From 47d085d1c20da0fa76756872b075260be8b63be6 Mon Sep 17 00:00:00 2001
From: Piotr Konopka <piotr.jan.konopka@cern.ch>
Date: Tue, 22 Apr 2025 15:27:02 +0200
Subject: [PATCH] Revert "Switch to C++20"

This reverts commit b81b4b24860861a00fdd6fcfc1807d6fa1fd0a7b.
---
 configure.ac | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/configure.ac b/configure.ac
index 24c5ff61fe7..b19440ae8a9 100644
--- a/configure.ac
+++ b/configure.ac
@@ -707,9 +707,9 @@ AX_CHECK_COMPILE_FLAG([-fstack-protector-strong],
   [AC_SUBST(STACK_PROTECTOR, "-fstack-protector-strong")],
   [AC_SUBST(STACK_PROTECTOR, "-fstack-protector")])
 
-# Ensure that CXX supports C++20 (with "strict" conformance), and set
+# Ensure that CXX supports C++11 (with "strict" conformance), and set
 # "--std=" flag and CXXFLAGS environment variable as appropriate.
-AX_CXX_COMPILE_STDCXX([20], [noext], [mandatory])
+AX_CXX_COMPILE_STDCXX([11], [noext], [mandatory])
 
 # Blacklist known incompatible C++ standard libraries to reduce chance
 # of users accidentally using them.