--- a/CMakeLists.txt_use_cxx17	2019-07-29 10:31:06.000000000 +0200
+++ b/CMakeLists.txt	2019-07-31 19:04:52.285195735 +0200
@@ -118,9 +118,9 @@
 endif()
 
 if (CMAKE_MAJOR_VERSION LESS 3 OR CMAKE_MINOR_VERSION LESS 1)
-  set(CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS} "-std=c++11")
+  set(CMAKE_CXX_FLAGS ${CMAKE_CXX_FLAGS} "-std=gnu++17")
 else()
-  set(CMAKE_CXX_STANDARD 11)
+  set(CMAKE_CXX_STANDARD 17)
 endif()
 
 CHECK_FUNCTION_EXISTS(strptime HAVE_STRPTIME)