How to use source_location in a variadic template function?

source_location.cpp

#include <iostream>
#include <utility>
#include <experimental/source_location>

/*
The C++20 feature std::source_location is used to capture information about the context in which a function is called. 
*/
template <typename... Ts>
struct debug
{    
    debug(Ts&&... ts, const std::experimental::source_location& loc = std::experimental::source_location::current())
    {
        std::cout << loc.function_name() << " line " << loc.line() << ": ";
        ((std::cout << std::forward<Ts>(ts) << " "), ...);
        std::cout << std::endl;
    }
};

template <typename... Ts>
debug(Ts&&...) -> debug<Ts...>;

int main()
{
    debug(5, 'A', 3.14f, "foo");
    debug("bar", 123, 2.72);
}