From 6383a93ce7b3ada3e17dd1c67970ba76a0c46cd3 Mon Sep 17 00:00:00 2001
From: ToruNiina <niina.toru.68u@gmail.com>
Date: Fri, 26 Apr 2019 16:33:48 +0900
Subject: [PATCH] chore: check CXX_STANDARD exists or not

---
 CMakeLists.txt | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 05dbef1..f76b700 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -4,7 +4,10 @@ project(toml11)
 
 include(CheckCXXCompilerFlag)
 if("${CMAKE_VERSION}" VERSION_GREATER 3.1)
-    set(CMAKE_CXX_STANDARD 11)
+    set(CMAKE_CXX_EXTENSIONS OFF)
+    if(NOT DEFINED CMAKE_CXX_STANDARD)
+        set(CMAKE_CXX_STANDARD 11)
+    endif()
     set(CXX_STANDARD_REQUIRED ON)
 else()
     # Manually check for C++11 compiler flag.