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* [gcc r9-9474] libstdc++: Define __cpp_lib_constexpr_string macro
@ 2021-04-29 11:14 Jonathan Wakely
0 siblings, 0 replies; only message in thread
From: Jonathan Wakely @ 2021-04-29 11:14 UTC (permalink / raw)
To: gcc-cvs, libstdc++-cvs
https://gcc.gnu.org/g:cd5a61a33f6223314b14ae1aa2eed09c20ef81e1
commit r9-9474-gcd5a61a33f6223314b14ae1aa2eed09c20ef81e1
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Wed Apr 28 15:56:04 2021 +0100
libstdc++: Define __cpp_lib_constexpr_string macro
As noted in r11-1339-gb6ab9ecd550227684643b41e9e33a4d3466724d8 we define
a non-standard __cpp_lib_constexpr_char_traits feature test macro to
indicate support for P0426R1 and P1032R1. At some point last year the
__cpp_lib_constexpr_string macro was retconned to indicate support for
those papers. This adds the new macro (which we didn't previously
define, because it referred to P0980R1 "Making std::string constexpr"
which we don't support).
libstdc++-v3/ChangeLog:
* include/bits/basic_string.h (__cpp_lib_constexpr_string): Define.
* include/std/version (__cpp_lib_constexpr_string): Define.
* testsuite/21_strings/char_traits/requirements/constexpr_functions_c++17.cc:
Check for __cpp_lib_constexpr_string.
* testsuite/21_strings/char_traits/requirements/version.cc: New test.
(cherry picked from commit 3da80ed7efd582575e7850a403ce693ec882d087)
Diff:
---
libstdc++-v3/include/bits/basic_string.h | 3 ++-
libstdc++-v3/include/std/version | 1 +
.../requirements/constexpr_functions_c++17.cc | 7 +++++++
.../21_strings/char_traits/requirements/version.cc | 16 ++++++++++++++++
4 files changed, 26 insertions(+), 1 deletion(-)
diff --git a/libstdc++-v3/include/bits/basic_string.h b/libstdc++-v3/include/bits/basic_string.h
index cacc31a9aa9..fbca63bb3aa 100644
--- a/libstdc++-v3/include/bits/basic_string.h
+++ b/libstdc++-v3/include/bits/basic_string.h
@@ -48,11 +48,12 @@
# include <string_view>
#endif
-
namespace std _GLIBCXX_VISIBILITY(default)
{
_GLIBCXX_BEGIN_NAMESPACE_VERSION
+#define __cpp_lib_constexpr_string 201611L
+
#if _GLIBCXX_USE_CXX11_ABI
_GLIBCXX_BEGIN_NAMESPACE_CXX11
/**
diff --git a/libstdc++-v3/include/std/version b/libstdc++-v3/include/std/version
index 0f704c054cf..51cc821558f 100644
--- a/libstdc++-v3/include/std/version
+++ b/libstdc++-v3/include/std/version
@@ -126,6 +126,7 @@
#define __cpp_lib_chrono 201611
#define __cpp_lib_clamp 201603
#define __cpp_lib_constexpr_char_traits 201611
+#define __cpp_lib_constexpr_string 201611L
#define __cpp_lib_enable_shared_from_this 201603
#define __cpp_lib_execution 201902L // FIXME: should be 201603L
#define __cpp_lib_filesystem 201703
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 92c301b1900..6dd181fd33c 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
@@ -73,6 +73,13 @@ template<typename CT>
return true;
}
+#ifndef __cpp_lib_constexpr_string
+# error Feature-test macro for constexpr char_traits is missing
+#elif __cpp_lib_constexpr_string < 201611
+# error Feature-test macro for constexpr char_traits has the wrong value
+#endif
+
+// We also provide this non-standard macro for P0426R1.
#ifndef __cpp_lib_constexpr_char_traits
# error Feature-test macro for constexpr char_traits is missing
#elif __cpp_lib_constexpr_char_traits != 201611
diff --git a/libstdc++-v3/testsuite/21_strings/char_traits/requirements/version.cc b/libstdc++-v3/testsuite/21_strings/char_traits/requirements/version.cc
new file mode 100644
index 00000000000..073fa36ab18
--- /dev/null
+++ b/libstdc++-v3/testsuite/21_strings/char_traits/requirements/version.cc
@@ -0,0 +1,16 @@
+// { dg-do compile { target c++17 } }
+
+#include <version>
+
+#ifndef __cpp_lib_constexpr_string
+# error Feature-test macro for constexpr char_traits is missing in <version>
+#elif __cpp_lib_constexpr_string < 201611
+# error Feature-test macro for constexpr char_traits has the wrong value in <version>
+#endif
+
+// We also provide this non-standard macro for P0426R1 and P1032R1.
+#ifndef __cpp_lib_constexpr_char_traits
+# error Feature-test macro for constexpr char_traits is missing in <version>
+#elif __cpp_lib_constexpr_char_traits != 201611
+# error Feature-test macro for constexpr char_traits has the wrong value in <version>
+#endif
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