ms-if-exists.cpp revision 65019acfc46ffb191fac4e781ac0c4b8d0c8434e 
1// RUN: %clang_cc1 -fms-extensions -std=c++11 %s -verify
2
3struct Nontemplate {
4  typedef int type;
5};
6
7template<typename T>
8struct 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
26X<int>::type i1;
27X<int>::type2 i2; // expected-error{{no type named 'type2' in 'X<int>'}}
28X<int>::type3 i3;
29X<int>::type4 i4; // expected-error{{no type named 'type4' in 'X<int>'}}
30
31struct HasFoo {
32  void foo();
33};
34struct HasBar {
35  void bar(int);
36  void bar(float);
37};
38
39template<typename T>
40void 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
52template void f(HasFoo); // expected-note{{in instantiation of function template specialization 'f<HasFoo>' requested here}}
53template void f(HasBar);
54
55template<typename T, typename ...Ts>
56void g(T, Ts...) {
57  __if_exists(T::operator Ts) { // expected-error{{__if_exists name contains unexpanded parameter pack 'Ts'}}
58  }
59
60  __if_not_exists(Ts::operator T) { // expected-error{{__if_not_exists name contains unexpanded parameter pack 'Ts'}}
61  }
62}
63