C++: class wrapper using variadic templates

Question

I wanna make a wrapper for other class objs. When a wrapper obj is initialized, I want to be able to pass to its constructor the parameters I wanna pass to the inner obj:

template <class U, class... Args> struct T {
    T(Args... args) {
        data = new U(args...);
    }
    U* data;
};

I made a dummy Obj :

struct Obj {
    Obj(int a, int b) {
        this->a = a;
        this->b = b;
    }
    int a;
    int b;
};

Now rather than using Obj obj(1, 2) to initialize it, I wanna use the wrapper, as I would do some computing and management. So what I try to achieve is:

T<Obj> obj(1, 2); // doesn't work, this is what I want to achieve
T<Obj, int, int> obj(1, 2); // works, but it's not what I want it to look like

Answer 1

class... Args should be a template parameter of the constructor, not of the entire class. Also you should use perfect forwarding here, even though it doesn't matter for struct Obj .

template <class U>
struct T
{
    template <class ...Args>
    T(Args &&... args)
    {
        data = new U(std::forward<Args>(args)...);
    }
    U *data;
};