[libc++] Fixed copy/copy_n/copy_backward for compilers that do not support is_constant_evaluated.
Differential Revision: https://reviews.llvm.org/D69940
Cr-Mirrored-From: sso://chromium.googlesource.com/_direct/external/github.com/llvm/llvm-project
Cr-Mirrored-Commit: 83901cbe5e21906523b7073f8ec7beb4d5a91021
diff --git a/include/__config b/include/__config
index 044cd0c..47b40c4 100644
--- a/include/__config
+++ b/include/__config
@@ -1002,6 +1002,14 @@
# define _LIBCPP_CONSTEXPR_AFTER_CXX17
#endif
+#if _LIBCPP_STD_VER > 17 && \
+ !defined(_LIBCPP_HAS_NO_CXX14_CONSTEXPR) && \
+ !defined(_LIBCPP_HAS_NO_BUILTIN_IS_CONSTANT_EVALUATED)
+# define _LIBCPP_CONSTEXPR_AFTER_CXX17_WITH_IS_CONSTANT_EVALUATED constexpr
+#else
+# define _LIBCPP_CONSTEXPR_AFTER_CXX17_WITH_IS_CONSTANT_EVALUATED
+#endif
+
// The _LIBCPP_NODISCARD_ATTRIBUTE should only be used to define other
// NODISCARD macros to the correct attribute.
#if __has_cpp_attribute(nodiscard) || defined(_LIBCPP_COMPILER_MSVC)
diff --git a/include/algorithm b/include/algorithm
index 419ec2c..7481cc2 100644
--- a/include/algorithm
+++ b/include/algorithm
@@ -1727,7 +1727,7 @@
}
template <class _InputIterator, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17_WITH_IS_CONSTANT_EVALUATED
_OutputIterator
copy(_InputIterator __first, _InputIterator __last, _OutputIterator __result)
{
@@ -1780,7 +1780,7 @@
}
template <class _BidirectionalIterator1, class _BidirectionalIterator2>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17_WITH_IS_CONSTANT_EVALUATED
_BidirectionalIterator2
copy_backward(_BidirectionalIterator1 __first, _BidirectionalIterator1 __last,
_BidirectionalIterator2 __result)
@@ -1818,7 +1818,7 @@
// copy_n
template<class _InputIterator, class _Size, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17_WITH_IS_CONSTANT_EVALUATED
typename enable_if
<
__is_input_iterator<_InputIterator>::value &&
@@ -1844,7 +1844,7 @@
}
template<class _InputIterator, class _Size, class _OutputIterator>
-inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17
+inline _LIBCPP_INLINE_VISIBILITY _LIBCPP_CONSTEXPR_AFTER_CXX17_WITH_IS_CONSTANT_EVALUATED
typename enable_if
<
__is_random_access_iterator<_InputIterator>::value,
diff --git a/test/std/algorithms/alg.modifying.operations/alg.copy/copy.pass.cpp b/test/std/algorithms/alg.modifying.operations/alg.copy/copy.pass.cpp
index 2cdd3b9..ab6aaa2 100644
--- a/test/std/algorithms/alg.modifying.operations/alg.copy/copy.pass.cpp
+++ b/test/std/algorithms/alg.modifying.operations/alg.copy/copy.pass.cpp
@@ -79,7 +79,7 @@
{
test();
-#if TEST_STD_VER > 17
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_BUILTIN_IS_CONSTANT_EVALUATED)
static_assert(test());
#endif
diff --git a/test/std/algorithms/alg.modifying.operations/alg.copy/copy_backward.pass.cpp b/test/std/algorithms/alg.modifying.operations/alg.copy/copy_backward.pass.cpp
index 6eb403d..11eb21f 100644
--- a/test/std/algorithms/alg.modifying.operations/alg.copy/copy_backward.pass.cpp
+++ b/test/std/algorithms/alg.modifying.operations/alg.copy/copy_backward.pass.cpp
@@ -58,7 +58,7 @@
{
test();
-#if TEST_STD_VER > 17
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_BUILTIN_IS_CONSTANT_EVALUATED)
static_assert(test());
#endif
diff --git a/test/std/algorithms/alg.modifying.operations/alg.copy/copy_n.pass.cpp b/test/std/algorithms/alg.modifying.operations/alg.copy/copy_n.pass.cpp
index 72c22b5..8c4900f 100644
--- a/test/std/algorithms/alg.modifying.operations/alg.copy/copy_n.pass.cpp
+++ b/test/std/algorithms/alg.modifying.operations/alg.copy/copy_n.pass.cpp
@@ -82,7 +82,7 @@
{
test();
-#if TEST_STD_VER > 17
+#if TEST_STD_VER > 17 && !defined(_LIBCPP_HAS_NO_BUILTIN_IS_CONSTANT_EVALUATED)
static_assert(test());
#endif