clang/test/SemaCXX/PR68542.cpp

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