1 // { dg-additional-options "-std=c++14 -Wno-return-type" }
3 template<typename Signature>
6 template<typename R, typename... Args>
10 virtual ~invoker_base() { }
13 template<typename F, typename R, typename... Args>
14 class functor_invoker : public invoker_base<R, Args...>
17 explicit functor_invoker(const F& f) : f(f) { }
22 template<typename R, typename... Args>
23 class function<R (Args...)> {
26 function(const F& f) : invoker(0) {
27 invoker = new functor_invoker<F, R, Args...>(f);
34 invoker_base<R, Args...>* invoker;
38 struct unique_ptr { };
41 template <class...> struct typelist {};
42 template <class... Cs> unique_ptr<A> chooseB(typelist<Cs...>);
43 template <class... Cs, class Idx, class... Rest>
44 unique_ptr<A> chooseB(typelist<Cs...> choices, Idx, Rest... rest) {
45 auto f = [=](auto) { return [=] { return chooseB(choices, rest...); }; };
46 function<unique_ptr<A>()> fs[]{f(Cs{})...};
48 main() { chooseB(typelist<double, char>{}, 0, 1, 2); }