Pull back cmake and C++ upgrade for now. Will reintroduce it in a
later change.
MODIFY
CMakeLists.txt
CMakeLists.txt
# -*- mode:cmake -*-
-cmake_minimum_required(VERSION 3.15)
+cmake_minimum_required(VERSION 3.5.1)
# Detect build type, fallback to release and throw a warning if use didn't
# specify any
@@ -30,7 +30,7 @@ add_subdirectory(third_party/antlr4/runtime/Cpp EXCLUDE_FROM_ALL)
add_subdirectory(third_party/UHDM)
add_subdirectory(third_party/googletest EXCLUDE_FROM_ALL)
-set(CMAKE_CXX_STANDARD 17)
+set(CMAKE_CXX_STANDARD 11)
set(CMAKE_CXX_STANDARD_REQUIRED ON)
set(CMAKE_EXPORT_COMPILE_COMMANDS ON)

Pull back cmake and C++ upgrade for now. Will reintroduce it in a
later change.