/* * 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 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 inline T Extract(U v) { /* Check if there are enough bits in v */ static_assert(N == EnumPropsT::num_bits); static_assert(S + N <= sizeof(U) * 8); static_assert(EnumPropsT::end <= (1 << N)); U masked = GB(v, S, N); return IsInsideMM(masked, EnumPropsT::begin, EnumPropsT::end) ? (T)masked : EnumPropsT::invalid; } #endif /* CMD_HELPER_H */