1 //===----------------------------------------------------------------------===// 2 // 3 // The LLVM Compiler Infrastructure 4 // 5 // This file is dual licensed under the MIT and the University of Illinois Open 6 // Source Licenses. See LICENSE.TXT for details. 7 // 8 //===----------------------------------------------------------------------===// 9 10 // <tuple> 11 12 // template <class... Types> class tuple; 13 14 // template <class... Types> 15 // class tuple_size<tuple<Types...>> 16 // : public integral_constant<size_t, sizeof...(Types)> { }; 17 18 // UNSUPPORTED: c++98, c++03 19 20 #include <tuple> 21 #include <array> 22 #include <type_traits> 23 24 struct Dummy1 {}; 25 struct Dummy2 {}; 26 struct Dummy3 {}; 27 28 template <> 29 class std::tuple_size<Dummy1> { 30 public: 31 static size_t value; 32 }; 33 34 template <> 35 class std::tuple_size<Dummy2> { 36 public: 37 static void value() {} 38 }; 39 40 template <> 41 class std::tuple_size<Dummy3> {}; 42 43 int main() 44 { 45 // Test that tuple_size<const T> is not incomplete when tuple_size<T>::value 46 // is well-formed but not a constant expression. 47 { 48 // expected-error@__tuple:* 1 {{is not a constant expression}} 49 (void)std::tuple_size<const Dummy1>::value; // expected-note {{here}} 50 } 51 // Test that tuple_size<const T> is not incomplete when tuple_size<T>::value 52 // is well-formed but not convertible to size_t. 53 { 54 // expected-error@__tuple:* 1 {{value of type 'void ()' is not implicitly convertible to}} 55 (void)std::tuple_size<const Dummy2>::value; // expected-note {{here}} 56 } 57 // Test that tuple_size<const T> generates an error when tuple_size<T> is 58 // complete but ::value isn't a constant expression convertible to size_t. 59 { 60 // expected-error@__tuple:* 1 {{no member named 'value'}} 61 (void)std::tuple_size<const Dummy3>::value; // expected-note {{here}} 62 } 63 } 64
