Fix PR39619 - iterator_traits isn't SFINAE-friendly enough. Thanks to Eric for the report

llvm-svn: 346738

2 files changed, 123 insertions, 0 deletions

diff --git a/libcxx/test/std/iterators/iterator.primitives/iterator.traits/empty.fail.cpp b/libcxx/test/std/iterators/iterator.primitives/iterator.traits/empty.fail.cpp
new file mode 100644
index 00000000000..02152348111
--- /dev/null
+++ b/libcxx/test/std/iterators/iterator.primitives/iterator.traits/empty.fail.cpp
@@ -0,0 +1,122 @@
+//===----------------------------------------------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+
+// <iterator>
+
+// struct iterator_traits
+// {
+// };
+
+#include <iterator>
+#include "test_macros.h"
+
+struct A {};
+struct NotAnIteratorEmpty {};
+
+struct NotAnIteratorNoDifference
+{
+//     typedef int                       difference_type;
+    typedef A                         value_type;
+    typedef A*                        pointer;
+    typedef A&                        reference;
+    typedef std::forward_iterator_tag iterator_category;
+};
+
+struct NotAnIteratorNoValue
+{
+    typedef int                       difference_type;
+//     typedef A                         value_type;
+    typedef A*                        pointer;
+    typedef A&                        reference;
+    typedef std::forward_iterator_tag iterator_category;
+};
+
+struct NotAnIteratorNoPointer
+{
+    typedef int                       difference_type;
+    typedef A                         value_type;
+//     typedef A*                        pointer;
+    typedef A&                        reference;
+    typedef std::forward_iterator_tag iterator_category;
+};
+
+struct NotAnIteratorNoReference
+{
+    typedef int                       difference_type;
+    typedef A                         value_type;
+    typedef A*                        pointer;
+//    typedef A&                        reference;
+    typedef std::forward_iterator_tag iterator_category;
+};
+
+struct NotAnIteratorNoCategory
+{
+    typedef int                       difference_type;
+    typedef A                         value_type;
+    typedef A*                        pointer;
+    typedef A&                        reference;
+//     typedef std::forward_iterator_tag iterator_category;
+};
+
+int main()
+{
+    {
+    typedef std::iterator_traits<NotAnIteratorEmpty> T;
+    typedef T::difference_type   DT; // expected-error-re {{no type named 'difference_type' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::value_type        VT; // expected-error-re {{no type named 'value_type' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::pointer           PT; // expected-error-re {{no type named 'pointer' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::reference         RT; // expected-error-re {{no type named 'reference' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::iterator_category CT; // expected-error-re {{no type named 'iterator_category' in 'std::__1::iterator_traits<{{.+}}>}}
+    }
+
+    {
+    typedef std::iterator_traits<NotAnIteratorNoDifference> T;
+    typedef T::difference_type   DT; // expected-error-re {{no type named 'difference_type' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::value_type        VT; // expected-error-re {{no type named 'value_type' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::pointer           PT; // expected-error-re {{no type named 'pointer' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::reference         RT; // expected-error-re {{no type named 'reference' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::iterator_category CT; // expected-error-re {{no type named 'iterator_category' in 'std::__1::iterator_traits<{{.+}}>}}
+    }
+
+    {
+    typedef std::iterator_traits<NotAnIteratorNoValue> T;
+    typedef T::difference_type   DT; // expected-error-re {{no type named 'difference_type' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::value_type        VT; // expected-error-re {{no type named 'value_type' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::pointer           PT; // expected-error-re {{no type named 'pointer' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::reference         RT; // expected-error-re {{no type named 'reference' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::iterator_category CT; // expected-error-re {{no type named 'iterator_category' in 'std::__1::iterator_traits<{{.+}}>}}
+    }
+
+    {
+    typedef std::iterator_traits<NotAnIteratorNoPointer> T;
+    typedef T::difference_type   DT; // expected-error-re {{no type named 'difference_type' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::value_type        VT; // expected-error-re {{no type named 'value_type' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::pointer           PT; // expected-error-re {{no type named 'pointer' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::reference         RT; // expected-error-re {{no type named 'reference' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::iterator_category CT; // expected-error-re {{no type named 'iterator_category' in 'std::__1::iterator_traits<{{.+}}>}}
+    }
+
+    {
+    typedef std::iterator_traits<NotAnIteratorNoReference> T;
+    typedef T::difference_type   DT; // expected-error-re {{no type named 'difference_type' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::value_type        VT; // expected-error-re {{no type named 'value_type' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::pointer           PT; // expected-error-re {{no type named 'pointer' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::reference         RT; // expected-error-re {{no type named 'reference' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::iterator_category CT; // expected-error-re {{no type named 'iterator_category' in 'std::__1::iterator_traits<{{.+}}>}}
+    }
+
+    {
+    typedef std::iterator_traits<NotAnIteratorNoCategory> T;
+    typedef T::difference_type   DT; // expected-error-re {{no type named 'difference_type' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::value_type        VT; // expected-error-re {{no type named 'value_type' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::pointer           PT; // expected-error-re {{no type named 'pointer' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::reference         RT; // expected-error-re {{no type named 'reference' in 'std::__1::iterator_traits<{{.+}}>}}
+    typedef T::iterator_category CT; // expected-error-re {{no type named 'iterator_category' in 'std::__1::iterator_traits<{{.+}}>}}
+    }
+}
diff --git a/libcxx/test/std/iterators/iterator.primitives/iterator.traits/iterator.pass.cpp b/libcxx/test/std/iterators/iterator.primitives/iterator.traits/iterator.pass.cpp
index 38f7c0b6b83..34f430ff3ee 100644
--- a/libcxx/test/std/iterators/iterator.primitives/iterator.traits/iterator.pass.cpp
+++ b/libcxx/test/std/iterators/iterator.primitives/iterator.traits/iterator.pass.cpp
@@ -39,5 +39,6 @@ int main()
     static_assert((std::is_same<It::difference_type, int>::value), "");
     static_assert((std::is_same<It::value_type, A>::value), "");
     static_assert((std::is_same<It::pointer, A*>::value), "");
+    static_assert((std::is_same<It::reference, A&>::value), "");
     static_assert((std::is_same<It::iterator_category, std::forward_iterator_tag>::value), "");
 }