std::tuple 遍历 传递到函数参数

#include 
#include 

struct Dr
{
    int a;
};
struct Mg
{
    int b;
};

struct Msg
{
    Dr dr;
    Mg mg;
};

class MsgBuilder
{
public:
Msg addData(const Dr& dr)
{
    std::cout << "Dr" << std::endl;
    msg.dr = dr;
    return msg;
}

Msg addData(const Mg& mg)
{
    std::cout << "Mg" << std::endl;
    msg.mg = mg;
    return msg;
}

    Msg msg;
};

int main()
{
    Dr dr{10};
    Mg mg{20};
    
    MsgBuilder builder;

    std::apply([&builder](auto&&... args) { (builder.addData(args), ...); }, std::make_tuple(dr, mg));
    
    std::cout << builder.msg.dr.a << ", " << builder.msg.mg.b << std::endl;
    
    return 0;
}