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1 /* $Id$ */ |
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2 |
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3 #ifndef HELPERS_HPP |
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4 #define HELPERS_HPP |
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5 |
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6 /** @file helpers.hpp */ |
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7 #include "macros.h" |
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8 |
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9 #ifdef __cplusplus |
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10 |
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11 /** When allocating using malloc/calloc in C++ it is usually needed to cast the return value |
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12 * from void* to the proper pointer type. Another alternative would be MallocT<> as follows */ |
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13 template <typename T> FORCEINLINE bool MallocT(T** t_ptr, size_t num_elements) |
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14 { |
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15 *t_ptr = (T*)malloc(num_elements * sizeof(T)); |
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16 return (*t_ptr != NULL); |
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17 } |
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18 /** When allocating using malloc/calloc in C++ it is usually needed to cast the return value |
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19 * from void* to the proper pointer type. Another alternative would be MallocT<> as follows */ |
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20 template <typename T> FORCEINLINE bool CallocT(T** t_ptr, size_t num_elements) |
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21 { |
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22 *t_ptr = (T*)calloc(num_elements, sizeof(T)); |
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23 return (*t_ptr != NULL); |
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24 } |
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25 /** When allocating using malloc/calloc in C++ it is usually needed to cast the return value |
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26 * from void* to the proper pointer type. Another alternative would be MallocT<> as follows */ |
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27 template <typename T> FORCEINLINE bool ReallocT(T** t_ptr, size_t num_elements) |
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28 { |
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29 *t_ptr = (T*)realloc(*t_ptr, num_elements * sizeof(T)); |
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30 return (*t_ptr != NULL); |
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31 } |
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32 |
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33 /** type safe swap operation */ |
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34 template <typename T> void SwapT(T *a, T *b); |
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35 |
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36 template <typename T> FORCEINLINE void SwapT(T *a, T *b) |
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37 { |
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38 T t = *a; |
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39 *a = *b; |
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40 *b = t; |
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41 } |
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42 |
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43 |
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44 /** returns the absolute value of (scalar) variable. @note assumes variable to be signed */ |
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45 template <typename T> static inline T myabs(T a) { return a < (T)0 ? -a : a; } |
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46 /** returns the (absolute) difference between two (scalar) variables */ |
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47 template <typename T> static inline T delta(T a, T b) { return a < b ? b - a : a - b; } |
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48 |
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49 /** Some enums need to have allowed incrementing (i.e. StationClassID) */ |
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50 #define DECLARE_POSTFIX_INCREMENT(type) \ |
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51 FORCEINLINE type operator ++(type& e, int) \ |
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52 { \ |
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53 type e_org = e; \ |
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54 e = (type)((int)e + 1); \ |
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55 return e_org; \ |
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56 } \ |
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57 FORCEINLINE type operator --(type& e, int) \ |
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58 { \ |
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59 type e_org = e; \ |
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60 e = (type)((int)e - 1); \ |
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61 return e_org; \ |
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62 } |
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63 |
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64 |
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65 |
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66 /** Operators to allow to work with enum as with type safe bit set in C++ */ |
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67 # define DECLARE_ENUM_AS_BIT_SET(mask_t) \ |
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68 FORCEINLINE mask_t operator | (mask_t m1, mask_t m2) {return (mask_t)((int)m1 | m2);} \ |
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69 FORCEINLINE mask_t operator & (mask_t m1, mask_t m2) {return (mask_t)((int)m1 & m2);} \ |
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70 FORCEINLINE mask_t operator ^ (mask_t m1, mask_t m2) {return (mask_t)((int)m1 ^ m2);} \ |
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71 FORCEINLINE mask_t& operator |= (mask_t& m1, mask_t m2) {m1 = m1 | m2; return m1;} \ |
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72 FORCEINLINE mask_t& operator &= (mask_t& m1, mask_t m2) {m1 = m1 & m2; return m1;} \ |
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73 FORCEINLINE mask_t& operator ^= (mask_t& m1, mask_t m2) {m1 = m1 ^ m2; return m1;} \ |
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74 FORCEINLINE mask_t operator ~(mask_t m) {return (mask_t)(~(int)m);} |
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75 |
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76 /** probably redundant enum combining operators (as we have conversion functions) |
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77 * but the old code is full of such arithmetics */ |
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78 # define DECLARE_ENUM_AS_BIT_INDEX(idx_t, mask_t) \ |
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79 FORCEINLINE mask_t operator << (int m, idx_t i) {return (mask_t)(m << (int)i);} \ |
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80 FORCEINLINE mask_t operator << (mask_t m, int i) {return (mask_t)(((int)m) << i);} \ |
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81 FORCEINLINE mask_t operator >> (mask_t m, int i) {return (mask_t)(((int)m) >> i);} |
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82 |
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83 |
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84 /** Informative template class exposing basic enumeration properties used by several |
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85 * other templates below. Here we have only forward declaration. For each enum type |
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86 * we will create specialization derived from MakeEnumPropsT<>. */ |
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87 template <typename Tenum_t> struct EnumPropsT; |
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88 |
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89 /** Helper template class that makes basic properties of given enumeration type visible |
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90 * from outsize. It is used as base class of several EnumPropsT specializations each |
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91 * dedicated to one of commonly used enumeration types. */ |
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92 template <typename Tenum_t, typename Tstorage_t, Tenum_t Tbegin, Tenum_t Tend, Tenum_t Tinvalid> |
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93 struct MakeEnumPropsT { |
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94 typedef Tenum_t type; ///< enum type (i.e. Trackdir) |
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95 typedef Tstorage_t storage; ///< storage type (i.e. byte) |
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96 static const Tenum_t begin = Tbegin; ///< lowest valid value (i.e. TRACKDIR_BEGIN) |
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97 static const Tenum_t end = Tend; ///< one after the last valid value (i.e. TRACKDIR_END) |
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98 static const Tenum_t invalid = Tinvalid; ///< what value is used as invalid value (i.e. INVALID_TRACKDIR) |
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99 }; |
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100 |
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101 |
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102 |
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103 /** In some cases we use byte or uint16 to store values that are defined as enum. It is |
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104 * necessary in order to control the sizeof() such values. Some compilers make enum |
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105 * the same size as int (4 or 8 bytes instead of 1 or 2). As a consequence the strict |
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106 * compiler type-checking causes errors like: |
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107 * 'HasPowerOnRail' : cannot convert parameter 1 from 'byte' to 'RailType' when |
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108 * u->u.rail.railtype is passed as argument or type RailType. In such cases it is better |
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109 * to teach the compiler that u->u.rail.railtype is to be treated as RailType. */ |
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110 template <typename Tenum_t> struct TinyEnumT; |
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111 |
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112 /** The general declaration of TinyEnumT<> (above) */ |
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113 template <typename Tenum_t> struct TinyEnumT |
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114 { |
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115 typedef Tenum_t enum_type; ///< expose our enumeration type (i.e. Trackdir) to outside |
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116 typedef EnumPropsT<Tenum_t> Props; ///< make easier access to our enumeration propeties |
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117 typedef typename Props::storage storage_type; ///< small storage type |
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118 static const enum_type begin = Props::begin; ///< enum beginning (i.e. TRACKDIR_BEGIN) |
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119 static const enum_type end = Props::end; ///< enum end (i.e. TRACKDIR_END) |
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120 static const enum_type invalid = Props::invalid;///< invalid value (i.e. INVALID_TRACKDIR) |
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121 |
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122 storage_type m_val; ///< here we hold the actual value in small (i.e. byte) form |
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123 |
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124 /** Cast operator - invoked then the value is assigned to the Tenum_t type */ |
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125 FORCEINLINE operator enum_type () const |
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126 { |
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127 return (enum_type)m_val; |
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128 } |
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129 |
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130 /** Assignment operator (from Tenum_t type) */ |
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131 FORCEINLINE TinyEnumT& operator = (enum_type e) |
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132 { |
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133 m_val = (storage_type)e; return *this; |
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134 } |
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135 |
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136 /** postfix ++ operator on tiny type */ |
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137 FORCEINLINE TinyEnumT& operator ++ (int) |
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138 { |
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139 if (++m_val >= end) m_val -= (storage_type)(end - begin); |
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140 return *this; |
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141 } |
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142 }; |
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143 |
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144 template <typename Tenum_t> FORCEINLINE void SwapT(TinyEnumT<Tenum_t> *a, TinyEnumT<Tenum_t> *b) |
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145 { |
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146 SwapT(&a->m_val, &b->m_val); |
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147 } |
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148 |
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149 template <typename T> FORCEINLINE T ClrBitT(T t, int bit_index) |
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150 { |
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151 int val = t; |
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152 CLRBIT(val, bit_index); |
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153 return (T)val; |
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154 } |
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155 |
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156 template <typename T> FORCEINLINE T SetBitT(T t, int bit_index) |
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157 { |
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158 int val = t; |
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159 SETBIT(val, bit_index); |
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160 return (T)val; |
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161 } |
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162 |
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163 template <typename T> FORCEINLINE T ToggleBitT(T t, int bit_index) |
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164 { |
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165 int val = t; |
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166 TOGGLEBIT(val, bit_index); |
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167 return (T)val; |
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168 } |
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169 |
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170 #else // __cplusplus |
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171 |
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172 #define DECLARE_POSTFIX_INCREMENT(E) |
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173 #define DECLARE_ENUM_AS_BIT_SET(E) |
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174 #define DECLARE_ENUM_AS_BIT_INDEX(E1,E2) |
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175 |
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176 #endif // __cplusplus |
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177 |
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178 #endif /* HELPERS_HPP */ |