[rowanG077]

These are not runtime errors. But regardless I rather like a runtime error instead of doing the wrong thing.

[colejohnson66]

Why would you prefer a runtime error over just not making the mistake in the first place?

[rowanG077]

Because I don't like having bombs in my software waiting to explode when you touch it. That's essentially what mutable by default is.

[colejohnson66]

Well then we’re on the same page: default immutability is better. You’re wording three comments up seemed to say you prefer default mutability