C++ How to make function pointer to class method

Question

I\'m having trouble making a function pointer to a class method. I made a function pointer to a non-class method and it works fine.

int foo(){
    return 5;
         


        

Answer 1

Just found out you can do

#include 
#include 

using namespace std;

struct Foo {
   int x;
   int foo() { return x; }
};

int main() {
  function f = &Foo::foo;
  Foo foo = { 3 };
  assert(f(foo) == 3);
  foo.x = 5;
  assert(f(foo) == 5);
}

std::mem_fn() might work too: https://en.cppreference.com/w/cpp/utility/functional/mem_fn