cmake variable `CMAKE_CXX_STANDARD` requires minimum version 3.1 of cmake. cmake_minimum_required line in `sources/CMakeLists.txt` should be updated to reflect this.
cmake variable
CMAKE_CXX_STANDARDrequires minimum version 3.1 of cmake.cmake_minimum_required line in
sources/CMakeLists.txtshould be updated to reflect this.