What is the use of mutable key word?
This keyword can only be applied to non-static and non- const data members of a class. If a data member is declared mutable, then it is legal to assign a value to this data member from a const member function. if u write a class do u write Assignment operator and copy constructor Compiler provide the assignment operator/ copy constructor by default. The assignment operator and copy constructor do the bit wise copy of the object. If user want to do the member wise copy(ex:allocating the memory from the heap) for the members, one can write his/her own assignment operator/ copy constructor.
