clang/test/SemaCXX/PR68542.cpp

   1 // RUN: %clang_cc1 -verify -std=c++20 -fsyntax-only %s
   2 // RUN: %clang_cc1 -verify -std=c++20 -fsyntax-only %s -fexperimental-new-constant-interpreter
   3
   4 struct S { // expected-note {{candidate constructor (the implicit move constructor) not viable: no known conversion from 'int' to 'S &&' for 1st argument}} \
   5            // expected-note {{candidate constructor (the implicit copy constructor) not viable: no known conversion from 'int' to 'const S &' for 1st argument}}
   6     int e;
   7 };
   8
   9 template<class T>
  10 consteval int get_format() {
  11         return nullptr; // expected-error {{cannot initialize return object of type 'int' with an rvalue of type 'std::nullptr_t'}}
  12 }
  13
  14 template<class T>
  15 constexpr S f(T) noexcept {
  16         return get_format<T>(); // expected-error {{no viable conversion from returned value of type 'int' to function return type 'S'}}
  17 }
  18
  19 constexpr S x = f(0); // expected-error {{constexpr variable 'x' must be initialized by a constant expression}} \
  20                       // expected-note {{in instantiation of function template specialization 'f<int>' requested here}}