/* $Id$ */ /** @file cmd_helper.h Helper functions to extract data from command parameters. */ #ifndef CMD_HELPER_H #define CMD_HELPER_H #include "direction_type.h" #include "road_type.h" template<uint N> static inline void ExtractValid(); template<> inline void ExtractValid<1>() {} template<typename T> struct ExtractBits; template<> struct ExtractBits<Axis> { static const uint Count = 1; }; template<> struct ExtractBits<DiagDirection> { static const uint Count = 2; }; template<> struct ExtractBits<RoadBits> { static const uint Count = 4; }; template<typename T, uint N, typename U> static inline T Extract(U v) { /* Check if there are enough bits in v */ ExtractValid<N + ExtractBits<T>::Count <= sizeof(U) * 8>(); return (T)GB(v, N, ExtractBits<T>::Count); } #endif