/* $Id$ */ /* * 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 <http://www.gnu.org/licenses/>. */ /** @file cmd_helper.h Helper functions to extract data from command parameters. */ #ifndef CMD_HELPER_H #define CMD_HELPER_H #include "core/enum_type.hpp" #include "core/bitmath_func.hpp" /** * Extracts a given type from a value. * @tparam T The type of data we're looking for. * @tparam S The offset in the data. * @tparam N The amount of bits to read. * @tparam U The type of data passed to us. * @param v The data to extract the value from. */ template<typename T, uint S, uint N, typename U> static inline T Extract(U v) { /* Check if there are enough bits in v */ assert_tcompile(N == EnumPropsT<T>::num_bits); assert_tcompile(S + N <= sizeof(U) * 8); assert_tcompile(EnumPropsT<T>::end <= (1 << N)); U masked = GB(v, S, N); return IsInsideMM(masked, EnumPropsT<T>::begin, EnumPropsT<T>::end) ? (T)masked : EnumPropsT<T>::invalid; } #endif /* CMD_HELPER_H */