clang/test/CXX/temp/temp.spec/temp.explicit/p3.cpp

   1 // RUN: %clang_cc1 -fsyntax-only -verify -Wc++11-compat %s
   2
   3 // A declaration of a function template shall be in scope at the point of the
   4 // explicit instantiation of the function template.
   5 template<typename T> void f0(T);
   6 template void f0(int); // okay
   7 template<typename T> void f0(T) { }
   8
   9 // A definition of the class or class template containing a member function
  10 // template shall be in scope at the point of the explicit instantiation of
  11 // the member function template.
  12 struct X0; // expected-note {{forward declaration}}
  13 template<typename> struct X1; // expected-note 5{{declared here}}
  14
  15 template void X0::f0<int>(int); // expected-error {{incomplete type}}
  16 template void X1<int>::f0<int>(int); // expected-error {{implicit instantiation of undefined template}}
  17
  18 // A definition of a class template or class member template shall be in scope
  19 // at the point of the explicit instantiation of the class template or class
  20 // member template.
  21 template struct X1<float>; // expected-error{{explicit instantiation of undefined template}}
  22
  23 template<typename T>
  24 struct X2 { // expected-note 4{{refers here}}
  25   template<typename U>
  26   struct Inner; // expected-note{{declared here}}
  27
  28   struct InnerClass; // expected-note{{forward declaration}}
  29 };
  30
  31 template struct X2<int>::Inner<float>; // expected-error{{explicit instantiation of undefined template}}
  32
  33 // A definition of a class template shall be in scope at the point of an
  34 // explicit instantiation of a member function or a static data member of the
  35 // class template.
  36 template void X1<int>::f1(int); // expected-error {{undefined template}}
  37 template void X1<int>::f1<int>(int); // expected-error {{undefined template}}
  38
  39 template int X1<int>::member; // expected-error {{undefined template}}
  40
  41 // A definition of a member class of a class template shall be in scope at the
  42 // point of an explicit instantiation of the member class.
  43 template struct X2<float>::InnerClass; // expected-error{{undefined member}}
  44
  45 // If the declaration of the explicit instantiation names an implicitly-declared
  46 // special member function (Clause 12), the program is ill-formed.
  47 template X2<int>::X2(); // expected-error{{not an instantiation}}
  48 template X2<int>::X2(const X2&); // expected-error{{not an instantiation}}
  49 template X2<int>::~X2(); // expected-error{{not an instantiation}}
  50 template X2<int> &X2<int>::operator=(const X2<int>&); // expected-error{{not an instantiation}}
  51
  52
  53 // A definition of a class template is sufficient to explicitly
  54 // instantiate a member of the class template which itself is not yet defined.
  55 namespace PR7979 {
  56   template <typename T> struct S {
  57     void f();
  58     static void g();
  59     static int i;
  60     struct S2 {
  61       void h();
  62     };
  63   };
  64
  65   template void S<int>::f();
  66   template void S<int>::g();
  67   template int S<int>::i;
  68   template void S<int>::S2::h();
  69
  70   template <typename T> void S<T>::f() {}
  71   template <typename T> void S<T>::g() {}
  72   template <typename T> int S<T>::i;
  73   template <typename T> void S<T>::S2::h() {}
  74 }
  75
  76 namespace PR11599 {
  77   template <typename STRING_TYPE> class BasicStringPiece;  // expected-note {{template is declared here}}
  78
  79   extern template class BasicStringPiece<int>;  // expected-error{{explicit instantiation of undefined template 'PR11599::BasicStringPiece<int>}}
  80   template class BasicStringPiece<int>;
  81 }