Lambda`s internal this in c++

If lambda function ic C++ is implemented by functor, why this is not possible?

#include <iostream>

class A
{
public: 
    int a;  
    void f1(){ [](){std::cout << this << std::endl ;}();};
};

int main()
{
    A a;
    a.f1();
}

I get error 9:34: error: 'this' was not captured for this lambda function. If I understand it right, if lambda is implemented as a functor class, why it is not possible to get it`s internal this?

EDIT: this of functor class, not this of instance of class A.