I’m trying to forward an r-value reference from a template class Foo to another template class Bar as follows:

#include <iostream>
#include <string>
#include <type_traits>
#include <utility>

template <typename... Ts>
struct Bar {
   void do_something(Ts... things) {
      std::cout << "Got " << sizeof...(Ts) << " things" << std::endl;
   }
};

template <typename... Ts>
struct Foo {
   void do_something(Ts... things) {
      m_bar.do_something(things...);
   }

   Bar<Ts...> m_bar;
};

int main(int argc, char** argv) {
   Foo<std::string&, std::string&&> foo;

   std::string hello1("Hello");
   std::string hello2("Howdy");

   foo.do_something(hello1, std::move(hello2));
   return 0;
}

However, when we get to Foo::do_something, the 2nd argument needs to be moved again. I can’t use std::move here because that would also move the 1st argument, for example:

m_bar.do_something(std::move(things)...);

So, is there a way to move only the 2nd argument?