#include <iostream>
#include <functional>

class Foo
{
  int x, y, z;
  std::function<void(void)> _func;

public:
  Foo(int a): x(a), y(0), z(0)  {}

  void bar()
  {
    int a = 1,b,c;
    _func = [=]()
    {
      int u = this->x + a;
      std::cout << u << std::endl;
    };
    
    _func(); // lambda call
  }
};

int main()
{
  Foo obj(1);
  obj.bar();
}