clang/test/SemaTemplate/instantiate-scope.cpp

   1 // RUN: %clang_cc1 -std=c++11 -verify %s
   2
   3 template<typename ...T> struct X {
   4   void f(int);
   5   void f(...);
   6   static int n;
   7 };
   8
   9 template<typename T, typename U> using A = T;
  10
  11 // These definitions are OK, X<A<T, decltype(...)>...> is equivalent to X<T...>
  12 // so this defines the member of the primary template.
  13 template<typename ...T>
  14 void X<A<T, decltype(f(T()))>...>::f(int) {} // expected-error {{undeclared}}
  15
  16 template<typename ...T>
  17 int X<A<T, decltype(f(T()))>...>::n = 0; // expected-error {{undeclared}}
  18
  19 struct Y {}; void f(Y);
  20
  21 void g() {
  22   // OK, substitution succeeds.
  23   X<Y>().f(0);
  24   X<Y>::n = 1;
  25
  26   // Error, substitution fails; this should not be treated as a SFINAE-able
  27   // condition, so we don't select X<void>::f(...).
  28   X<void>().f(0); // expected-note {{instantiation of}}
  29   X<void>::n = 1; // expected-note {{instantiation of}}
  30 }