mutable

int m=9;

struct C{
    int f() const{
        return ++e;
    }
private:
      mutable  int e;
    static int d;
};

int C::d = 2;

int main(int argc, char *argv[])
{
    int c = 4;
    std::cout<<&c<<'\n';
    auto e= [=]() mutable {
        std::cout<<&c<<'\n';
        std::cout<<c;

    };
    e();
    return 0;
}