clang/test/SemaTemplate/class-template-id.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -verify=expected,precxx23,precxx17 %std_cxx98-14 %s
   2 // RUN: %clang_cc1 -fsyntax-only -verify=expected,precxx23,cxx17 %std_cxx17-20 %s
   3 // RUN: %clang_cc1 -fsyntax-only -verify=expected,cxx17,cxx23 %std_cxx23- %s
   4 template<typename T, typename U = float> struct A { };
   5
   6 typedef A<int> A_int;
   7
   8 typedef float FLOAT;
   9
  10 A<int, FLOAT> *foo(A<int> *ptr, A<int> const *ptr2, A<int, double> *ptr3) {
  11   if (ptr)
  12     return ptr; // okay
  13   else if (ptr2)
  14     return ptr2; // precxx23-error{{cannot initialize return object of type 'A<int, FLOAT> *' (aka 'A<int, float> *') with an lvalue of type 'const A<int> *'}} \
  15                     cxx23-error{{cannot initialize return object of type 'A<int, FLOAT> *' (aka 'A<int, float> *') with an rvalue of type 'const A<int> *'}}
  16   else {
  17     return ptr3; // precxx23-error{{cannot initialize return object of type 'A<int, FLOAT> *' (aka 'A<int, float> *') with an lvalue of type 'A<int, double> *'}} \
  18                     cxx23-error{{cannot initialize return object of type 'A<int, FLOAT> *' (aka 'A<int, float> *') with an rvalue of type 'A<int, double> *'}}
  19   }
  20 }
  21
  22 template<int I> struct B;
  23
  24 const int value = 12;
  25 B<17 + 2> *bar(B<(19)> *ptr1, B< (::value + 7) > *ptr2, B<19 - 3> *ptr3) {
  26   if (ptr1)
  27     return ptr1;
  28   else if (ptr2)
  29     return ptr2;
  30   else
  31     return ptr3; // precxx23-error{{cannot initialize return object of type 'B<17 + 2> *' with an lvalue of type 'B<19 - 3>}} \
  32                     cxx23-error{{cannot initialize return object of type 'B<17 + 2> *' with an rvalue of type 'B<19 - 3>}}
  33 }
  34
  35 typedef B<5> B5;
  36
  37
  38 namespace N {
  39   template<typename T> struct C {};
  40 }
  41
  42 N::C<int> c1;
  43 typedef N::C<float> c2;
  44
  45 // PR5655
  46 template<typename T> struct Foo { }; // precxx17-note {{template is declared here}} \
  47                                         cxx17-note {{candidate template ignored: couldn't infer template argument 'T'}} \
  48                                         cxx17-note {{implicit deduction guide declared as 'template <typename T> Foo() -> Foo<T>'}} \
  49                                         cxx17-note {{implicit deduction guide declared as 'template <typename T> Foo(Foo<T>) -> Foo<T>'}} \
  50                                         cxx17-note {{candidate function template not viable: requires 1 argument, but 0 were provided}}
  51
  52 void f(void) { Foo bar; } // precxx17-error {{use of class template 'Foo' requires template arguments}} \
  53                              cxx17-error {{no viable constructor or deduction guide for deduction of template arguments of 'Foo'}}
  54
  55 template <typename T> class Party;
  56 template <> class Party<T> { friend struct Party<>; }; // expected-error {{use of undeclared identifier 'T'}}