forked from OSchip/llvm-project
142 lines
2.6 KiB
C++
142 lines
2.6 KiB
C++
// RUN: %clang_cc1 -fsyntax-only -std=c++20 -verify %s
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// expected-no-diagnostics
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template <typename, typename>
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constexpr bool is_same = false;
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template <typename T>
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constexpr bool is_same<T, T> = true;
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struct S {
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int i;
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int &j;
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};
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void check_category() {
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int a = 42;
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{
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auto [v, r] = S{1, a};
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(void)[ v, r ] {
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static_assert(is_same<decltype(v), int>);
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static_assert(is_same<decltype(r), int &>);
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};
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}
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{
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auto [v, r] = S{1, a};
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(void)[&v, &r ] {
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static_assert(is_same<decltype(v), int>);
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static_assert(is_same<decltype(r), int &>);
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};
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}
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{
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S s{1, a};
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const auto &[v, r] = s;
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(void)[ v, r ] {
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static_assert(is_same<decltype(v), const int>);
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static_assert(is_same<decltype(r), int &>);
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};
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}
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{
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S s{1, a};
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const auto &[v, r] = s;
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(void)[&v, &r ] {
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static_assert(is_same<decltype(v), const int>);
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static_assert(is_same<decltype(r), int &>);
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};
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}
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}
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void check_array() {
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int arr[2] = {42, 42};
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auto &[a, b] = arr;
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(void)[ a, &b ] {
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static_assert(is_same<decltype(a), int>);
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static_assert(is_same<decltype(b), int>);
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};
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}
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struct tuple {
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template <unsigned long I>
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decltype(auto) get() {
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if constexpr (I == 0) {
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return a;
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} else {
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return b;
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}
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}
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template <unsigned long I>
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decltype(auto) get() const {
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if constexpr (I == 0) {
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return a;
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} else {
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return b;
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}
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}
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int a = 0;
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int &b = a;
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};
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namespace std {
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template <typename T>
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struct tuple_size {
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static constexpr unsigned long value = 2;
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};
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template <unsigned long, typename T>
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struct tuple_element;
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template <>
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struct tuple_element<0, tuple> {
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using type = int;
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};
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template <>
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struct tuple_element<1, tuple> {
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using type = int &;
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};
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template <>
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struct tuple_element<0, const tuple> {
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using type = int;
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};
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template <>
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struct tuple_element<1, const tuple> {
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using type = const int &;
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};
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} // namespace std
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void check_tuple_like() {
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tuple t;
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{
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auto [v, r] = t;
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(void)[ v, r ] {
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static_assert(is_same<decltype(v), int>);
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static_assert(is_same<decltype(r), int &>);
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};
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}
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{
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auto &[v, r] = t;
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(void)[&v, &r ] {
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static_assert(is_same<decltype(v), int>);
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static_assert(is_same<decltype(r), int &>);
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};
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}
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{
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const auto &[v, r] = t;
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(void)[ v, r ] {
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static_assert(is_same<decltype(v), int>);
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static_assert(is_same<decltype(r), const int &>);
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};
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}
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{
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const auto &[v, r] = t;
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(void)[&v, &r ] {
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static_assert(is_same<decltype(v), int>);
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static_assert(is_same<decltype(r), const int &>);
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};
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}
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}
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