clang/test/CXX/temp/temp.fct.spec/temp.arg.explicit/p9-0x.cpp

   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.
  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.
  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
  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
  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 }