/* * This file is part of OpenTTD. * OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2. * OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. * See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see . */ /** @file ottd_optional.h Header to select between native. */ #ifndef OTTD_OPTIONAL_H #define OTTD_OPTIONAL_H #if defined(__has_include) # if __has_include() # include # endif #endif #if (__cplusplus >= 201703L) || (defined(__cpp_lib_optional) && __cpp_lib_optional >= 201606L) /* Native std::optional. */ #include namespace opt = std; #else /* No std::optional, use local copy instead. */ #include "optional.hpp" namespace opt = std::experimental; #endif #endif /* OTTD_OPTIONAL_H */