|Synopsis:||A member function that should not change the state of the object shall be declared const|
It is possible that a const method requires non-const access to some of the data members, without changing the objects state. For example, when a lock variable (i.e. critical section) is used to synchronize access to other data members. In this case, the lock variable should be made mutable. See also [CON#005].
|Ellemtel Rule 23|
|ISC++ Rule 7.11|