p9-0x.cpp revision 3cae5c9a79bfd2e27eb44c32b13dfacd2ce5c66f
1// RUN: %clang_cc1 -std=c++0x -fsyntax-only -verify %s 2 3// Metafunction to extract the Nth type from a set of types. 4template<unsigned N, typename ...Types> struct get_nth_type; 5 6template<unsigned N, typename Head, typename ...Tail> 7struct get_nth_type<N, Head, Tail...> : get_nth_type<N-1, Tail...> { }; 8 9template<typename Head, typename ...Tail> 10struct get_nth_type<0, Head, Tail...> { 11 typedef Head type; 12}; 13 14// Placeholder type when get_nth_type fails. 15struct no_type {}; 16 17template<unsigned N> 18struct get_nth_type<N> { 19 typedef no_type type; 20}; 21 22template<typename ...Args> 23typename get_nth_type<0, Args...>::type first_arg(Args...); 24 25template<typename ...Args> 26typename get_nth_type<1, Args...>::type second_arg(Args...); 27 28// Test explicit specification of function template arguments. 29void test_explicit_spec_simple() { 30 int *ip1 = first_arg<int *>(0); 31 int *ip2 = first_arg<int *, float*>(0, 0); 32 float *fp1 = first_arg<float *, double*, int*>(0, 0, 0); 33} 34 35// Template argument deduction can extend the sequence of template 36// arguments corresponding to a template parameter pack, even when the 37// sequence contains explicitly specified template arguments. 38void test_explicit_spec_extension(double *dp) { 39 int *ip1 = first_arg<int *>(0, 0); 40 int *ip2 = first_arg<int *, float*>(0, 0, 0, 0); 41 float *fp1 = first_arg<float *, double*, int*>(0, 0, 0); 42 int *i1 = second_arg<float *>(0, (int*)0, 0); 43 double *dp1 = first_arg<>(dp); 44} 45 46template<typename ...Types> 47struct tuple { }; 48 49template<typename ...Types> 50void accept_tuple(tuple<Types...>); 51 52void test_explicit_spec_extension_targs(tuple<int, float, double> t3) { 53 accept_tuple(t3); 54 accept_tuple<int, float, double>(t3); 55 accept_tuple<int>(t3); 56 accept_tuple<int, float>(t3); 57} 58 59template<typename R, typename ...ParmTypes> 60void accept_function_ptr(R(*)(ParmTypes...)); 61 62void test_explicit_spec_extension_funcparms(int (*f3)(int, float, double)) { 63 accept_function_ptr(f3); 64 accept_function_ptr<int>(f3); 65 accept_function_ptr<int, int>(f3); 66 accept_function_ptr<int, int, float>(f3); 67 accept_function_ptr<int, int, float, double>(f3); 68} 69