1 files changed, 4 insertions, 15 deletions
diff --git a/src/cmd_helper.h b/src/cmd_helper.h
index 8c9c789ca..a034f1217 100644
--- a/src/cmd_helper.h
+++ b/src/cmd_helper.h
@@ -12,25 +12,14 @@
 #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; };
-
+#include "core/enum_type.hpp"
 
 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);
+	assert_tcompile(N + EnumPropsT<T>::num_bits <= sizeof(U) * 8);
+	assert_tcompile(EnumPropsT<T>::end <= (1 << EnumPropsT<T>::num_bits));
+	return (T)GB(v, N, EnumPropsT<T>::num_bits);
 }
 
 #endif