blob: 468db9894d5d5955fac6bfef0c37f56ab64e9485 (
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
|
/* Copyright (c) 2012-2017 The ANTLR Project. All rights reserved.
* Use of this file is governed by the BSD 3-clause license that
* can be found in the LICENSE.txt file in the project root.
*/
// A standard C++ class loosely modeled after boost::Any.
#pragma once
#include "antlr4-common.h"
#ifdef _MSC_VER
#pragma warning(push)
#pragma warning(disable: 4521) // 'antlrcpp::Any': multiple copy constructors specified
#endif
namespace antlrcpp {
template<class T>
using StorageType = typename std::decay<T>::type;
struct ANTLR4CPP_PUBLIC Any
{
bool isNull() const { return _ptr == nullptr; }
bool isNotNull() const { return _ptr != nullptr; }
Any() : _ptr(nullptr) {
}
Any(Any& that) : _ptr(that.clone()) {
}
Any(Any&& that) : _ptr(that._ptr) {
that._ptr = nullptr;
}
Any(const Any& that) : _ptr(that.clone()) {
}
Any(const Any&& that) : _ptr(that.clone()) {
}
template<typename U>
Any(U&& value) : _ptr(new Derived<StorageType<U>>(std::forward<U>(value))) {
}
template<class U>
bool is() const {
auto derived = getDerived<U>(false);
return derived != nullptr;
}
template<class U>
StorageType<U>& as() {
auto derived = getDerived<U>(true);
return derived->value;
}
template<class U>
const StorageType<U>& as() const {
auto derived = getDerived<U>(true);
return derived->value;
}
template<class U>
operator U() {
return as<StorageType<U>>();
}
template<class U>
operator const U() const {
return as<const StorageType<U>>();
}
Any& operator = (const Any& a) {
if (_ptr == a._ptr)
return *this;
auto * old_ptr = _ptr;
_ptr = a.clone();
if (old_ptr)
delete old_ptr;
return *this;
}
Any& operator = (Any&& a) {
if (_ptr == a._ptr)
return *this;
std::swap(_ptr, a._ptr);
return *this;
}
virtual ~Any();
virtual bool equals(Any other) const {
return _ptr == other._ptr;
}
private:
struct Base {
virtual ~Base() {};
virtual Base* clone() const = 0;
};
template<typename T>
struct Derived : Base
{
template<typename U> Derived(U&& value_) : value(std::forward<U>(value_)) {
}
T value;
Base* clone() const {
return clone<>();
}
private:
template<int N = 0, typename std::enable_if<N == N && std::is_nothrow_copy_constructible<T>::value, int>::type = 0>
Base* clone() const {
return new Derived<T>(value);
}
template<int N = 0, typename std::enable_if<N == N && !std::is_nothrow_copy_constructible<T>::value, int>::type = 0>
Base* clone() const {
return nullptr;
}
};
Base* clone() const
{
if (_ptr)
return _ptr->clone();
else
return nullptr;
}
template<class U>
Derived<StorageType<U>>* getDerived(bool checkCast) const {
typedef StorageType<U> T;
auto derived = dynamic_cast<Derived<T>*>(_ptr);
if (checkCast && !derived)
throw std::bad_cast();
return derived;
}
Base *_ptr;
};
template<> inline
Any::Any(std::nullptr_t&& ) : _ptr(nullptr) {
}
} // namespace antlrcpp
#ifdef _MSC_VER
#pragma warning(pop)
#endif
|
