From 8ab4958e4421d9b7f7f8ccdb9c8d6c0e9ff8ef75 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jean-Micha=C3=ABl=20Celerier?=
 <jeanmichael.celerier@gmail.com>
Date: Tue, 7 Sep 2021 16:16:30 +0200
Subject: [PATCH] Fix build for the clang-10 / libstdc++-9 couple

---
 include/fmt/core.h | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/include/fmt/core.h b/include/fmt/core.h
index 4cfa00bf..1f782647 100644
--- a/include/fmt/core.h
+++ b/include/fmt/core.h
@@ -94,7 +94,8 @@
 #  define FMT_CONSTEXPR_DECL
 #endif
 
-#if __cplusplus >= 202002L || \
+#if ((__cplusplus >= 202002L) && \
+     (!defined(_GLIBCXX_RELEASE) || _GLIBCXX_RELEASE > 9)) || \
     (__cplusplus >= 201709L && FMT_GCC_VERSION >= 1002)
 #  define FMT_CONSTEXPR20 constexpr
 #else