re PR c++/62134 ([C++11] ICE with template alias)

2015-01-16  Paolo Carlini  <paolo.carlini@oracle.com>

	PR c++/62134
	* g++.dg/cpp0x/alias-decl-46.C: New.

From-SVN: r219766

gcc/testsuite/ChangeLog

+2015-01-16  Paolo Carlini  <paolo.carlini@oracle.com>
+
+	PR c++/62134
+	* g++.dg/cpp0x/alias-decl-46.C: New.
+
 2015-01-16  Christophe Lyon  <christophe.lyon@linaro.org>
 
 	* gcc.target/aarch64/advsimd-intrinsics/arm-neon-ref.h (CHECK):

gcc/testsuite/g++.dg/cpp0x/alias-decl-46.C

+// PR c++/62134
+// { dg-do compile { target c++11 } }
+
+template<typename... T> struct tuple;
+template<__SIZE_TYPE__, typename U> struct tuple_element;
+
+template<bool, typename T = void> struct enable_if  { };
+template<typename T> struct enable_if<true, T> { typedef T type; };
+
+template <int V> struct int_t { static constexpr int value = V; };
+template <int V> int constexpr int_t<V>::value;
+
+template <class A, class Val, int i=0>
+struct Index
+{
+    static int const value = -1;
+};
+
+template <class ... A, class Val, int i>
+struct Index<tuple<Val, A ...>, Val, i>
+{
+    static int const value = i;
+};
+
+template <class A0, class ... A, class Val, int i>
+struct Index<tuple<A0, A ...>, Val, i>
+{
+    static int const value = Index<tuple<A ...>, Val, i+1>::value;
+};
+
+template <class C, class R> struct PermutationSign;
+
+template <int w, class C, class R>
+struct PermutationSignIfFound
+{
+    static int const value = 0;
+};
+
+template <class C, class R>
+struct PermutationSignIfFound<-1, C, R>
+{
+    static int const value = 0;
+};
+
+template <>
+struct PermutationSign<tuple<>, tuple<>>
+{
+    static int const value = 1;
+};
+
+template <class C>
+struct PermutationSign<C, tuple<>>
+{
+    static int const value = 0;
+};
+
+template <class R>
+struct PermutationSign<tuple<>, R>
+{
+    static int const value = 0;
+};
+
+template <class C, class Org>
+struct PermutationSign
+{
+    static int const value
+    = PermutationSignIfFound
+      <Index<C, typename tuple_element<0, Org>::type>::value,
+       C, Org>::value;
+};
+
+template <class A, template <class> class Pred, int i=0, class Enable=void>
+struct IndexIf
+{
+    static int const value = -1;
+    using type = tuple<>;
+};
+
+template <class A0, class ... A, template <class> class Pred, int i>
+struct IndexIf<tuple<A0, A ...>, Pred, i,
+	       typename enable_if<Pred<A0>::value>::type>
+{
+    using type = A0;
+    static int const value = i;
+};
+
+template <class A0, class ... A, template <class> class Pred, int i>
+struct IndexIf<tuple<A0, A ...>, Pred, i,
+	       typename enable_if<!Pred<A0>::value>::type>
+{
+    using next = IndexIf<tuple<A ...>, Pred, i+1>;
+    using type = typename next::type;
+    static int const value = next::value;
+};
+
+template <class P>
+struct MatchPermutationP
+{
+    template <class A> using type = PermutationSign<P, A>;
+};
+
+template <class P, class Plist> struct FindCombination
+{
+    using type = IndexIf<Plist, MatchPermutationP<P>::template type>;
+    static int const where = type::value;
+    static int const sign
+    = (where>=0) ? PermutationSign<P, typename type::type>::value : 0;
+};
+
+int main()
+{
+  using finder = FindCombination<tuple<>, tuple<tuple<>>>;
+  static_assert(finder::where==0 && finder::sign==+1, "bad");
+}