--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/core/enum_type.hpp	Tue Dec 18 19:52:14 2007 +0000
@@ -0,0 +1,115 @@
+/* $Id$ */
+
+/** @file enum_type.hpp Type (helpers) for enums */
+
+#ifndef ENUM_TYPE_HPP
+#define ENUM_TYPE_HPP
+
+/** Some enums need to have allowed incrementing (i.e. StationClassID) */
+#define DECLARE_POSTFIX_INCREMENT(type) \
+	FORCEINLINE type operator ++(type& e, int) \
+	{ \
+		type e_org = e; \
+		e = (type)((int)e + 1); \
+		return e_org; \
+	} \
+	FORCEINLINE type operator --(type& e, int) \
+	{ \
+		type e_org = e; \
+		e = (type)((int)e - 1); \
+		return e_org; \
+	}
+
+
+
+/** Operators to allow to work with enum as with type safe bit set in C++ */
+# define DECLARE_ENUM_AS_BIT_SET(mask_t) \
+	FORCEINLINE mask_t operator | (mask_t m1, mask_t m2) {return (mask_t)((int)m1 | m2);} \
+	FORCEINLINE mask_t operator & (mask_t m1, mask_t m2) {return (mask_t)((int)m1 & m2);} \
+	FORCEINLINE mask_t operator ^ (mask_t m1, mask_t m2) {return (mask_t)((int)m1 ^ m2);} \
+	FORCEINLINE mask_t& operator |= (mask_t& m1, mask_t m2) {m1 = m1 | m2; return m1;} \
+	FORCEINLINE mask_t& operator &= (mask_t& m1, mask_t m2) {m1 = m1 & m2; return m1;} \
+	FORCEINLINE mask_t& operator ^= (mask_t& m1, mask_t m2) {m1 = m1 ^ m2; return m1;} \
+	FORCEINLINE mask_t operator ~(mask_t m) {return (mask_t)(~(int)m);}
+
+
+/** Informative template class exposing basic enumeration properties used by several
+ *  other templates below. Here we have only forward declaration. For each enum type
+ *  we will create specialization derived from MakeEnumPropsT<>.
+ *  i.e.:
+ *    template <> struct EnumPropsT<Track> : MakeEnumPropsT<Track, byte, TRACK_BEGIN, TRACK_END, INVALID_TRACK> {};
+ *  followed by:
+ *    typedef TinyEnumT<Track> TrackByte;
+ */
+template <typename Tenum_t> struct EnumPropsT;
+
+/** Helper template class that makes basic properties of given enumeration type visible
+ *  from outsize. It is used as base class of several EnumPropsT specializations each
+ *  dedicated to one of commonly used enumeration types.
+ *  @param Tenum_t enumeration type that you want to describe
+ *  @param Tstorage_t what storage type would be sufficient (i.e. byte)
+ *  @param Tbegin first valid value from the contiguous range (i.e. TRACK_BEGIN)
+ *  @param Tend one past the last valid value from the contiguous range (i.e. TRACK_END)
+ *  @param Tinvalid value used as invalid value marker (i.e. INVALID_TRACK)
+ */
+template <typename Tenum_t, typename Tstorage_t, Tenum_t Tbegin, Tenum_t Tend, Tenum_t Tinvalid>
+struct MakeEnumPropsT {
+	typedef Tenum_t type;                     ///< enum type (i.e. Trackdir)
+	typedef Tstorage_t storage;               ///< storage type (i.e. byte)
+	static const Tenum_t begin = Tbegin;      ///< lowest valid value (i.e. TRACKDIR_BEGIN)
+	static const Tenum_t end = Tend;          ///< one after the last valid value (i.e. TRACKDIR_END)
+	static const Tenum_t invalid = Tinvalid;  ///< what value is used as invalid value (i.e. INVALID_TRACKDIR)
+};
+
+
+
+/** In some cases we use byte or uint16 to store values that are defined as enum. It is
+	*  necessary in order to control the sizeof() such values. Some compilers make enum
+	*  the same size as int (4 or 8 bytes instead of 1 or 2). As a consequence the strict
+	*  compiler type-checking causes errors like:
+	*     'HasPowerOnRail' : cannot convert parameter 1 from 'byte' to 'RailType' when
+	*  u->u.rail.railtype is passed as argument or type RailType. In such cases it is better
+	*  to teach the compiler that u->u.rail.railtype is to be treated as RailType. */
+template <typename Tenum_t> struct TinyEnumT;
+
+/** The general declaration of TinyEnumT<> (above) */
+template <typename Tenum_t> struct TinyEnumT
+{
+	typedef Tenum_t enum_type;                      ///< expose our enumeration type (i.e. Trackdir) to outside
+	typedef EnumPropsT<Tenum_t> Props;              ///< make easier access to our enumeration propeties
+	typedef typename Props::storage storage_type;   ///< small storage type
+	static const enum_type begin = Props::begin;    ///< enum beginning (i.e. TRACKDIR_BEGIN)
+	static const enum_type end = Props::end;        ///< enum end (i.e. TRACKDIR_END)
+	static const enum_type invalid = Props::invalid;///< invalid value (i.e. INVALID_TRACKDIR)
+
+	storage_type m_val;  ///< here we hold the actual value in small (i.e. byte) form
+
+	/** Cast operator - invoked then the value is assigned to the Tenum_t type */
+	FORCEINLINE operator enum_type () const
+	{
+		return (enum_type)m_val;
+	}
+
+	/** Assignment operator (from Tenum_t type) */
+	FORCEINLINE TinyEnumT& operator = (enum_type e)
+	{
+		m_val = (storage_type)e; return *this;
+	}
+
+	/** postfix ++ operator on tiny type */
+	FORCEINLINE TinyEnumT operator ++ (int)
+	{
+		TinyEnumT org = *this;
+		if (++m_val >= end) m_val -= (storage_type)(end - begin);
+		return org;
+	}
+
+	/** prefix ++ operator on tiny type */
+	FORCEINLINE TinyEnumT& operator ++ ()
+	{
+		if (++m_val >= end) m_val -= (storage_type)(end - begin);
+		return *this;
+	}
+};
+
+#endif /* HELPERS_HPP */