From 76e06c89e419db196cda20e0e43171f9461139ae Mon Sep 17 00:00:00 2001
From: Dean Moldovan <dean0x7d@gmail.com>
Date: Sun, 13 Aug 2017 15:48:08 +0200
Subject: [PATCH] Avoid duplicate C++ standard flags if CMAKE_CXX_STANDARD is
 set

CMAKE_CXX_STANDARD is only available on CMake >= 3.1. If the flag is
set, we avoid initializing PYBIND11_CPP_STANDARD.
---
 tools/pybind11Tools.cmake | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/pybind11Tools.cmake b/tools/pybind11Tools.cmake
index 63752ead1..a7c471a07 100644
--- a/tools/pybind11Tools.cmake
+++ b/tools/pybind11Tools.cmake
@@ -18,7 +18,7 @@ find_package(PythonLibsNew ${PYBIND11_PYTHON_VERSION} REQUIRED)
 include(CheckCXXCompilerFlag)
 include(CMakeParseArguments)
 
-if(NOT PYBIND11_CPP_STANDARD)
+if(NOT PYBIND11_CPP_STANDARD AND NOT CMAKE_CXX_STANDARD)
   if(NOT MSVC)
     check_cxx_compiler_flag("-std=c++14" HAS_CPP14_FLAG)