From 1849735f127c86deed80d90521b7117d1ebb38da Mon Sep 17 00:00:00 2001
From: Victor Zverovich <victor.zverovich@gmail.com>
Date: Sun, 11 Feb 2018 07:25:53 -0800
Subject: [PATCH] Fallback to c++11 if c++14 not available

---
 support/cmake/cxx14.cmake | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/support/cmake/cxx14.cmake b/support/cmake/cxx14.cmake
index c86cf508..d725917a 100644
--- a/support/cmake/cxx14.cmake
+++ b/support/cmake/cxx14.cmake
@@ -40,6 +40,17 @@ if (FMT_USE_CPP14)
     check_cxx_compiler_flag(-std=c++1y HAVE_STD_CPP1Y_FLAG)
     if (HAVE_STD_CPP1Y_FLAG)
       set(CPP14_FLAG -std=c++1y)
+    else ()
+      # Fallback on c++11 if c++14 is not available.
+      check_cxx_compiler_flag(-std=c++11 HAVE_STD_CPP11_FLAG)
+      if (HAVE_STD_CPP11_FLAG)
+        set(CPP14_FLAG -std=c++11)
+      else ()
+        check_cxx_compiler_flag(-std=c++0x HAVE_STD_CPP11_FLAG)
+        if (HAVE_STD_CPP0X_FLAG)
+          set(CPP14_FLAG -std=c++0x)
+        endif ()
+      endif ()
     endif ()
   endif ()
 endif ()