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author | tron <tron@openttd.org> | 2007-02-24 09:42:39 +0000 |
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committer | tron <tron@openttd.org> | 2007-02-24 09:42:39 +0000 |
commit | d3b29bcacb4589922a3afc85cf648609b49679dc (patch) | |
tree | cfdc363aade39ceff0da3ef6b20dbd7e95b49c83 /src/cmd_helper.h | |
parent | 1d1121f85a975a6b9ed8305c154fc39f4f5db7fd (diff) | |
download | openttd-d3b29bcacb4589922a3afc85cf648609b49679dc.tar.xz |
(svn r8876) -Fix
Replace tests with magic numbers by a simple extraction template for command parameters
Diffstat (limited to 'src/cmd_helper.h')
-rw-r--r-- | src/cmd_helper.h | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/src/cmd_helper.h b/src/cmd_helper.h new file mode 100644 index 000000000..115b0e1cf --- /dev/null +++ b/src/cmd_helper.h @@ -0,0 +1,28 @@ +/* $Id$ */ + +#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 |