CODEWITHSUNDEEP
c++
user103214
user103214

Reputation: 3668

Pointers to static members of class

From this reference:

(8.3.3/3) A pointer to member shall not point to a static member of a class (9.4), a member with reference type, or "cv void."

Why a pointer cannot point to a static member of a class?

struct S {
     static int f() { /*...*/ };

};

int main()
{
     int (S::*s)() = &S::f; // why?
}

Upvotes: 1

Views: 195

Answers (3)

Vlad
Vlad

Reputation: 18633

You'd have to use a regular function pointer, like so:

int (*s)()=&S::f;

Like GMan said, static methods don't work on instances, so they don't receive the hidden this pointer. This effectively makes them have a different signature from instance methods with the same arguments.

Upvotes: 0

Konrad Rudolph
Konrad Rudolph

Reputation: 546153

Why a pointer cannot point to a static member of a class?

Because for the purpose of membership it isn’t a member, merely for the purpose of scope. Apart from scope, static members are just like free functions, unattached to an instance of a class. You can use non-member function pointers:

int (*s)() = &S::f;

Upvotes: 4

GManNickG
GManNickG

Reputation: 504313

Whenever you do T::*, you're saying "this thing requires an instance of T to use." That statement does not hold for static functions, which are callable without any instances of the class.

Upvotes: 1

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