seanmonstar

Accessors can reveal internal representation

As a library maintainer, it’s common to receive requests from users to add a “simple accessor”. The data is right there. But that accessor can end up revealing internal representation details that you can no longer change.

This is one reason why it could be a better practice to return an impl Iterator instead of &[T]. The latter freezes you in place to always storing the data in consecutive memory. (Such as String::as_bytes().)

View types might help too, like Ref<'_>. Returning a reference requires the data already exist in that shape in self. You can’t change its shape in the accessor and return a reference to that.