| 1 | //===----------------------------------------------------------------------===// |
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| 2 | // |
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| 3 | // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
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| 4 | // See https://llvm.org/LICENSE.txt for license information. |
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| 5 | // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
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| 6 | // |
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| 7 | //===----------------------------------------------------------------------===// |
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| 8 | |
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| 9 | // <tuple> |
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| 10 | |
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| 11 | // template <class... Types> class tuple; |
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| 12 | |
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| 13 | // template <class... Types> |
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| 14 | // struct tuple_size<tuple<Types...>> |
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| 15 | // : public integral_constant<size_t, sizeof...(Types)> { }; |
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| 16 | |
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| 17 | // UNSUPPORTED: c++03 |
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| 18 | |
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| 19 | #include <tuple> |
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| 20 | #include <array> |
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| 21 | #include <type_traits> |
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| 22 | |
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| 23 | struct Dummy1 {}; |
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| 24 | struct Dummy2 {}; |
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| 25 | struct Dummy3 {}; |
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| 26 | |
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| 27 | template <> |
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| 28 | struct std::tuple_size<Dummy1> { |
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| 29 | public: |
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| 30 | static std::size_t value; |
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| 31 | }; |
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| 32 | |
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| 33 | template <> |
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| 34 | struct std::tuple_size<Dummy2> { |
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| 35 | public: |
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| 36 | static void value() {} |
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| 37 | }; |
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| 38 | |
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| 39 | template <> |
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| 40 | struct std::tuple_size<Dummy3> {}; |
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| 41 | |
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| 42 | void f() { |
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| 43 | // Test that tuple_size<const T> is not incomplete when tuple_size<T>::value |
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| 44 | // is well-formed but not a constant expression. |
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| 45 | { |
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| 46 | // expected-error@*:* 1 {{is not a constant expression}} |
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| 47 | (void)std::tuple_size<const Dummy1>::value; // expected-note {{here}} |
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| 48 | } |
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| 49 | // Test that tuple_size<const T> is not incomplete when tuple_size<T>::value |
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| 50 | // is well-formed but not convertible to size_t. |
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| 51 | { |
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| 52 | // expected-error@*:* 1 {{value of type 'void ()' is not implicitly convertible to}} |
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| 53 | (void)std::tuple_size<const Dummy2>::value; // expected-note {{here}} |
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| 54 | } |
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| 55 | // Test that tuple_size<const T> generates an error when tuple_size<T> is |
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| 56 | // complete but ::value isn't a constant expression convertible to size_t. |
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| 57 | { |
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| 58 | // expected-error@*:* 1 {{no member named 'value'}} |
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| 59 | (void)std::tuple_size<const Dummy3>::value; // expected-note {{here}} |
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| 60 | } |
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| 61 | } |
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| 62 | |
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