The point of const-correctness is to be able to provide a view of an instance that can\'t be altered or deleted by the user. The compiler supports this by pointing out when
Interfaces are the answer, and are actually more powerful than "const" in C++. const is a one-size-fits-all solution to the problem where "const" is defined as "doesn't set members or call something that sets members". That's a good shorthand for const-ness in many scenarios, but not all of them. For example, consider a function that calculates a value based on some members but also caches the results. In C++, that's considered non-const, although from the user's perspective it is essentially const.
Interfaces give you more flexibility in defining the specific subset of capabilities you want to provide from your class. Want const-ness? Just provide an interface with no mutating methods. Want to allow setting some things but not others? Provide an interface with just those methods.