On 22/04/20 22:59 +0100, Jonathan Wakely wrote:
This macro should have been updated to 201811 when the last C++20
changes were implemented. However those changes are not enabled for
C++17 mode, so the macro should only have the new value in C++20 mode.
This change ensures that the macro is defined to 201603 for C++17 and
201811 for C++20.
* include/bits/stl_iterator.h (__cpp_lib_array_constexpr): Define
different values for C++17 and C++20, to indicate different feature
sets. Update value for C++20 to indicate P1032R1 support.
* include/std/version (__cpp_lib_array_constexpr): Likewise.
* testsuite/23_containers/array/comparison_operators/constexpr.cc:
Check feature test macro.
* testsuite/23_containers/array/element_access/constexpr_c++17.cc:
New test.
* testsuite/23_containers/array/requirements/constexpr_fill.cc: Check
feature test macro.
* testsuite/23_containers/array/requirements/constexpr_iter.cc: Test
in C++17 mode and check feature test macro.
On second thoughts, changing __cpp_lib_array_constexpr for C++17 was
wrong, it should have been left at 201803.
This partially reverts my previous change related to this macro. The
C++20 constexpr iterator requirements are always met by array:iterator,
because it's just a pointer. So the macro can be set to 201803 even in
C++17 mode.
Tested powerpc64le-linux, committed to master.
commit 40541efe1c063e9ce894b5f11ff727e4aec56e8b
Author: Jonathan Wakely <jwak...@redhat.com>
Date: Thu Apr 23 21:39:33 2020 +0100
libstdc++: Change __cpp_lib_array_constexpr for C++17 again
This partially reverts my previous change related to this macro. The
C++20 constexpr iterator requirements are always met by array:iterator,
because it's just a pointer. So the macro can be set to 201803 even in
C++17 mode.
* include/bits/stl_iterator.h (__cpp_lib_array_constexpr): Revert
value for C++17 to 201803L because P0858R0 is supported for C++17.
* include/std/version (__cpp_lib_array_constexpr): Likewise.
* testsuite/23_containers/array/element_access/constexpr_c++17.cc:
Check for value corresponding to P0031R0 features being tested.
* testsuite/23_containers/array/requirements/constexpr_iter.cc:
Check for value corresponding to P0858R0 features being tested.
diff --git a/libstdc++-v3/include/bits/stl_iterator.h b/libstdc++-v3/include/bits/stl_iterator.h
index d7e85b84041..cc0b3e0a766 100644
--- a/libstdc++-v3/include/bits/stl_iterator.h
+++ b/libstdc++-v3/include/bits/stl_iterator.h
@@ -72,7 +72,7 @@
#if __cplusplus > 201703L
# define __cpp_lib_array_constexpr 201811L
#elif __cplusplus == 201703L
-# define __cpp_lib_array_constexpr 201603L
+# define __cpp_lib_array_constexpr 201803L
#endif
#if __cplusplus > 201703L
diff --git a/libstdc++-v3/include/std/version b/libstdc++-v3/include/std/version
index 1beb9aa938e..fa505f25e98 100644
--- a/libstdc++-v3/include/std/version
+++ b/libstdc++-v3/include/std/version
@@ -123,7 +123,7 @@
#if _GLIBCXX_HOSTED
#define __cpp_lib_any 201606L
#define __cpp_lib_apply 201603
-#define __cpp_lib_array_constexpr 201603L
+#define __cpp_lib_array_constexpr 201803L
#define __cpp_lib_as_const 201510
#define __cpp_lib_boyer_moore_searcher 201603
#define __cpp_lib_chrono 201611
diff --git a/libstdc++-v3/testsuite/23_containers/array/element_access/constexpr_c++17.cc b/libstdc++-v3/testsuite/23_containers/array/element_access/constexpr_c++17.cc
index 56d1cf256be..dd69645833f 100644
--- a/libstdc++-v3/testsuite/23_containers/array/element_access/constexpr_c++17.cc
+++ b/libstdc++-v3/testsuite/23_containers/array/element_access/constexpr_c++17.cc
@@ -24,8 +24,6 @@
# error "Feature test macro for array constexpr is missing in <array>"
#elif __cpp_lib_array_constexpr < 201603L
# error "Feature test macro for array constexpr has wrong value in <array>"
-#elif __cpp_lib_array_constexpr > 201603L && __cplusplus == 201703
-# error "Feature test macro for array constexpr has wrong value for C++17"
#endif
constexpr std::size_t test01()
diff --git a/libstdc++-v3/testsuite/23_containers/array/requirements/constexpr_iter.cc b/libstdc++-v3/testsuite/23_containers/array/requirements/constexpr_iter.cc
index a119937f773..566388405b6 100644
--- a/libstdc++-v3/testsuite/23_containers/array/requirements/constexpr_iter.cc
+++ b/libstdc++-v3/testsuite/23_containers/array/requirements/constexpr_iter.cc
@@ -22,12 +22,13 @@
#ifndef __cpp_lib_array_constexpr
# error "Feature test macro for array constexpr is missing in <array>"
-#elif __cpp_lib_array_constexpr < 201603L
+#elif __cpp_lib_array_constexpr < 201803L
# error "Feature test macro for array constexpr has wrong value in <array>"
-#elif __cpp_lib_array_constexpr > 201603L && __cplusplus == 201703
-# error "Feature test macro for array constexpr has wrong value for C++17"
#endif
+// This test is compiled as C++17 because array::iterator is just a pointer,
+// so always meets the C++20 constexpr iterator requirements, even in C++17.
+
constexpr int
test()
{
