1 // RUN: %clang_cc1 -fsyntax-only -std=c++11 -verify %s
2 // expected-no-diagnostics
3 
4 // Test default template arguments for function templates.
5 template<typename T = int>
6 void f0();
7 
8 template<typename T>
9 void f0();
10 
11 void g0() {
12   f0(); // okay!
13 }
14 
15 template<typename T, int N = T::value>
16 int &f1(T);
17 
18 float &f1(...);
19 
20 struct HasValue {
21   static const int value = 17;
22 };
23 
24 void g1() {
25   float &fr = f1(15);
26   int &ir = f1(HasValue());
27 }
28 
29 namespace PR16689 {
30   template <typename T1, typename T2> class tuple {
31   public:
32       template <typename = T2>
33       constexpr tuple() {}
34   };
35   template <class X, class... Y> struct a : public X {
36     using X::X;
37   };
38   auto x = a<tuple<int, int> >();
39 }
40 
41 namespace PR16975 {
42   template <typename...> struct is {
43     constexpr operator bool() const { return false; }
44   };
45 
46   template <typename... Types>
47   struct bar {
48     template <typename T,
49               bool = is<Types...>()>
50     bar(T);
51   };
52 
53   bar<> foo{0};
54 
55   struct baz : public bar<> {
56     using bar::bar;
57   };
58 
59   baz data{0};
60 }
61 
62 // rdar://23810407
63 // An IRGen failure due to a symbol collision due to a default argument
64 // being instantiated twice.  Credit goes to Richard Smith for this
65 // reduction to a -fsyntax-only failure.
66 namespace rdar23810407 {
67   // Instantiating the default argument multiple times will produce two
68   // different lambda types and thus instantiate this function multiple
69   // times, which will produce conflicting extern variable declarations.
70   template<typename T> int f(T t) {
71     extern T rdar23810407_variable;
72     return 0;
73   }
74   template<typename T> int g(int a = f([] {}));
75   void test() {
76     g<int>();
77     g<int>();
78   }
79 }
80 
81 // rdar://problem/24480205
82 namespace PR13986 {
83   constexpr unsigned Dynamic = 0;
84   template <unsigned> class A { template <unsigned = Dynamic> void m_fn1(); };
85   class Test {
86     ~Test() {}
87     A<1> m_target;
88   };
89 }
90