1 files changed, 274 insertions, 0 deletions
diff --git a/clang/test/CXX/temp/temp.decls/temp.variadic/metafunctions.cpp b/clang/test/CXX/temp/temp.decls/temp.variadic/metafunctions.cpp
new file mode 100644
index 0000000..73cbd07
--- /dev/null
+++ b/clang/test/CXX/temp/temp.decls/temp.variadic/metafunctions.cpp
@@ -0,0 +1,274 @@
+// RUN: %clang_cc1 -std=c++11 -fsyntax-only -verify %s
+
+// This is a collection of various template metafunctions involving
+// variadic templates, which are meant to exercise common use cases.
+template<typename T, typename U>
+struct is_same {
+  static const bool value = false;
+};
+
+template<typename T>
+struct is_same<T, T> {
+  static const bool value = true;
+};
+
+template<typename...> struct tuple { };
+template<int ...> struct int_tuple { };
+template<typename T, typename U> struct pair { };
+
+namespace Count {
+  template<typename Head, typename ...Tail>
+  struct count {
+    static const unsigned value = 1 + count<Tail...>::value;
+  };
+
+  template<typename T>
+  struct count<T> {
+    static const unsigned value = 1;
+  };
+
+  int check1[count<int>::value == 1? 1 : -1];
+  int check2[count<float, double>::value == 2? 1 : -1];
+  int check3[count<char, signed char, unsigned char>::value == 3? 1 : -1];
+}
+
+namespace CountWithPackExpansion {
+  template<typename ...> struct count;
+
+  template<typename Head, typename ...Tail>
+  struct count<Head, Tail...> {
+    static const unsigned value = 1 + count<Tail...>::value;
+  };
+
+  template<>
+  struct count<> {
+    static const unsigned value = 0;
+  };
+
+  int check0[count<>::value == 0? 1 : -1];
+  int check1[count<int>::value == 1? 1 : -1];
+  int check2[count<float, double>::value == 2? 1 : -1];
+  int check3[count<char, signed char, unsigned char>::value == 3? 1 : -1];
+}
+
+namespace Replace {
+  // Simple metafunction that replaces the template arguments of
+  // template template parameters with 'int'.
+  template<typename T>
+  struct EverythingToInt;
+
+  template<template<typename ...> class TT, typename T1, typename T2>
+  struct EverythingToInt<TT<T1, T2> > {
+    typedef TT<int, int> type;
+  };
+
+  int check0[is_same<EverythingToInt<tuple<double, float>>::type, 
+             tuple<int, int>>::value? 1 : -1];
+}
+
+namespace Math {
+  template<int ...Values>
+  struct double_values {
+    typedef int_tuple<Values*2 ...> type;
+  };
+
+  int check0[is_same<double_values<1, 2, -3>::type, 
+                     int_tuple<2, 4, -6>>::value? 1 : -1];
+
+  template<int ...Values>
+  struct square {
+    typedef int_tuple<(Values*Values)...> type;
+  };
+
+  int check1[is_same<square<1, 2, -3>::type, 
+                     int_tuple<1, 4, 9>>::value? 1 : -1];
+
+  template<typename IntTuple> struct square_tuple;
+
+  template<int ...Values>
+  struct square_tuple<int_tuple<Values...>> {
+    typedef int_tuple<(Values*Values)...> type;
+  };
+
+  int check2[is_same<square_tuple<int_tuple<1, 2, -3> >::type, 
+                     int_tuple<1, 4, 9>>::value? 1 : -1];
+
+  template<int ...Values> struct sum;
+
+  template<int First, int ...Rest> 
+  struct sum<First, Rest...> {
+    static const int value = First + sum<Rest...>::value;
+  };
+
+  template<>
+  struct sum<> {
+    static const int value = 0;
+  };
+
+  int check3[sum<1, 2, 3, 4, 5>::value == 15? 1 : -1];
+
+  template<int ... Values>
+  struct lazy_sum {
+    int operator()() {
+      return sum<Values...>::value;
+    }
+  };
+
+  void f() {
+    lazy_sum<1, 2, 3, 4, 5>()();
+  }
+}
+
+namespace ListMath {
+  template<typename T, T ... V> struct add;
+
+  template<typename T, T i, T ... V>
+  struct add<T, i, V...> {
+    static const T value = i + add<T, V...>::value; 
+  };
+
+  template<typename T>
+  struct add<T> {
+    static const T value = T(); 
+  };
+
+  template<typename T, T ... V>
+  struct List {
+    struct sum {
+      static const T value = add<T, V...>::value;
+    };
+  };
+
+  template<int ... V>
+  struct ListI : public List<int, V...> {
+  };
+
+  int check0[ListI<1, 2, 3>::sum::value == 6? 1 : -1];
+}
+
+namespace Indices {
+  template<unsigned I, unsigned N, typename IntTuple>
+  struct build_indices_impl;
+
+  template<unsigned I, unsigned N, int ...Indices>
+  struct build_indices_impl<I, N, int_tuple<Indices...> >
+    : build_indices_impl<I+1, N, int_tuple<Indices..., I> > {
+  };
+
+  template<unsigned N, int ...Indices> 
+  struct build_indices_impl<N, N, int_tuple<Indices...> > {
+    typedef int_tuple<Indices...> type;
+  };
+
+  template<unsigned N>
+  struct build_indices : build_indices_impl<0, N, int_tuple<> > { };
+
+  int check0[is_same<build_indices<5>::type,
+                     int_tuple<0, 1, 2, 3, 4>>::value? 1 : -1];
+}
+
+namespace TemplateTemplateApply {
+  template<typename T, template<class> class ...Meta>
+  struct apply_each {
+    typedef tuple<typename Meta<T>::type...> type;
+  };
+
+  template<typename T> 
+  struct add_reference {
+    typedef T& type;
+  };
+
+  template<typename T> 
+  struct add_pointer {
+    typedef T* type;
+  };
+
+  template<typename T> 
+  struct add_const {
+    typedef const T type;
+  };
+
+  int check0[is_same<apply_each<int, 
+                                add_reference, add_pointer, add_const>::type,
+                     tuple<int&, int*, int const>>::value? 1 : -1];
+
+  template<typename T, template<class> class ...Meta>
+  struct apply_each_indirect {
+    typedef typename apply_each<T, Meta...>::type type;
+  };
+
+  int check1[is_same<apply_each_indirect<int, add_reference, add_pointer, 
+                                         add_const>::type,
+                     tuple<int&, int*, int const>>::value? 1 : -1];
+
+  template<typename T, typename ...Meta>
+  struct apply_each_nested {
+    typedef typename apply_each<T, Meta::template apply...>::type type;
+  };
+
+  struct add_reference_meta {
+    template<typename T>
+    struct apply {
+      typedef T& type;
+    };
+  };
+
+  struct add_pointer_meta {
+    template<typename T>
+    struct apply {
+      typedef T* type;
+    };
+  };
+
+  struct add_const_meta {
+    template<typename T>
+    struct apply {
+      typedef const T type;
+    };
+  };
+
+  int check2[is_same<apply_each_nested<int, add_reference_meta, 
+                                       add_pointer_meta, add_const_meta>::type,
+                     tuple<int&, int*, int const>>::value? 1 : -1];
+
+}
+
+namespace FunctionTypes {
+  template<typename FunctionType>
+  struct Arity;
+
+  template<typename R, typename ...Types>
+  struct Arity<R(Types...)> {
+    static const unsigned value = sizeof...(Types);
+  };
+
+  template<typename R, typename ...Types>
+  struct Arity<R(Types......)> {
+    static const unsigned value = sizeof...(Types);
+  };
+
+  template<typename R, typename T1, typename T2, typename T3, typename T4>
+  struct Arity<R(T1, T2, T3, T4)>; // expected-note{{template is declared here}}
+
+  int check0[Arity<int()>::value == 0? 1 : -1];
+  int check1[Arity<int(float, double)>::value == 2? 1 : -1];
+  int check2[Arity<int(float...)>::value == 1? 1 : -1];
+  int check3[Arity<int(float, double, long double...)>::value == 3? 1 : -1];
+  Arity<int(float, double, long double, char)> check4; // expected-error{{implicit instantiation of undefined template 'FunctionTypes::Arity<int (float, double, long double, char)>'}}
+}
+
+namespace SuperReplace {
+  template<typename T>
+  struct replace_with_int {
+    typedef int type;
+  };
+  
+  template<template<typename ...> class TT, typename ...Types>
+  struct replace_with_int<TT<Types...>> {
+    typedef TT<typename replace_with_int<Types>::type...> type;
+  };
+  
+  int check0[is_same<replace_with_int<pair<tuple<float, double, short>,
+                                           pair<char, unsigned char>>>::type,
+                     pair<tuple<int, int, int>, pair<int, int>>>::value? 1 : -1];
+}