OpenTTD-patches/src/cmd_helper.h

35 lines
1.4 KiB
C++

/*
* 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 */
static_assert(N == EnumPropsT<T>::num_bits);
static_assert(S + N <= sizeof(U) * 8);
static_assert(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 */