summaryrefslogtreecommitdiffstats
path: root/src/corelib/global/qflags.h
blob: cc028e0095eb3ccdcea63c47e130a5a9918e620c (plain)
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
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
// Copyright (C) 2016 The Qt Company Ltd.
// SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only

#ifndef QFLAGS_H
#define QFLAGS_H

#include <QtCore/qcompare_impl.h>
#include <QtCore/qtypeinfo.h>

#include <initializer_list>

QT_BEGIN_NAMESPACE

class QDataStream;

class QFlag
{
    int i;
public:
    constexpr inline Q_IMPLICIT QFlag(int value) noexcept : i(value) {}
    constexpr inline Q_IMPLICIT operator int() const noexcept { return i; }

#if !defined(Q_CC_MSVC)
    // Microsoft Visual Studio has buggy behavior when it comes to
    // unsigned enums: even if the enum is unsigned, the enum tags are
    // always signed
#  if !defined(__LP64__) && !defined(Q_QDOC)
    constexpr inline Q_IMPLICIT QFlag(long value) noexcept : i(int(value)) {}
    constexpr inline Q_IMPLICIT QFlag(ulong value) noexcept : i(int(long(value))) {}
#  endif
    constexpr inline Q_IMPLICIT QFlag(uint value) noexcept : i(int(value)) {}
    constexpr inline Q_IMPLICIT QFlag(short value) noexcept : i(int(value)) {}
    constexpr inline Q_IMPLICIT QFlag(ushort value) noexcept : i(int(uint(value))) {}
    constexpr inline Q_IMPLICIT operator uint() const noexcept { return uint(i); }
#endif
};
Q_DECLARE_TYPEINFO(QFlag, Q_PRIMITIVE_TYPE);

class QIncompatibleFlag
{
    int i;
public:
    constexpr inline explicit QIncompatibleFlag(int i) noexcept;
    constexpr inline Q_IMPLICIT operator int() const noexcept { return i; }
};
Q_DECLARE_TYPEINFO(QIncompatibleFlag, Q_PRIMITIVE_TYPE);

constexpr inline QIncompatibleFlag::QIncompatibleFlag(int value) noexcept : i(value) {}


template<typename Enum>
class QFlags
{
    static_assert((sizeof(Enum) <= sizeof(int)),
                  "QFlags uses an int as storage, so an enum with underlying "
                  "long long will overflow.");
    static_assert((std::is_enum<Enum>::value), "QFlags is only usable on enumeration types.");

public:
#if defined(Q_CC_MSVC) || defined(Q_QDOC)
    // see above for MSVC
    // the definition below is too complex for qdoc
    typedef int Int;
#else
    typedef typename std::conditional<
            std::is_unsigned<typename std::underlying_type<Enum>::type>::value,
            unsigned int,
            signed int
        >::type Int;
#endif
    typedef Enum enum_type;
    // compiler-generated copy/move ctor/assignment operators are fine!
    constexpr inline QFlags() noexcept : i(0) {}
    constexpr inline Q_IMPLICIT QFlags(Enum flags) noexcept : i(Int(flags)) {}
    constexpr inline Q_IMPLICIT QFlags(QFlag flag) noexcept : i(flag) {}

    constexpr inline QFlags(std::initializer_list<Enum> flags) noexcept
        : i(initializer_list_helper(flags.begin(), flags.end())) {}

    constexpr static inline QFlags fromInt(Int i) noexcept { return QFlags(QFlag(i)); }
    constexpr inline Int toInt() const noexcept { return i; }

#ifndef QT_TYPESAFE_FLAGS
    constexpr inline QFlags &operator&=(int mask) noexcept { i &= mask; return *this; }
    constexpr inline QFlags &operator&=(uint mask) noexcept { i &= mask; return *this; }
#endif
    constexpr inline QFlags &operator&=(QFlags mask) noexcept { i &= mask.i; return *this; }
    constexpr inline QFlags &operator&=(Enum mask) noexcept { i &= Int(mask); return *this; }
    constexpr inline QFlags &operator|=(QFlags other) noexcept { i |= other.i; return *this; }
    constexpr inline QFlags &operator|=(Enum other) noexcept { i |= Int(other); return *this; }
    constexpr inline QFlags &operator^=(QFlags other) noexcept { i ^= other.i; return *this; }
    constexpr inline QFlags &operator^=(Enum other) noexcept { i ^= Int(other); return *this; }

#ifdef QT_TYPESAFE_FLAGS
    constexpr inline explicit operator Int() const noexcept { return i; }
    constexpr inline explicit operator bool() const noexcept { return i; }
    // For some reason, moc goes through QFlag in order to read/write
    // properties of type QFlags; so a conversion to QFlag is also
    // needed here. (It otherwise goes through a QFlags->int->QFlag
    // conversion sequence.)
    constexpr inline explicit operator QFlag() const noexcept { return QFlag(i); }
#else
    constexpr inline Q_IMPLICIT operator Int() const noexcept { return i; }
    constexpr inline bool operator!() const noexcept { return !i; }
#endif

    constexpr inline QFlags operator|(QFlags other) const noexcept { return QFlags(QFlag(i | other.i)); }
    constexpr inline QFlags operator|(Enum other) const noexcept { return QFlags(QFlag(i | Int(other))); }
    constexpr inline QFlags operator^(QFlags other) const noexcept { return QFlags(QFlag(i ^ other.i)); }
    constexpr inline QFlags operator^(Enum other) const noexcept { return QFlags(QFlag(i ^ Int(other))); }
#ifndef QT_TYPESAFE_FLAGS
    constexpr inline QFlags operator&(int mask) const noexcept { return QFlags(QFlag(i & mask)); }
    constexpr inline QFlags operator&(uint mask) const noexcept { return QFlags(QFlag(i & mask)); }
#endif
    constexpr inline QFlags operator&(QFlags other) const noexcept { return QFlags(QFlag(i & other.i)); }
    constexpr inline QFlags operator&(Enum other) const noexcept { return QFlags(QFlag(i & Int(other))); }
    constexpr inline QFlags operator~() const noexcept { return QFlags(QFlag(~i)); }

    constexpr inline void operator+(QFlags other) const noexcept = delete;
    constexpr inline void operator+(Enum other) const noexcept = delete;
    constexpr inline void operator+(int other) const noexcept = delete;
    constexpr inline void operator-(QFlags other) const noexcept = delete;
    constexpr inline void operator-(Enum other) const noexcept = delete;
    constexpr inline void operator-(int other) const noexcept = delete;

    constexpr inline bool testFlag(Enum flag) const noexcept { return testFlags(flag); }
    constexpr inline bool testFlags(QFlags flags) const noexcept { return flags.i ? ((i & flags.i) == flags.i) : i == Int(0); }
    constexpr inline bool testAnyFlag(Enum flag) const noexcept { return testAnyFlags(flag); }
    constexpr inline bool testAnyFlags(QFlags flags) const noexcept { return (i & flags.i) != Int(0); }
    constexpr inline QFlags &setFlag(Enum flag, bool on = true) noexcept
    {
        return on ? (*this |= flag) : (*this &= ~QFlags(flag));
    }

    friend constexpr inline bool operator==(QFlags lhs, QFlags rhs) noexcept
    { return lhs.i == rhs.i; }
    friend constexpr inline bool operator!=(QFlags lhs, QFlags rhs) noexcept
    { return lhs.i != rhs.i; }
    friend constexpr inline bool operator==(QFlags lhs, Enum rhs) noexcept
    { return lhs == QFlags(rhs); }
    friend constexpr inline bool operator!=(QFlags lhs, Enum rhs) noexcept
    { return lhs != QFlags(rhs); }
    friend constexpr inline bool operator==(Enum lhs, QFlags rhs) noexcept
    { return QFlags(lhs) == rhs; }
    friend constexpr inline bool operator!=(Enum lhs, QFlags rhs) noexcept
    { return QFlags(lhs) != rhs; }

#ifdef QT_TYPESAFE_FLAGS
    // Provide means of comparing flags against a literal 0; opt-in
    // because otherwise they're ambiguous against operator==(int,int)
    // after a QFlags->int conversion.
    friend constexpr inline bool operator==(QFlags flags, QtPrivate::CompareAgainstLiteralZero) noexcept
    { return flags.i == Int(0); }
    friend constexpr inline bool operator!=(QFlags flags, QtPrivate::CompareAgainstLiteralZero) noexcept
    { return flags.i != Int(0); }
    friend constexpr inline bool operator==(QtPrivate::CompareAgainstLiteralZero, QFlags flags) noexcept
    { return Int(0) == flags.i; }
    friend constexpr inline bool operator!=(QtPrivate::CompareAgainstLiteralZero, QFlags flags) noexcept
    { return Int(0) != flags.i; }
#endif

private:
    constexpr static inline Int initializer_list_helper(typename std::initializer_list<Enum>::const_iterator it,
                                                               typename std::initializer_list<Enum>::const_iterator end)
    noexcept
    {
        return (it == end ? Int(0) : (Int(*it) | initializer_list_helper(it + 1, end)));
    }

    Int i;
};

#ifndef Q_MOC_RUN
#define Q_DECLARE_FLAGS(Flags, Enum)\
typedef QFlags<Enum> Flags;
#endif

#ifdef QT_TYPESAFE_FLAGS

// These are opt-in, for backwards compatibility
#define QT_DECLARE_TYPESAFE_OPERATORS_FOR_FLAGS_ENUM(Flags) \
[[maybe_unused]] \
constexpr inline Flags operator~(Flags::enum_type e) noexcept \
{ return ~Flags(e); } \
[[maybe_unused]] \
constexpr inline void operator|(Flags::enum_type f1, int f2) noexcept = delete;
#else
#define QT_DECLARE_TYPESAFE_OPERATORS_FOR_FLAGS_ENUM(Flags) \
[[maybe_unused]] \
constexpr inline QIncompatibleFlag operator|(Flags::enum_type f1, int f2) noexcept \
{ return QIncompatibleFlag(int(f1) | f2); }
#endif

#define Q_DECLARE_OPERATORS_FOR_FLAGS(Flags) \
[[maybe_unused]] \
constexpr inline QFlags<Flags::enum_type> operator|(Flags::enum_type f1, Flags::enum_type f2) noexcept \
{ return QFlags<Flags::enum_type>(f1) | f2; } \
[[maybe_unused]] \
constexpr inline QFlags<Flags::enum_type> operator|(Flags::enum_type f1, QFlags<Flags::enum_type> f2) noexcept \
{ return f2 | f1; } \
[[maybe_unused]] \
constexpr inline QFlags<Flags::enum_type> operator&(Flags::enum_type f1, Flags::enum_type f2) noexcept \
{ return QFlags<Flags::enum_type>(f1) & f2; } \
[[maybe_unused]] \
constexpr inline QFlags<Flags::enum_type> operator&(Flags::enum_type f1, QFlags<Flags::enum_type> f2) noexcept \
{ return f2 & f1; } \
[[maybe_unused]] \
constexpr inline QFlags<Flags::enum_type> operator^(Flags::enum_type f1, Flags::enum_type f2) noexcept \
{ return QFlags<Flags::enum_type>(f1) ^ f2; } \
[[maybe_unused]] \
constexpr inline QFlags<Flags::enum_type> operator^(Flags::enum_type f1, QFlags<Flags::enum_type> f2) noexcept \
{ return f2 ^ f1; } \
constexpr inline void operator+(Flags::enum_type f1, Flags::enum_type f2) noexcept = delete; \
constexpr inline void operator+(Flags::enum_type f1, QFlags<Flags::enum_type> f2) noexcept = delete; \
constexpr inline void operator+(int f1, QFlags<Flags::enum_type> f2) noexcept = delete; \
constexpr inline void operator-(Flags::enum_type f1, Flags::enum_type f2) noexcept = delete; \
constexpr inline void operator-(Flags::enum_type f1, QFlags<Flags::enum_type> f2) noexcept = delete; \
constexpr inline void operator-(int f1, QFlags<Flags::enum_type> f2) noexcept = delete; \
constexpr inline void operator+(int f1, Flags::enum_type f2) noexcept = delete; \
constexpr inline void operator+(Flags::enum_type f1, int f2) noexcept = delete; \
constexpr inline void operator-(int f1, Flags::enum_type f2) noexcept = delete; \
constexpr inline void operator-(Flags::enum_type f1, int f2) noexcept = delete; \
QT_DECLARE_TYPESAFE_OPERATORS_FOR_FLAGS_ENUM(Flags)

// restore bit-wise enum-enum operators deprecated in C++20,
// but used in a few places in the API
#if __cplusplus > 201702L // assume compilers don't warn if in C++17 mode
  // in C++20 mode, provide user-defined operators to override the deprecated operations:
# define Q_DECLARE_MIXED_ENUM_OPERATOR(op, Ret, LHS, RHS) \
    [[maybe_unused]] \
    constexpr inline Ret operator op (LHS lhs, RHS rhs) noexcept \
    { return static_cast<Ret>(qToUnderlying(lhs) op qToUnderlying(rhs)); } \
    /* end */
#else
  // in C++17 mode, statically-assert that this compiler's result of the
  // operation is the same that the C++20 version would produce:
# define Q_DECLARE_MIXED_ENUM_OPERATOR(op, Ret, LHS, RHS) \
    static_assert(std::is_same_v<decltype(std::declval<LHS>() op std::declval<RHS>()), Ret>);
#endif

#define Q_DECLARE_MIXED_ENUM_OPERATORS(Ret, Flags, Enum) \
    Q_DECLARE_MIXED_ENUM_OPERATOR(|, Ret, Flags, Enum) \
    Q_DECLARE_MIXED_ENUM_OPERATOR(&, Ret, Flags, Enum) \
    Q_DECLARE_MIXED_ENUM_OPERATOR(^, Ret, Flags, Enum) \
    /* end */

#define Q_DECLARE_MIXED_ENUM_OPERATORS_SYMMETRIC(Ret, Flags, Enum) \
    Q_DECLARE_MIXED_ENUM_OPERATORS(Ret, Flags, Enum) \
    Q_DECLARE_MIXED_ENUM_OPERATORS(Ret, Enum, Flags) \
    /* end */


QT_END_NAMESPACE

#endif // QFLAGS_H