extended lambda

gistfile1.cpp

enum class lambda_state {DELETE,EXECUTE,PAUSED,DIRECT,ASYNC};

template<typename T> class method;
template <typename Res, typename... Args> class method<Res(Args...)> 
{
public:    
    using F = std::function<Res(Args...)>;                  // functor
    using R = typename std::result_of<F(Args...)>::type;    // result type   
    using L = std::function<void(R)>;                       // result lambda

    method() : 
        func([](...){})
    {}
    method(const F &f, lambda_state s = lambda_state::DIRECT) : 
        func(f),
        state(s)
    {}
    
    template<typename ... A> R operator() (A && ... args) {return func(args ...);}    
    template<typename ... A> void operator() (A && ... args, const L & lambda) 
    {
        state = lambda_state::EXECUTE;
        resLambda = lambda;
    }
    void remove()  {state = lambda_state::DELETE;}
    void pause()   {state = lambda_state::PAUSED;}
    void unpause() {state = lambda_state::DIRECT;}
    
  private:
    lambda_state state ;
    F func      {};
    R result    {};
    L resLambda {};
};