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>
f(int)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
g()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 }
31