|  | // RUN: %clang_cc1 -std=c++2a -x c++ %s -verify | 
|  |  | 
|  | template<auto T, decltype(T) U> | 
|  | concept C1 = sizeof(U) >= 4; | 
|  | // sizeof(U) >= 4 [U = U (decltype(T))] | 
|  |  | 
|  | template<typename Y, char V> | 
|  | concept C2 = C1<Y{}, V>; | 
|  | // sizeof(U) >= 4 [U = V (decltype(Y{}))] | 
|  |  | 
|  | template<char W> | 
|  | constexpr int foo() requires C2<int, W> { return 1; } | 
|  | // sizeof(U) >= 4 [U = W (decltype(int{}))] | 
|  |  | 
|  | template<char X> | 
|  | // expected-note@+1{{candidate function}} | 
|  | constexpr int foo() requires C1<1, X> && true { return 2; } | 
|  | // sizeof(U) >= 4 [U = X (decltype(1))] | 
|  |  | 
|  | static_assert(foo<'a'>() == 2); | 
|  |  | 
|  | template<char Z> | 
|  | // expected-note@+1{{candidate function}} | 
|  | constexpr int foo() requires C2<long long, Z> && true { return 3; } | 
|  | // sizeof(U) >= 4 [U = Z (decltype(long long{}))] | 
|  |  | 
|  | static_assert(foo<'a'>() == 3); | 
|  | // expected-error@-1{{call to 'foo' is ambiguous}} |