Question

I have a template class Delegate, with an overloaded += operator, that makes using delegates similar to C#.

// ... generalized version of the template omitted from code
template<typename... TArgs>
    class Delegate<void, TArgs...>
    {
        private:
            using Func = std::function<void(TArgs...)>;
            std::vector<Func> funcs;

        public:
            template<typename T> Delegate& operator+=(T mFunc) { funcs.push_back(Func(mFunc)); return *this; }
            void operator()(TArgs... mParams) { for (auto& f : funcs) f(mParams...); }
    };

This is what I’m trying to do:

struct s
{
    void test() { }
    void run()
    {
        Delegate<void> d;
        d += [] { /* do something */ ; };
        d += test; // does not compile
    }
};

Is there a way to allow d += test; to work?

Answer 1

void test(int x, int y) { return x - y; }

How can it compile? This function is supposed to return nothing. Its return type is void.

Also, I assume you have defined (or declared ) the primary template:

template<typename R, typename... TArgs>
class Delegate;

Also assuming that delegate is a typo, as the class template is Delegate.

Anyway, with test returning nothing, it compiles fine:

http://stacked-crooked.com/view?id=c56b7a2e758f8fbc361228834c90822b

---

As for member-function-pointers, your current implementation doesn’t support it. Note that a non-static member function pointer takes the form of R (C::*MemPtr)(Args...) cv. Just work on it.