[libcxx] r346738 - Fix PR39619 - iterator_traits isn't SFINAE-friendly enough. Thanks to Eric for the report
Marshall Clow
mclow.lists at gmail.com
Mon Nov 12 21:33:31 PST 2018
Author: marshall
Date: Mon Nov 12 21:33:31 2018
New Revision: 346738
URL: http://llvm.org/viewvc/llvm-project?rev=346738&view=rev
Log:
Fix PR39619 - iterator_traits isn't SFINAE-friendly enough. Thanks to Eric for the report
Added:
libcxx/trunk/test/std/iterators/iterator.primitives/iterator.traits/empty.fail.cpp
Modified:
libcxx/trunk/include/iterator
libcxx/trunk/test/std/iterators/iterator.primitives/iterator.traits/iterator.pass.cpp
Modified: libcxx/trunk/include/iterator
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/include/iterator?rev=346738&r1=346737&r2=346738&view=diff
==============================================================================
--- libcxx/trunk/include/iterator (original)
+++ libcxx/trunk/include/iterator Mon Nov 12 21:33:31 2018
@@ -438,6 +438,23 @@ struct _LIBCPP_TEMPLATE_VIS bidirectiona
struct _LIBCPP_TEMPLATE_VIS random_access_iterator_tag : public bidirectional_iterator_tag {};
template <class _Tp>
+struct __has_iterator_typedefs
+{
+private:
+ struct __two {char __lx; char __lxx;};
+ template <class _Up> static __two __test(...);
+ template <class _Up> static char __test(typename std::__void_t<typename _Up::iterator_category>::type* = 0,
+ typename std::__void_t<typename _Up::difference_type>::type* = 0,
+ typename std::__void_t<typename _Up::value_type>::type* = 0,
+ typename std::__void_t<typename _Up::reference>::type* = 0,
+ typename std::__void_t<typename _Up::pointer>::type* = 0
+ );
+public:
+ static const bool value = sizeof(__test<_Tp>(0,0,0,0,0)) == 1;
+};
+
+
+template <class _Tp>
struct __has_iterator_category
{
private:
@@ -479,7 +496,7 @@ struct __iterator_traits<_Iter, true>
template <class _Iter>
struct _LIBCPP_TEMPLATE_VIS iterator_traits
- : __iterator_traits<_Iter, __has_iterator_category<_Iter>::value> {};
+ : __iterator_traits<_Iter, __has_iterator_typedefs<_Iter>::value> {};
template<class _Tp>
struct _LIBCPP_TEMPLATE_VIS iterator_traits<_Tp*>
Added: libcxx/trunk/test/std/iterators/iterator.primitives/iterator.traits/empty.fail.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/iterators/iterator.primitives/iterator.traits/empty.fail.cpp?rev=346738&view=auto
==============================================================================
--- libcxx/trunk/test/std/iterators/iterator.primitives/iterator.traits/empty.fail.cpp (added)
+++ libcxx/trunk/test/std/iterators/iterator.primitives/iterator.traits/empty.fail.cpp Mon Nov 12 21:33:31 2018
@@ -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<{{.+}}>}}
+ }
+}
Modified: libcxx/trunk/test/std/iterators/iterator.primitives/iterator.traits/iterator.pass.cpp
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/test/std/iterators/iterator.primitives/iterator.traits/iterator.pass.cpp?rev=346738&r1=346737&r2=346738&view=diff
==============================================================================
--- libcxx/trunk/test/std/iterators/iterator.primitives/iterator.traits/iterator.pass.cpp (original)
+++ libcxx/trunk/test/std/iterators/iterator.primitives/iterator.traits/iterator.pass.cpp Mon Nov 12 21:33:31 2018
@@ -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), "");
}
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