/* $Id$ */ #ifndef HELPERS_HPP #define HELPERS_HPP /** @file helpers.hpp */ #include "macros.h" /** When allocating using malloc/calloc in C++ it is usually needed to cast the return value * from void* to the proper pointer type. Another alternative would be MallocT<> as follows */ template <typename T> FORCEINLINE T* MallocT(size_t num_elements) { T *t_ptr = (T*)malloc(num_elements * sizeof(T)); return t_ptr; } /** When allocating using malloc/calloc in C++ it is usually needed to cast the return value * from void* to the proper pointer type. Another alternative would be MallocT<> as follows */ template <typename T> FORCEINLINE T* CallocT(size_t num_elements) { T *t_ptr = (T*)calloc(num_elements, sizeof(T)); return t_ptr; } /** When allocating using malloc/calloc in C++ it is usually needed to cast the return value * from void* to the proper pointer type. Another alternative would be MallocT<> as follows */ template <typename T> FORCEINLINE T* ReallocT(T* t_ptr, size_t num_elements) { t_ptr = (T*)realloc(t_ptr, num_elements * sizeof(T)); return t_ptr; } /** type safe swap operation */ template<typename T> void Swap(T& a, T& b) { T t = a; a = b; b = t; } /** returns the absolute value of (scalar) variable. @note assumes variable to be signed */ template <typename T> static inline T myabs(T a) { return a < (T)0 ? -a : a; } /** returns the (absolute) difference between two (scalar) variables */ template <typename T> static inline T delta(T a, T b) { return a < b ? b - a : a - b; } /** 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);} /** probably redundant enum combining operators (as we have conversion functions) * but the old code is full of such arithmetics */ # define DECLARE_ENUM_AS_BIT_INDEX(idx_t, mask_t) \ FORCEINLINE mask_t operator << (int m, idx_t i) {return (mask_t)(m << (int)i);} \ FORCEINLINE mask_t operator << (mask_t m, int i) {return (mask_t)(((int)m) << i);} \ FORCEINLINE mask_t operator >> (mask_t m, int i) {return (mask_t)(((int)m) >> i);} /** 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<>. */ 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. */ 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) { if (++m_val >= end) m_val -= (storage_type)(end - begin); return *this; } }; template <typename T> FORCEINLINE T ClrBitT(T t, int bit_index) { int val = t; CLRBIT(val, bit_index); return (T)val; } template <typename T> FORCEINLINE T SetBitT(T t, int bit_index) { int val = t; SETBIT(val, bit_index); return (T)val; } template <typename T> FORCEINLINE T ToggleBitT(T t, int bit_index) { int val = t; TOGGLEBIT(val, bit_index); return (T)val; } #endif /* HELPERS_HPP */