Pass multiple arguments to stream operator

I have a class, let's call it Sample with variadic template arguments. This class contains a function run(Args... args). This class also implements a stream operator that calls this function.

The class looks like this:

template<typename ...Args>
class Sample
{
    void run(Args... args)
    {
        // do something
    }

    Sample& operator<<(const tuple<Args...>& args)
    {
        run(unpack_somehow(args)...);
        return *this;
    }
};

Now I want to use the stream operator to concat multiple calls, by passing the arguments via the brace initialization of tuples:

void main()
{
    Sample<int, string, int> s;

    // doesn't work :(
    s << {1, "msg", 2} << {1, "msg", 2};
}

I know I could just write make_tuple(1, "msg", 2) and it would work, but I'm looking for a solution that doesn't need additional function calls like make_tuple.

Is there a way to implement such a feature that I can pass the arguments in braces (or maybe by comma separation by overloading the comma operator)?

When you use the line s << {1, "msg", 2} << {1, "msg", 2}; it does not provide the C++ compiler with enough information to deduce what you mean by those initializer lists.

Unless you give a hint to compiler (use a make_tuple or pass an actual tuple variable) it won't know what you mean and won't be able to call the appropriate operator<<().

Looks like you are out of luck. This cannot be done in the way your question is posted.