Merge pull request NVIDIA#1457 from jrhemstad/fix-const-pair

Fix tuple_size/tuple_element for cv-qualified types

testing/pair.cu

@@ -213,22 +213,42 @@ struct TestPairGet
 };
 SimpleUnitTest<TestPairGet, BuiltinNumericTypes> TestPairGetInstance;
 
+using PairConstVolatileTypes =
+    unittest::type_list<thrust::pair<int, float>, thrust::pair<int, float> const,
+                        thrust::pair<int, float> const volatile>;
 
-void TestPairTupleSize(void)
+template <typename Pair> 
+struct TestPairTupleSize
 {
-  int result = thrust::tuple_size< thrust::pair<int,int> >::value;
-  ASSERT_EQUAL(2, result);
+  void operator()()
+  {
+    ASSERT_EQUAL(2, static_cast<int>(thrust::tuple_size<Pair>::value));
+  }
 };
-DECLARE_UNITTEST(TestPairTupleSize);
+SimpleUnitTest<TestPairTupleSize, PairConstVolatileTypes> TestPairTupleSizeInstance;
 
 
 void TestPairTupleElement(void)
 {
-  typedef thrust::tuple_element<0, thrust::pair<int, float> >::type type0;
-  typedef thrust::tuple_element<1, thrust::pair<int, float> >::type type1;
-
-  ASSERT_EQUAL_QUIET(typeid(int),   typeid(type0));
-  ASSERT_EQUAL_QUIET(typeid(float), typeid(type1));
+  using type0 = thrust::tuple_element<0, thrust::pair<int, float> >::type;
+  using type1 = thrust::tuple_element<1, thrust::pair<int, float> >::type;
+  static_assert(std::is_same<int, type0>::value,"");
+  static_assert(std::is_same<float, type1>::value,"");
+
+  using c_type0 = thrust::tuple_element<0, thrust::pair<int, float> const>::type;
+  using c_type1 = thrust::tuple_element<1, thrust::pair<int, float> const>::type;
+  static_assert(std::is_same<int const, c_type0>::value,"");
+  static_assert(std::is_same<float const, c_type1>::value,"");
+
+  using v_type0 = thrust::tuple_element<0, thrust::pair<int, float> volatile>::type;
+  using v_type1 = thrust::tuple_element<1, thrust::pair<int, float> volatile>::type;
+  static_assert(std::is_same<int volatile, v_type0>::value,"");
+  static_assert(std::is_same<float volatile, v_type1>::value,"");
+
+  using cv_type0 = thrust::tuple_element<0, thrust::pair<int, float> const volatile>::type;
+  using cv_type1 = thrust::tuple_element<1, thrust::pair<int, float> const volatile>::type;
+  static_assert(std::is_same<int const volatile, cv_type0>::value,"");
+  static_assert(std::is_same<float const volatile, cv_type1>::value,"");
 };
 DECLARE_UNITTEST(TestPairTupleElement);
 

thrust/detail/pair.inl

@@ -16,6 +16,7 @@
 
 #include <thrust/pair.h>
 #include <thrust/detail/swap.h>
+#include <thrust/tuple.h>
 
 namespace thrust
 {
@@ -140,21 +141,21 @@ template <typename T1, typename T2>
 
 // specializations of tuple_element for pair
 template<typename T1, typename T2>
-  struct tuple_element<0, pair<T1,T2> >
+  struct tuple_element<0, pair<T1,T2>>
 {
   typedef T1 type;
 }; // end tuple_element
 
 template<typename T1, typename T2>
-  struct tuple_element<1, pair<T1,T2> >
+  struct tuple_element<1, pair<T1,T2>>
 {
   typedef T2 type;
 }; // end tuple_element
 
 
 // specialization of tuple_size for pair
 template<typename T1, typename T2>
-  struct tuple_size< pair<T1,T2 > >
+  struct tuple_size<pair<T1,T2>>
 {
   static const unsigned int value = 2;
 }; // end tuple_size

thrust/detail/tuple.inl

@@ -50,38 +50,79 @@ template <
   class T9 = null_type>
 class tuple;
 
-// forward declaration of tuple_element
-template<size_t N, class T> struct tuple_element;
 
-// specializations for tuple_element
-template<class T>
-  struct tuple_element<0,T>
-{
-  typedef typename T::head_type type;
-}; // end tuple_element<0,T>
+template <size_t N, class T> struct tuple_element;
 
 template<size_t N, class T>
-  struct tuple_element<N, const T>
+  struct tuple_element_impl
 {
   private:
     typedef typename T::tail_type Next;
-    typedef typename tuple_element<N-1, Next>::type unqualified_type;
 
   public:
-    typedef typename thrust::detail::add_const<unqualified_type>::type type;
-}; // end tuple_element<N, const T>
+    /*! The result of this metafunction is returned in \c type.
+     */
+    typedef typename tuple_element_impl<N-1, Next>::type type;
+}; // end tuple_element
 
 template<class T>
-  struct tuple_element<0,const T>
+  struct tuple_element_impl<0,T>
+{
+  typedef typename T::head_type type;
+};
+
+template <size_t N, class T> 
+  struct tuple_element<N, T const> 
 {
-  typedef typename thrust::detail::add_const<typename T::head_type>::type type;
-}; // end tuple_element<0,const T>
+    using type = typename std::add_const<typename tuple_element<N, T>::type>::type;
+};
 
+template <size_t N, class T> 
+struct tuple_element<N, T volatile> 
+{
+    using type = typename std::add_volatile<typename tuple_element<N, T>::type>::type;
+};
 
+template <size_t N, class T> 
+  struct tuple_element<N, T const volatile> 
+{
+    using type = typename std::add_cv<typename tuple_element<N, T>::type>::type;
+};
+
+template <size_t N, class T>
+struct tuple_element{
+    using type = typename tuple_element_impl<N,T>::type;
+};
 
 // forward declaration of tuple_size
 template<class T> struct tuple_size;
 
+template<class T>
+  struct tuple_size<T const> : public tuple_size<T> {};
+
+template<class T>
+  struct tuple_size<T volatile> : public tuple_size<T> {};
+
+template<class T>
+  struct tuple_size<T const volatile> : public tuple_size<T> {};
+
+/*! This metafunction returns the number of elements
+ *  of a \p tuple type of interest.
+ *
+ *  \tparam T A \c tuple type of interest.
+ *
+ *  \see pair
+ *  \see tuple
+ */
+template<class T>
+  struct tuple_size
+{
+  /*! The result of this metafunction is returned in \c value.
+   */
+  static const int value = 1 + tuple_size<typename T::tail_type>::value;
+}; // end tuple_size
+
+
 // specializations for tuple_size
 template<>
   struct tuple_size< tuple<> >

thrust/tuple.h

@@ -62,17 +62,7 @@ struct null_type;
  *  \see pair
  *  \see tuple
  */
-template<size_t N, class T>
-  struct tuple_element
-{
-  private:
-    typedef typename T::tail_type Next;
-
-  public:
-    /*! The result of this metafunction is returned in \c type.
-     */
-    typedef typename tuple_element<N-1, Next>::type type;
-}; // end tuple_element
+template <size_t N, class T> struct tuple_element;
 
 /*! This metafunction returns the number of elements
  *  of a \p tuple type of interest.
@@ -82,13 +72,8 @@ template<size_t N, class T>
  *  \see pair
  *  \see tuple
  */
-template<class T>
-  struct tuple_size
-{
-  /*! The result of this metafunction is returned in \c value.
-   */
-  static const int value = 1 + tuple_size<typename T::tail_type>::value;
-}; // end tuple_size
+template <class T> struct tuple_size;
+
 
 // get function for non-const cons-lists, returns a reference to the element