From 83ddde6b78b92c802abf538e077c36f2913caccd Mon Sep 17 00:00:00 2001
From: Peter Dimov <pdimov@pdimov.com>
Date: Sun, 14 Jan 2018 15:55:23 +0200
Subject: [PATCH] Disable constexpr on g++ 7/8 in C++17 mode due to
 https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83835

---
 include/boost/system/error_code.hpp | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/boost/system/error_code.hpp b/include/boost/system/error_code.hpp
index ba0b04a..abef021 100644
--- a/include/boost/system/error_code.hpp
+++ b/include/boost/system/error_code.hpp
@@ -42,6 +42,11 @@
 # define BOOST_SYSTEM_HAS_CONSTEXPR
 #endif
 
+#if defined(__GNUC__) && (__GNUC__ == 7 || __GNUC__ == 8) && __cplusplus >= 201700L
+// https://gcc.gnu.org/bugzilla/show_bug.cgi?id=83835
+#  undef BOOST_SYSTEM_HAS_CONSTEXPR
+#endif
+
 #if defined(BOOST_SYSTEM_HAS_CONSTEXPR)
 # define BOOST_SYSTEM_CONSTEXPR constexpr
 #else