When you apply the const
qualifier to a nonstatic member function, it affects the this
pointer. For a const-qualified member function of class C
, the this
pointer is of type C const*
, whereas for a member function that is not const-qualified, the this
pointer is of type C*
.
A static member function does not have a this
pointer (such a function is not called on a particular instance of a class), so const qualification of a static member function doesn’t make any sense.