Comment by realharo
2 days ago
The type of the value in C is `char*`.
That's what led some people to write code where it crashes without checks. Which is still their mistake. But if the type was something that can't be implicitly used like an always-present value, that would have prevented the situation, even with those same people.
A pointer is a type where a null pointer can't be used as a regular value but leads to a trap when dereferenced.
By "can't be used as a regular value", I meant that it would be a compile-time error. That you have to explicitly opt into skipping the check, e.g. with `unwrap` in Rust, or with something like `!` in languages where `string` and `string?` are different types (like TypeScript, Kotlin, Swift, C#, etc.)
Trying to change a function return type from e.g. `string` to `string?` would make the backwards-incompatible breaking change immediately visible, and break the builds of all code that relied on not having to check it back when it was `string` - at compile time.
I see. For safety a run-time check is enough though.
But it turns out one can have a compile-time error forthis in C as well: https://godbolt.org/z/8E9z66cfs