From 225c8cde6380721691d0668e4c8874b3de6fa770 Mon Sep 17 00:00:00 2001
From: Stefan Siegl <stesie@brokenpipe.de>
Date: Fri, 24 Jun 2022 21:27:33 +0200
Subject: [PATCH] test compiler for c++17 support

---
 config.m4 | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/config.m4 b/config.m4
index bb823f4..0cccd8c 100644
--- a/config.m4
+++ b/config.m4
@@ -39,11 +39,15 @@ if test "$PHP_V8JS" != "no"; then
 
 
   AC_CACHE_CHECK(for C standard version, ac_cv_v8_cstd, [
-    ac_cv_v8_cstd="c++14"
+    ac_cv_v8_cstd="c++17"
     old_CPPFLAGS=$CPPFLAGS
     AC_LANG_PUSH([C++])
     CPPFLAGS="-std="$ac_cv_v8_cstd
-    AC_RUN_IFELSE([AC_LANG_SOURCE([[int main() { return 0; }]])],[],[ac_cv_v8_cstd="c++1y"],[])
+    AC_RUN_IFELSE([AC_LANG_SOURCE([[int main() { return 0; }]])],[],[
+      ac_cv_v8_cstd="c++14"
+      CPPFLAGS="-std="$ac_cv_v8_cstd
+      AC_RUN_IFELSE([AC_LANG_SOURCE([[int main() { return 0; }]])],[],[ ac_cv_v8_cstd="c++1y" ],[])
+    ],[])
     AC_LANG_POP([C++])
     CPPFLAGS=$old_CPPFLAGS
   ]);