1 // RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
2 // expected-no-diagnostics
3
4 // Metafunction to extract the Nth type from a set of types.
5 template<unsigned N, typename ...Types> struct get_nth_type;
6
7 template<unsigned N, typename Head, typename ...Tail>
8 struct get_nth_type<N, Head, Tail...> : get_nth_type<N-1, Tail...> { };
9
10 template<typename Head, typename ...Tail>
11 struct get_nth_type<0, Head, Tail...> {
12 typedef Head type;
13 };
14
15 // Placeholder type when get_nth_type fails.
16 struct no_type {};
17
18 template<unsigned N>
19 struct get_nth_type<N> {
20 typedef no_type type;
21 };
22
23 template<typename ...Args>
24 typename get_nth_type<0, Args...>::type first_arg(Args...);
25
26 template<typename ...Args>
27 typename get_nth_type<1, Args...>::type second_arg(Args...);
28
29 // Test explicit specification of function template arguments.
test_explicit_spec_simple()30 void test_explicit_spec_simple() {
31 int *ip1 = first_arg<int *>(0);
32 int *ip2 = first_arg<int *, float*>(0, 0);
33 float *fp1 = first_arg<float *, double*, int*>(0, 0, 0);
34 }
35
36 // Template argument deduction can extend the sequence of template
37 // arguments corresponding to a template parameter pack, even when the
38 // sequence contains explicitly specified template arguments.
test_explicit_spec_extension(double * dp)39 void test_explicit_spec_extension(double *dp) {
40 int *ip1 = first_arg<int *>(0, 0);
41 int *ip2 = first_arg<int *, float*>(0, 0, 0, 0);
42 float *fp1 = first_arg<float *, double*, int*>(0, 0, 0);
43 int *i1 = second_arg<float *>(0, (int*)0, 0);
44 double *dp1 = first_arg<>(dp);
45 }
46
47 template<typename ...Types>
48 struct tuple { };
49
50 template<typename ...Types>
51 void accept_tuple(tuple<Types...>);
52
test_explicit_spec_extension_targs(tuple<int,float,double> t3)53 void test_explicit_spec_extension_targs(tuple<int, float, double> t3) {
54 accept_tuple(t3);
55 accept_tuple<int, float, double>(t3);
56 accept_tuple<int>(t3);
57 accept_tuple<int, float>(t3);
58 }
59
60 template<typename R, typename ...ParmTypes>
61 void accept_function_ptr(R(*)(ParmTypes...));
62
test_explicit_spec_extension_funcparms(int (* f3)(int,float,double))63 void test_explicit_spec_extension_funcparms(int (*f3)(int, float, double)) {
64 accept_function_ptr(f3);
65 accept_function_ptr<int>(f3);
66 accept_function_ptr<int, int>(f3);
67 accept_function_ptr<int, int, float>(f3);
68 accept_function_ptr<int, int, float, double>(f3);
69 }
70