lamdba.cpp

#include <functional>
#include <string>
#include <vector>
#include <iostream>

using namespace std;

struct Runnable {
  virtual ~Runnable(){};
  virtual int operator()() = 0;
};

struct TaskContainer;

typedef function<void(TaskContainer&)> block_t;

struct It : public Runnable {
  string descr;
  function<int(It&)> body;
  int operator()() { 
    std::cout << "Called It::()" << std::endl;
    return body(*this); 
  }
  It(string descr, function<int(It&)> body) : descr(descr), body(body) {}
};

struct TaskContainer : public Runnable {
  vector <Runnable*> tasks;

  void it(string name, function<int(It&)> body) {
    std::cout << "Called TaskContainer::it" << std::endl;
    tasks.push_back(new It(name, body));
  };
  int operator()() { 
    std::cout << "Called TaskContainer::()" << std::endl;
    int result = 0; 
    for (Runnable *task : tasks) {
      result |= (*task)();
    }
    return result;
  }
};


class Description : public TaskContainer {
  string descr;
  block_t body;
 public:
  Description(string descr, block_t body) : descr(descr), body(body) {};
  int operator()(){
    body(*this);
    return TaskContainer::operator()();
  }
};

#define _desc [](TaskContainer &self)
#define _it [](It &self)
#define it self.it

typedef Description describe;

int main(void) {

  describe my_test("my test",  _desc{
      it("adds two numbers", _it{
         return 2 + 2 ;
        });
    });

  cout << my_test();

}