From 233fa165adf091bf19a56957560d0625bd373bae Mon Sep 17 00:00:00 2001
From: Jonathan Wakely <jwakely@redhat.com>
Date: Fri, 20 Oct 2017 22:05:11 +0100
Subject: [PATCH] Update value of __cpp_lib_chrono feature-test macro

	* include/std/chrono (__cpp_lib_chrono): Update macro value to
	indicate support for P0505R0.
	* testsuite/20_util/duration/arithmetic/constexpr_c++17.cc: Check
	for updated macro.

From-SVN: r253959
---
 libstdc++-v3/ChangeLog                                     | 5 +++++
 libstdc++-v3/include/std/chrono                            | 4 ++--
 .../20_util/duration/arithmetic/constexpr_c++17.cc         | 7 +++++++
 3 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/libstdc++-v3/ChangeLog b/libstdc++-v3/ChangeLog
index 179361d9223..7ec3f90befd 100644
--- a/libstdc++-v3/ChangeLog
+++ b/libstdc++-v3/ChangeLog
@@ -1,5 +1,10 @@
 2017-10-20  Jonathan Wakely  <jwakely@redhat.com>
 
+	* include/std/chrono (__cpp_lib_chrono): Update macro value to
+	indicate support for P0505R0.
+	* testsuite/20_util/duration/arithmetic/constexpr_c++17.cc: Check
+	for updated macro.
+
 	* include/c_global/cstddef: Define __cpp_lib_byte feature-test macro.
 	* testsuite/18_support/byte/requirements.cc: Check macro.
 
diff --git a/libstdc++-v3/include/std/chrono b/libstdc++-v3/include/std/chrono
index fc058fcd8d8..9491508e637 100644
--- a/libstdc++-v3/include/std/chrono
+++ b/libstdc++-v3/include/std/chrono
@@ -214,8 +214,8 @@ _GLIBCXX_BEGIN_NAMESPACE_VERSION
         treat_as_floating_point<_Rep>::value;
 #endif // C++17
 
-#if __cplusplus > 201402L
-# define __cpp_lib_chrono 201510
+#if __cplusplus >= 201703L
+# define __cpp_lib_chrono 201611
 
     template<typename _ToDur, typename _Rep, typename _Period>
       constexpr __enable_if_is_duration<_ToDur>
diff --git a/libstdc++-v3/testsuite/20_util/duration/arithmetic/constexpr_c++17.cc b/libstdc++-v3/testsuite/20_util/duration/arithmetic/constexpr_c++17.cc
index 438d50afddf..0ba1b8cc706 100644
--- a/libstdc++-v3/testsuite/20_util/duration/arithmetic/constexpr_c++17.cc
+++ b/libstdc++-v3/testsuite/20_util/duration/arithmetic/constexpr_c++17.cc
@@ -20,6 +20,13 @@
 
 #include <chrono>
 #include <testsuite_common_types.h>
+
+#ifndef __cpp_lib_chrono
+# error "Feature-test macro for constexpr <chrono> missing"
+#elif __cpp_lib_chrono != 201611
+# error "Feature-test macro for constexpr <chrono> has wrong value"
+#endif
+
 constexpr auto test_operators()
 {
   std::chrono::nanoseconds d1 { 1 };
-- 
2.30.2