[libcxx-commits] [PATCH] D138268: [libcxx] Fix std::equal not accepting volatile types

[Alvin Wong via Phabricator via libcxx-commits]

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update test


alvinhochun added a comment.

add the actual fix


alvinhochun added a comment.

update test


alvinhochun added a comment.

fix test


Fixes https://github.com/llvm/llvm-project/issues/59021


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D138268

Files:
  libcxx/include/__algorithm/equal.h
  libcxx/test/libcxx/algorithms/equal.pass.cpp


Index: libcxx/test/libcxx/algorithms/equal.pass.cpp
===================================================================
--- /dev/null
+++ libcxx/test/libcxx/algorithms/equal.pass.cpp
@@ -0,0 +1,47 @@
+//===----------------------------------------------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+// <algorithm>
+
+// check that std::equal can accept iterators with cv-qualified types.
+
+#include <algorithm>
+
+#include "test_macros.h"
+
+// GCC 12 gives "warning: 'a' may be used uninitialized [-Wmaybe-uninitialized]"
+#if defined(__GNUC__) && !defined(__clang__)
+#  pragma GCC diagnostic ignored "-Wmaybe-uninitialized"
+#endif
+
+template <class T1, class T2>
+void f() {
+  int a[3] = {1, 2, 3};
+  T1* x    = a;
+  T2* y    = a;
+  (void)std::equal(x, x + 3, y);
+  (void)std::equal(y, y + 3, x);
+#if TEST_STD_VER >= 14
+  (void)std::equal(x, x + 3, y, y + 3);
+  (void)std::equal(y, y + 3, x, x + 3);
+#endif
+}
+
+int main(int, char**) {
+  f<int, int>();
+  f<int, const int>();
+  f<int, volatile int>();
+  f<int, const volatile int>();
+  f<const int, const int>();
+  f<const int, volatile int>();
+  f<const int, const volatile int>();
+  f<volatile int, volatile int>();
+  f<volatile int, const volatile int>();
+  f<const volatile int, const volatile int>();
+  return 0;
+}
Index: libcxx/include/__algorithm/equal.h
===================================================================
--- libcxx/include/__algorithm/equal.h
+++ libcxx/include/__algorithm/equal.h
@@ -33,8 +33,8 @@
 template <class _InputIterator1, class _InputIterator2>
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2) {
-  typedef typename iterator_traits<_InputIterator1>::value_type __v1;
-  typedef typename iterator_traits<_InputIterator2>::value_type __v2;
+  typedef typename iterator_traits<_InputIterator1>::reference __v1;
+  typedef typename iterator_traits<_InputIterator2>::reference __v2;
   return _VSTD::equal(__first1, __last1, __first2, __equal_to<__v1, __v2>());
 }
 
@@ -72,8 +72,8 @@
 template <class _InputIterator1, class _InputIterator2>
 _LIBCPP_NODISCARD_EXT inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_SINCE_CXX20 bool
 equal(_InputIterator1 __first1, _InputIterator1 __last1, _InputIterator2 __first2, _InputIterator2 __last2) {
-  typedef typename iterator_traits<_InputIterator1>::value_type __v1;
-  typedef typename iterator_traits<_InputIterator2>::value_type __v2;
+  typedef typename iterator_traits<_InputIterator1>::reference __v1;
+  typedef typename iterator_traits<_InputIterator2>::reference __v2;
   return _VSTD::__equal(__first1, __last1, __first2, __last2, __equal_to<__v1, __v2>(),
                         typename iterator_traits<_InputIterator1>::iterator_category(),
                         typename iterator_traits<_InputIterator2>::iterator_category());


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