From 1e7a6b6e31171d6cf6e1f425ea7033acddacdef7 Mon Sep 17 00:00:00 2001
From: Moritz Bunkus <moritz@bunkus.org>
Date: Sat, 18 May 2019 17:12:27 +0200
Subject: [PATCH] build system: test for and use -std=c++17 compiler flag if
 supported

---
 ac/c++-features.m4 | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/ac/c++-features.m4 b/ac/c++-features.m4
index d7c0963af..6081624f7 100644
--- a/ac/c++-features.m4
+++ b/ac/c++-features.m4
@@ -1,10 +1,10 @@
 AC_DEFUN([AX_CXX_STD_CXX_FLAG],[
-  AC_CACHE_CHECK([for support for the "-std=c++14" flag], [ax_cv_std_cxx_flag],[
+  AC_CACHE_CHECK([for support for the "-std=c++17" flag], [ax_cv_std_cxx_flag],[
 
     AC_LANG_PUSH(C++)
     CXXFLAGS_SAVED="$CXXFLAGS"
 
-    for flag in gnu++14 c++14 gnu++11 c++11 c++0x; do
+    for flag in c++17 gnu++14 c++14 gnu++11 c++11 c++0x; do
       CXXFLAGS="$CXXFLAGS_SAVED -std=$flag"
       AC_TRY_COMPILE([], [true;], [ax_cv_std_cxx_flag="-std=$flag"], [ax_cv_std_cxx_flag="undecided"])