c++ - Constant Member Functions

Question

After reading this, it is my understanding that declaring a method as const prevents it from accidentally modifying the class's member variables.

• Are const methods commonly used?
• Should they be used for everything that shouldn't modify member variables?

Answer 1

Yes, const should always be used, when appropriate.

It lets your compiler check your application logic, statically asserting const-correctness for free!

Some people even say that const should be the default, and you should be forced to use mutable for what is non-constant.