1*cc92866eSRichard Smith // RUN: %clang_cc1 -std=c++11 -verify %s
2*cc92866eSRichard Smith 
3*cc92866eSRichard Smith template<typename ...T> struct X {
4*cc92866eSRichard Smith   void f(int);
5*cc92866eSRichard Smith   void f(...);
6*cc92866eSRichard Smith   static int n;
7*cc92866eSRichard Smith };
8*cc92866eSRichard Smith 
9*cc92866eSRichard Smith template<typename T, typename U> using A = T;
10*cc92866eSRichard Smith 
11*cc92866eSRichard Smith // These definitions are OK, X<A<T, decltype(...)>...> is equivalent to X<T...>
12*cc92866eSRichard Smith // so this defines the member of the primary template.
13*cc92866eSRichard Smith template<typename ...T>
f(int)14*cc92866eSRichard Smith void X<A<T, decltype(f(T()))>...>::f(int) {} // expected-error {{undeclared}}
15*cc92866eSRichard Smith 
16*cc92866eSRichard Smith template<typename ...T>
17*cc92866eSRichard Smith int X<A<T, decltype(f(T()))>...>::n = 0; // expected-error {{undeclared}}
18*cc92866eSRichard Smith 
19*cc92866eSRichard Smith struct Y {}; void f(Y);
20*cc92866eSRichard Smith 
g()21*cc92866eSRichard Smith void g() {
22*cc92866eSRichard Smith   // OK, substitution succeeds.
23*cc92866eSRichard Smith   X<Y>().f(0);
24*cc92866eSRichard Smith   X<Y>::n = 1;
25*cc92866eSRichard Smith 
26*cc92866eSRichard Smith   // Error, substitution fails; this should not be treated as a SFINAE-able
27*cc92866eSRichard Smith   // condition, so we don't select X<void>::f(...).
28*cc92866eSRichard Smith   X<void>().f(0); // expected-note {{instantiation of}}
29*cc92866eSRichard Smith   X<void>::n = 1; // expected-note {{instantiation of}}
30*cc92866eSRichard Smith }
31