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131
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1 // { dg-additional-options "-std=c++14 -Wno-return-type" }
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2
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3 template<typename Signature>
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4 class function;
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5
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6 template<typename R, typename... Args>
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7 class invoker_base
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8 {
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9 public:
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10 virtual ~invoker_base() { }
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11 };
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12
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13 template<typename F, typename R, typename... Args>
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14 class functor_invoker : public invoker_base<R, Args...>
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15 {
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16 public:
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17 explicit functor_invoker(const F& f) : f(f) { }
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18 private:
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19 F f;
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20 };
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21
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22 template<typename R, typename... Args>
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23 class function<R (Args...)> {
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24 public:
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25 template<typename F>
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26 function(const F& f) : invoker(0) {
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27 invoker = new functor_invoker<F, R, Args...>(f);
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28 }
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29 ~function() {
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30 if (invoker)
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31 delete invoker;
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32 }
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33 private:
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34 invoker_base<R, Args...>* invoker;
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35 };
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36
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37 template<typename>
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38 struct unique_ptr { };
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39
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40 struct A {};
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41 template <class...> struct typelist {};
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42 template <class... Cs> unique_ptr<A> chooseB(typelist<Cs...>);
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43 template <class... Cs, class Idx, class... Rest>
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44 unique_ptr<A> chooseB(typelist<Cs...> choices, Idx, Rest... rest) {
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45 auto f = [=](auto) { return [=] { return chooseB(choices, rest...); }; };
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46 function<unique_ptr<A>()> fs[]{f(Cs{})...};
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47 }
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48 main() { chooseB(typelist<double, char>{}, 0, 1, 2); }
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