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
|
// file : libbutl/optional.mxx -*- C++ -*-
// copyright : Copyright (c) 2014-2018 Code Synthesis Ltd
// license : MIT; see accompanying LICENSE file
#ifndef __cpp_modules
#pragma once
#endif
// C includes.
#ifndef __cpp_lib_modules
#include <utility> // move()
#include <functional> // hash
#include <type_traits> // is_trivially_destructible
#endif
// Other includes.
#ifdef __cpp_modules
export module butl.optional;
#ifdef __cpp_lib_modules
import std.core;
#endif
#endif
#include <libbutl/export.hxx>
LIBBUTL_MODEXPORT namespace butl
{
// Simple optional class template while waiting for std::optional.
//
struct nullopt_t {constexpr explicit nullopt_t (int) {}};
#if defined(__cpp_modules) && defined(__clang__) //@@ MOD Clang duplicate sym.
inline
#endif
constexpr nullopt_t nullopt (1);
namespace details
{
template <typename T, bool = std::is_trivially_destructible<T>::value>
struct optional_data;
template <typename T>
struct optional_data<T, false>
{
struct empty {};
union
{
empty e_;
T d_;
};
bool v_;
#if !defined(_MSC_VER) || _MSC_VER > 1900
constexpr optional_data (): e_ (), v_ (false) {}
constexpr optional_data (nullopt_t): e_ (), v_ (false) {}
constexpr optional_data (const T& v): d_ (v), v_ (true) {}
constexpr optional_data (T&& v): d_ (std::move (v)), v_ (true) {}
#else
optional_data (): e_ (), v_ (false) {}
optional_data (nullopt_t): e_ (), v_ (false) {}
optional_data (const T& v): d_ (v), v_ (true) {}
optional_data (T&& v): d_ (std::move (v)), v_ (true) {}
#endif
#if (!defined(_MSC_VER) || _MSC_VER > 1900) && \
(!defined(__GNUC__) || __GNUC__ > 4 || defined(__clang__))
constexpr optional_data (const optional_data& o): v_ (o.v_) {if (v_) new (&d_) T (o.d_);}
constexpr optional_data (optional_data&& o): v_ (o.v_) {if (v_) new (&d_) T (std::move (o.d_));}
#else
optional_data (const optional_data& o): v_ (o.v_) {if (v_) new (&d_) T (o.d_);}
optional_data (optional_data&& o): v_ (o.v_) {if (v_) new (&d_) T (std::move (o.d_));}
#endif
optional_data& operator= (nullopt_t);
optional_data& operator= (const T&);
optional_data& operator= (T&&);
optional_data& operator= (const optional_data&);
optional_data& operator= (optional_data&&);
~optional_data ();
};
template <typename T>
struct optional_data<T, true>
{
struct empty {};
union
{
empty e_;
T d_;
};
bool v_;
#if !defined(_MSC_VER) || _MSC_VER > 1900
constexpr optional_data (): e_ (), v_ (false) {}
constexpr optional_data (nullopt_t): e_ (), v_ (false) {}
constexpr optional_data (const T& v): d_ (v), v_ (true) {}
constexpr optional_data (T&& v): d_ (std::move (v)), v_ (true) {}
#else
optional_data (): e_ (), v_ (false) {}
optional_data (nullopt_t): e_ (), v_ (false) {}
optional_data (const T& v): d_ (v), v_ (true) {}
optional_data (T&& v): d_ (std::move (v)), v_ (true) {}
#endif
#if (!defined(_MSC_VER) || _MSC_VER > 1900) && \
(!defined(__GNUC__) || __GNUC__ > 4 || defined(__clang__))
constexpr optional_data (const optional_data& o): v_ (o.v_) {if (v_) new (&d_) T (o.d_);}
constexpr optional_data (optional_data&& o): v_ (o.v_) {if (v_) new (&d_) T (std::move (o.d_));}
#else
optional_data (const optional_data& o): v_ (o.v_) {if (v_) new (&d_) T (o.d_);}
optional_data (optional_data&& o): v_ (o.v_) {if (v_) new (&d_) T (std::move (o.d_));}
#endif
optional_data& operator= (nullopt_t);
optional_data& operator= (const T&);
optional_data& operator= (T&&);
optional_data& operator= (const optional_data&);
optional_data& operator= (optional_data&&);
};
}
template <typename T>
class optional: private details::optional_data<T>
{
using base = details::optional_data<T>;
public:
using value_type = T;
#if !defined(_MSC_VER) || _MSC_VER > 1900
constexpr optional () {}
constexpr optional (nullopt_t) {}
constexpr optional (const T& v): base (v) {}
constexpr optional (T&& v): base (std::move (v)) {}
#else
optional () {}
optional (nullopt_t) {}
optional (const T& v): base (v) {}
optional (T&& v): base (std::move (v)) {}
#endif
#if (!defined(_MSC_VER) || _MSC_VER > 1900) && \
(!defined(__GNUC__) || __GNUC__ > 4 || defined(__clang__))
constexpr optional (const optional&) = default;
constexpr optional (optional&&) = default;
#else
optional (const optional&) = default;
optional (optional&&) = default;
#endif
optional& operator= (nullopt_t v) {static_cast<base&> (*this) = v; return *this;}
optional& operator= (const T& v) {static_cast<base&> (*this) = v; return *this;}
optional& operator= (T&& v) {static_cast<base&> (*this) = std::move (v); return *this;}
optional& operator= (const optional&) = default;
optional& operator= (optional&&) = default;
T& value () {return this->d_;}
const T& value () const {return this->d_;}
T* operator-> () {return &value ();}
const T* operator-> () const {return &value ();}
T& operator* () {return value ();}
const T& operator* () const {return value ();}
bool has_value () const {return this->v_;}
explicit operator bool () const {return this->v_;}
};
template <typename T>
inline auto
operator== (const optional<T>& x, const optional<T>& y)
{
bool px (x), py (y);
return px == py && (!px || *x == *y);
}
template <typename T>
inline auto
operator!= (const optional<T>& x, const optional<T>& y)
{
return !(x == y);
}
template <typename T>
inline auto
operator< (const optional<T>& x, const optional<T>& y)
{
bool px (x), py (y);
return px < py || (px && py && *x < *y);
}
template <typename T>
inline auto
operator> (const optional<T>& x, const optional<T>& y)
{
return y < x;
}
}
namespace std
{
template <typename T>
struct hash<butl::optional<T>>: hash<T>
{
using argument_type = butl::optional<T>;
size_t
operator() (const butl::optional<T>& o) const
noexcept (noexcept (hash<T> {} (*o)))
{
return o ? hash<T>::operator() (*o) : static_cast<size_t> (-3333);
}
};
}
#include <libbutl/optional.ixx>
|
