/
enum_type.hpp
177 lines (149 loc) · 6.74 KB
/
enum_type.hpp
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
/* $Id$ */
/*
* This file is part of OpenTTD.
* OpenTTD is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, version 2.
* OpenTTD is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
* See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with OpenTTD. If not, see <http://www.gnu.org/licenses/>.
*/
/** @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) \
inline type operator ++(type& e, int) \
{ \
type e_org = e; \
e = (type)((int)e + 1); \
return e_org; \
} \
inline 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) \
inline mask_t operator | (mask_t m1, mask_t m2) {return (mask_t)((int)m1 | m2);} \
inline mask_t operator & (mask_t m1, mask_t m2) {return (mask_t)((int)m1 & m2);} \
inline mask_t operator ^ (mask_t m1, mask_t m2) {return (mask_t)((int)m1 ^ m2);} \
inline mask_t& operator |= (mask_t& m1, mask_t m2) {m1 = m1 | m2; return m1;} \
inline mask_t& operator &= (mask_t& m1, mask_t m2) {m1 = m1 & m2; return m1;} \
inline mask_t& operator ^= (mask_t& m1, mask_t m2) {m1 = m1 ^ m2; return m1;} \
inline 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)
* @param Tnum_bits Number of bits for storing the enum in command parameters
*/
template <typename Tenum_t, typename Tstorage_t, Tenum_t Tbegin, Tenum_t Tend, Tenum_t Tinvalid, uint Tnum_bits = 8 * sizeof(Tstorage_t)>
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)
static const uint num_bits = Tnum_bits; ///< Number of bits for storing the enum in command parameters
};
/**
* 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 properties
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 */
inline operator enum_type () const
{
return (enum_type)m_val;
}
/** Assignment operator (from Tenum_t type) */
inline TinyEnumT& operator = (enum_type e)
{
m_val = (storage_type)e;
return *this;
}
/** Assignment operator (from Tenum_t type) */
inline TinyEnumT& operator = (uint u)
{
m_val = (storage_type)u;
return *this;
}
/** postfix ++ operator on tiny type */
inline TinyEnumT operator ++ (int)
{
TinyEnumT org = *this;
if (++m_val >= end) m_val -= (storage_type)(end - begin);
return org;
}
/** prefix ++ operator on tiny type */
inline TinyEnumT& operator ++ ()
{
if (++m_val >= end) m_val -= (storage_type)(end - begin);
return *this;
}
};
/** Template of struct holding enum types (on most archs, enums are stored in an int32). No math operators are provided. */
template <typename enum_type, typename storage_type>
struct SimpleTinyEnumT {
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 storage_type */
inline operator enum_type () const
{
return (enum_type)this->m_val;
}
/** Assignment operator (from enum_type) */
inline SimpleTinyEnumT &operator = (enum_type e)
{
this->m_val = (storage_type)e;
return *this;
}
/** Assignment operator (from general uint) */
inline SimpleTinyEnumT &operator = (uint u)
{
this->m_val = (storage_type)u;
return *this;
}
/** Bit math (or) assignment operator (from enum_type) */
inline SimpleTinyEnumT &operator |= (enum_type e)
{
this->m_val = (storage_type)((enum_type)this->m_val | e);
return *this;
}
/** Bit math (and) assignment operator (from enum_type) */
inline SimpleTinyEnumT &operator &= (enum_type e)
{
this->m_val = (storage_type)((enum_type)this->m_val & e);
return *this;
}
};
#endif /* ENUM_TYPE_HPP */