Use case:
class A {
static int s_common;
public:
static int getCommon () const { s_common; };
};
Typically this results in an error as:
cv-qualifiers affect the function's signature. So you could have:
class A {
static int s_common;
public:
static void getCommon () const { };
static void getCommon () { };
};
Now... how would you call the const one? There's no const object to call it on (well, you could call it on a const object, but that's not the point).
I'm just guessing here, there probably are other reasons. :)