1 // RUN: %clang_cc1 -fms-extensions -std=c++11 %s -verify
2 
3 struct Nontemplate {
4   typedef int type;
5 };
6 
7 template<typename T>
8 struct X {
9   __if_exists(Nontemplate::type) {
10     typedef Nontemplate::type type;
11   }
12 
13   __if_exists(Nontemplate::value) {
14     typedef Nontemplate::value type2;
15   }
16 
17   __if_not_exists(Nontemplate::value) {
18     typedef int type3;
19   }
20 
21   __if_exists(T::X) { // expected-warning{{dependent __if_exists declarations are ignored}}
22     typedef T::X type4;
23   }
24 };
25 
26 X<int>::type i1;
27 X<int>::type2 i2; // expected-error{{no type named 'type2' in 'X<int>'}}
28 X<int>::type3 i3;
29 X<int>::type4 i4; // expected-error{{no type named 'type4' in 'X<int>'}}
30 
31 struct HasFoo {
32   void foo();
33 };
34 struct HasBar {
35   void bar(int);
36   void bar(float);
37 };
38 
39 template<typename T>
40 void f(T t) {
41   __if_exists(T::foo) {
42     { }
43     t.foo();
44   }
45 
46   __if_not_exists(T::bar) {
47     int *i = t; // expected-error{{no viable conversion from 'HasFoo' to 'int *'}}
48     { }
49   }
50 
51   int array2[] = {
52     0,
53     __if_exists(T::bar) {2, }// expected-warning{{dependent __if_exists declarations are ignored}}
54     3
55   };
56 }
57 
58 template void f(HasFoo); // expected-note{{in instantiation of function template specialization 'f<HasFoo>' requested here}}
59 template void f(HasBar);
60 
61 template<typename T, typename ...Ts>
62 void g(T, Ts...) {
63   __if_exists(T::operator Ts) { // expected-error{{__if_exists name contains unexpanded parameter pack 'Ts'}}
64   }
65 
66   __if_not_exists(Ts::operator T) { // expected-error{{__if_not_exists name contains unexpanded parameter pack 'Ts'}}
67   }
68 }
69