forked from OSchip/llvm-project
63 lines
1.5 KiB
C++
63 lines
1.5 KiB
C++
// RUN: %clang_cc1 -std=c++20 -fsyntax-only -verify %s
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// expected-no-diagnostics
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template <class T, class U> constexpr bool is_same_v = false;
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template <class T> constexpr bool is_same_v<T, T> = true;
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template <class T, class U>
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concept is_same = is_same_v<T, U>;
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template <class T> struct X {};
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template <class T, class U>
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concept C1 = is_same<T, X<U>>;
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template <class T1> X<X<X<T1>>> t1() {
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return []<class T2>(T2) -> X<X<T2>> {
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struct S {
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static X<X<T2>> f() {
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return []<class T3>(T3) -> X<T3> {
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static_assert(is_same<T2, X<T1>>);
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static_assert(is_same<T3, X<T2>>);
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return X<T3>();
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}(X<T2>());
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}
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};
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return S::f();
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}(X<T1>());
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};
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template X<X<X<int>>> t1<int>();
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#if 0 // FIXME: crashes
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template<class T1> auto t2() {
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return []<class T2>(T2) {
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struct S {
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static auto f() {
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return []<class T3>(T3) {
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static_assert(is_same<T2, X<T1>>);
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static_assert(is_same<T3, X<T2>>);
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return X<T3>();
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}(X<T2>());
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}
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};
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return S::f();
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}(X<T1>());
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};
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template auto t2<int>();
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static_assert(is_same<decltype(t2<int>()), X<X<X<int>>>>);
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template<class T1> C1<X<X<T1>>> auto t3() {
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return []<C1<T1> T2>(T2) -> C1<X<T2>> auto {
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struct S {
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static auto f() {
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return []<C1<T2> T3>(T3) -> C1<T3> auto {
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return X<T3>();
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}(X<T2>());
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}
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};
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return S::f();
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}(X<T1>());
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};
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template C1<X<X<int>>> auto t3<int>();
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static_assert(is_same<decltype(t3<int>()), X<X<X<int>>>>);
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#endif
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