p9-0x.cpp revision 8e8fb3be5bd78f0564444eca02b404566a5f3b5d 
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.
5template<unsigned N, typename ...Types> struct get_nth_type;
6
7template<unsigned N, typename Head, typename ...Tail>
8struct get_nth_type<N, Head, Tail...> : get_nth_type<N-1, Tail...> { };
9
10template<typename Head, typename ...Tail>
11struct get_nth_type<0, Head, Tail...> {
12  typedef Head type;
13};
14
15// Placeholder type  when get_nth_type fails.
16struct no_type {};
17
18template<unsigned N>
19struct get_nth_type<N> {
20  typedef no_type type;
21};
22
23template<typename ...Args>
24typename get_nth_type<0, Args...>::type first_arg(Args...);
25
26template<typename ...Args>
27typename get_nth_type<1, Args...>::type second_arg(Args...);
28
29// Test explicit specification of function template arguments.
30void 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.
39void 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
47template<typename ...Types>
48struct tuple { };
49
50template<typename ...Types>
51void accept_tuple(tuple<Types...>);
52
53void 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
60template<typename R, typename ...ParmTypes>
61void accept_function_ptr(R(*)(ParmTypes...));
62
63void 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