https://gcc.gnu.org/g:06848c239bda1458c8a4550307a2afc63b962036
commit 06848c239bda1458c8a4550307a2afc63b962036
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Mon Jun 15 14:31:26 2020 +0100
libstdc++: Update value of __cpp_lib_constexpr_char_traits for C++20
Although not required by SD-6 or the C++20 draft, we define the macro
__cpp_lib_constexpr_char_traits to indicate support for P0432R1. This
updates the value in C++20 mode for the P1032R1 changes to char_traits.
* include/bits/char_traits.h (__cpp_lib_constexpr_char_traits):
Update value for C++20.
* include/std/version (__cpp_lib_constexpr_char_traits): Likewise.
* testsuite/21_strings/char_traits/requirements/constexpr_functions_c++17.cc:
Update expected value.
* testsuite/21_strings/char_traits/requirements/constexpr_functions_c++20.cc:
Likewise.
Diff:
---
libstdc++-v3/include/bits/char_traits.h | 9 ++++++++-
libstdc++-v3/include/std/version | 6 ++++--
.../char_traits/requirements/constexpr_functions_c++17.cc | 4 +++-
.../char_traits/requirements/constexpr_functions_c++20.cc | 2 +-
4 files changed, 16 insertions(+), 5 deletions(-)
diff --git a/libstdc++-v3/include/bits/char_traits.h b/libstdc++-v3/include/bits/char_traits.h
index c623a6713f6..84c2d1b7ff2 100644
--- a/libstdc++-v3/include/bits/char_traits.h
+++ b/libstdc++-v3/include/bits/char_traits.h
@@ -236,7 +236,14 @@ namespace std _GLIBCXX_VISIBILITY(default)
_GLIBCXX_BEGIN_NAMESPACE_VERSION
#if __cplusplus >= 201703L
-#define __cpp_lib_constexpr_char_traits 201611
+
+#if __cplusplus == 201703L
+// Unofficial macro indicating P0426R1 support
+# define __cpp_lib_constexpr_char_traits 201611L
+#else
+// Also support P1032R1 in C++20
+# define __cpp_lib_constexpr_char_traits 201811L
+#endif
/**
* @brief Determine whether the characters of a NULL-terminated
diff --git a/libstdc++-v3/include/std/version b/libstdc++-v3/include/std/version
index c6bde2cfbda..f64aff4f520 100644
--- a/libstdc++-v3/include/std/version
+++ b/libstdc++-v3/include/std/version
@@ -127,7 +127,7 @@
#define __cpp_lib_boyer_moore_searcher 201603
#define __cpp_lib_chrono 201611
#define __cpp_lib_clamp 201603
-#define __cpp_lib_constexpr_char_traits 201611
+#define __cpp_lib_constexpr_char_traits 201611L
#define __cpp_lib_enable_shared_from_this 201603
#define __cpp_lib_execution 201902L // FIXME: should be 201603L
#define __cpp_lib_filesystem 201703
@@ -192,16 +192,18 @@
#if _GLIBCXX_HOSTED
#undef __cpp_lib_array_constexpr
+#undef __cpp_lib_constexpr_char_traits
#define __cpp_lib_array_constexpr 201811L
#define __cpp_lib_assume_aligned 201811L
#define __cpp_lib_bind_front 201907L
// FIXME: #define __cpp_lib_execution 201902L
#define __cpp_lib_integer_comparison_functions 202002L
#define __cpp_lib_constexpr_algorithms 201806L
+#define __cpp_lib_constexpr_char_traits 201811L
#define __cpp_lib_constexpr_complex 201711L
#define __cpp_lib_constexpr_dynamic_alloc 201907L
#define __cpp_lib_constexpr_functional 201907L
-# define __cpp_lib_constexpr_iterator 201811L
+#define __cpp_lib_constexpr_iterator 201811L
#define __cpp_lib_constexpr_memory 201811L
#define __cpp_lib_constexpr_numeric 201911L
#define __cpp_lib_constexpr_string_view 201811L
diff --git a/libstdc++-v3/testsuite/21_strings/char_traits/requirements/constexpr_functions_c++17.cc b/libstdc++-v3/testsuite/21_strings/char_traits/requirements/constexpr_functions_c++17.cc
index 7cb950b89f5..55dcba48db6 100644
--- a/libstdc++-v3/testsuite/21_strings/char_traits/requirements/constexpr_functions_c++17.cc
+++ b/libstdc++-v3/testsuite/21_strings/char_traits/requirements/constexpr_functions_c++17.cc
@@ -75,8 +75,10 @@ template<typename CT>
#ifndef __cpp_lib_constexpr_char_traits
# error Feature-test macro for constexpr char_traits is missing
-#elif __cpp_lib_constexpr_char_traits != 201611
+#elif __cpp_lib_constexpr_char_traits < 201611
# error Feature-test macro for constexpr char_traits has the wrong value
+#elif __cpp_lib_constexpr_char_traits > 201611 && __cplusplus == 201703
+# error Feature-test macro for constexpr char_traits has wrong value for C++17
#endif
static_assert( test_assign<std::char_traits<char>>() );
diff --git a/libstdc++-v3/testsuite/21_strings/char_traits/requirements/constexpr_functions_c++20.cc b/libstdc++-v3/testsuite/21_strings/char_traits/requirements/constexpr_functions_c++20.cc
index 6358640c1cb..63c7c9cbb57 100644
--- a/libstdc++-v3/testsuite/21_strings/char_traits/requirements/constexpr_functions_c++20.cc
+++ b/libstdc++-v3/testsuite/21_strings/char_traits/requirements/constexpr_functions_c++20.cc
@@ -32,7 +32,7 @@ template<typename CT>
#ifndef __cpp_lib_constexpr_char_traits
# error Feature-test macro for constexpr char_traits is missing
-#elif __cpp_lib_constexpr_char_traits != 201611
+#elif __cpp_lib_constexpr_char_traits != 201811
# error Feature-test macro for constexpr char_traits has the wrong value
#endif