From a8fa4d318f46a877f31bf6d64339e7e81cd01561 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?G=C3=A1bor=20Cs=C3=A1rdi?= <csardi.gabor@gmail.com>
Date: Mon, 4 Dec 2023 11:22:50 +0100
Subject: [PATCH] Require C++17 on macOS

To be able to install the package on older R versions,
e.g. R 3.6 to R 4.2, which default to C++14 or C++11.
This is surely ok for macOS systems since Big Sur.
---
 tools/config/configure.R | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/config/configure.R b/tools/config/configure.R
index cef801f..a76102b 100644
--- a/tools/config/configure.R
+++ b/tools/config/configure.R
@@ -182,7 +182,7 @@ for (src_ in gle_cc) {
 pkg_sources <- sort(dir("./src", ".cpp$|.c$"), decreasing = TRUE)
 
 # compiler flags
-cxxflags <- ""
+cxxflags <- if (mac) "-std=gnu++17" else ""
 
 fix_flags <- function(x) {
   x <- gsub("-Wno-float-conversion ", "", x, fixed = TRUE)