Implement LWG 2711. Constrain path members.

llvm-svn: 279945

1 files changed, 13 insertions, 11 deletions

diff --git a/libcxx/test/support/test_iterators.h b/libcxx/test/support/test_iterators.h
index d4a079971b1..fb5c06ad943 100644
--- a/libcxx/test/support/test_iterators.h
+++ b/libcxx/test/support/test_iterators.h
@@ -53,25 +53,27 @@ public:
     void operator,(T const &) DELETE_FUNCTION;
 };
 
-template <class It>
+template <class It,
+    class ItTraits = It>
 class input_iterator
 {
+    using Traits = std::iterator_traits<ItTraits>;
     It it_;
 
-    template <class U> friend class input_iterator;
+    template <class U, class T> friend class input_iterator;
 public:
     typedef          std::input_iterator_tag                   iterator_category;
-    typedef typename std::iterator_traits<It>::value_type      value_type;
-    typedef typename std::iterator_traits<It>::difference_type difference_type;
+    typedef typename Traits::value_type                        value_type;
+    typedef typename Traits::difference_type                   difference_type;
     typedef It                                                 pointer;
-    typedef typename std::iterator_traits<It>::reference       reference;
+    typedef typename Traits::reference                         reference;
 
     It base() const {return it_;}
 
     input_iterator() : it_() {}
     explicit input_iterator(It it) : it_(it) {}
-    template <class U>
-        input_iterator(const input_iterator<U>& u) :it_(u.it_) {}
+    template <class U, class T>
+        input_iterator(const input_iterator<U, T>& u) :it_(u.it_) {}
 
     reference operator*() const {return *it_;}
     pointer operator->() const {return it_;}
@@ -89,18 +91,18 @@ public:
     void operator,(T const &) DELETE_FUNCTION;
 };
 
-template <class T, class U>
+template <class T, class TV, class U, class UV>
 inline
 bool
-operator==(const input_iterator<T>& x, const input_iterator<U>& y)
+operator==(const input_iterator<T, TV>& x, const input_iterator<U, UV>& y)
 {
     return x.base() == y.base();
 }
 
-template <class T, class U>
+template <class T, class TV, class U, class UV>
 inline
 bool
-operator!=(const input_iterator<T>& x, const input_iterator<U>& y)
+operator!=(const input_iterator<T, TV>& x, const input_iterator<U, UV>& y)
 {
     return !(x == y);
 }