summaryrefslogtreecommitdiff
path: root/src/cmd_helper.h
blob: 9b5c12a0694fc282dd8c6bfb178c9d47435bffda (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
/* $Id$ */

/** @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