1 #include <compare>
2 #include <iostream>
3 #include <nlohmann/json.hpp>
4 
5 using json = nlohmann::json;
6 
to_string(const std::partial_ordering& po)7 const char* to_string(const std::partial_ordering& po)
8 {
9     if (std::is_lt(po))
10     {
11         return "less";
12     }
13     else if (std::is_gt(po))
14     {
15         return "greater";
16     }
17     else if (std::is_eq(po))
18     {
19         return "equivalent";
20     }
21     return "unordered";
22 }
23 
main()24 int main()
25 {
26     // create several JSON values
27     json array_1 = {1, 2, 3};
28     json array_2 = {1, 2, 4};
29     json object_1 = {{"A", "a"}, {"B", "b"}};
30     json object_2 = {{"B", "b"}, {"A", "a"}};
31     json number = 17;
32     json string = "foo";
33     json discarded = json(json::value_t::discarded);
34 
35 
36     // output values and comparisons
37     std::cout << array_1 << " <=> " << array_2 << " := " << to_string(array_1 <=> array_2) << '\n'; // *NOPAD*
38     std::cout << object_1 << " <=> " << object_2 << " := " << to_string(object_1 <=> object_2) << '\n'; // *NOPAD*
39     std::cout << string << " <=> " << number << " := " << to_string(string <=> number) << '\n'; // *NOPAD*
40     std::cout << string << " <=> " << discarded << " := " << to_string(string <=> discarded) << '\n'; // *NOPAD*
41 }
42