Заплатка для версий CMake < 3.8.0

CMLibCompilerFlags.cmake

@@ -36,10 +36,14 @@ set(CMAKE_CXX_STANDARD_REQUIRED YES)
 
 check_cxx_compiler_flag(-std=c++17 HAVE_FLAG_STD_CXX17)
 if(HAVE_FLAG_STD_CXX17)
-  set(CMAKE_CXX_STANDARD 17)
-  check_cxx_compiler_flag(-std=gnu++17 HAVE_FLAG_STD_GNUXX17)
-  if(HAVE_FLAG_STD_GNUXX17)
-    set(CMAKE_CXX_EXTENSIONS YES)
+  if(${CMAKE_VERSION} VERSION_LESS "3.8.0")
+    check_enable_cxx_flag(-std=c++17)
+  else()
+    set(CMAKE_CXX_STANDARD 17)
+    check_cxx_compiler_flag(-std=gnu++17 HAVE_FLAG_STD_GNUXX17)
+    if(HAVE_FLAG_STD_GNUXX17)
+      set(CMAKE_CXX_EXTENSIONS YES)
+    endif()
   endif()
 else()
   check_cxx_compiler_flag(-std=c++14 HAVE_FLAG_STD_CXX14)