/
primitive_iterator.hpp
132 lines (109 loc) · 3.15 KB
/
primitive_iterator.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
// __ _____ _____ _____
// __| | __| | | | JSON for Modern C++
// | | |__ | | | | | | version 3.11.3
// |_____|_____|_____|_|___| https://github.com/nlohmann/json
//
// SPDX-FileCopyrightText: 2013-2023 Niels Lohmann <https://nlohmann.me>
// SPDX-License-Identifier: MIT
#pragma once
#include <cstddef> // ptrdiff_t
#include <limits> // numeric_limits
#include <nlohmann/detail/macro_scope.hpp>
NLOHMANN_JSON_NAMESPACE_BEGIN
namespace detail
{
/*
@brief an iterator for primitive JSON types
This class models an iterator for primitive JSON types (boolean, number,
string). It's only purpose is to allow the iterator/const_iterator classes
to "iterate" over primitive values. Internally, the iterator is modeled by
a `difference_type` variable. Value begin_value (`0`) models the begin,
end_value (`1`) models past the end.
*/
class primitive_iterator_t
{
private:
using difference_type = std::ptrdiff_t;
static constexpr difference_type begin_value = 0;
static constexpr difference_type end_value = begin_value + 1;
JSON_PRIVATE_UNLESS_TESTED:
/// iterator as signed integer type
difference_type m_it = (std::numeric_limits<std::ptrdiff_t>::min)();
public:
constexpr difference_type get_value() const noexcept
{
return m_it;
}
/// set iterator to a defined beginning
void set_begin() noexcept
{
m_it = begin_value;
}
/// set iterator to a defined past the end
void set_end() noexcept
{
m_it = end_value;
}
/// return whether the iterator can be dereferenced
constexpr bool is_begin() const noexcept
{
return m_it == begin_value;
}
/// return whether the iterator is at end
constexpr bool is_end() const noexcept
{
return m_it == end_value;
}
friend constexpr bool operator==(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept
{
return lhs.m_it == rhs.m_it;
}
friend constexpr bool operator<(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept
{
return lhs.m_it < rhs.m_it;
}
primitive_iterator_t operator+(difference_type n) noexcept
{
auto result = *this;
result += n;
return result;
}
friend constexpr difference_type operator-(primitive_iterator_t lhs, primitive_iterator_t rhs) noexcept
{
return lhs.m_it - rhs.m_it;
}
primitive_iterator_t& operator++() noexcept
{
++m_it;
return *this;
}
primitive_iterator_t operator++(int)& noexcept // NOLINT(cert-dcl21-cpp)
{
auto result = *this;
++m_it;
return result;
}
primitive_iterator_t& operator--() noexcept
{
--m_it;
return *this;
}
primitive_iterator_t operator--(int)& noexcept // NOLINT(cert-dcl21-cpp)
{
auto result = *this;
--m_it;
return result;
}
primitive_iterator_t& operator+=(difference_type n) noexcept
{
m_it += n;
return *this;
}
primitive_iterator_t& operator-=(difference_type n) noexcept
{
m_it -= n;
return *this;
}
};
} // namespace detail
NLOHMANN_JSON_NAMESPACE_END