OpenTTD-patches/src/cmd_helper.h

30 lines
801 B
C++

/* $Id$ */
/** @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