clang/test/CXX/temp/temp.constr/temp.constr.decl/class-template-decl.cpp

   1 // RUN: %clang_cc1 -std=c++2a -x c++ -verify %s
   2
   3 namespace nodiag {
   4
   5 template <typename T> requires (bool(T()))
   6 struct A;
   7 template <typename U> requires (bool(U()))
   8 struct A;
   9
  10 template<typename T>
  11 concept C1 = true;
  12
  13 template <C1 T> requires (bool(T()))
  14 struct B;
  15 template <C1 U> requires (bool(U()))
  16 struct B;
  17
  18 } // end namespace nodiag
  19
  20 namespace diag {
  21
  22 template <typename T> requires true // expected-note{{previous template declaration is here}}
  23 struct A;
  24 template <typename T> struct A; // expected-error{{requires clause differs in template redeclaration}}
  25
  26 template <typename T> struct B; // expected-note{{previous template declaration is here}}
  27 template <typename T> requires true // expected-error{{requires clause differs in template redeclaration}}
  28 struct B;
  29
  30 template <typename T> requires true // expected-note{{previous template declaration is here}}
  31 struct C;
  32 template <typename T> requires (!0) // expected-error{{requires clause differs in template redeclaration}}
  33 struct C;
  34
  35 template<typename T>
  36 concept C1 = true;
  37
  38 template <C1 T> // expected-note{{previous template declaration is here}}
  39 struct D;
  40 template <typename T> requires C1<T> // expected-error{{type constraint differs in template redeclaration}}
  41 struct D;
  42
  43 } // end namespace diag
  44
  45 namespace nodiag {
  46
  47 struct AA {
  48   template <typename T> requires (someFunc(T()))
  49   struct A;
  50 };
  51
  52 template <typename U> requires (someFunc(U()))
  53 struct AA::A { };
  54
  55 struct AAF {
  56   template <typename T> requires (someFunc(T()))
  57   friend struct AA::A;
  58 };
  59
  60 } // end namespace nodiag
  61
  62 namespace diag {
  63
  64 template <unsigned N>
  65 struct TA {
  66   template <template <unsigned> class TT> requires TT<N>::happy // expected-note {{previous template declaration is here}}
  67   struct A;
  68
  69   template <template <unsigned> class TT> requires TT<N>::happy // expected-note {{previous template declaration is here}}
  70   struct B;
  71
  72   struct AF;
  73 };
  74
  75 template <unsigned N>
  76 template <template <unsigned> class TT> struct TA<N>::A { }; // expected-error{{requires clause differs in template redeclaration}}
  77
  78
  79 template <unsigned N>
  80 template <template <unsigned> class TT> requires TT<N + 1>::happy struct TA<N>::B { }; // expected-error{{requires clause differs in template redeclaration}}
  81
  82 template <unsigned N>
  83 struct TA<N>::AF {
  84   // we do not expect a diagnostic here because the template parameter list is dependent.
  85   template <template <unsigned> class TT> requires TT<N + 0>::happy
  86   friend struct TA::A;
  87 };
  88
  89 } // end namespace diag