43 lines · cpp
1// RUN: %clang_cc1 -std=c++2a -verify %s2 3namespace std_example {4 namespace std { template<typename T> T &&move(T &); }5 6 void g(...);7 8 template <class... Args> void f(Args... args) {9 auto lm = [&, args...] { return g(args...); };10 lm();11 12 auto lm2 = [... xs = std::move(args)] { return g(xs...); };13 lm2();14 }15}16 17template<typename ...T> constexpr int f(int k, T ...t) {18 auto a = [...v = t] (bool b) mutable {19 if (!b) {20 ((v += 1), ...);21 return (__SIZE_TYPE__)0;22 }23 return (v * ... * 1) + sizeof...(v);24 };25 for (int i = 0; i != k; ++i)26 a(false);27 return a(true);28}29 30static_assert(f(1, 2, 3, 4) == 3 * 4 * 5 + 3);31static_assert(f(5) == 1);32 33auto q = [...x = 0] {}; // expected-error {{does not contain any unexpanded parameter packs}}34 35template<typename ...T> constexpr int nested(T ...t) {36 return [...a = t] {37 return [a...] {38 return (a + ...);39 }();40 }();41}42static_assert(nested(1, 2, 3) == 6);43