clang/test/CXX/temp/temp.constr/temp.constr.atomic/constrant-satisfaction-conversions.cpp

   1 // RUN: %clang_cc1 -std=c++20 -x c++ -Wno-constant-logical-operand -verify %s
   2
   3 template<typename T> concept C =
   4 sizeof(T) == 4 && !true;      // requires atomic constraints sizeof(T) == 4 and !true
   5
   6 template<typename T> concept C2 = sizeof(T); // expected-error{{atomic constraint must be of type 'bool' (found }}
   7
   8 template<typename T> struct S {
   9   constexpr operator bool() const { return true; }
  10 };
  11
  12 // expected-error@+3{{atomic constraint must be of type 'bool' (found 'S<int>')}}
  13 // expected-note@#FINST{{while checking constraint satisfaction}}
  14 // expected-note@#FINST{{in instantiation of function template specialization}}
  15 template<typename T> requires (S<T>{})
  16 void f(T);
  17 void f(int);
  18
  19 // Ensure this applies to operator && as well.
  20 // expected-error@+3{{atomic constraint must be of type 'bool' (found 'S<int>')}}
  21 // expected-note@#F2INST{{while checking constraint satisfaction}}
  22 // expected-note@#F2INST{{in instantiation of function template specialization}}
  23 template<typename T> requires (S<T>{} && true)
  24 void f2(T);
  25 void f2(int);
  26
  27 template<typename T> requires requires {
  28   requires S<T>{};
  29   // expected-error@-1{{atomic constraint must be of type 'bool' (found 'S<int>')}}
  30   // expected-note@-2{{while checking the satisfaction}}
  31   // expected-note@-3{{in instantiation of requirement}}
  32   // expected-note@-4{{while checking the satisfaction}}
  33   // expected-note@-6{{while substituting template arguments}}
  34   // expected-note@#F3INST{{while checking constraint satisfaction}}
  35   // expected-note@#F3INST{{in instantiation of function template specialization}}
  36   //
  37 }
  38 void f3(T);
  39 void f3(int);
  40
  41 // Doesn't diagnose, since this is no longer a compound requirement.
  42 template<typename T> requires (bool(1 && 2))
  43 void f4(T);
  44 void f4(int);
  45
  46 void g() {
  47   f(0); // #FINST
  48   f2(0); // #F2INST
  49   f3(0); // #F3INST
  50   f4(0);
  51 }
  52
  53 template<typename T>
  54 auto Nullptr = nullptr;
  55
  56 template<typename T> concept NullTy = Nullptr<T>;
  57 // expected-error@-1{{atomic constraint must be of type 'bool' (found }}
  58 // expected-note@+1{{while checking the satisfaction}}
  59 static_assert(NullTy<int>);
  60
  61 template<typename T>
  62 auto Struct = S<T>{};
  63
  64 template<typename T> concept StructTy = Struct<T>;
  65 // expected-error@-1{{atomic constraint must be of type 'bool' (found 'S<int>')}}
  66 // expected-note@+1{{while checking the satisfaction}}
  67 static_assert(StructTy<int>);