1// __ _____ _____ _____
2// __| | __| | | | JSON for Modern C++
3// | | |__ | | | | | | version 3.11.3
4// |_____|_____|_____|_|___| https://github.com/nlohmann/json
5//
6// SPDX-FileCopyrightText: 2013-2023 Niels Lohmann <https://nlohmann.me>
7// SPDX-License-Identifier: MIT
8
9#pragma once
10
11#include <array> // array
12#include <cstddef> // size_t
13#include <cstdint> // uint8_t
14#include <string> // string
15
16#include <nlohmann/detail/macro_scope.hpp>
17#if JSON_HAS_THREE_WAY_COMPARISON
18 #include <compare> // partial_ordering
19#endif
20
21NLOHMANN_JSON_NAMESPACE_BEGIN
22namespace detail
23{
24
25///////////////////////////
26// JSON type enumeration //
27///////////////////////////
28
29/*!
30@brief the JSON type enumeration
31
32This enumeration collects the different JSON types. It is internally used to
33distinguish the stored values, and the functions @ref basic_json::is_null(),
34@ref basic_json::is_object(), @ref basic_json::is_array(),
35@ref basic_json::is_string(), @ref basic_json::is_boolean(),
36@ref basic_json::is_number() (with @ref basic_json::is_number_integer(),
37@ref basic_json::is_number_unsigned(), and @ref basic_json::is_number_float()),
38@ref basic_json::is_discarded(), @ref basic_json::is_primitive(), and
39@ref basic_json::is_structured() rely on it.
40
41@note There are three enumeration entries (number_integer, number_unsigned, and
42number_float), because the library distinguishes these three types for numbers:
43@ref basic_json::number_unsigned_t is used for unsigned integers,
44@ref basic_json::number_integer_t is used for signed integers, and
45@ref basic_json::number_float_t is used for floating-point numbers or to
46approximate integers which do not fit in the limits of their respective type.
47
48@sa see @ref basic_json::basic_json(const value_t value_type) -- create a JSON
49value with the default value for a given type
50
51@since version 1.0.0
52*/
53enum class value_t : std::uint8_t
54{
55 null, ///< null value
56 object, ///< object (unordered set of name/value pairs)
57 array, ///< array (ordered collection of values)
58 string, ///< string value
59 boolean, ///< boolean value
60 number_integer, ///< number value (signed integer)
61 number_unsigned, ///< number value (unsigned integer)
62 number_float, ///< number value (floating-point)
63 binary, ///< binary array (ordered collection of bytes)
64 discarded ///< discarded by the parser callback function
65};
66
67/*!
68@brief comparison operator for JSON types
69
70Returns an ordering that is similar to Python:
71- order: null < boolean < number < object < array < string < binary
72- furthermore, each type is not smaller than itself
73- discarded values are not comparable
74- binary is represented as a b"" string in python and directly comparable to a
75 string; however, making a binary array directly comparable with a string would
76 be surprising behavior in a JSON file.
77
78@since version 1.0.0
79*/
80#if JSON_HAS_THREE_WAY_COMPARISON
81 inline std::partial_ordering operator<=>(const value_t lhs, const value_t rhs) noexcept // *NOPAD*
82#else
83 inline bool operator<(const value_t lhs, const value_t rhs) noexcept
84#endif
85{
86 static constexpr std::array<std::uint8_t, 9> order = {._M_elems: {
87 0 /* null */, 3 /* object */, 4 /* array */, 5 /* string */,
88 1 /* boolean */, 2 /* integer */, 2 /* unsigned */, 2 /* float */,
89 6 /* binary */
90 }
91 };
92
93 const auto l_index = static_cast<std::size_t>(lhs);
94 const auto r_index = static_cast<std::size_t>(rhs);
95#if JSON_HAS_THREE_WAY_COMPARISON
96 if (l_index < order.size() && r_index < order.size())
97 {
98 return order[l_index] <=> order[r_index]; // *NOPAD*
99 }
100 return std::partial_ordering::unordered;
101#else
102 return l_index < order.size() && r_index < order.size() && order[l_index] < order[r_index];
103#endif
104}
105
106// GCC selects the built-in operator< over an operator rewritten from
107// a user-defined spaceship operator
108// Clang, MSVC, and ICC select the rewritten candidate
109// (see GCC bug https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105200)
110#if JSON_HAS_THREE_WAY_COMPARISON && defined(__GNUC__)
111inline bool operator<(const value_t lhs, const value_t rhs) noexcept
112{
113 return std::is_lt(cmp: lhs <=> rhs); // *NOPAD*
114}
115#endif
116
117} // namespace detail
118NLOHMANN_JSON_NAMESPACE_END
119