C ++使用元组作为模板中的参数包

Question

I am using boost::callable_traits::args_t to get std::tuple of arguments types from method. Is it possible to use that tuple as parameter pack?

void doJob(int i) {
  std::cout << i << std::endl;
}
template<auto F>
void magic(boost::callable_traits::args_t<F> ...args) { // here is the magic
  F(args...)
}
magic<doJob>(1);

This is something I want to implement. I want to make this without using variadic templates.

Answer 1

If you can use C++17 you can use std::apply to call the function. std::apply takes a callable and a tuple and calls the callable with the unpacked tuple as the function arguments. That would make magic look like

template<auto F>
void magic(boost::callable_traits::args_t<F> args) { // here is the magic
  std::apply(F, args);
}