/* $Id$ */

#ifndef CMD_HELPER_H

#define CMD_HELPER_H

#include "direction.h"

#include "macros.h"

#include "road.h"

template<uint N> static inline void ExtractValid();

template<> static 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