use a Maybe or Either monad to capture success/failure and you assume you’re on the happy path. Then you put the error handling at the consumer end of the pipeline when you unwrap the Maybe or Either.

I believe Rust has adopted similar idioms. I’ve heard the overall idea referred to as Railway-oriented programming.

In C++ you could implement it with exceptions, though they bring in a bunch of their own baggage that you don’t have to deal with when using monads.