1#pragma once
2
3#include <array> // array
4#include <ciso646> // and
5#include <cstddef> // size_t
6#include <cstdint> // uint8_t
7#include <string> // string
8
9namespace nlohmann
10{
11namespace detail
12{
13///////////////////////////
14// JSON type enumeration //
15///////////////////////////
16
17/*!
18@brief the JSON type enumeration
19
20This enumeration collects the different JSON types. It is internally used to
21distinguish the stored values, and the functions @ref basic_json::is_null(),
22@ref basic_json::is_object(), @ref basic_json::is_array(),
23@ref basic_json::is_string(), @ref basic_json::is_boolean(),
24@ref basic_json::is_number() (with @ref basic_json::is_number_integer(),
25@ref basic_json::is_number_unsigned(), and @ref basic_json::is_number_float()),
26@ref basic_json::is_discarded(), @ref basic_json::is_primitive(), and
27@ref basic_json::is_structured() rely on it.
28
29@note There are three enumeration entries (number_integer, number_unsigned, and
30number_float), because the library distinguishes these three types for numbers:
31@ref basic_json::number_unsigned_t is used for unsigned integers,
32@ref basic_json::number_integer_t is used for signed integers, and
33@ref basic_json::number_float_t is used for floating-point numbers or to
34approximate integers which do not fit in the limits of their respective type.
35
36@sa @ref basic_json::basic_json(const value_t value_type) -- create a JSON
37value with the default value for a given type
38
39@since version 1.0.0
40*/
41enum class value_t : std::uint8_t
42{
43 null, ///< null value
44 object, ///< object (unordered set of name/value pairs)
45 array, ///< array (ordered collection of values)
46 string, ///< string value
47 boolean, ///< boolean value
48 number_integer, ///< number value (signed integer)
49 number_unsigned, ///< number value (unsigned integer)
50 number_float, ///< number value (floating-point)
51 discarded ///< discarded by the the parser callback function
52};
53
54/*!
55@brief comparison operator for JSON types
56
57Returns an ordering that is similar to Python:
58- order: null < boolean < number < object < array < string
59- furthermore, each type is not smaller than itself
60- discarded values are not comparable
61
62@since version 1.0.0
63*/
64inline bool operator<(const value_t lhs, const value_t rhs) noexcept
65{
66 static constexpr std::array<std::uint8_t, 8> order = {{
67 0 /* null */, 3 /* object */, 4 /* array */, 5 /* string */,
68 1 /* boolean */, 2 /* integer */, 2 /* unsigned */, 2 /* float */
69 }
70 };
71
72 const auto l_index = static_cast<std::size_t>(lhs);
73 const auto r_index = static_cast<std::size_t>(rhs);
74 return l_index < order.size() and r_index < order.size() and order[l_index] < order[r_index];
75}
76} // namespace detail
77} // namespace nlohmann
78