70 lines
2.1 KiB
C++
70 lines
2.1 KiB
C++
// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
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// expected-no-diagnostics
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// Metafunction to extract the Nth type from a set of types.
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template<unsigned N, typename ...Types> struct get_nth_type;
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template<unsigned N, typename Head, typename ...Tail>
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struct get_nth_type<N, Head, Tail...> : get_nth_type<N-1, Tail...> { };
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template<typename Head, typename ...Tail>
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struct get_nth_type<0, Head, Tail...> {
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typedef Head type;
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};
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// Placeholder type when get_nth_type fails.
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struct no_type {};
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template<unsigned N>
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struct get_nth_type<N> {
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typedef no_type type;
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};
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template<typename ...Args>
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typename get_nth_type<0, Args...>::type first_arg(Args...);
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template<typename ...Args>
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typename get_nth_type<1, Args...>::type second_arg(Args...);
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// Test explicit specification of function template arguments.
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void test_explicit_spec_simple() {
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int *ip1 = first_arg<int *>(0);
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int *ip2 = first_arg<int *, float*>(0, 0);
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float *fp1 = first_arg<float *, double*, int*>(0, 0, 0);
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}
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// Template argument deduction can extend the sequence of template
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// arguments corresponding to a template parameter pack, even when the
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// sequence contains explicitly specified template arguments.
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void test_explicit_spec_extension(double *dp) {
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int *ip1 = first_arg<int *>(0, 0);
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int *ip2 = first_arg<int *, float*>(0, 0, 0, 0);
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float *fp1 = first_arg<float *, double*, int*>(0, 0, 0);
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int *i1 = second_arg<float *>(0, (int*)0, 0);
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double *dp1 = first_arg<>(dp);
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}
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template<typename ...Types>
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struct tuple { };
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template<typename ...Types>
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void accept_tuple(tuple<Types...>);
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void test_explicit_spec_extension_targs(tuple<int, float, double> t3) {
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accept_tuple(t3);
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accept_tuple<int, float, double>(t3);
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accept_tuple<int>(t3);
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accept_tuple<int, float>(t3);
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}
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template<typename R, typename ...ParmTypes>
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void accept_function_ptr(R(*)(ParmTypes...));
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void test_explicit_spec_extension_funcparms(int (*f3)(int, float, double)) {
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accept_function_ptr(f3);
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accept_function_ptr<int>(f3);
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accept_function_ptr<int, int>(f3);
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accept_function_ptr<int, int, float>(f3);
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accept_function_ptr<int, int, float, double>(f3);
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}
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